Donate Help Contact The AHA Sign In Home
American Heart Association
Arteriosclerosis, Thrombosis, and Vascular Biology
Search: search_blue_button Advanced Search
« Previous Article | Table of Contents | Next Article »
Arteriosclerosis, Thrombosis, and Vascular Biology. 1998;18:1716-1722

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Giltay, E. J.
Right arrow Articles by Stehouwer, C. D. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Giltay, E. J.
Right arrow Articles by Stehouwer, C. D. A.
(Arteriosclerosis, Thrombosis, and Vascular Biology. 1998;18:1716-1722.)
© 1998 American Heart Association, Inc.

Original Contributions

Visceral Fat Accumulation Is an Important Determinant of PAI-1 Levels in Young, Nonobese Men and Women

Modulation by Cross-Sex Hormone Administration

E. J. Giltay; J. M. H. Elbers; L. J. G. Gooren; J. J. Emeis; T. Kooistra; H. Asscheman; ; C. D. A. Stehouwer

From the Institute of Endocrinology, Reproduction and Metabolism (E.J.G., J.M.H.E., L.J.G.G., H.A.), the Department of Internal Medicine (C.D.A.S.), and the Institute for Cardiovascular Research (C.D.A.S.), Hospital Vrije Universiteit, Amsterdam, and the Gaubius Laboratory (J.J.E., T.K.), TNO-PG, Leiden, The Netherlands.

Correspondence to Prof Dr Louis J.G. Gooren, MD, Department of Endocrinology, Division of Andrology, Hospital Vrije Universiteit, PO Box 7057, 1007 MB, Amsterdam, Netherlands. E-mail l.gooren{at}inter.nl.net


*    Abstract
up arrowTop
 *Abstract
down arrowIntroduction
 down arrowMethods
 down arrowResults
 down arrowDiscussion
 down arrowReferences
 
Abstract—Increased plasminogen activator inhibitor type-1 (PAI-1) levels, leading to impaired fibrinolysis, are associated with increased visceral fat in middle-aged and obese subjects. It is unknown, however, whether this association is independent of other disturbances clustered in the insulin resistance syndrome. We analyzed this association in young, nonobese transsexual men and women before and after administration of cross-sex steroids, which potentially influence many elements of the insulin resistance syndrome, including PAI-1 levels and visceral fat accumulation. We assessed the visceral fat area (by MRI); total body fat; insulin sensitivity (with a glucose clamp technique); and plasma levels of PAI-1, insulin, and triglycerides in young (<37 years old), nonobese (body mass index <28 kg/m2), healthy men (n=18) and women (n=15) before and after 12 months of cross-sex hormone administration. Men were treated with ethinyl estradiol 100 µg/d plus cyproterone acetate 100 mg/d, and women were treated with testosterone esters 250 mg IM every 2 weeks. At baseline, only visceral fat area was significantly correlated with plasma PAI-1 levels in both men (r=0.57, P=0.03) and women (r=0.59, P=0.03). In multivariate linear regression analysis, this association was independent of total body fat, insulin sensitivity, and plasma levels of triglycerides and insulin. After 12 months of cross-sex hormone administration, the plasma PAI-1 levels were no longer correlated with visceral fat (which had increased).We conclude that in young, nonobese men and women, visceral fat area is an important determinant of plasma PAI-1 levels. After cross-sex hormone administration, this association was no longer demonstrable.


Key Words: plasminogen activator inhibitor type-1 • visceral fat accumulation • insulin sensitivity • sex hormones


*    Introduction
up arrowTop
 up arrowAbstract
 *Introduction
down arrowMethods
 down arrowResults
 down arrowDiscussion
 down arrowReferences
 
Impaired fibrinolysis is a risk factor for cardiovascular disease (CVD).1 2 3 Fibrinolysis is activated by tissue plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA).4 Plasmatic type 1 plasminogen activator inhibitor (PAI-1) inhibits the action of both tPA and uPA.4 The exact origin of plasmatic PAI-1 is unknown, but in vitro studies show that it is produced by a wide variety of cell types,4 including endothelial cells, vascular smooth muscle cells, hepatocytes,5 and adipocytes.6 7 8 Correlations have been found between plasma PAI-1 levels and visceral fat accumulation measured by means of the waist-to-hip ratio (WHR),9 10 11 12 13 14 ultrasonographic techniques,15 or CT.7 16 It is unknown, however, whether this association already exists in young, nonobese subjects, since previous studies included middle-aged subjects,7 9 10 11 12 13 14 15 16 obese subjects,9 10 11 12 13 14 15 16 or subjects with essential hypertension.14 Associations of plasma PAI-1 levels have also been described with other disturbances that are clustered in the insulin resistance syndrome, ie, insulin resistance, hyperinsulinemia, glucose intolerance, dyslipidemia, and hypertension.17 Therefore, it is unknown whether the association between plasma PAI-1 levels and visceral fat accumulation is independent of these disturbances.18 Previous studies either did not include all of these elements of the insulin resistance syndrome in one statistical model7 9 10 or used indirect or crude estimates, such as WHR, to estimate fat distribution,9 11 12 13 14 19 and insulin levels after a glucose tolerance test,12 15 16 the minimal-model method,11 13 or a hyperglycemic clamp14 to estimate insulin sensitivity.

Sex differences have been found in the interrelations between fibrinolytic variables and elements of the insulin resistance syndrome,14 many of which are influenced by administration of sex steroids. Oral estrogen administration increases triglyceride and HDL cholesterol levels20 and decreases insulin sensitivity.21 22 Exogenous estrogens are also known to reduce plasma PAI-1 levels.23 24 25 Testosterone administration has no effect on triglyceride26 27 28 and insulin28 levels but decreases HDL cholesterol levels,26 27 decreases22 29 or has no effect28 on insulin sensitivity, reduces total body fat28 and abdominal subcutaneous fat depots,30 31 and increases visceral fat depots.30 31 It is unknown whether the shifts in PAI-1 levels during sex-steroid administration are partly mediated by quantitative changes in visceral fat accumulation or by other elements of the insulin resistance syndrome.

The aim of this study was to examine the association between plasma PAI-1 levels and visceral fat accumulation in young, nonobese subjects. We aimed particularly to examine whether this association was independent of other variables clustered in the insulin resistance syndrome. Furthermore, because we selected transsexual subjects for these studies, we were able to reassess this association after 12 months of cross-sex hormone administration, which is known to influence many elements of the insulin resistance syndrome, including PAI-1 levels and visceral fat accumulation. Transsexuals, being no different from members of their own genital sex from an endocrine32 33 34 or metabolic22 27 31 viewpoint, provide us with the opportunity to study the effects of high-dose sex steroid administration in young, nonobese subjects. We therefore consider transsexuals as a valid model for a study of the regulation of PAI-1 levels.


*    Methods
up arrowTop
 up arrowAbstract
 up arrowIntroduction
 *Methods
down arrowResults
 down arrowDiscussion
 down arrowReferences
 
Patients
Eighteen male-to-female (M->F) transsexuals with a median age of 27 years (range, 18 to 37) and 15 female-to-male (F->M) transsexuals with a median age of 23 years (range, 16 to 33) were recruited between October 1993 and April 1996 and agreed to participate in the study. Subjects with a body mass index (BMI) (weight/height2) >28 kg/m2 were excluded. All subjects were judged to be clinically healthy on the basis of medical history, physical examination, and routine laboratory tests. In particular, hypertension, diabetes mellitus, and evidence of cardiovascular, liver, or endocrine diseases were not noted. None reported intake of hormones (such as oral contraceptives) or medications known to affect sex-steroid or lipid metabolism or insulin sensitivity. Ten M->F transsexuals and 7 F->M transsexuals were smokers. Before the start of hormone therapy, all F->M transsexuals had regular menstrual cycles (28 to 31 days).

We measured the variables reflecting insulin resistance (glucose and insulin levels and glucose utilization), plasma lipids (triglyceride and HDL cholesterol levels), fat distribution (BMI, WHR, total body fat, abdominal subcutaneous fat, and visceral fat area), and mean arterial pressure at baseline and again after 12 months of cross-sex hormone administration. For logistical reasons, some measurements were not obtained in all subjects. Mean arterial pressure was measured directly, not calculated, with an automatic device (BP-8800, Colin) at baseline and after 12 months of cross-sex hormone administration after the patient had rested for at least 15 minutes (mean of 4 recordings repeated every 3 minutes). M->F transsexuals were treated with ethinyl estradiol 100 µg/d (Lynoral, Organon) in combination with the antiandrogen cyproterone acetate 100 mg/d (Androcur, Schering) to counteract the effects of testosterone. F->M transsexuals were treated with testosterone esters (Sustanon, Organon) 250 mg every 2 weeks intramuscularly. Informed consent was obtained from all subjects, and the study was approved by the Ethical Review Board of the Hospital Vrije Universiteit.

Blood Sampling and Analysis
In F->M transsexuals, blood was drawn at baseline between days 3 and 9 of the menstrual cycle during the follicular phase, and during hormone treatment, within 5 to 9 days after the most recent testosterone injection. Blood samples were obtained between 9:30 and 10:30 AM after a 12-hour fast. Standardized radioimmunoassays were used to measure serum levels of 17ß-estradiol and testosterone. Serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured by immunometric luminescence assays. Immunoradiometric assays were used to measure serum levels of sex hormone–binding globulin (SHBG) and insulin (Biosource Diagnostics). Plasma levels of glucose, triglycerides, and HDL cholesterol were measured by using standard laboratory methods. Blood was also collected into evacuated tubes (Diatube H CTAD, Becton Dickinson). Samples were immediately placed on ice and centrifuged at 3500g for 30 minutes at 4°C. Plasma was separated and snap-frozen within 1 hour and stored at -70°C until analysis. Plasma levels of tPA and PAI-1 antigen were measured by using commercially available enzyme immunoassay kits (Thrombonostika tPA and Thrombonostika PAI-1, Organon Teknika), and uPA antigen was evaluated by using an in-house enzyme immunoassay.35

Measurement of Fat Distribution
The lean body mass (LBM) and the total body fat were estimated at baseline and after 12 months of cross-sex hormone treatment by bioelectrical impedance analysis (BIA 101/S, RJL Systems).36 In addition, body circumferences were measured in duplicate with a flexible plastic tape at the level of the abdomen (midway between the lower rib margin and the iliac crest) and the hip (over the greater trochanters) to calculate the WHR. Areas of abdominal subcutaneous and visceral fat depots were assessed by MRI technique in 15 M->F and 14 F->M transsexuals. The procedure of image analysis has been described in detail elsewhere.31 Repeated measurements were obtained by using the same MRI and scanning parameters. An inversion recovery pulse sequence was used, and appropriate scanning parameters were chosen to obtain good image contrast between adipose and other tissues. Three transverse images were taken at the abdominal level: 1 at the anatomic marker (lower edge of the umbilicus) and 1 above and 1 below this position (slice thickness, 10 or 12 mm, depending on the imager used). The image-analyzing computer program (developed by our Department of Biomedical Engineering) is based on a "seed-growing" procedure. In short, after a seed point is placed in the abdominal subcutaneous or the visceral fat depot, it can be circumscribed by selection of a pixel intensity range. The intensity range is selected for each image separately according to the pixel intensity histogram. The areas of the circumscribed abdominal subcutaneous and visceral fat depots were calculated by converting the number of pixels to square centimeters, and the mean of the 3 abdominal images was taken. To reduce variability, all measurements were performed by a single experienced observer. The intraobserver coefficients of variation were 2.3% for abdominal subcutaneous fat and 9.8% for visceral fat.

Hyperinsulinemic Euglycemic Clamp
Insulin sensitivity was measured at baseline and after 12 months of cross-sex hormone treatment by using a glucose clamp technique.37 Two intravenous catheters were placed in contralateral antecubital or antebrachial veins of each arm, 1 for blood withdrawal and the other for insulin and glucose infusion. The insulin solution for intravenous infusion was prepared by adding 0.5 mL human insulin (100 IU/mL; Velosulin, Novo Nordisk A/S) and 4.5 mL human albumin (20%) (Central Blood Transfusion Laboratory, Amsterdam, Netherlands) to 45 mL of 0.9% NaCl to a final insulin concentration of 1 IU/mL. The insulin infusion rate was calculated per kilogram of LBM. The procedure consisted of a 2-hour period with the insulin infusion rate at 62.5 mU/kg LBM per hour. The clamp procedure was started 30 minutes after cannulation (0 minutes). After the start of the insulin infusion, arterial blood glucose levels were measured every 5 minutes with the use of a Yellow Springs Instruments glucose analyzer (glucose oxidase method), and the 20% glucose infusion rate was adjusted to maintain blood glucose concentration at the fasting level (ie, mean blood glucose level from -30 to 0 minutes). Blood samples for the determination of insulin levels were collected every half hour. In the second hour, the glucose disposal rate was calculated from the steady-state glucose infusion rate, the LBM, and the mean insulin level, ie, M/I value=(100xmg glucose/kg LBM per min per pmol insulin per L).

Statistical Analysis
Data are given as mean±SD. Variables with a skewed distribution (abdominal subcutaneous fat area, total body fat, and plasma levels of PAI-1, uPA, and triglycerides) were logarithmically transformed before analysis to normalize their distributions. Student's t test for independent samples and an ANCOVA was used to compare baseline differences between men and women. In the M->F and F->M groups separately, the ANOVA test for repeated measurements or the t test for paired samples were used to explore the effects of cross-sex hormones on plasma PAI-1 levels and other variables of interest. Baseline values, values after 12 months of treatment, and proportional changes between baseline and 12 months were correlated by using Spearman's correlation coefficient. Both groups were pooled in a multiple linear regression analysis to further explore interrelationships between the logarithmically transformed plasma PAI-1 level and elements of the insulin resistance syndrome. Interaction terms were included to test whether the associations of the plasma PAI-1 level and the visceral fat area differed between men and women or before and after cross-sex hormone administration. When endocrine measurements were below the lower limit of detection, the value of that lower limit was used for statistical calculations (for LH 0.3 IU/L, for FSH 0.5 IU/L, for 17ß-estradiol 90 pmol/L, and for testosterone 1.0 nmol/L). Two-sided P<0.05 was considered statistically significant. The software used was SPSS for Windows 7.0.


*    Results
up arrowTop
 up arrowAbstract
 up arrowIntroduction
 up arrowMethods
 *Results
down arrowDiscussion
 down arrowReferences
 
Determinants of PAI-1 Levels at Baseline
All subjects were eugonadal at baseline by clinical and laboratory criteria. Baseline characteristics are presented in Table 1Down. Plasma PAI-1 levels were statistically significantly higher in women than in men (P=0.049), a difference that disappeared (P=0.93) after controlling for total body fat (higher in women) in an ANCOVA. Plasma tPA and uPA levels were not statistically significantly different between men and women (P=0.63 and P=0.50). Plasma PAI-1 levels were positively and significantly correlated with plasma tPA levels in men (r=0.72, P=0.001) and women (r=0.63, P=0.01), negatively with serum SHBG levels in men (r=-0.50, P=0.05), and negatively with serum 17ß-estradiol levels in women (r=-0.55, P=0.03).


View this table:
[in this window]
[in a new window]
  		Table 1. Baseline Characteristics in Men and Women

The PAI-I level was correlated significantly with the visceral fat area in men (r=0.57, P=0.03) and with the visceral fat area and total body fat in women (r=0.59, P=0.03 and r=0.70, P=0.006) but not with WHR or insulin sensitivity (Figure 1Down). Also, no significant correlations were found with levels of glucose, insulin, triglycerides, HDL cholesterol, BMI, abdominal subcutaneous fat area, and mean arterial pressure (data not shown).



View larger version (30K):
[in this window]
[in a new window]
  		Figure 1. Scatterplots of data for 16 men and 14 women at baseline with plasma PAI-1 levels on a logarithmic scale. The visceral fat area (using an MRI technique) was significantly correlated with plasma PAI-I levels in men (r=0.57, P=0.03) and women (r=0.59, P=0.03). The logarithmically transformed total body fat was significantly correlated with plasma PAI-I levels in women (r=0.70, P=0.006). No correlations were found between PAI-1 levels and WHR or insulin sensitivity for men and women separately or when the data were pooled in the analysis.

A multiple linear regression analysis was performed on pooled data from all subjects, with the plasma PAI-1 level as the dependent variable and biological sex, age, total body fat, and the visceral fat area forced into the model. The visceral fat area was the only variable that added significantly to the model (ß=0.53, P=0.02). Interaction analysis showed that the relationship of plasma PAI-1 level and the visceral fat area was not significantly different between men and women (P=0.84). To further analyze the relationship between plasma PAI-1 level and the visceral fat area, the biological sex, insulin level, insulin sensitivity, triglyceride levels, total body fat, and the visceral fat area were forced into the model. The visceral fat area maintained a positive, independent association with plasma PAI-1 levels after controlling for these possible confounding variables (Table 2Down). The use of the M value instead of the M/I value did not lead to different conclusions in any of the analyses (data not shown).


View this table:
[in this window]
[in a new window]
  		Table 2. Standardized Regression Coefficients From Multiple Linear Regression Analysis of Plasma PAI-1 Levels in Relation to Visceral Fat Area and Possible Confounding Variables in Pooled Data for Men and Women at Baseline

Effects of Cross-Sex Hormone Administration
After estrogen and antiandrogen administration to M->F transsexuals, serum levels of testosterone decreased to undetectable levels. The ethinyl estradiol administered could not be detected by the assay used, but the biological effects of estrogens were reflected in a large increase of serum levels of SHBG. After testosterone administration to F->M transsexuals, serum levels of testosterone increased markedly while serum 17ß-estradiol levels decreased. In 2 F->M subjects the serum 17ß-estradiol levels decreased to below the lower limit of detection. The serum level of SHBG decreased, reflecting the biological effects of androgens. Serum levels of LH and FSH were not significantly suppressed (Table 3Down).


View this table:
[in this window]
[in a new window]
  		Table 3. Endocrine and Fibrinolytic Variables Before and After 4 and 12 Months of Cross-Sex Hormone Administration in Transsexual Subjects

Ethinyl estradiol plus cyproterone acetate administration to men during a 12-month period was associated with decreases in plasma levels of PAI-1 by 62% (Figure 2Down), tPA by 53%, and uPA by 37% (Table 3Up). Testosterone treatment of women during the same 12 months was not associated with changes in PAI-1 (Figure 2Down) or tPA levels; however, uPA levels increased by 28% (Table 3Up). This increase in uPA level was only apparent after 12 months. There was a positive correlation between the proportional changes in plasma levels of PAI-1 and tPA in the men (r=0.77, P<0.001) and in the women (r=0.70, P=0.004). After 12 months of treatment, the plasma levels of PAI-1 and tPA were significantly correlated in M->F (r=0.58, P=0.01) and F->M (r=0.69, P=0.005) transsexuals, similar to the situation before hormone administration.



View larger version (24K):
[in this window]
[in a new window]
  		Figure 2. Plots showing the individual plasma PAI-1 levels on a logarithmic scale in 18 M->F transsexuals receiving estrogens plus antiandrogens ({bullet}) and 15 F->M transsexuals receiving androgens ({square}) at baseline, after 4 months, and after 12 months of cross-sex hormone administration. P values were assessed by ANOVA for repeated measurements.

In men treated with ethinyl estradiol plus cyproterone acetate, significant increases were found in the fasting insulin levels (by 38%), the triglyceride levels (by 88%), the HDL cholesterol level (by 18%), the BMI (by 5%), the WHR (by 1%), the total body fat (by 38%), the abdominal subcutaneous fat area (by 54%), and the visceral fat area (by 17%). Insulin sensitivity (M/I value) and mean arterial pressure did not change significantly. In women treated with testosterone, plasma levels of glucose, insulin, and triglycerides; insulin sensitivity; and mean arterial pressure did not change significantly. The HDL cholesterol level decreased by 23%. The BMI did not change significantly, but the LBM increased by 9%, the WHR increased by 3%, the total body fat decreased by 24%, the abdominal subcutaneous fat area decreased by 18%, and the visceral fat area increased by 18%, all significantly.

Proportional changes in plasma PAI-1 levels were not correlated with any of the proportional changes of the elements of the insulin resistance syndrome, including visceral fat area. For values obtained after 12 months of cross-sex hormone treatment, plasma PAI-1 levels were not correlated with any of these variables except for mean arterial pressure, which was correlated positively with plasma PAI-1 levels in M->F transsexuals (r=0.70, P=0.004). A multiple linear regression analysis in data pooled from all subjects with the plasma PAI-1 level as the dependent variable and the biological sex and the visceral fat area forced into the model showed that the visceral fat area had lost the association with the plasma PAI-1 (ß=0.16, P=0.13). When 12-month values were compared with baseline values in a linear regression analysis, the association between the plasma PAI-1 level and the visceral fat area was weakened significantly in M->F (P<0.001) and nonsignificantly in F->M (P=0.16; Figure 3Down) transsexuals.



View larger version (19K):
[in this window]
[in a new window]
  		Figure 3. Scatterplots of data for 16 M->F transsexuals and 14 F->M transsexuals with plasma PAI-1 levels on a logarithmic scale. The visceral fat area (using an MRI technique) was significantly correlated with plasma PAI-I levels in either group at baseline (r=0.57, P=0.03 and r=0.59, P=0.03, respectively) but not after cross-sex hormone administration for 12 months (r=0.19, P=0.51 and r=0.27, P=0.35, respectively).


*    Discussion
up arrowTop
 up arrowAbstract
 up arrowIntroduction
 up arrowMethods
 up arrowResults
 *Discussion
down arrowReferences
 
An increased plasma PAI-1 level, an important cause of impaired fibrinolysis, is a risk factor for CVD.1 2 3 We studied the relation between plasma PAI-1 levels and the visceral fat area. The strengths of our study are the inclusion of only healthy, nonobese men and women under the age of 37 years and the use of "gold standard" techniques to assess the visceral fat mass and insulin sensitivity. In previous studies, correlations have been found between plasma PAI-1 levels and the visceral fat area measured by means of CT in middle-aged men and women7 and in middle-aged men including obese subjects.16 Our findings show this association to exist even in healthy, young, nonobese subjects by the use of an accurate MRI technique. This raises the possibility that visceral fat accumulation is directly connected to CVD through increased PAI-1 levels.1 2 3 Indeed, increasing mortality due to CVD is already apparent with increasing BMI in nonobese and mildly overweight women (BMI <29 kg/m2 )38 and is also apparent in obesity, especially if the depot of fat is visceral.38 39 40 41 42

The insulin resistance syndrome includes a cluster of metabolic and hemodynamic disturbances, ie, insulin resistance, hyperinsulinemia, glucose intolerance, dyslipidemia including hypertriglyceridemia, visceral fat accumulation, hypertension, and hypofibrinolysis, which increase the risk of CVD.17 Many studies in healthy subjects have suggested that beside visceral fat accumulation, other elements of the insulin resistance syndrome are associated with increased plasma PAI-1 levels. PAI-1 levels were reported to be positively correlated with increased insulin levels,9 10 12 13 14 16 43 decreased insulin sensitivity,10 13 14 19 43 increased plasma triglyceride levels,11 12 14 15 43 and increased blood pressure.16 43 However, these associations could well be indirect and, at least in part, depend on the relationship between PAI-1 and visceral fat, because visceral fat is associated with insulin resistance44 and increased glucose, insulin, and triglyceride levels.40 41 This concept is supported by our data showing that the association between plasma PAI-1 levels and visceral fat area was independent of insulin sensitivity and plasma levels of insulin and triglycerides. Moreover, some previous studies may have lacked sufficient sensitivity to show the influence of visceral fat, because WHR or BMI was used in multivariate analysis as an estimate of intra-abdominal fat.9 11 12 13 14 19 These measures are reasonable but imprecise estimates of visceral fat, as illustrated by our finding of no relation between PAI-1 and WHR or BMI in the face of a strong relation between PAI-1 and MRI-estimated visceral fat mass.

In our young, nonobese subjects, PAI-1 levels were higher in women than in men. However, this sex difference disappeared after adjustment for total body fat. Previous large population-based studies in healthy men and premenopausal women found similar PAI-1 activity levels45 and higher PAI-1 levels in men versus women.46 The assumption, based on previous studies,23 24 25 47 48 that oral estrogen plus antiandrogen administration would decrease PAI-1 levels and that testosterone administration would not change PAI-1, was indeed confirmed by our data. Furthermore, uPA levels had increased after 12, but not after 4, months of testosterone administration in women.

In both groups, the correlation between the visceral fat area and plasma PAI-1 level at baseline had disappeared after 12 months of sex-steroid hormone administration. This was especially clear in M->F transsexuals, but in this group the administered sex steroids had a substantially larger effect. What might explain this dissociation? First, sex steroid–induced shifts in metabolic variables that are included in the insulin resistance syndrome could be involved in PAI-1 metabolism. This concept is not supported by our data, because proportional changes in PAI-1 levels were not correlated with proportional changes in insulin sensitivity or plasma levels of insulin, glucose, triglycerides, and HDL cholesterol. Second, changes in hepatic clearance might be relevant. The parallel decrease in PAI-1, tPA, and uPA in M->F transsexuals is consistent with a clearance effect, because PAI-1, tPA, and uPA share a major hepatic clearance pathway.49 50 This idea is further supported by the observation that oral, but not transdermal, administration of estrogens reduces plasma PAI-1 levels.24 25 A clearance effect, however, appears less likely to explain the changes in the testosterone-treated F->M transsexuals. Third, sex steroids could have altered adipocyte metabolism.51 PAI-1 synthesis can take place in hepatocytes5 and adipocytes.6 7 8 Therefore, shifts could have occurred directly in the secretion of PAI-1 by adipocytes or indirectly in the secretion of substances influencing the hepatic secretion of PAI-1.8 52 In this respect, it is noteworthy that the cytokines interleukin-6 and tumor necrosis factor-{alpha} and the acute-phase reactant C-reactive protein were not associated with plasma PAI-1 levels either before or after 12 months of hormone administration (data not shown). We have, however, not studied portal concentrations of these cytokines or free fatty acids, because the topography of the portal vein makes these studies difficult.40

Our data indicate that in young, nonobese men and women, the visceral fat area is an important determinant of plasma PAI-1 level, independent of insulin sensitivity and plasma levels of insulin and triglycerides. Visceral fat may be directly linked to a low fibrinolytic activity and thereby to an increased risk of CVD. After oral estrogen and antiandrogen administration to men, plasma levels of PAI-1, tPA, and uPA decreased substantially, and after testosterone administration to women, only plasma uPA levels increased. After administration of cross-sex hormones, the association between plasma PAI-1 and the ensuing increases in visceral fat area was no longer demonstrable. This dissociation could not be explained by changes in elements of the insulin resistance syndrome, but whether it should be ascribed to changes in hepatic clearance of PAI-1 or changes in adipocyte metabolism directly or indirectly involved in PAI-1 synthesis remains to be elucidated.


*    Acknowledgments
 
Dr Stehouwer is supported by a Clinical Research Fellowship from the Diabetes Fonds Nederland and the Netherlands Organization for Scientific Research (NWO). We are indebted to J.A.J. Megens and Dr P.J.M. van Kesteren for assistance in the logistics of this study.

Received February 26, 1998; accepted April 24, 1998.


*    References
up arrowTop
 up arrowAbstract
 up arrowIntroduction
 up arrowMethods
 up arrowResults
 up arrowDiscussion
 *References
 

  1. Hamsten A, Walldius G, Szamosi A, Blombäck M, De Faire U, Dahlén G, Landou C, Wiman B. Plasminogen activator inhibitor in plasma: risk factor for recurrent myocardial infarction. Lancet. 1987;2:3–8.[Medline] [Order article via Infotrieve]
  2. Meade TW, Ruddock V, Stirling Y, Charkrabarti R, Miller GJ. Fibrinolytic activity, clotting factors, and long-term incidence of ischaemic heart disease in the Northwick Park Heart Study. Lancet. 1993;342:1076–1079.[Medline] [Order article via Infotrieve]
  3. Juhan-Vague I, Pyke SD, Alessi MC, Jespersen J, Haverkate F, Thompson SG. Fibrinolytic factors and the risk of myocardial infarction or sudden death in patients with angina pectoris: ECAT Study Group. Circulation. 1996;94:2057–2063.[Abstract/Free Full Text]
  4. Lijnen HR, Collen D. Mechanism of physiological fibrinolysis. Baillières Clin Haematol. 1995;8:277–290.[Medline] [Order article via Infotrieve]
  5. Kooistra T, Bosma P, Tons H, Van Den Ende A, Meyer P, Princen H. Plasminogen activator inhibitor 1: biosynthesis and mRNA levels are increased by insulin in cultured human hepatocytes. Thromb Haemost. 1989;62:723–728.[Medline] [Order article via Infotrieve]
  6. Lundgren CH, Brown SL, Nordt TK, Sobel BE, Fujii S. Elaboration of type-1 plasminogen activator inhibitor from adipocytes: a potential pathogenetic link between obesity and cardiovascular disease. Circulation. 1996;93:106–110.[Abstract/Free Full Text]
  7. Shimomura I, Funahashi T, Takahashi M, Maeda K, Kotani K, Nakamura T, Yamashita S, Miura M, Fukuda Y, Takemura K, Tokunaga K, Matsuzawa Y. Enhanced expression of PAI-1 in visceral fat: possible contributor to vascular disease in obesity. Nat Med. 1996;2:800–803.[Medline] [Order article via Infotrieve]
  8. Alessi MC, Peiretti F, Morage P, Henry M, Nalbone G, Juhan-Vague I. Production of plasminogen activator inhibitor 1 by human adipose tissue: possible link between visceral fat accumulation and vascular disease. Diabetes. 1997;46:860–867.[Abstract]
  9. Vague P, Juhan-Vague I, Chabert V, Alessi MC, Atlan C. Fat distribution and plasminogen inhibitor activity in nondiabetic obese women. Metabolism. 1989;38:913–915.[Medline] [Order article via Infotrieve]
  10. Landin K, Stigendal L, Eriksson E, Krotkiewski M, Risberg B, Tengborn L, Smith U. Abdominal obesity is associated with an impaired fibrinolytic activity and elevated plasminogen activator inhibitor-1. Metabolism. 1990;39:1044–1048.[Medline] [Order article via Infotrieve]
  11. Asplund-Carlson A, Hamsten A, Wiman B, Carlson LA. Relationship between plasma plasminogen activator inhibitor-1 activity and VLDL triglyceride concentration, insulin levels and insulin sensitivity: studies in randomly selected normo- and hypertriglyceridaemic men. Diabetologia. 1993;36:817–825.[Medline] [Order article via Infotrieve]
  12. Cigolini M, Targher G, Seidell JC, Schiavon R, Manara F, Zenti MG, Mattioli C, De Sandre G. Relationships of plasminogen activator inhibitor-1 to anthropometry, serum insulin, triglycerides and adipose tissue fatty acids in healthy men. Atherosclerosis. 1994;106:139–147.[Medline] [Order article via Infotrieve]
  13. Mykkänen L, Rönnemaa T, Marniemi J, Haffner SM, Bergman R, Laakso M. Insulin sensitivity is not an independent determinant of plasma plasminogen activator inhibitor-1 activity. Arterioscler Thromb. 1994;14:1264–1271.[Abstract/Free Full Text]
  14. Toft I, Bonaa KH, Ingebretsen OC, Nordoy A, Birkeland KI, Jenssen T. Gender differences in the relationships between plasma plasminogen activator inhibitor-1 activity and factors linked to the insulin resistance syndrome in essential hypertension. Arterioscler Thromb Vasc Biol. 1997;17:553–559.[Abstract/Free Full Text]
  15. Targher G, Tonoli M, Agostino G, Rigo L, Boschini K, Muggeo M, De Sandre G, Cigolini M. Ultrasonographic intra-abdominal depth and its relation to haemostatic factors in healthy males. Int J Obes. 1996;20:882–885.
  16. Cigolini M, Targher G, Bergamo Andreis IA, Tonoli M, Agostino G, De Sandre G. Visceral fat accumulation and its relation to plasma hemostatic factors in healthy men. Arterioscler Thromb Vasc Biol. 1996;16:368–374.[Abstract/Free Full Text]
  17. Reaven GM. Role of insulin resistance in human disease. Diabetes. 1988;37:1595–1607.[Abstract]
  18. Juhan-Vague I, Alessi MC. PAI-1, obesity, insulin resistance and risk of cardiovascular events. Thromb Haemost. 1997;78:656–660.[Medline] [Order article via Infotrieve]
  19. Potter van Loon BJ, Kluft C, Radder JK, Blankenstein MA, Meinders AE. The cardiovascular risk factor plasminogen activator inhibitor type 1 is related to insulin resistance. Metabolism. 1993;42:945–949.[Medline] [Order article via Infotrieve]
  20. Lindberg U, Crona N, Enk L, Samsioe G, Silfverstolpe G. Effects of cyproterone acetate (CPA) on serum lipoproteins when administered alone and in combination with ethinyl estradiol (EE). Horm Metab Res. 1987;19:222–225.[Medline] [Order article via Infotrieve]
  21. Godsland IF, Walton C, Felton C, Proudler A, Patel A, Wynn V. Insulin resistance, secretion and metabolism in users of oral contraceptives. J Clin Endocrinol Metab. 1992;74:64–70.[Abstract]
  22. Polderman KH, Gooren LJG, Asscheman H, Bakker A, Heine RJ. Induction of insulin resistance by androgens and estrogens. J Clin Endocrinol Metab. 1994;79:265–271.[Abstract]
  23. Gevers Leuven JA, Kluft C, Bertina RM, Hessel LW. Effects of two low-dose oral contraceptives on circulating components of the coagulation and fibrinolytic systems. J Lab Clin Med. 1987;109:631–636.[Medline] [Order article via Infotrieve]
  24. Kroon U, Silfverstolpe G, Tengborn L. The effects of transdermal estradiol and oral conjugated estrogens on haemostasis variables. Thromb Haemost. 1994;71:420–423.[Medline] [Order article via Infotrieve]
  25. Kon Koh K, Mincemoyer R, Bui MN, Csako G, Pucino F, Guetta V, Waclawiw M, Cannon RO. Effects of hormone-replacement therapy on fibrinolysis in postmenopausal women. N Engl J Med. 1997;336:683–690.[Abstract/Free Full Text]
  26. Tenover JS. Effects of testosterone supplementation in the aging male. J Clin Endocrinol Metab. 1992;75:1092–1098.[Abstract]
  27. Asscheman H, Gooren LJG, Megens JAJ, Nauta J, Kloosterboer HJ, Eikelboom F. Serum testosterone level is the major determinant of the male-female differences in serum levels of high-density lipoprotein (HDL) cholesterol and HDL2 cholesterol. Metabolism. 1994;43:935–939.[Medline] [Order article via Infotrieve]
  28. Arslanian S, Suprasongsin C. Testosterone treatment in adolescents with delayed puberty: changes in body composition, protein, fat, and glucose metabolism. J Clin Endocrinol Metab. 1997;82:3213–3220.[Abstract/Free Full Text]
  29. Cohen JC, Hickman R. Insulin resistance and diminished glucose tolerance in powerlifters ingesting anabolic steroids. J Clin Endocrinol Metab. 1987;64:960–963.[Abstract]
  30. Lovejoy JC, Bray GA, Greeson CS, Klemperer M, Morris J, Partington C, Tulley R. Oral anabolic steroid treatment, but not parenteral androgen treatment, decreases abdominal fat in obese, older men. Int J Obes Relat Metab Disord. 1995;19:614–624.[Medline] [Order article via Infotrieve]
  31. Elbers JMH, Asscheman H, Seidell JC, Megens JAJ, Gooren LJG. Long-term testosterone administration increases visceral fat in female to male transsexuals. J Clin Endocrinol Metab. 1997;82:2044–2047.[Abstract/Free Full Text]
  32. Gooren L. The neuroendocrine response of luteinizing hormone to estrogen administration in heterosexual, homosexual, and transsexual subjects. J Clin Endocrinol Metab. 1986;63:583–588.[Abstract]
  33. Spijkstra JJ, Spinder T, Gooren LJ. Short-term patterns of pulsatile luteinizing hormone secretion do not differ between male-to-female transsexuals and heterosexual men. Psychoneuroendocrinology. 1988;13:279–283.[Medline] [Order article via Infotrieve]
  34. Spinder T, Spijkstra JJ, Gooren LJ, Burger CW. Pulsatile luteinizing hormone release and ovarian steroid levels in female-to-male transsexuals compared to heterosexual women. Psychoneuroendocrinology. 1989;14:97–102.[Medline] [Order article via Infotrieve]
  35. Koolwijk P, Van Erck MG, De Vree WJ, Vermeer MA, Weich HA, Hanemaaijer R, Van Hinsbergh VW. Cooperative effect of TNF{alpha}, bFGF, and VEGF on the formation of tubular structures of human microvascular endothelial cells in a fibrin matrix: role of urokinase activity. J Cell Biol. 1996;132:1177–1188.[Abstract/Free Full Text]
  36. Segal KR, Van Loan M, Fitzgerald PI, Hodgdon JA, Van Itallie TB. Lean body mass estimation by bioelectrical impedance analysis: a four-site cross-validation study. Am J Clin Nutr. 1988;47:7–14.[Abstract/Free Full Text]
  37. DeFronzo RA, Tobin JD, Andres R. Glucose clamp technique: a method for quantifying insulin secretion and resistance. Am J Physiol. 1979;237:E214–E223.[Abstract/Free Full Text]
  38. Manson JE, Willett WC, Stampfer MJ, Colditz GA, Hunter DJ, Hankinson SE, Hennekens CH, Speizer FE. Body weight and mortality among women. N Engl J Med. 1995;333:677–685.[Abstract/Free Full Text]
  39. Larsson B, Svärdsudd K, Welin L, Wilhelmsen L, Björntorp P, Tibblin G. Abdominal adipose tissue distribution, obesity, and risk of cardiovascular disease and death: 13 year follow up of participants in the study of men born in 1913. BMJ. 1984;288:1401–1404.
  40. Björntorp P. `Portal' adipose tissue as a generator of risk factors for cardiovascular disease and diabetes. Arteriosclerosis. 1990;10:493–496.[Free Full Text]
  41. Després J, Moorjani S, Lupien PJ, Tremblay A, Nadeau A, Bouchard C. Regional distribution of body fat, plasma lipoproteins, and cardiovascular disease. Arteriosclerosis. 1990;10:497–511.[Abstract/Free Full Text]
  42. Nakamura T, Tokunaga K, Shimomura I, Nishida M, Yoshida S, Kotani K, Islam AHMW, Keno Y, Kobatake T, Nagai Y, Fujioka S, Tarui S, Matsuzawa Y. Contribution of visceral fat accumulation to the development of coronary artery disease in non-obese men. Atherosclerosis. 1994;107:239–246.[Medline] [Order article via Infotrieve]
  43. Landin K, Tengborn L, Smith U. Elevated fibrinogen and plasminogen activator inhibitor (PAI-1) in hypertension are related to metabolic risk factors for cardiovascular disease. J Intern Med. 1990;227:273–278.[Medline] [Order article via Infotrieve]
  44. Ohlson L, Larsson B, Svärdsudd K, Welin L, Eriksson H, Wilhelmsen L, Björntorp P, Tibblin G. The influence of body fat distribution on the incidence of diabetes mellitus: 13.5 years of follow-up of the participants in the study of men born in 1913. Diabetes. 1985;34:1055–1058.[Abstract]
  45. Eliasson M, Evrin P, Lundblad D, Asplund K, Ranby M. Influence of gender, age and sampling time on plasma fibrinolytic variables and fibrinogen: a population study. Fibrinolysis. 1993;7:316–323.
  46. Gebara OCE, Mittleman MA, Sutherland P, Lipinska I, Matheney T, Xu P, Welty FK, Wilson PWF, Levy D, Muller JE, Tofler GH. Association between increased estrogen status and increased fibrinolytic potential in the Framingham Offspring Study. Circulation. 1995;91:1952–1958.[Abstract/Free Full Text]
  47. Van Kesteren PJM, Kooistra T, Lansink M, Van Kamp GJ, Asscheman H, Gooren LJG, Emeis JJ, Vischer UM, Stehouwer CDA. The effects of sex steroids on plasma levels of marker proteins of endothelial cell functioning. Thromb Haemost.. 1998;79:1029–1033.[Medline] [Order article via Infotrieve]
  48. Anderson RA, Ludlam CA, Wu FCW. Haemostatic effects of supraphysiological levels of testosterone in normal men. Thromb Haemost. 1995;74:693–697.[Medline] [Order article via Infotrieve]
  49. Bu G, Willams S, Strickland DK, Schwartz AI. Low density lipoprotein receptor-related protein/{alpha}2-macroglobulin receptor is an hepatic receptor for tissue-type plasminogen activator. Proc Natl Acad Sci U S A. 1992;89:7427–7431.[Abstract/Free Full Text]
  50. Nykjaer A, Petersen CM, Moller B, Jensen PH, Moestrup SK, Holtet TL, Etzerodt M, Thogersen HC, Munch M, Andreasen PA, Gliemann J. Purified {alpha}2-macroglobulin receptor/LDL receptor-related protein binds urokinase plasminogen activator inhibitor type-1 complex: evidence that the {alpha}2-macroglobulin receptor mediates cellular degradation of urokinase receptor-bound complexes. J Biol Chem. 1992;267:14543–14546.[Abstract/Free Full Text]
  51. Björntorp P. Adipose tissue distribution and function. Int J Obes. 1991;15(suppl 2)67–81.
  52. Samad F, Loskutoff DJ. The fat mouse: a powerful genetic model to study elevated plasminogen activator inhibitor 1 in obesity/NIDDM. Thromb Haemost. 1997;78:652–655.[Medline] [Order article via Infotrieve]



This article has been cited by other articles:


Home page
 J. Clin. Endocrinol. Metab.Home page
L. J. Gooren, E. J. Giltay, and M. C. Bunck
Long-Term Treatment of Transsexuals with Cross-Sex Hormones: Extensive Personal Experience
J. Clin. Endocrinol. Metab., January 1, 2008; 93(1): 19 - 25.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
E. Nisoli, E. Clementi, M. O. Carruba, and S. Moncada
Defective Mitochondrial Biogenesis: A Hallmark of the High Cardiovascular Risk in the Metabolic Syndrome?
Circ. Res., March 30, 2007; 100(6): 795 - 806.
[Abstract] [Full Text] [PDF]

Home page
 DiabetesHome page
D. B. Carr, K. M. Utzschneider, R. L. Hull, K. Kodama, B. M. Retzlaff, J. D. Brunzell, J. B. Shofer, B. E. Fish, R. H. Knopp, and S. E. Kahn
Intra-Abdominal Fat Is a Major Determinant of the National Cholesterol Education Program Adult Treatment Panel III Criteria for the Metabolic Syndrome
Diabetes, August 1, 2004; 53(8): 2087 - 2094.
[Abstract] [Full Text] [PDF]

Home page
 Arterioscler. Thromb. Vasc. Bio.Home page
H. R. Lijnen, E. Maquoi, P. Morange, G. Voros, B. Van Hoef, F. Kopp, D. Collen, I. Juhan-Vague, and M.-C. Alessi
Nutritionally Induced Obesity Is Attenuated in Transgenic Mice Overexpressing Plasminogen Activator Inhibitor-1
Arterioscler. Thromb. Vasc. Biol., January 1, 2003; 23(1): 78 - 84.
[Abstract] [Full Text] [PDF]

Home page
 Arterioscler. Thromb. Vasc. Bio.Home page
D. Bastelica, P. Morange, B. Berthet, H. Borghi, O. Lacroix, M. Grino, I. Juhan-Vague, and M.-C. Alessi
Stromal Cells Are the Main Plasminogen Activator Inhibitor-1-Producing Cells in Human Fat: Evidence of Differences Between Visceral and Subcutaneous Deposits
Arterioscler. Thromb. Vasc. Biol., January 1, 2002; 22(1): 173 - 178.
[Abstract] [Full Text] [PDF]

Home page
 Arterioscler. Thromb. Vasc. Bio.Home page
E. J. Giltay, L. J. G. Gooren, J. J. Emeis, T. Kooistra, and C. D. A. Stehouwer
Oral, but Not Transdermal, Administration of Estrogens Lowers Tissue-Type Plasminogen Activator Levels in Humans Without Affecting Endothelial Synthesis
Arterioscler. Thromb. Vasc. Biol., May 1, 2000; 20(5): 1396 - 1403.
[Abstract] [Full Text] [PDF]

Home page
 J Am Coll CardiolHome page
S. M. Grundy, R. Pasternak, P. Greenland, S. Smith Jr, and V. Fuster
Assessment of cardiovascular risk by use of multiple-risk-factor assessment equations: A statement for healthcare professionals from the American Heart Association and the American College of Cardiology
J. Am. Coll. Cardiol., October 1, 1999; 34(4): 1348 - 1359.
[Full Text] [PDF]

Home page
 CirculationHome page
S. M. Grundy, R. Pasternak, P. Greenland, S. Smith Jr, and V. Fuster
Assessment of Cardiovascular Risk by Use of Multiple-Risk-Factor Assessment Equations : A Statement for Healthcare Professionals From the American Heart Association and the American College of Cardiology
Circulation, September 28, 1999; 100(13): 1481 - 1492.
[Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Giltay, E. J.
Right arrow Articles by Stehouwer, C. D. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Giltay, E. J.
Right arrow Articles by Stehouwer, C. D. A.

ATVB Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search
Copyright © 1998 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited.