Population attributable risks of hypertension and diabetes for cardiovascular disease and stroke in the Northern Manhattan study

Background-Understanding the population-level risk factor contribution to disease incidence is critical for effective allocation of resources for prevention. There are little data on the contribution of cardiovascular disease (CVD) risk factors in multiethnic elderly populations. Methods and Results-The Northern Manhattan Study (n=3298) is a population-based prospective cohort study of CVD outcomes in a multiethnic urban population. Multivariable Cox's models were used to calculate hazard ratios, population attributable risk (PAR), and 95% confidence intervals (CIs) for (1) combined vascular event (VE) endpoint of stroke/myocardial infarction/vascular death (n=835) and (2) stroke (n=347). The PAR resulting from hypertension (HTN) was 24.3% (95% CI, 13.2 to 35.4) for VE and 29.9% (95% CI, 12.5 to 47.4) for stroke; PAR resulting from diabetes was 12.7% (95% CI, 8.2 to 17.2) for VE and 19.5% (95% CI, 12.4 to 26.5) for stroke. The PAR resulting from HTN and diabetes for stroke differed by race-ethnicity and age (P for differences <0.05). PAR for stroke reslting from HTN was greater among Hispanics (50.6%; 95% CI, 29.2 to 71.9) than non-Hispanic whites (2.6%; 95% CI, -33.2 to 38.6) and in those <80 years of age (35.6%; 95% CI, 18.9 to 52.3) than in those ≥80 (-0.3%; 95% CI, -34.2 to 33.6). Similarly, the PAR for stroke resulting from diabetes was 23.6% among those <80 years of age (95% CI, 15.7 to 31.5) and 2.3% among those ≥80 (95% CI, -8.2 to 12.7; P for difference=0.001). The PAR for VE did not differ by age/sex/raceethnicity. Conclusions-HTN and diabetes have important effects on the burden of stroke, particularly among those younger than age 80 and Hispanics. Public health campaigns targeted at specific risk factors in specific populations can lead to a greater reduction in CVD.