Sonographic determination of renal volume and its correlation with body mass index among healthy adults in Kano, Nigeria

Abstract

Background: Kidney dimensions, including volume, of a patient is a valuable diagnostic parameter in nephrology and urologic practice and vary with age, gender, body mass index, pregnancy and co-morbid conditions. Congenital and some important morbid conditions affect renal dimensions and some of these pathologic conditions have close relationship with BMI. Aim and Objectives: To determine the normal ultrasound volume in healthy adults and to correlate it with the Body Mass Index (BMI). Materials and Methods: This was a descriptive cross-sectional study in which kidney dimensions were acquired and from which the volumes were determined using the ellipsoid formula. The anthropometric variables of the patients were documented, and the BMI calculated. Variations of the renal volume with sex and age, and the relationship of the renal volumes with BMI were determined. Results: A total number of 400 adult subjects were recruited for the study, with a M:F ratio of 3:1. The mean age was 39±13.2 years. The mean BMI was 22.95±3.20kg/m². The mean renal volumes were 140.0±30.5cm3 and 149.5±34.6cm³ on the right and left sides respectively. There was a positive correlation between the BMI and right renal volume (p<0.01; r= 0.188) and BMI with left renal volume (p<0.01; r=0.218). There was also positive correlation between the right and left renal volumes and age (P<0.01) and gender (P<0.01; P<0.05). Conclusion: Positive correlations were noted between the renal volumes and body mass index, age, sex and sides.