The relation of mean platelet volume with microalbuminuria and glomerular filtration rate in obese individuals without other metabolic risk factors: the role of platelets on renal functions.

INTRODUCTION

Mean platelet volume (MPV) is an indirect indicator of platelet activity that plays a major role in the pathogenesis of endothelial injury. Obese individuals have higher microalbuminuria which is the initial step of renal endothelial injury. We aimed to analyze the relation of microalbuminuria and MPV in obese individuals without metabolic risk factors.

METHODS

A total of 290 obese individuals (body mass index (BMI)>30 kg/m2) without an accompanying chronic disorder, and 204 nonobese healthy subjects were enrolled into the study. All participants underwent physical examination. Biochemical, hemogram, and hormonal parameters along with urine albumin analysis were performed. Glomerular filtration rate (GFR) was measured by Cockcroft-Gault (GFRC&G), modification of diet in renal disease (MDRD). The BMI was calculated as weight/height2 (kg/m2). Logistic regression analysis was used to analyze relation of variables.

RESULTS

The patient group consisted of 171 (59%) female (mean age: 37.15±8.05 years) and 119 (41%) male (mean age 38.98±10.68 years) obese individuals. 130 (63.7%) age matched female (mean age 36.18±8.26 years) and 74 (36.3%) age matched male (mean age 36.49±10.25 years) controls were assigned to the control group. There was a significant difference between groups with regard to BMI, spot microalbuminuria, spot urine microalbuminuria/creatinine ratio but not with to MPV and spot urine creatinine (p: 0.01, 0.004, 0.002; respectively). GFR measured by MDRD and Cockcroft-Gault formula were significantly higher in the obese group (p<0.001 for both). Correlation analysis revealed a significant correlation between BMI and spot urine microalbuminuria, spot urine microalbuminuria/creatinine ratio, GFR (Cockcroft-Gault Formula), Homeostasis Model Assessment of Insulin resistance (HOMA-IR), insulin, C-peptide, diastolic blood pressure, glucose, uric acid, total cholesterol, low density lipoprotein (LDL)-cholesterol, c-reactive protein (CRP), thyroid stimulating hormone (TSH), leukocyte count, platelet count. MPV was inversely and significantly correlated with spot urine creatinine, systolic blood pressure, triglyceride, C-peptide, and platelet count. Mean urea, creatinine, uric acid, triglyceride, total cholesterol, LDL-cholesterol, insulin, C-peptide, HOMA-IR were significantly higher in obese male individuals while obese female individuals had higher levels of mean high density lipoprotein (HDL), CRP, TSH, platelet count, spot urine microalbumin/creatinine rate, and GFR measured by MDRD.

CONCLUSIONS

Obese individuals have higher microalbuminuria and nonsignificantly elevated MPV, however, urine albumin loss is independent of MPV.