Ultrasound assessment of kidney size and its correlation with body mass index in healthy volunteers without renal disease

Abstract

Introduction:Renal length as well as renal cortical thickness has been closely related to creatinine clearance in patients with chronic kidney disease. Our primary aim was to establish a normal range of values for kidney length in our adult population with normal renal function.Materials and Methods:This was a prospective observational study. Ultrasonographic assessment of renal parameters in 499 healthy volunteers between 18 to 80 years of age was done. Volunteers with any known renal condition or any comorbidity were excluded from the study population. Correlation between BMI and renal parameters was assessed. Results:Out of 499 volunteers 327 (65%) were males and 172(35%) were females. 17.8% volunteers were less than 30 years of age, 51.5% volunteers were in the age group of 30-60 years and 30.7 % were above 60 years of age. Mean Body mass index (BMI) in males was 25.20 +/- 3.96 whereas mean BMI in females was 24.08+/- 3.28. In males the mean cortical thickness in Right kidney was 13.68+/- 2.47 mm and in left kidney CT was 13.94+/- 2.6 mm. In females right kidney cortical thickness was 12.63+/- 1.91 mm and left kidney CT was 13.40+/-2.37 mm. In the present study the right mean renal length was 9.9± 40cm and left renal length was 10.19±0.97cm.Discussion:In the present study, we analyzed renal size in terms of length, breadth, and cortical thickness which are simple, reproducible, reliable and objective measurements. Our finding that left side kidney length is greater than right sided kidney length is similar to the previous studies showing left side kidney length is greater than right sided kidney length. We observed positive correlation BMIwith renal length.Conclusion: Size of kidney has significant ethnic and geographic basis and there is a positive correlation between BMI and kidney size in our study population.