Risk and Age of Cardiovascular Event in Women with Metabolic Syndrome: Menopause Age in Focus

Age at natural menopause in women with a history of chronic diseases-A population-based cohort study

OBJECTIVE

This study was carried out to determine whether chronic diseases can influence age at natural menopause (ANM).

STUDY DESIGN AND MAIN OUTCOME MEASURES

This population-based prospective study recruited all eligible women from participants in the Tehran Lipid and Glucose Study (TLGS). The Cox proportional-hazards model (unadjusted and adjusted) was used to assess associations of ANM with chronic diseases, including diabetes mellitus (DM), hypertension (HTN), dyslipidemia, metabolic syndrome (MetS), cardiovascular disease (CVD), chronic kidney disease (CKD), and thyroid disorders, which were not included simultaneously in the model because there were correlations between chronic diseases.

RESULTS

A total of 4662 women, aged 15-50 years, who had not reached menopause at initiation of the TLGS were included. Of these women, 1220 (26.2%) experienced menopause during the study follow-up. In the multivariable Cox regression model adjusted for potential confounders, women with DM [HR:1.75; 95%CI: (1.32, 2.32)], HTN [HR: 2.11; 95%CI: (1.64, 2.72)], MetS [HR: 2.01; 95%CI: (1.57, 2.58)], CVD [HR: 3.02; 95%CI: (1.93, 4.73)], CKD [HR: 2.64; 95%CI: (2.16, 3.22)], and thyroid disorders [HR: 1.41; 95%CI: (1.06, 1.88)] reached menopause earlier, while dyslipidemia was not associated with ANM.

CONCLUSION

This study demonstrates that women with a history of chronic diseases, such as metabolic disorders, cardiovascular events, and CKD, experience menopause earlier than their counterparts without such a history.

Metabolic Syndrome During Menopause

The metabolic syndrome (MetS) comprises individual components including central obesity, insulin resistance, dyslipidaemia and hypertension and it is associated with an increased risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). The menopause per se increases the incidence of MetS in aging women. The effect(s) of menopause on individual components of MetS include: i) increasing central obesity with changes in the fat tissue distribution, ii) potential increase in insulin resistance, iii) changes in serum lipid concentrations, which seem to be associated with increasing weight rather than menopause itself, and, iv) an association between menopause and hypertension, although available data are inconclusive. With regard to the consequences of MetS during menopause, there is no consistent data supporting a causal relationship between menopause and CVD. However, concomitant MetS during menopause appears to increase the risk of CVD. Furthermore, despite the data supporting the association between early menopause and increased risk of T2DM, the association between natural menopause itself and risk of T2DM is not evident. However, the presence and the severity of MetS appears to be associated with an increased risk of T2DM. Although the mechanism is not clear, surgical menopause is strongly linked with a higher incidence of MetS. Interestingly, women with polycystic ovary syndrome (PCOS) have an increased risk of MetS during their reproductive years; however, with menopausal transition, the risk of MetS becomes similar to that of non-PCOS women.