Association between hyperlipidemia and microalbuminuria in essential hypertension

Background. Some patients with essential hypertension manifest greater than normal urinary albumin excretion (UAE). A few retrospective studies have suggested that there is an association between microalbuminuria and cardiovascular risk. The reasons for this association are not well established, and they are the object of this review. Results. We found that hypertensive patients with microalbuminuria manifest greater levels of blood pressure, particularly at night. Serum levels of cholesterol, triglycerides, and uric acid in patients with microalbuminuria were higher than levels in those with normal UAE, whereas levels of high-density lipoprotein cholesterol in patients with microalbuminuria were lower than levels in patients with normal UAE. Patients with microalbuminuria manifest a greater incidence of insulin resistance, and thicker carotid arteries. After a follow-up of seven years we observed that 12 cardiovascular events occurred among 54 (21.3%) patients with microalbuminuria, and only two such events among 87 patients with normal UAE (P < 0.0002). Stepwise logistical regression analysis showed that UAE, cholesterol level and diastolic blood pressure were independent predictors of the cardiovascular outcome. The rate of clearance of creatinine from patients with microalbuminuria decreased more than did that from those with normal urinary albumin excretion. Conclusions. These studies suggest that hypertensive individuals with microalbuminuria manifest a variety of biochemical and hormonal derangements with pathogenic potential, which result in greater incidence of cardiovascular events and a greater decline in renal function than do patients with normal UAE.