High risk for cardiovascular disease in Chinese type 2 diabetic patients with major depression--a 7-year prospective analysis of the Hong Kong Diabetes Registry.

BACKGROUND

Depression is known to be associated with premature mortality and cardiovascular disease (CVD) in type 2 diabetes, although there is a paucity of similar data in Chinese population. In this study, we examined the risk association of major depression with premature mortality and CVD in a hospital clinic-based cohort.

METHODS

In a prospective cohort of 7835 Hong Kong Chinese with type 2 diabetes but without CVD at baseline, 153 patients were diagnosed with major depression by psychiatrists in public hospitals. After a median follow-up period of 7.4 years, 827 patients died and 829 patients developed CVD mainly due to stroke (n=384). We used Cox proportional hazard regression to obtain the hazard ratio (HR, 95% confidence interval, CI) of depression for the risk of mortality and CVD.

RESULTS

Depressed patients were younger (51.6 versus 56.6 years, p<0.001), more likely to be female (78.4% versus 53.0%, p<0.001), had higher LDL-cholesterol (3.2 versus 3.0 mmol/L, p=0.038) at baseline and longer hospitalization stays per year (median:0.8 nights per 100-person-years versus 0.1 nights per 100-person-years, p<0.001). After adjusting for conventional risk factors, depression independently predicted CVD [HR=2.18(95% CI=1.45-3.27)], mainly due to stroke [HR=3.55(95% CI=2.15-5.84)].

LIMITATIONS

The young age and small sample size of patients with depression did not give sufficient power to confirm risk association of depression with premature mortality and myocardial infarction.

CONCLUSIONS

In Chinese type 2 diabetic patients, depression was associated with a 2-3 fold increase in the risk of incident CVD, especially stroke.