Background: Albuminuria predicts cardiovascular risk, but its function as a marker of endothelial damage and atherosclerosis is uncertain, as is the complex relationship with hypertension and diabetes.
Objective: To determine whether hypertension contributes to albuminuria across levels of atherosclerosis and type 2 diabetes.
Methods: Cross-sectional associations of cardiovascular risk factors and albuminuria were examined in 10,113 middle-aged participants in the atherosclerosis risk in communities study divided into four subgroups: type 2 diabetes with marked atherosclerosis, type 2 diabetes without marked atherosclerosis, without diabetes with marked atherosclerosis, and without diabetes without marked atherosclerosis. Marked atherosclerosis was defined as high levels of carotid atherosclerosis or prevalent coronary heart disease.
Results: Hyperglycemia and hypertriglyceridemia were associated with albuminuria, but only among patients with type 2 diabetes. In multivariate models, increasing blood pressure levels (but not albuminuria) were significantly associated (P-trend <0.001) with carotid atherosclerosis when stratified by prevalent coronary heart disease. Excluding individuals on hypertension medication, higher blood pressure was associated with albuminuria in all groups (P-trend<0.05). The association was strong even for high-normal blood pressure among individuals without diabetes without marked atherosclerosis (odds ratio 2.7, 95% confidence interval 1.6-4.6) and patients with type 2 diabetes with marked atherosclerosis (12.0, 1.3-108.2).
Conclusion: Blood pressure, even at high-normal levels, is consistently associated with albuminuria across categories of type 2 diabetes and atherosclerosis. Our results suggest that the effects of blood pressure on albuminuria are not solely mediated through generalized vascular damage, as represented by degree of atherosclerosis.