Microalbuminuria in obese patients with or without hypertension.
OBJECTIVE
To evaluate the prevalence in obese patients of an increased urinary albumin excretion rate (UAER) and the factors involved in this parameter.


METHODS
Two hundred and seven nondiabetic obese patients with BMI = 34.7 +/- 5.7 (SD) kg/m2. None had proteinuria or a history of nephropathy or uropathy. Fifty-two had moderate hypertension. A control group of 22 lean healthy subjects was also studied.


METHODS
The UAER was determined from 24-h urine samples by means of immunonephelemetry laser method. Creatinine clearance was calculated. Glycemia and plasma C peptide at fasting and 120 mine after glucose oral administration, HbA1c, serum fructosamine, plasma total cholesterol and triglycerides, HDL and LDL cholesterol were measured. Food intakes were determined by dietary history.


RESULTS
Compared with the control group, the UAER was significantly higher in the obese patients (18.0 +/- 20.1 mg/24 h vs 3.2 +/- 2.8 mg/24 h, P < 0.0001). It was elevated (> 30 mg/24 h) in 25 obese patients (12.1%) and in particular, in 19.2% of the obese patients with hypertension. It was significantly higher in the patients with android or mixed (both android and gynoid) obesity than in those with gynoid obesity (p = 0.050). Log UAER correlated negatively with the duration of hypertension (p = 0.038) and was higher in the patients with familial hypertension than in those without (p = 0.002). Log UAER correlated strongly with log creatinine clearance (p < 0.0001) and fractional albumin clearance (p < 0.0001). It correlated significantly with fasting and 120 min after glucose plasma C peptide concentrations (p = 0.018 and p = 0.046, respectively). Creatinine clearance was significantly higher in the patients with android or mixed obesity than in those with gynoid obesity (p = 0.001). Log creatinine clearance correlated negatively with age (p = 0.046), and log LDL cholesterol (p = 0.025) and positively with log lipid caloric intake (p = 0.014).


CONCLUSIONS
These results show the high prevalence of microalbuminuria in nondiabetic obese patients and suggest the involvement of renal hyperfiltration. Microalbuminuria may be an indicator of familial hypertension in obese subjects. Insulin resistance may be involved in the increase in the UAER. Nutritional factors, particularly lipid intake, may contribute to this increase in the UAER via an increase in glomerular hyperfiltration.
Valensi
P
P
Department of Endocrinology-Diabetiology-Nutrition, Jean Verdier Hospital, Paris-Nord University, Bondy, France.
Assayag
M
M
Busby
M
M
Pariès
J
J
Lormeau
B
B
Attali
J R
JR
D000328:Adult; D000419:Albuminuria / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D002096:C-Peptide / Q000097:blood; D002784:Cholesterol / Q000097:blood; D003404:Creatinine / Q000097:blood / Q000652:urine; D005260:Female; D019270:Fructosamine; D005919:Glomerular Filtration Rate / Q000502:physiology; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis; D006595:Hexosamines / Q000097:blood; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D015995:Prevalence; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
D002096:C-Peptide; D002784:Cholesterol; D003404:Creatinine; D019270:Fructosamine; D006442:Glycated Hemoglobin; D006595:Hexosamines; D014280:Triglycerides