Type 2 diabetes in South Asians compared to Europeans: Higher risk and earlier development of major cardiovascular events irrespective of the presence and degree of retinopathy. Results from The HinDu The Hague Diabetes Study

Introduction South Asians with diabetes have more severe diabetic retinopathy (DR) and cardiovascular complications than white Caucasians. However, how big this gap is and the relation with the severity of DR has not been studied. Here, we quantify the difference in time from diabetes diagnosis until a first non-fatal Major Adverse Cardiovascular Event (TUF MACE) in different DR groups in South Asians and Europeans. Methods 3831 adults with type 2 diabetes, 1358 South Asians and 2473 Europeans, treated in our diabetes clinic between 2006 and 2017 were included. Data on risk factors, diabetes duration, age of diagnosis and diabetes complications were collected from the diabetes-specific database and analysed using descriptive statistics and Cox regression. DR was graded in 3 categories, and non-fatal MACE was pre-specified. Results Prevalence of non-fatal MACE was the same when DR was absent, increased with increasing severity of DR in both ethnic groups, but was more frequent in South Asians with DR (mild: 50 vs. 42% and severe 62 vs. 46%. Classic risk factors only differed in relation to smoking habits, which were significantly lower in South Asians. After correction for classic risk factors and age at diabetes diagnosis TUF MACE was significantly shorter in South Asians, an effect also seen in the no-DR group (4.1 yrs. HR 1.5, 95% CI 1.3-1.8 and 7.4 yrs. earlier, HR 2.0, 95% CI 1.6-2.6 for no-DR and severe DR, respectively). Conclusions When adjusted for age at diabetes diagnosis, we show that time until first non-fatal MACE in South Asians is significantly shorter compared to Europeans and increases from no- to severe DR.