Hemostatic and metabolic variables in women with polycystic ovary syndrome*

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1 FERTILITY AND STERILITY Coyright 1994 The American Fertility Society Printed on acid-free aer in U. S. A. Hemostatic and metabolic variables in women with olycystic ovary syndrome* Eva Dahlgren, M.D., Ph.D.t:\: Per Olof Janson, M.D., Ph.D.t Saga Johansson, M.D., Ph.D. Leif Laidus, M.D., Ph.D.11 Goran Lindstedt, M.D., Ph.D.~ Lilian Tengborn, M.D., Ph.D. II Sahlgrenska Hosital, and Ostra Hosital, Faculty of Medicine, University of G6teborg, G6teborg, Sweden Objective: To study whether a reviously demonstrated increased morbidity in cardiovascular disease (CVD) and diabetes mellitus in women with olycystic ovary syndrome (PCOS) is associated with certain hemostatic variables that are known to be markers for CVD. Design: The study was a trans-sectional follow-u study from a cohort of women with PCOS. Setting: The women with PCOS were recruited from hosital clinics and referents were randomized from a oulation study of women from the same area. Particiants: The investigation involved 28 women aged 43 to 62 years diagnosed to have PCOS on ovarian histoathology at wedge resection 25 to 34 years reviously and 56 referents who were matched by age and body mass index. Main Outcome Measures: In connection with a clinical investigation, the hemostatic variables fibrinogen, von Willebrand factor antigen, factor VII rocoagulant activity, factor VII antigen, and lasminogen activator inhibitor as well as the metabolic variables serum insulin and serum triglycerides were assayed. Results: There was a strong ositive correlation between serum concentrations of triglyceride, basal insulin, and abdominal obesity on the one hand, and lasminogen activator inhibitor, fibrinogen, and von Willebrand factor on the other, among women with PC OS as well as among referents. There were significantly higher mean concentrations of fibrinogen and factor VII:Ag among referents, but the mean values of most hemostatic variables studied showed no differences between the grous. Conclusion: Women with an altered metabolic rofile were also found to have affected hemostatic factors, but PCOS in itself did not seem to influence them. Fertil Steril 1994;61: Key Words: Polycystic ovary syndrome, hemostasis, cardiovascular disease, metabolic factors, risk factor The interest in the olycystic ovary syndrome (PCOS) has in the latest decade focused not only on Received March 23, 1993; revised and acceted November 5, * Suorted by grants from the Faculty of Medicine, University of Goteborg, The Goteborg Medical Society, The Research and Develoment Foundation, Bohuslandstinget, and The Hjalmar Svensson Fund. t Deartments of Obstetrics and Gynecology, Sahlgrenska Hosital. :j: Rerint requests: Eva Dahlgren, M.D. Ph.D., Deartment of Obstetrics and Gynecology, Sahlgrenska Hosital, University of Goteborg, S Goteborg, Sweden. the hormonal imbalance but also on metabolic disturbances, such as abdominal obesity, hyerinsuline mia, and hyerlioroteinemia. Women who have undergone coronary angiograhy due to angina ectoris have also been found to have clinical symtoms of hyerandrogenism, which is suggestive of PCOS (1). These findings indicate a ossible Section of Preventive Cardiology, Deartment of Internal Medicine, Ostra Hosital. II Deartment of Internal Medicine, Sahlgrenska Hosital. ~ Deartment of Clinical Chemistry, Sahlgrenska Hosital. Dahlgren et al. cas and hemostatic variables 455

2 relationshi between PCOS and the develoment of cardiovascular disease (CVD). In a revious study on women with PCOS comared with agematched referents (2), we found a significantly higher revalence of central obesity, exressed as a high waist/hi circumference ratio, an imortant redictor of cardiovascular morbidity and mortality in women (3). In our study (2) fasting serum insulin was also elevated in women with PCOS comared with a randomized age-matched samle of the ou- 1ation' and the PCOS women showed a higher revalence of hyertension and of manifest diabetes mellitus. Angiograhy and angioscoy have contributed to establish the role of thrombosis in unstable angina ectoris, myocardial infarction, and sudden death (4-6), indicating that an imbalance between coagulation and fibrinolysis may be involved in arterial vascular comlications. Thus, coagulation factors fibrinogen, factor VII rocoagulant activity, and von Willebrand Factor antigen were increased in atients with CVD (4-10) as was lasminogen activator inhibitor (11-13), indicating an imaired fibrinolysis. The aim of the resent study was to evaluate whether women with PCOS, aart from being metabolically disturbed, also are affected by an imbalance in the coagulation and fibrinolytic factors, which have been suggested as risk indicators for CVD (7,8, 11). Subjects MATERIALS AND METHODS Twenty-eight women aged 43 to 62 years with PCOS were investigated in The diagnosis was based on histoathological changes in ovarian biosies from all women who underwent ovarian surgery for benign disease between 1956 and 1965 at the three gynecological deartments in the area of Goteborg. Ovaries in PCOS were histoathologically defined as ovaries demonstrating a fibrotic thickening of tunica albuginea and the outer cortex and multile cystic follicles with rominent theca, often with a tendency for luteinization. The histoathological diagnosis of PCOS was reconfirmed by one athologist. Of the 38 women who were diagnosed to have PCOS, 33 were investigated by a questionnaire on medical and natural history and 30 also arti~iated in a clinical investigation including venous samling in At the time of the investigation in 1987, three women had died and two were unwilling to articiate (2). Infertility, hirsutism, and oligomenorrhea were significantly more common among women with PCOS comared with age-matched referents. The hormonal data showed a tyical rofile for PCOS and, comared with referents, the women with PCOS showed centrally located obesity, measured as increased waist/hi circumference ratio, increased basal serum insulin concentrations, and a higher revalence of diabetes mellitus and hyertension (2). Of the 30 women, 28 attended the reinvestigation in The remaining two declined the invitation because they lived far away. Fifty-six women were selected from a randomized female oulation study in Goteborg (WHO MONICA [Monitoring of trends and determinants in cardiovascular disease study, initiated by WHO in 1984] [14]) and were matched by age and body mass index (BMI). Clinical Examination Information about medical treatment, smoking, and menstrual data was obtained by a questionnaire and sulemented by a ersonal interview. Subjects who smoked:2:1 cigarette er day were defined as smokers. Subjects who had stoed smoking were defined as exsmokers and women who had never smoked or had smoked <1 month were defined as nonsmokers. Diabetes mellitus was defined as a manifest disease demanding dietary and/or medical treatment. Hyertension was defined as an elevated blood ressure requiring medical treatment. Menoause was defined as an absence of menstrual eriods for :2: 1 year and a serum value of FSH :2: 50 U /L (conversion factor to SI, 1.00). In hysterectomized women, menoause was considered to have occurred when the serum value of FSH was :2: 50.0 U/L (conversion factor to SI, 1.00). Body weight and height were measured in the fasting state with the subjects wearing indoor clothes, without shoes. Body weight was measured to the nearest 0.1 kg and height was measured to the nearest 0.5 cm. Body mass index was calculated as weight/height 2 Waist circumference was measured with a soft tae at the level ofthe umbilicus to the nearest centimeter with the woman breathing normally, in standing osition. Hi circumference was measured to the nearest centimeter at the level of the iliac crest (sina iliaca anterior suerior). From these measurements the waist/hi circumference ratio was calculated. Blood ressure was measured after a 10-minute rest with the subjects sitting. The diastolic blood ressure was measured as Korotkoff hase V. 456 Dahlgren et al. eas and hemostatic variables Fertility and Sterility

3 Metabolic Variables Venous blood samles were drawn from an antecubital vein after an overnight fast. Serum insulin concentration was analyzed by a RIA method (Phadebas; Pharmacia, Usala, Sweden). Serum triglyceride levels were determined enzymatically by commercial kits (Boehringer Mannheim, Mannheim, Germany). Serum concentrations of FSH were determined by enzyme immunoassays using luminometry (Amerlite FSH (monoclonal) assay, Amersham International Ic, Amersham, UK). Coagulation and Fibrinolytic Comonents After an overnight fast venous blood samles were drawn between 7:30 and 9:00 A.M. in 5-mL tubes containing 0.5 ml M trisodiumcitrate (Becton Dickinson Vacutainer Systems Euroe, Meylan, Celex, France). For fibrinogen determination, blood was drawn in 5-mL tubes containing 0.5 ml of M trisodiumcitrate and 50 mg esilonaminocaroic acid. The tubes were immediately centrifuged at 2,000 X g for 20 minutes at 4 C, and then the lasma was divided into aliquots, sna frozen, and stored in -70 C until analysis. Fibrinogen was analyzed with a syneresis method (15). Factor VII rocoagulant activity (VII:C) was assayed in a one-stage system using Neolastin (Stago, Asnieres, France) and factor VII-deficient lasma from the same manufacturer. Factor VII antigen (VII:Ag) was measured using an ELISA (Stago). Von Willebrand factor antigen (vwf:ag) was determined by means of ELISA using antibodies from Dakoatts (Coenhagen, Denmark). Plasminogen activator inhibitor (PAl-I) activity was measured with the kit Sectrolyse L (Bioool, Umea, Sweden). C-reactive rotein (CRP) was analyzed using a nehelometic latex method (Behring Nehelometer A, Marburg, Germany). Statistics Data on hemostatic and metabolic variables are given as mean, standard deviation (SD), and range. Significance of differences between the grous was tested using a nonarametric test (Mann-Whitney U test). Comarisons between roortions, i.e., revalence of hyertension, diabetes mellitus, and menoausal and smoking status, were erformed by using Fisher's exact test. Comarisons between hemostatic variables of subgrous in women with PCOS and refetents (e.g., women with diabetes mellitus versus nondiabetics) were erformed by Student's t-test. Linear regression analysis was Table 1 Variables Measured in * Women With PCDS and Age- and BMI-matched Age (y) Postmenoausal (%) BMI (kg/m') Waist/hi circumference ratio vwf:ag (IU/mL) VII:C (IU/mL) VII:Ag (IU/mL) Fibrinogen (g/l) PAI-1 (U/mL) Insulin (mu/l) Triglycerides (mm) PCDS*t (n = 28) 52.7 ± 5.10 (43 to 62) ± 5.10 (17.8 to 38.1) 0.81 ± 0.10 (0.70 to 0.98) 1.20 ± 0.52 (0.54 to 2.86) 1.19 ± 0.32 (0.62 to 1.75) 1.15 ± 0.25 (0.80 to 1.68) 2.87 ± 0.59 (1.80 to 4.10) ± (0.40 to 63.5) ± 8.82 (4.14 to 47.4) 1.29 ± 0.73 (0.60 to 3.73) t (n = 56) 53.3 ± 5.2 (43.0 to 65.0) 58.5* 25.1 ± 4.3 (17.5 to 40.6) 0.79 ± 0.1 (0.59 to 0.99) 1.10 ± 0.36 (0.64 to 2.96) 1.23 ± 0.30 (0.76 to 2.00) 1.30 ± 0.26 (0.74 to 1.83) 3.21 ± 0.60 (1.90 to 4.60) ± 11.9 (1.3 to 76.6) 9.75 ± 5.66 (3.2 to 32.0) 1.36 ± 0.61 (0.61 to 3.23) * Results of VII:C and VII:Ag were omitted in one PCDS woman due to warfarin medication. t Values are means ± SD with ranges in arentheses. * P < P < used when correlating continuous variables within the grous. A P value ::5; 0.05 was regarded as statistically significant. RESULTS Table 1 shows the variables analyzed in the PC OS women and in the age- and BMI-matched referents. Fibrinogen and VII:Ag showed significantly higher mean values in the referent women, but the mean values of the other assayed coagulation and fibrinolytic factors in the two grous did not differ significantly. Neither was there any significant difference in the mean values of waist/hi circumference ratio between the grous, but twice as many PCOS women (32.1%) as referents (16.1%) had a waist/hi circumference ratio of ;::::0.85. The revalence of hyertension was 39.3% in the PCOS women comared with 19.6% among the referents (P = 0.09) and the revalence of diabetes mellitus was 14.3% in the PCOS women comared with 1.8% in the referents (P = 0.08). The smoking habits were similar in the two grous but PCOS women with a waist/hi circumference ratio ;::::0.85 smoked to a lesser extent (11.1%) than corresonding referents (55.5%). Dahlgren et at. eas and hemostatic variables 457

4 Table 2 Linear Regression Analyses Correlating Waist/Hi Circumference Ratio and BMI to Hemostatic and Metabolic Variables in Women With cas and Age and BMI-matched Fibrinogen PAI-1 Insulin Triglycerides BMI Waist/hi circumference ratio cos (n = 28)* 0.59 < < < < <0.001 (n = 56) 0.38 < < < < <0.01 cos (n = 28)* < <0.01 BMI (n = 56) < < * Correlations to VII:C and VII:Ag were omitted in one PC OS woman due to warfarin medication. The menoause was assed in 28.6% of the cas women and in 58.5% of the referents (P = 0.02). Nine ercent of the referents reorted oligomenorrhea and obesity (BMI ~ 25.0), which was suggestive of a clinical diagnosis of cas. Eleven ercent in both grous were on hormonal relacement theray (HRT). Exclusion of the women on HRT or oligomenorrhea, resectively, from the comarisons caused insignificant changes of the mean, SD, and differences between the grous and, consequently, it was decided not to exclude them from the results. Serum insulin tended to be higher in the cas women whereas serum triglycerides tended to be higher in the referent women, but there were no statistically significant differences between the grous. C-reactive rotein as an indicator of reactive rocesses was normal in all subjects excet for one in the cas grou. Table 2 shows linear regression analyses between hemostatic and metabolic factors on the one hand and waist/hi circumference ratio and BMI on the other. There was a ositive correlation between waist/hi circumference ratio on the one hand and fibrinogen, PAI-1, serum insulin, serum triglycerides, and BMI on the other in both cas women and referents. In the cas women a significantly ositive correlation was found between BMI on the one hand and VII:Ag (r = 0.44; P = 0.02), fibrinogen, PAI-1, serum insulin, and serum triglycerides on the other. In the referents, significant correlations were observed between BMI on the one hand and PAI-1 and insulin on the other. Table 3 shows the linear regression correlations between hemostatic and some metabolic variables. Insulin covaried with vwf:ag, factor VII:Ag, fibrinogen, and PAl among the women with cas and with PAl in referents. Triglycerides covaried with vwf:ag, factor VII:C, factor VII:Ag, and PAl in women with cas and with factor VII:C, factor VII:Ag, and fibrinogen in the referents. The mean values ofvwf:ag and PAl were significantly higher in women with cas and diabetes mellitus comared with the women with cas without diabetes mellitus (vwf:ag, 1.72 ± 0.51 versus 1.12 ± 0.48 IU/mL [P < 0.05] and PAl, 29.9 ± 23.9 versus 12.3 ± 7.4 U/mL [P < 0.01]; mean ± SD). The correlation between the two methods of assaying factor VII was highly significant in both grous (PCaS, r = 0.79, P < 0.001); referents, r = 0.69, P < 0.001). ane cas woman showed a markedly elevated PAl -1 level of 63.5 U /ml (in the entire material the mean ± 2 SD was 37.3 U/mL). She suffered from hyertension, non-insulin-deendent diabetes mellitus (NIDDM) with a basal serum insulin concentration of 20.0 mu /L, and had a history ofthrombosis cerebri at an age of 32. She was on continuous treatment with metorolol and warfarin. Because warfarin decreases factor VII, her values of VII:C and VII:Ag were omitted from analyses of mean values and correlations concerning VII:C and VII:Ag whereas her values were included in the analyses of the other hemostatic and metabolic variables. ane woman among the referents showed a massively increased PAI-1 activity of 76.6 U/mL. She suffered from hyertension and angina ectoris, and her basal serum insulin concentration was 19.0 mull. She was on continuous treatment with metorolol and nifediin, the combined imact of which on the hemostatic factors is not clear. She was included in the analyses. Table 3 Linear Regreession Analyses Correlating Hemostatic Variables to Serum Insulin and Serum Triglycerides in Women With cas and Age- and BMImatched Insulin Triglycerides r r P vwf:ag cas' Referent 0.02 > >0.200 VII:C cas' 0.20 > Referent VII:Ag cas' Referent Fibrinogen cas' >0.200 Referent PAI-1 cas' <0.001 Referent Correlations to VII:C and VII:Ag were omitted in one cas woman due to warfarin medication. 458 Dahlgren et al. cas and hemostatic variables Fertility and Sterility

5 If these two women with extreme PAl -1 values were excluded, the mean, ± SD and range of PAI-1 would be 13.0 ± 7.8 (range, 0.4 to 28.5) in PCOS and 11.3 ± 8.0 (range, 1.3 to 39.5) in referents (P = 0.36). One woman in the PCOS grou, included in the study, had a slightly elevated CRP concentration of 25.7 mg/ml, her PAl -1 level was 28.5 U/mL, she suffered from NIDDM with a serum insulin of 25 m U /L, and she had a fibrinogen value of 4.1 gil. DISCUSSION Polycystic ovary syndrome, also called chronic hyerandrogen anovulation, is clinically characterized by hirsutism, obesity, oligomenorrhea, and infertility. Research in the last decade has revealed metabolic stigmata in remenoausal women with PCOS, such as hyertriglyceridemia, hyerinsulinemia, and insulin resistance (16, 17). In a revious study on the long-term effects of PCOS in women around the menoause, a strong suort was found for such a metabolic syndrome being art of the PCOS (2). In a risk -factor model taking into consideration the metabolic variables waist/hi circumference ratio, triglyceride concentration, as well as hyertension and diabetes'mellitus, the estimated risk to develo CVD in PCOS women aged 40 to 49 years was the same as in males in corresonding ages (four times the estimated risk for the normal female oulation). In PCOS women aged 50 to 60 years of age there was an 11-fold estimated increased risk (18). The revalence of end oints of cardiovascular disease (ischemic heart disease and stroke) already in 1987 showed a tendency to be increased in the PCOS women (18). For the diagnosis of PCOS, we used ovarian histoathology, obtained at wedge resection of the ovaries 25 to 34 years before, as a diagnostic criterion. This was the only way to get information on ovarian morhology because the ovaries in ostmenoausal women with PCOS do not differ from normal when examined with ultrasound. Women with PCOS seem to reach the menoause at a somewhat later age comared with referents. This was also shown in an earlier study using another referent oulation. Desite a significant difference with regard to the time of menoause, the HRT was equal (10.7%) in the two grous. The manifestation of arterial thrombosis in unstable angina ectoris, myocardial infarction, and sudden death (19, 20), evidenced by angiograhy and angioscoy, indicates that an imbalance be- tween coagulation and fibrinolysis may be involved in arterial vascular comlications. Increased vwf:ag levels have been associated with myocardial infarction in women (11) and ischemic cerebrovascular disease (4, 5). The strong correlations found in this study between vwf:ag and diabetes mellitus, serum insulin, and triglycerides in the PCOS grou are interesting findings because vwf:ag has been suggested to be an indicator of atherosclerotic changes (4,5). In the rosective Northwick Park Heart Study, an indeendent association between VII:C and cardiovascular death was reorted, although a similar correlation to VII:Ag could not be shown (6). It was suggested in another study that factor VII lays a role in the develoment of arteriosclerosis by having a secial affinity to lioroteins (21). Other researchers (9) confirmed that men with high risk for CVD had elevated levels ofvii:c and demonstrated that the increase was due to a hosholiid-vii comlex that correlated ositively with the level of triglycerides. In this investigation we found no differences in mean concentrations of VII:C between PCOS women and their referents whereas referents showed higher levels of VII:Ag. Increased concentrations of fibrinogen are described to be associated with coronary artery disease (6-8, 10). In this material, fibrinogen showed a strong correlation with waist/hi circumference ratio in both grous and, in the PCOS grou, also with serum insulin and BMI and, among referents, also to serum triglycerides. Smoking is known to increase the fibrinogen levels (22, 23) but in this study there were no differences in smoking habits between the materials. Plasminogen activator inhibitor levels are reorted to be increased in obesity, hyertriglyceridemia, and hyerinsulinemia (12, 24). Hamsten and co-workers (11, 13) showed an elevated PAI-1 activity in younger subjects, earlier having suffered from a myocardial infarction. They also found an increased PAl -1 level after an ischemic heart disease in atients later develoing reinfarction. These findings may indicate that PAl -1 is a link between the metabolic syndrome and atherosclerosis and thrombogenesis due to imaired fibrinolysis. In our study, where referents were matched by age and BMI to the PCOS women, no differences in mean values were demonstrated in PAl -1. There was, however, a strong ositive correlation between PAl -1 and most of the metabolic factors in both grous, which is in accordance with earlier studies (12,24,25). were randomly selected from the female middle-aged oulation and were not Dahlgren et al. eas and hemostatic variables 459

6 just healthy controls. This is illustrated by the relatively high revalence of hyertension among referents. It was, in fact, not significantly lower than in the grou of women with PCOS. This might be one exlanation to the small differences in hemostatic variables between women with PCOS and referents in erimenoausal women, because the metabolic variables are increasingly affected by age. In conclusion, we have demonstrated few differences between the PCOS women and the age- and BMI-matched referents concerning the studied hemostatic comonents. However, women with deranged metabolic factors also had imairment of coagulation and fibrinolytic comonents, but PCOS in its own right did not affect the assayed hemostatic factors. Acknowledgments. We thank Anders Odim, Ph.D., for exert statistical assistance and Ms. Ann -Louise Dahl for skillful rearation of the manuscrit. REFERENCES 1. Wild RA, Grubb B, Hartz A, VanNort JJ, Bachman W, Bartholomew M. Clinical signs of androgen excess as risk factors for coronary artery disease. Fertil Steril 1990;54: Dahlgren E, Johansson S, Lindstedt G, Knutsson F, Oden A, Janson PO, et al. Women with olycystic ovary syndrome wedge resected in 1956 to 1965: a long-term follow-u focusing on natural history and circulating hormones. Fertil Steril1992;57: Laidus L, Bengtsson C, Larsson B, Pennert K, Rybo E, Sjostrom L. Distribution of adiose tissue and risk of cardiovascular disease and death: a 12 year follow u of articiants in the oulation study of women in Gothenburg, Sweden. Br Med J 1984;289: Wahlberg T, Blomback M, Overmark I. Blood coagulation studies in 45 atients with ischemic cerebrovascular disease and 44 atients with venous thromboembolic disease. Acta Med Scand 1980;207: Mettinger KL. A study of hemostasis in ischemic cerebrovascular disease I. Abnormalities in factor VIII and antithrombine. Thromb Res 1982;26: Meade TW, North WRS, Chakrabarti R, Stirling Y, Haines AP, Thomson SG. Haemostatic function and cardiovascu- 1ar death: Early results of a rosective study. Lancet 1980;1: Wilhelmsen L, Svardsudd K, Korsan-Bengtsen K, Larsson B, Welin L, Tibblin G. Fibrinogen as a risk factor for stroke and myocardial infarction. N Engl J Med 1984;311: Meade TW, Mellows S, Brozovic M, Miller GJ, Chakrabarti RR, North WRS, et al. Haemostatic function and ischemic heart disease: rincile results of the Northwick Park Heart Study. Lancet 1986;2: Dalaker K, HjertIan I, Prydz H. A novel form of Factor VII in lasma from men at risk for cardiovascular disease. Br J Haematol 1985;61: Stone MC, Thore JM. Plasma fibrinogen-a major coronary risk factor. J R Coli Gen Pract 1985;35: Hamsten A, Wiman B, Faire U, Blomback M. Increased lasma levels of a raid inhibitor of tissue lasminogen activator in young survivors of myocardial infarction. N Engl J Med 1985;313: Sundell B, Nilsson TK, Hallmans G, Hellsten G, Dahlen GH. Interrelationshis between lasma levels of lasminogen activator inhibitor, tissue lasminogen activator, liorotein (a), and established cardiovascular risk factors in a north Swedish oulation. Atherosclerosis 1989;80: Hamsten A, de Faire U, Walldius G, Dahlen G, Szamosi A, Landou C, et al. Plasminogen activator inhibitor in lasma: risk factor for recurrent myocardial infarction. Lancet 1987;2: The WHO MONICA roject. Geograhical variation in the major risk factors of cardiac heart disease in men and women aged years. World Health Stat Q 1988;41: Nilsson 1M, Olow B. Determinations of fibrinogen and fibrinogenolytic activity. Thromb Diath Haemorrh 1962;8: Mattsson L-A, Cullberg G, Hamberger L, Samsioe G, Silfverstole G. Liid metabolism in women with olycystic ovary syndrome: ossible imlications for an increased risk of coronary heart disease. Fertil Steril 1984;42: Chang RJ, Nakamura RM, Judd HL, Kalan SA. Insulin resistance in non-obese atients with olycystic ovarian disease. J Clin Endocrinol Metab 1983;57: Dahlgren E, Johansson S, Laidus L, Oden A, Janson PO. Polycystic ovary syndrome and risk for myocardial infarction-evaluation from a risk factor model based on a rosective oulation study of women. Acta Obstet Gynecol Scand 1992;71: De Wood MA, Sores J, Notske R, Mouser LT, Burroughs R. Prevalence of total coronary occlusion during the early hours of transmural myocardial infarction. N Engl J Med 1980;303: Davies MJ, Thomas A. Thrombosis and acute coronary artery lesions in sudden cardiac ischemic death. N Engl J Med 1984;310: Miller GJ, Martin JC, Webster J, Wilkes H, Miller NE, Wilkinson WH, et al. Association between dietary fat intake and lasma Factor coagulant activity-a redictor of cardiovascular mortality. Atherosclerosis 1986;60: Craig WY, Palmaki GE, Haddow JE. Cigarette smoking and serum liid and liorotein concentrations: an analysis of ublished data. Br Med J 1989;298: Meade TW, Imeson J, Stirling Y. Effects of smoking on oral fat tolerance and high density liorotein cholesterol. Lancet 1987;2: Vague P, Juhan-Vague I, Aillaud MF, Badier C, Viard R, Alessi M, et al. Correlation between blood fibrinolytic activity, lasminogen activator inhibitor level, lasma insulin level and relative body weight in normal and obese subjects. Metabolism 1986;35: Landin K, Tengborn L, Smith U. Elevated fibrinogen and lasminogen activator inhibitor (PAl -I) in hyertension are related to metabolic risk factors for cardiovascular disease. J Intern Med 1990;227: Dahlgren et al. cas and hemostatic variables Fertility and Sterility