AbstractAims/hypothesisThe aim of this work was to determine how weight patterns together with blood glucose, BP and lipids vary at diagnosis of diabetes by age, sex and ethnicity.MethodsUsing the UK Clinical Practice Research Datalink, we identified people with type 2 diabetes (n = 187,601) diagnosed in 1998–2015 and compared their weights, HbA_1c, BP and lipid levels at diagnosis with age-matched people without diabetes (n = 906,182), by sex and ethnic group.ResultsYounger age at diagnosis was associated with greater adjusted mean difference (95% CI) in weight between those with vs without type 2 diabetes: 18.7 (18.3, 19.1) kg at age 20–39 years and 5.3 (5.0, 5.5) kg at age ≥ 80 years. Weight differentials were maximal in white women, and were around double in white people compared with South Asian and black people. Despite lower absolute values, BP differences were also greater at younger age of diabetes onset: 7 (6, 7) mmHg at age 20–39 years vs −0.5 (−0.9, −0.2) at age ≥ 80 years. BP differences were greatest in white people, and especially in women. Triacylglycerol level differences were greatest in younger men. Finally, HbA_1clevels were also higher with younger onset diabetes, particularly in black people.Conclusions/interpretationAt diagnosis of type 2 diabetes, when compared with people without diabetes, weight and BP differentials were greater in younger vs older people, in women vs men and in white vs South Asian and black people. These differences were observed even though South Asian and black people tend to develop diabetes a decade earlier with either similar or greater dysglycaemia. These striking patterns may have implications for management and prevention.