Ethnic specific changes in body composition, lifestyle and cardio-metabolic factors in healthy South Asian and White European women across the reproductive stages

Abstract

South Asian women migrating to the Western World have substantially higher risk of developing type 2 diabetes mellitus (T2DM) compared with their White counterparts. The discrepancy is becoming even greater as they grow older and especially over the age of 50 years. We sought to determine whether there are ethnic specific patterns in lifestyle and cardio-metabolic risk factors across the reproductive stages that may explain why post-menopausal South Asian women have a disproportionally greater risk of T2DM. Prospective cross-sectional study of healthy South Asian and White European women who reside in the UK. Reproductive stages were defined by the STRAW criteria. Anthropometric measures included weight, height, waist and hip circumference. Physical activity was assessed objectively with the use of accelerometers that were worn for at least four consecutive days. Cardio-respiratory fitness (VO2 maximum) was measured with the use of the Chester step test. Dietary intake was assessed with validated food frequency questionnaires. Assessed cardiometabolic risk factors included fasting glucose, insulin, lipids, glycosylated haemoglobin (HbA1c) and blood pressure. Ethnic distribution did not differ in each reproductive category: 39 premenopausal South Asians and 34 Europeans; 10 perimenopausal South Asians and 14 Europeans; and 42 postmenoapusal South Asians and 39 Europeans. Body fatness variables increased with reproductive ageing to an almost similar degree in both ethnic groups (p for trend greater than 0.05 for all associations) without ethnicity modifying the gradient of the associations between menopausal state and body fatness (p for interaction with ethnicity greater than 0.05 for all associations). Moderate to vigorous physical activity and VO2max decreased in a similar fashion across the reproductive stages in both ethnic groups whereas energy intake remained unchanged. Body fatness, physical activity and fitness did not differ among the ethnic groups for each reproductive stage either. Metabolic biomarkers (insulin, total cholesterol, triglycerides and blood pressure) deteriorated with reproductive ageing in both ethnic groups in a similar degree. Notably, HbA1c levels increased to a much greater degree with reproductive ageing in the South Asians than in the Europeans (p=0.02 for interaction with ethnicity). The increase in HbA1c levels in healthy women without overt T2DM during menopausal transition was much greater in the South Asians than in their White counterparts and this discrepancy was not explained by a greater deterioration in body composition or physical activity variables along with reproductive ageing.