Is there any Gender Difference in the Association between Obesity, Chronic Kidney Disease and Anemia

Abstract

Abstract Introduction. Nowadays, obesity has emerged as one of the most independent risk factors for chronic kidney disease (CKD) in both economically developed and undeveloped countries. The number of patients requiring dialysis as a consequence of obesity-related renal diseases, such as diabetes mellitus and hypertension, is increasing worldwide. Moreover, obesity has been shown to favorize the risk of cardiovascular diseases (CVD) with premature death due to CKD and/or end-stage renal disease (ESRD). The aim of the study was to investigate the association between obesity [e.g. body mass index (BMI)], kidney function [e.g. glomerular filtration rate (GFR)] and renal anemia in CKD patients. Methods. Retrospectively, data from the register of 315 pre-dialysis patients with different stages of CKD not on erythropoiesis stimulation agents (ESAs) during the period between 1 Jan 2013-30 June 2013 were used to assess the association between the degree of CKD impairment with the degree of obesity and anemia. The stage and/or progression of CKD was calculated by GFR, while the degree of obesity by the body mass index (BMI). CKD was defined as a glomerular filtration rate (GFR) <60 mL/min per 1.73 m2. Data analysis was performed by means of the simple Microsoft excel program. Results. Within the study population of 315 CKD patients, 123 were males with mean age of 63.4±1.33 years and 192 females of 57.3±1.2 years. The GFR reduced with the increased BMI in both genders, and majority of patients (n=243) were in CKD stage 3, with a mean GFR of 44.5 ml/min/1.73 m2. The BMI values in female patients with first and second degree of obesity negatively correlated with GFR (r=−0.46, p<0.05). Only female patients with second degree of obesity (BMI of 35-39.9 kg/m2) had a positive correlation between the decreased renal function and reduced Hb levels. Conclusions. Our study provided an unconditional evidence not only for the presence of an association between the degree of obesity (BMI) and the degree of renal function impairment (GFR), but also an association between the higher BMI and the higher degree of kidney anemia seen in women with second degree of obesity. Further larger scale trials and interventional studies are required to see the effect of body weight reduction on renal function and especially anemia.