Increased 5-year mortality in the migrant South Asian stroke patients with diabetes mellitus in the United Kingdom: the West Birmingham Stroke Project

BACKGROUND: Stroke is a major cause of premature mortality in Britain, but its burden is markedly greater amongst South Asians. Because of the paucity of data in this area, we investigated the magnitude and impact of risk from cardiovascular comorbidities on survival amongst South Asian stroke patients. METHODS: We reviewed hospital case records of consecutive first in life time ischaemic stroke patients [self reported ethnicity and International Classification of Disease (ICD) 10th revision, codes 430-438] admitted to an inner city hospital in the UK between 1997 and 2001. In-hospital mortality data and CVD risk factors were analysed. Five-year mortality data was obtained from the National Health Tracing Services. RESULTS: Of 1474 ischaemic stroke patients, 242 (16%) were South Asian of whom, 143 (59.1%) were male. The prevalence of hypertension was 70.2%, followed by diabetes 56.2%, hyperlipidaemia 7% and myocardial infarction 10.3%. At 5 years follow-up, 40.5% had died. Cumulative event-free survival at 5 years was significantly poorer in patients with diabetes (log-rank test, p=0.009). On Cox regression analysis, incorporating age, gender and other CVD risk factors, diabetes mellitus was an independent predictor of mortality odds ratio=1.65 (1.02-2.6, p=0.039). Hypertension and dyslipidaemia did not discriminate survival amongst South Asian patients. CONCLUSION: Stroke mortality in South Asians is associated with presence of diabetes mellitus. This highlights the significance of early and intensive CVD risk modification strategies in ethnic minorities particularly in patients with diabetes. Further research is warranted in South Asians to examine the underlying basis and related pathophysiological abnormalities.