ABSTRACT Aims Bodyweight change is an important determinant of cardiometabolic health, but its metabolic impact may differ by ethnicity. This study investigated whether ethnicity (White European, South Asian) modifies the association between change in bodyweight and changes in HbA1c and oral glucose tolerance test (OGTT)–derived measures. Materials and Methods Cohort data were analysed from the UK PROPELS trial (ISRCTN:83465245), which recruited adults at high risk of type 2 diabetes. Bodyweight and metabolic biomarkers were measured at baseline, 1‐ and 4‐years. Trial arms were analysed as a single cohort. Generalised estimating equation models examined interactions between ethnicity and change in bodyweight with changes in HbA1c and OGTT‐derived measures, adjusting for randomisation group, age, sex, socioeconomic factors, smoking, medication use and baseline values. Results A total of 543 participants with ≥ 2 bodyweight and OGTT observations were included (371 White European; 172 South Asian). Each 5 kg change in bodyweight was associated with a greater change in HbA1c in South Asians (1.5 mmol/mol, 95% CI: 1.0–2.0) than White Europeans (0.9 mmol/mol, 0.6–1.3; p for ethnicity interaction = 0.034). A significant ethnicity interaction was also observed for 2‐h post‐challenge glucose ( p = 0.003), with larger changes in South Asians (0.9 mmol/L) than White Europeans (0.4 mmol/L). No ethnicity interactions were observed for fasting glucose or insulin measures. Conclusions Bodyweight changes have a greater adverse impact on glycaemic control in South Asian populations at high risk of type 2 diabetes, driven by stronger associations with post‐challenge glucose, highlighting the potential risks and benefits of modest bodyweight perturbations.
Arsenyadis et al. (Mon,) studied this question.