Effectiveness of statin prescribing on reducing mortality in South Asian, Chinese, and White patients with diabetes

Abstract

Background: Clinical trials have shown that 3-hydroxy-3-methylgutaryl coenzyme A reductase inhibitors (statins) reduce mortality in patients with diabetes. However, as these trials were conducted in largely white populations, it is unknown whether the benefits of statins can be extended to other ethnic populations in which the incidence of diabetes is rising sharply. We investigated associations between statin prescription and outcomes in a multiethnic population with diabetes.

Methods: We identified all patients with newly diagnosed diabetes in British Columbia, Canada (1993-2006), using administrative data. Validated surname analysis was used to identify South Asian and Chinese patients. Statin prescribing was defined as any prescription filled within 1 year of diabetes diagnosis according to a provincial pharmacy database. Median length of follow-up was 4 years. Cox proportional hazards models were constructed for each ethnic group to determine the association of statin prescribing with time to death, adjusting for covariates including age, sex, socioeconomic status, and comorbid conditions.

Results: There were 143,630 white, 9529 South Asian, and 14,084 Chinese persons with newly diagnosed diabetes. White patients were older and had more comorbidity than the other groups. Statin prescribing was associated with lower mortality compared with no prescribing within each ethnic group: South Asian (Hazard Ratio [HR], 0.69; 95% confidence interval [CI], 0.55-0.86; P = 0.001), Chinese (HR, 0.60; 95% CI, 0.49-0.72; P < 0.0001), and white (HR, 0.65; 95% CI, 0.63-0.67; P < 0.0001).

Conclusions: Statin prescribing is associated with lower mortality in white, Chinese, and South Asian patients with newly diagnosed diabetes, confirming the benefits of statins across these ethnic groups.