Effects of age at menarche, reproductive years, and menopause on metabolic risk factors for cardiovascular diseases.

BACKGROUND: Early menarche is associated with increased adult body fatness, however, this association has been studied primarily in young women. The impact of changes in some metabolic risk factors of cardiovascular disease (CVD) after menopause remains controversial and ageing is an important confounder. OBJECTIVES: To investigate the effect of age at menarche, reproductive years, and years post-menopause on body composition and metabolic risk factors for CVD independent of the normal ageing process in a large sample size of Chinese women. DESIGN: Nine thousand ninety seven women aged 25-64 were recruited from Anhui, China in 2004-2005. Anthropometric measurement, body composition, blood pressure, plasma lipids, fasting glucose and insulin, as well as a questionnaire-based interview on menstruation and lifestyle information were obtained from each participant. RESULTS: After adjusting for age and other covariates, age at menarche was inversely associated with body fatness, HOMA-IR, triacylglycerol and the total number of metabolic syndrome components, and was positively associated with HDL-C (p<0.05). The number of reproductive years was associated with increased body fatness, decreased total cholesterol and HDL-C (p<0.05). Post-menopausal women had significantly lower BMI but higher abdominal fat percentage, increased plasma levels of triacylglycerol, total cholesterol, HDL-C, and LDL-C, and lower systolic blood pressure than pre-menopausal women (p<0.05). CONCLUSION: Age at menarche, reproductive years, and menopause status were significantly associated with body composition, insulin sensitivity and blood lipid levels.

Prevalence of metabolic syndrome and its relation to body composition in a Chinese rural population.

OBJECTIVE: To investigate the prevalence of metabolic syndrome (MetS) with three different working definitions in a rural Chinese population and to examine its relation to body composition. RESEARCH METHODS AND PROCEDURES: A total of 18,630 adults 25 to 64 years old (mean age, 45.8 years; 51.2% men) from 5686 families were enrolled from Anhui province of China during 2004 to 2005. Anthropometric measurement, body composition, blood pressure, plasma lipids, and fasting glucose and insulin and a questionnaire-based interview were obtained from each participant. Three different working definitions for MetS, including the U.S. National Cholesterol Education Program's Adult Treatment Panel III, a modified Adult Treatment Panel III that adopts the World Health Organization's criterion for central obesity in Asian populations, and one recently proposed by the International Diabetes Federation, were used in the study. RESULTS: According to the three definitions, the age-adjusted prevalence of MetS for adults 25 to 64 years old was 3.2%, 4.9%, and 3.9% in men and 7.2%, 11.5%, and 10.9% in women, respectively. MetS prevalence increases significantly with age in women, but not in men. Body fat percentage and BMI and waist circumference were significantly associated with each component of MetS, especially with triglyceride level, insulin resistance index, and number of MetS components (r = 0.28 to 0.49). DISCUSSION: The age-adjusted prevalence of MetS in our study population is lower than that reported in other urban Chinese populations. Significant gender differences in MetS prevalence were observed. The waist circumference is a good surrogate for abdominal fat percentage.