Albuminuria and incident coronary heart disease in Australian Aboriginal people

Abstract

It has been suggested that albuminuria is useful in identifying persons at increased risk of coronary heart disease (CHD). Australian Aborigines have exceedingly high rates of renal failure together with increased CHD mortality. We undertook this prospective cohort study to assess the independent effect of albuminuria on CHD risk in Aboriginal people in the Northern Territory of Australia. We examined the relation between micro- and macroalbuminuria and incident CHD in a sample of 870 Aboriginal adults aged 20 to 74 years old without prevalent baseline CHD. Cox proportional hazards models were used to assess the association between baseline albuminuria and CHD incidence. During a median of 9.2 years of follow-up, 89 CHD events occurred during the follow-up period (1992 to 2003). The incidence of CHD increased significantly across categories of albuminuria (4.4, 10.9, and 29.8 per 1000 person-years for normoalbuminuria, microalbuminuria, and macroalbuminuria, respectively). The multiple Cox proportional hazards regression showed the hazard ratio was 3.4 (95% CI 1.6, 7.3), adjusting for age, gender, body mass index (BMI), blood pressure, total cholesterol, diabetes status, cigarette smoking, and alcohol consumption, for macroalbuminuria group. Hazard ratio for microalbuminuria group was not significantly different from unity during the first 6 years of follow-up but significantly higher during the follow-up period > or = 6 years with adjusted hazard ratio 9.0 (95% CI 2.0, 40.0). Independent of traditional cardiovascular risk factors, both microalbuminuria and macroalbuminuria may be useful in identifying persons at increased risk of CHD in Aboriginal people.