Evaluation of glomerular hyper filtration in obesity: Which formula to use?

Abstract

Introduction: Obesity is a progressive chronic disease that is a renal risk factor. Renal hyperfiltration is an early stage in the development of chronic kidney disease (CKD). The objective of our study is to determine the prevalence of glomerular hyperfiltration in obese patients. Materials and Methods: This is a prospective and descriptive study conducted over a period of 4 months. All patients with BMI over 30 kg/m2 who do not have diabetes, hypertension or another apparent cause of CKD. Results: A total of 85 patients were included, the mean age was 41.96 years, with a female majority. The mean BMI was 38.24kg/m2 and the mean abdominal waist circumference was 114.57cm. Obesity was common in 55.88% and secondary in 44.11%. The prevalence of glomerular hyperfiltration was 85.18% by Cockcroft formula and 48.33% by MDRD formula. Discussion: Obesity is a risk factor for CKD, which promotes increased renal blood flow by vasodilation of the afferent glomerular arteriole, resulting in glomerular hyperfiltration that leads to a change in the glomerular barrier, increasing the risk of developing CKD. According to several studies, the Cockcroft formula is a better predictor of renal function in obese patients. A 51% increase in GFR in obese patients has been observed. In our study, the prevalence of glomerular hyperfiltration is 85.18% according to the Cockcroft formula. Conclusion: Obesity is a risk factor for CKD that needs to be carefully considered.