Determinants of sex hormone-binding globulin blood concentrations in premenopausal and postmenopausal women with different estrogen status. Virgilio-Menopause-Health Group.

In women, sex hormone-binding globulin (SHBG) concentrations are the result of a balanced effect of stimulatory and inhibitory factors. Estrogens represent the principal stimulatory hormones, whereas androgens, insulin, excess body fat, and the pattern of body fat distribution have inhibitory effects. Menopause is characterized by major changes in blood sex steroid concentrations, notably a marked reduction of estradiol levels. In this study, we therefore investigated the relationship between hormonal and nonhormonal regulatory factors of SHBG and its blood levels in two groups of premenopausal and postmenopausal women characterized by normal-high or reduced estrogen concentrations. The data were obtained from an analysis of the cross-sectional database obtained during the first survey of the Virgilio-Menopause-Health Project, an epidemiologic longitudinal study aimed at investigating the impact of menopause on body weight, fat distribution, and related major metabolic, hormonal, and cardiovascular risk factors. A total of 329 women, 133 in premenopause and 196 in postmenopause without diabetes, thyroid diseases, or relevant cardiovascular, renal, and hepatic dysfunction, were included in the study. A clinical history (including dietary and physical-activity habits), anthropometry (body mass index [BMI], waist to hip ratio [WHR], and bioelectrical impedance analysis [BIA]), and morning blood samples in the fasting state for sex hormones, insulin, and biochemistry were available for all the women. Premenopausal and postmenopausal women showed no significant difference in SHBG concentrations (38.7 +/- 17.9 v 36.6 +/- 17.5 nmol/L, respectively). On the contrary, postmenopausal women were characterized by a marked reduction of estradiol levels and significantly lower levels of testosterone. After adjusting for age, insulin was lower and the glucose to insulin ratio was higher in postmenopause than in premenopause. Age-adjusted values for all anthropometric parameters were not significantly different in the two groups. In simple correlation models, SHBG was significantly and negatively correlated with BMI, WHR, and insulin and testosterone levels in both premenopausal and postmenopausal women, whereas estradiol levels correlated positively and significantly with SHBG only in the premenopausal group. A significant positive correlation between the glucose to insulin ratio and SHBG was present in both groups. Using multiple regression models, in the premenopausal group, SHBG levels were correlated positively with estradiol and negatively with testosterone and insulin, but not with the WHR. On the contrary, in the postmenopausal group, SHBG values had a significant negative correlation with the WHR, whereas the relationship with estradiol was not significant; moreover, the relationship with testosterone and insulin, although significant, became less marked. In conclusion, this study indicates that (1) there is no significant difference in SHBG blood concentrations between premenopause and postmenopause; (2) SHBG values are correlated positively with estradiol and negatively with insulin and testosterone concentrations, but the predictive value of these variabiles on SHBG appears to be different in premenopause and postmenopause; and (3) SHBG levels decrease with increasing WHRs, particularly in the postmenopausal group. Therefore, determinants of SHBG blood concentrations are likely to change on passing from premenopausal to postmenopausal status. In particular, there seems to be a threshold level for which estradiol is an important determinant of SHBG blood concentrations.

[Gynecomastia in chronic renal insufficiency. Presentation of a clinical case]. / Ginecomastia in corso di insufficienca renale cronica. Presentazione di un caso clinico.

Gynecomastia may occur in men with chronic renal failure, developing in the course of complex endocrine abnormalities. It is often associated with aberration in the hypothalamo-pituitary-testicular axis even producing a severe hypogonadism. A case of monolateral gynecomastia in a hemodialyzed young man, without other clinical and endocrine signs, is described.

Age-dependent changes of relaxation and its load sensitivity in rat cardiac muscle.

The relaxation phase and its load dependence were studied in papillary muscles isolated from the left ventricle of rats of the following ages: 20 days, 2, 8, 18, and 24 months. The myofibrillar ATPase activity and the force-velocity relation were determined in each age group in order to characterize the kinetic properties of the contractile material. Both shortening velocity and myofibrillar ATPase activity showed a progressive reduction with maturation and aging. This observation suggested an age-dependent decrease in cross bridge formation rate. The relaxation phase was characterized by its duration and the maximum rate of tension decline in isometric conditions, and by the speed of relengthening in isotonic conditions. Relaxation became faster and of shorter duration with maturation from 20 days to 2 months and then became slower and of longer duration with further maturation and aging. The sensitivity of relaxation to changes in length or load was evaluated by measuring how much earlier tension declined in the presence of a given length change. An increase in load sensitivity of relaxation was observed during maturation from 20 days to 8 months. This increase was followed by a reduction during aging from 8 to 24 months. Such a biphasic trend of the age-related changes in load sensitivity of relaxation could result from the interplay between the progressive decrease in cross bridge formation rate and a reduction in activation decay rate. The latter was suggested by the prolongation of the relaxation phase and by the maintenance of developed tension during aging.

Influence of menopause on blood cholesterol levels in women: the role of body composition, fat distribution and hormonal milieu. Virgilio Menopause Health Group.

OBJECTIVES: In this study we investigated the relationships between blood lipids and menopausal status. SETTING AND SUBJECTS: All data were obtained from the first cross-sectional examination of the Virgilio Menopause Health Project in a large cohort of middle-aged women in pre, peri-, and postmenopausal age. The data refer to 426 women without metabolic or endocrine diseases, relevant hepatic, renal and cardiovascular abnormalities, none were dieting or taking medications. MAIN OUTCOME MEASURES: A precoded questionnaire including full clinical history, socio-economic and personal information, habitual diet, physical activity, drug use and smoking habits, careful recording of gynaecological events and family history for disease was completed. Several anthropometric parameters and the bioelectrical impedance analysis was used to measure free fatty mass. Blood samples for hormones and biochemistry were also obtained. RESULTS: There were no significant differences on body mass index, fatty mass, free fatty mass and parameters of body fat distribution between the three groups. Again, there were no differences in smoking habits, dietary intake or indices of physical activity amongst the groups. There was a significant increase from pre to postmenopause of LH and FSH and a decrease of oestradiol and testosterone, whereas no difference was found in sex hormone-binding globulin. Age-adjusted values of glucose, triglycerides and high density lipoprotein (HDL-) cholesterol were similar in all groups, whereas postmenopausal women had significantly higher values of total and low density lipoprotein (LDL-) cholesterol. On the contrary, there was a significant fall in insulin levels passing from pre to postmenopause. In multiple regression models, total and LDL-cholesterol correlated positively with body mass index, waist-to-hip ratio and age, and negatively with free fatty mass and oestradiol blood levels. CONCLUSIONS: These results are consistent with the hypothesis that menopausal status may have a significant and independent effect in determining increased total and LDL-cholesterol concentrations in postmenopausal women.

Body weight, fat distribution and the menopausal status in women. The VMH Collaborative Group.

Since sex hormones are involved in the regulation of body composition and adipose tissue metabolism, in this study we investigated whether menopause may alter body weight and fat distribution in women. Data were obtained from the Virgilio-Menopause-Health Study, which is a longitudinal epidemiological project aimed at investigating the relationship between menopause and related plasma hormonal concentrations, body weight, fat distribution and health. Only data from the first cross-sectional examination are presented. Out of the 952 women living in the town of Virgilio, Mantua (Italy) and born between January 1st, 1932 and December 31st, 1946, 596 (62.6%) participated in the study. Since incomplete data were present in 19 women, 577 was the final sample size available for statistical analysis. The protocol included a collection of blood for hormones and biochemistry, a full clinical history with socioeconomic and personal information, drug use, smoking, dietary and physical activity habits, and several anthropometric measurements. According to the clinical and hormonal status, 160 women were classified as pre-menopausal, 124 as peri-menopausal and 293 as post-menopausal. After adjusting for age, we found that body mass index (BMI) was significantly higher in peri-menopausal than in pre-menopausal women and remained slightly, but again significantly, higher in post-menopausal women. Although waist-to-hip and waist-to-thigh ratios increased significantly and progressively from pre- to post-menopause, any difference was not significant after adjusting for age. Diet, physical activity and smoking habits did not explain the difference in BMI values. No difference was found in the use of estro-progestagen compounds between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)