Objective: To understand the ethnic differences in coronary heart disease risk among inpatients with diabetes following acute coronary syndrome.
Design: Single-centre retrospective cohort-analysis of patients with type II diabetes over a six-year period receiving standard care.
Setting: Birmingham, UK.
Participants: One thousand and one hundred and five patients with type II diabetes from a multi-ethnic background.
Main outcome measures: Odds ratios of coronary heart disease events among three ethnic groups.
Results: The prevalence of coronary heart disease events was 20.7% in Asian, 13.2% in Caucasian and 7.7% in Afro-Caribbean patients. Asian patients were younger at diagnosis of diabetes (-5.1 years p < 0.001 versus Afro-Caribbeans and -7.1 years p < 0.001 versus Caucasians). The mean number of events was highest amongst Asian (1.2) compared to Caucasian (1.1) and Afro-Caribbean (1.0) patients (p = 0.04). The mean age at first event was 61.3 years for Asians, 62.5 years and 65.8 for Afro-Caribbeans and Caucasians, respectively (analysis of variance F[2,131] = 2.36 p = 0.09). Un-adjusted odds ratios for at least one coronary heart disease event were highest among Asian men (OR 5.04; 95% CI 2.31-11.01; p < 0.0001) with Afro-Caribbean women as baseline (OR 1.0). The odds ratios remain largely unchanged (1.0 Afro-Caribbeans [baseline], 1.27 [p = 0.56] Caucasians and 3.2 [p = 0.001] for Asians) when corrected for age, gender, duration of diabetes, insulin dependency, mean low-density lipoprotein-cholesterol, triglycerides and high-density lipoprotein-cholesterol, mean glycated haemoglobin, mean systolic and diastolic blood pressure (logistic regression; ROC: 79% AUC). Afro-Caribbean patients had the highest mean high-density lipoprotein-cholesterol (1.6 mmol/L) and the lowest risk for coronary heart disease events.
Conclusions: Asian patients were younger at their first event and diagnosed earlier with diabetes. Asian men had the highest risk of coronary heart disease event which correlated with the lowest levels of high-density lipoprotein-cholesterol.
Keywords: Cardiology and cardiovascular medicine; coronary heart disease; diabetes; epidemiology; evidence-based practice.