The relationship of cardiovascular risk factors to microalbuminuria in older adults with or without diabetes mellitus or hypertension: the cardiovascular health study.

BACKGROUND: Microalbuminuria is a risk factor for coronary heart disease (CHD). It occurs most commonly in the settings of diabetes and hypertension. The mechanisms by which it increases CHD risk are uncertain.
METHODS: We examined the cross-sectional association of microalbuminuria with a broad range of CHD risk factors in 3 groups of adults aged 65 years or older with and without microalbuminuria: those with (1) no diabetes or hypertension (n = 1,098), (2) hypertension only (n = 1,450), and (3) diabetes with or without hypertension (n = 465).
RESULTS: Three factors were related to microalbuminuria in all 3 groups: age, elevated systolic blood pressure, and markers of systemic inflammation. In patients with neither diabetes nor hypertension, increasing C-reactive protein levels were associated with microalbuminuria (odds ratio per 1-mg/L increase, 1.46; 95% confidence interval [CI], 1.15 to 1.84). Among those with diabetes, an increase in white blood cell (WBC) count was associated with microalbuminuria (odds ratio per 1,000-cell/mL increase, 2.57; 95% CI, 1.12 to 5.89). Among those with hypertension, an increase in WBC count (odds ratio per 1,000-cell/mL increase, 1.83; 95% CI, 1.04 to 3.23) and fibrinogen level (odds ratio per 10-mg/dL increase, 1.02; 95% CI, 1.00 to 1.05) were significantly associated with microalbuminuria. In all 3 groups, prevalent CHD was related to an elevated WBC count. In none of the 3 groups was brachial artery reactivity to ischemia, an in vivo marker of endothelial function, related to microalbuminuria.
CONCLUSION: Microalbuminuria is associated with age, systolic blood pressure, and markers of inflammation. These associations reflect potential mechanisms by which microalbuminuria is related to CHD risk.