Obesity and intermediate clinical outcomes in diabetes: evidence of a differential relationship across ethnic groups

Aim To examine associations between obesity, ethnicity and intermediate clinical outcomes in diabetes. Methods Population‐based, cross‐sectional study using electronic primary care medical records of 7300 people with diabetes from White, Black and south Asian ethnic groups. Results The pattern of obesity differed within ethnic groups, with rates significantly higher in younger when compared to older Black (women, 63% vs. 44%, P = 0.002; men, 37% vs. 20%, P = 0.005) and south Asian (women, 47% vs. 27%, P = 0.01; men, 21% vs. 13%, P = 0.05) people. Obese people with diabetes were significantly less likely to achieve an established target for blood pressure control (adjusted odds ratio 0.50, 95% confidence interval 0.42, 0.59). Differences in mean systolic blood pressure in obese and normal weight persons were significant in the White group but not in the Black groups or south Asian groups (6.9 mmHg, 1.9 mmHg and 2.7 mmHg, respectively). Differences in mean diastolic blood pressure between obese and normal weight persons were 4.8 mmHg, 3.6 mmHg and 3.4 mmHg in the White, Black and south Asian groups. Mean HbA_1c and achievement of an established treatment target did not differ significantly with obesity in any ethnic group. Conclusions Obesity is more prevalent amongst younger people than older people with diabetes in ethnic minority groups. The relationship between obesity and blood pressure control in diabetes differs markedly across ethnic groups. Major efforts must be implemented, especially in young people, to reduce levels of obesity in diabetes and improve long‐term outcomes.