Perirenal fat thickness was associated with reduced estimated glomerular filtration rate in the hospital-based population: a mediation analysis

It is unclear how perirenal fat thickness (PrFT) and impaired renal function are related, particularly in patients with metabolic risk factors. A hospital-based cohort of individuals was examined to determine whether perirenal fat thickness, as measured by magnetic resonance imaging (MRI), is associated with impaired renal function. We also examined and quantified the potential mediating effect of a variety of factors on the association between PrFT and impaired renal function. In total, 297 participants were recruited consecutively from the Department of Endocrinology at a tertiary hospital. MRI was used to measure the thickness of PrFT. An analysis of mediation was performed to determine whether metabolic markers mediated the relationship between PrFT and impaired renal function. There was a significant correlation between elevated PrFT and reduced estimated glomerular filtration rate (eGFR). Based on multivariate regression models adjusted for confounders, PrFT showed a significant independent inverse correlation with eGFR, but not with urinary albumin-to-creatinine ratio (UACR). The results of an exploratory mediation analysis revealed that HDLc, nonHDLc, and uric acid (UA) accounted for part of the association between PrFT and reduced eGFR, with respective percentages explaining 16.1%, 13.6%, and 23.1% of the total association. In this hospital-based cohort, serum UA and specific lipid parameters may contribute to the association between PrFT and reduced eGFR.