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

Abstract

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.

Figures

Figure 1. The distribution of ages at menopause (A) and at menarche (B) in the study population

Figure 2. The smoothing curves of some metabolic phenotypes across age in pre-(n=2391, solid line) and post- (n=1429, dash line) menopausal women aged 40 to 55 years

BMI: body mass index; HDL-C: high density lipoprotein cholesterol; LDL-C: low density lipoprotein cholesterol

Figure 3. The smoothing curves of some metabolic phenotypes across age in women with early (EM, solid line), intermediate (IM, dash line) and late menarche (LM, dot line) in the total study population (n=9097)

BMI: body mass index; HOMA-IR: insulin resistance index of homeostatic model assessment; HDL-C: high density lipoprotein cholesterol