Baroreflex responsiveness is attenuated in middle-aged women compared with men, but the tonic vagal modulation of HR is augmented. Hormone replacement therapy appears to have favorable effects on the cardiovascular autonomic regulation in postmenopausal women.

Abstract. Rantala AO, Kauma H, Lilja M, Savolainen MJ, Reunanen A, Kesäniemi YA (University of Oulu, Oulu, and The National Public Health Institute, Helsinki, Finland). Prevalence of the metabolic syndrome in drug-treated hypertensives and control subjects. J Intern Med 1999; 245: 163-74. Objectives.To determine the prevalence of the metabolic abnormalities associated with hypertension and to define the predictors of the metabolic syndrome by different definitions in random population-based samples. Design. A cross-sectional epidemiological study of hypertensive patients and controls. Setting. The participating study subjects visited the research laboratory of the Department of Internal Medicine, University of Oulu, Oulu, Finland. Subjects. Six hundred treated male and female hypertensives aged 40-59 years and 600 age-and sexmatched controls were randomly selected by age stratification from population registers. Main outcome measures. A wide range of laboratory analyses were conducted. After fasting blood had been drawn, the subjects were given a 75 g glucose load except previously known insulin-treated diabetics. Both 1 h and 2 h glucose and insulin concentrations were determined. During the same visit, a standardized health questionnaire covering the past medical history, current and former medication use, physical activity, smoking habits, alcohol consumption and family history was completed. Ten different definitions of the metabolic syndrome were applied to achieve a wide perspective of the prevalence of the different combinations.Results. The prevalence of the metabolic syndrome in different samples varied depending on the definition from 0.8 to 35.3%, being lowest in the control men and women and highest in the hypertensive men. Three-quarters of a random, middle-aged, urban population show at least one cardiovascular risk factor and 91.3% of all the hypertensive subjects show at least one cardiovascular risk factor in addition to hypertension itself. The independent predictors of the metabolic syndrome were waist circumference, uric acid, total cholesterol and gamma-glutamyl transpeptidase in logistic analysis after adjustment for age, measure of obesity and gender. Conclusions. This cross-sectional, epidemiological study shows that the magnitude of the prevalence rates of the metabolic syndrome is at the same level in various populations, being less than one-third in population-based samples in spite of the different definitions. The cluster of several cardiovascular risk factors, especially in the hypertensives, leads to an increased relative risk of cardiovascular diseases.

Abstract. Rantala AO, Lilja M, Kauma H, Savolainen MJ, Reunanen A, Kesa Èniemi YA (University of Oulu, Oulu; and The National Public Health Institute, Helsinki, Finland). Gamma-glutamyl transpeptidase and the metabolic syndrome. J Intern Med 2000; 248: 230±238.Objective. To analyse the associations between serum gamma-glutamyl transpeptidase activity (GTP) and the components of the metabolic syndrome. Design. Cross-sectional, observational study of hypertensive patients and controls. Setting. The participating subjects visited the research laboratory of the Department of Internal Medicine, University of Oulu, Oulu, Finland. Subjects. A total of 1045 Caucasians, 40±59 years of age, consisting of 261 drug-treated hypertensive men, 258 drug-treated hypertensive women and 526 ageand sex-matched controls. Main outcome measures. The associations between GTP and the cardiovascular risk factors were analysed through multiple regression and logistic methods and by GTP tertiles. The independent effect of GTP on different insulin measures, calculated from the values of 2 h of oral glucose tolerance test, was estimated after concurrent adjustment for age, obesity and alcohol consumption. Results. GTP correlated highly significantly with the components of the metabolic syndrome. The correlation coefficient were 0.33 between GTP and body mass index, 0.25 between GTP and systolic blood pressure in control men (P = 0.0001), 0.39 between GTP and triglycerides, and 0.32 between GTP and fasting insulin in hypertensive women (P = 0.0001). The association between GTP and blood pressure remained significant only at upright measurements in controls. All insulin measures had a significant positive association with increasing GTP tertiles in all the study groups (e.g. fasting insulin 8.1 mU L 21 in the lowest and 11.0 mU L 21 in the highest tertile in control women, P = 0.0001), with the exception of fasting insulin in control men. In a pooled logistic analysis after adjustment for age, body mass index, alcohol consumption and gender, the independent predictors of the metabolic syndrome were body mass index, uric acid, total cholesterol and GTP (for logtransformed GTP odds ratio 4.0, 95% CI: 2.80±5.69).Conclusions. There are significant associations between GTP and the components of the metabolic syndrome. Elevated levels of GTP may not always indicate increased alcohol consumption, but may also suggest the existence of the metabolic syndrome with its subsequent deleterious consequences.

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Association between high density lipoprotein (HDL) cholesterol concentration and restriction fragment length polymorphisms at the cholesteryl ester transfer protein (CETP) gene locus was studied in a random population-based cohort of 526 Caucasian subjects (259 men, mean age 50.9 years, and 267 women, mean age 51.8 years). HDL cholesterol concentration was adjusted for age, body mass index, alcohol consumption, smoking and plasma triglyceride and low density lipoprotein cholesterol levels. In females, the HDL cholesterol levels were associated with TaqIB polymorphism (1.46 mmol/l in the B1B1 genotype, 1.56 mmol/l in B1B2 and 1.72 mmol/l in B2B2, P = 0.0001 for the trend). In contrast, this was not observed in men (1.24, 1.20, 1.27 mmol/l, NS). The association was seen even in women who were current smokers (1.41, 1.56, 1.75 mmol/l, n = 72, P = 0.007), but not in male smokers (1.26, 1.19, 1.14 mmol/l, n = 102, NS). In male non-smokers the association was weak (1.22, 1.20, 1.32 mmol/l, n = 157, P = 0.05). In postmenopausal women not receiving hormone replacement therapy (n = 108), the association continued to be present, although weaker (1.50, 1.58, 1.70 mmol/l, P = 0.06). CETP activity (n = 101) tended to be lower in subjects with the B2B2 genotype. In conclusion, a clear-cut sex difference was observed in the genotype effect on plasma HDL cholesterol levels. The slight attenuation of the gene dosage effect after menopause suggests that the gender difference may be, at least in part, due to sex hormones. A genetic subgroup (men with the B2B2 genotype) particularly susceptible to the HDL cholesterol decreasing effect of smoking could be demonstrated.