Association of life course type 2 diabetes duration with adverse cardiac structure independent of current glycaemia in the British MRC National Survey of Health and Development Birth Cohort

Background Type 2 diabetes mellitus (T2DM) is associated with adverse left ventricular (LV) remodelling and hypertrophy. With earlier onset of T2DM globally, understanding the impact of T2DM duration on future cardiac structure in later life is essential. This study aimed to investigate the association between T2DM duration across adulthood and cardiac structure in later life. Research design and methods Participants from the Medical Research Council National Survey of Health and Development, (1946 British birth cohort) underwent comprehensive investigations including echocardiography at ages 60–64 years. T2DM diagnosis and age at onset were determined by self-report, physician diagnosis and/or glycated haemoglobin (HbA1c). Associations between T2DM duration and LV structure (LV mass indexed to height1.7 (LVMi), end-diastolic and end-systolic volumes indexed to height1.7, remodelling index and relative wall thickness) measured at ages 60–64 years were investigated using multivariable linear regression adjusted for potential confounders (age, sex, socioeconomic status/social class, education, body mass index, leisure-time physical activity and smoking status) and for current HbA1c. Results Age at echocardiography was 63.25±1.10 years, and 700 (47.4%) were men. Longer T2DM duration was associated with higher LVMi independent of confounders (1.09 g/m1.7 (95% CI 0.36 to 1.81), per year duration; p=0.003). This association was independent of HbA1c at age 60–64 years. No associations were observed between T2DM duration and other measures of LV structure. Conclusions Longer duration of T2DM across adulthood is associated with increased LVMi in later life, independent of current glycaemia.