Urinary albumin excretion in lean, overweight and obese glucose tolerant individuals: its relationship with dyslipidaemia, hyperinsulinaemia and blood pressure

The presence of microalbuminuria has become an important tool for therapeut ic intervention. In this study we investigated whether the dysmetabolic syn drome of obesity was associated with or could occur in the absence of micro albuminuria. The study was conducted in 71 clinically healthy, glucose tole rant Hispanics (age: 43 +/- 1.4 years, body mass index (BMI): 28.7 +/- 0.6 kg/m(2), systolic blood pressure (SBP): 117 +/- 2 mm Hg, diastolic blood pr essure (DBP): 77 +/- 1.3 mm Hg, urinary albumin excretion: 10.2 +/- 0.6 mg/ 24 h). Subjects were classified as lean (BMI < 25), overweight (BMI > 25 < 30) and obsese (BMI > 30 kg/m(2)). Greater BMI was associated with higher b ody weight, waist-to-hip ratio (WHR), BP, fasting insulin, triglyceride, po st glucose load insulin and glucose, and lower high-density lipoprotein (HD L) cholesterol levels. However, no significant differences in the urinary a lbumin excretion (mg/24 h) were found between lean (9.0 +/-0.9; median: 9.1 ), overweight (11.3 +/- 1.2; median: 10.5) and obese (11.1 +/- 1.2; median: 9.7) subjects. In addition, microalbuminuria (urinary albumin excretion >3 0 mg/24 h) was not found in any of the study subjects. For all subjects com bined, as well as for each of the groups separately, the urinary albumin ex cretion was unrelated to the BMI, WHR, body weight, triglyceride, cholester ol (total, LDL or HDL), fasting or post-load glucose and insulin plasma con centrations. Neither in females nor in males, abdominal fat accumulation wa s associated with an increase in the urinary albumin excretion. However, in the obese groups, urinary albumin excretion was strongly related to the le vel of SEP (r(2): 0.67; P < 0.0001) and DBP (r(2): 0.55; P < 0.0001). In su mmary, obesity, hyperinsulinaemia and dyslipidaemia per se are not determin ants of increased albumin excretion. However, in the obese subjects, the BP , particularly the SEP, was a strong determinant of the level of albumin in the urine. Microalbuminuria may occur later in the course of the dysmetabo lic syndrome, due to worsening of hypertension and development of hyperglyc aemia.