Diabetic patients of South Asian or Chinese ancestry had a lower risk of cardiovascular complications and death over a 5-year period compared with those with a European background, researchers found.
The risk of being hospitalized for coronary artery disease, stroke, or lower-extremity amputation was marginally lower among South Asian patients (HR 0.95, 95% CI 0.90-1.00) but substantially lower for Chinese patients (HR 0.50, 95% CI 0.46-0.53), according to Baiju Shah, MD, PhD, of the Institute for Clinical Evaluative Sciences in Toronto, and colleagues.
And the risk of dying through a median of 4.7 years of follow-up was more than 40% lower for both South Asian patients (HR 0.58, 95% CI 0.55-0.62) and Chinese patients (HR 0.56, 95% CI 0.52-0.60), the researchers reported in the September issue of Diabetes Care.
Compared with people of European ancestry, many ethnic groups have an elevated risk of diabetes, although it remains unclear how the occurrence of diabetes-related cardiovascular complications might vary, particularly outside of black and Hispanic populations.
Of the components of the cardiovascular complication endpoint, coronary artery disease was less frequent among Chinese patients (but not South Asian patients), stroke was less frequent among South Asians (but not Chinese patients), and lower-extremity amputation was less frequent for both ethnic groups compared with Europeans.
Europeans carried a greater risk of cardiovascular complications and death during follow-up despite having more intensive diabetes screening before receiving their diagnosis; the average number of lab tests for diabetes screening in the 2 years before diagnosis was 2.47 for Europeans and 2.38 and 2.37 for South Asians and Chinese patients, respectively (P<0.001 for both).
The authors acknowledged that the study was limited in that the data did not include important clinical information -- including diabetes treatments and glycemic and risk factor control. In addition, the assigning of ethnicity based on surnames might have lumped some other non-European ethnic groups aside from South Asians and Chinese patients in with the Europeans.