Can elastography visualize kidney changes in bodybuilders with high protein intake?

Abstract

Introduction: High protein nutrition is postulated to change kidney function and morphology in bodybuilding athletes. The ultrasound elastography technique is an examination method in which tissue stiffness is evaluated in numerical expressions. In our study, we investigated the correlation between kidney-stiffness, kidney measurements and renal function tests of bodybuilding athletes who were fed with high protein diets. Materials and Methods: Bodybuilders (n=19) who were on a high-protein diet were compared with control subjects (n=20). Blood urea nitrogen/creatinine ratios and estimated glomerular filtration rates (eGFR) were calculated. Bodybuilders were divided into two subgroups according to eGFR levels (Group A and B for eGFR below or above 90; respectively). Length, width, volume, cortical thickness, and echogenicity of both kidneys were analyzed by ultrasound. Elastographic Shear Wave Velocity (SWV) measurements were performed, and the mean SWV values (m/s) were calculated for each kidney. Comparison of mean SWV values was performed between the groups and subgroups. Results: Mean BUN and serum Cr levels were higher in bodybuilders than control subjects (p<0,05). Cortical thicknesses and echogenicity were both higher in bodybuilders (p<0,05). The SWV values were higher in bodybuilders than the control group, indicating increased stiffness (p<0,05). Among bodybuilders, SWV values were significantly higher in group A than in group B (p<0,001). Conclusions: Elastography can be utilized for detection and follow-up of alterations in kidneys of bodybuilders or patients consuming high protein diets. High SWV can be considered as an indicator of renal damage, while the levels of conventional biomarkers may give confusing results.