Age at menarche, type 2 diabetes and cardiovascular disease complications in US women aged under 65 years: NHANES 1999-2018.

Background: Diabetes and diabetes complications are on the rise in US adults aged <65 years, while onset of menarche at a younger age is also increasing. We examined the associations of age at menarche with type 2 diabetes among women aged <65 years and with cardiovascular disease (CVD) complications among women with diabetes. Methods: Using the nationally representative cross-sectional National Health and Nutrition Examination Survey 1999-2018, women aged 20-65 years free of cancer were included in the current analysis. Diabetes was defined as a self-reported diabetes diagnosis. CVD was defined as coronary heart disease or stroke. Age at menarche was self-reported age of first menstruation and categorised into ≤10, 11, 12, 13, 14 and ≥15 years. Results: Of 17 377 women included in the analysis, 1773 (10.2%) reported having type 2 diabetes. Earlier age at menarche was associated with type 2 diabetes compared with median age at menarche of 13 years, after adjustment for age, race/ethnicity, education, parity, menopause status and family history of diabetes, smoking status, physical activity, alcohol consumption and body mass index (p for trend=0.02). Among women with diabetes, earlier age at menarche was associated with stroke with similar adjustment (p for trend=0.03), but not with total CVD. Extremely early age at menarche (≤10 years) was significantly associated with stroke (adjusted OR 2.66 (95% CI 1.07 to 6.64)) among women aged <65 years with diabetes with similar adjustment. Conclusions: Earlier age at menarche was associated with type 2 diabetes among young and middle-aged women in the USA and with stroke complications among these women living with diabetes.