Abstract
Objective:
To determine the attributable risks (AR) for vascular events (VE: stroke, myocardial infarction, and vascular death) due to hypertension and diabetes by race/ethnicity, sex and age.
Background:
Understanding the distribution of risk factors and their contribution to disease incidence is critical for effective allocation of resources for disease prevention. There is little data on the relative contribution of vascular risk factors among multiethnic elderly populations.
Methods:
The Northern Manhattan Study is a population-based prospective cohort study of incidence, risk factors, and outcomes in a multiethnic urban population. Multi-variable Cox models adjusted for socio-demographic and vascular risk factors were used to calculate hazard ratios, AR and 95% confidence intervals (95%CI) for (1) all stroke and (2) VE.
Results:
The cohort (n=3,298) had mean age 69.2+/-10 years with 63% women, 52% Hispanic, 73% hypertensive and 21% diabetics. There were 347 strokes and 835 VE during a median follow-up of 12 years. The AR due to hypertension was 30% (95%CI 13-48%) for stroke and 24% (95%CI 13-35%) for VE; AR due to diabetes was 19% (95%CI 12-27%) for stroke and 13% (95%CI 8-17%) for VE.The AR for stroke from hypertension differed by age and race-ethnicity (table), while for diabetes it only differed by age. For VE, the AR of hypertension and diabetes did not differ by age, sex, or race-ethnicity.
Conclusions:
On a population level diabetes and hypertension have important effects on the risk of VE across all socio-demographic groups. For stroke, these effects are more notable at age< 80. Our results may in part be driven by competing risks for other VE outcomes with stroke, or a differential impact of risk factors on stroke in younger individuals.