Normal Renal Dimensions in an Adult Nigerian Population

Abstract

A total of 310 subjects were randomly selected from Southeast Nigerian adults with absence of any disease that could modify renal dimensions. Length, width and area of both kidneys were measured by Transabdominal ultrasound and correlated with gender, age, height, body weight, and body mass index (BMI). 135 (43.5%) of the subjects were males while 175 (56.5%) were females. Age ranged from 18 to 80 years old, height from 1.45 to 1.85m (1.67 + 0.08) for men and (1.60 + 0.08 for women), body weight from 46 to 102 kg (68.1 + 6.0 for men and 63.5 + 65.5 for women) and BMI from 17.3 to 40.1 kg/m² (24.4 + 2.4 for men and 24.8 + 2.8 for women). There was an association (one-way ANOVA test) between length, width and area for each kidney and for both, with height (P < 0.001), body weight (P < 0.001), BMI (P < 0.001), and gender (P < 0.001). Renal lengths and area reduced with age (P < 0.001). Considerable reduction was noted from the 5th decade when compared to the other age ranges. Notably, kidney lengths decreased by about 0.3cm per decade from the 5th decade onwards. The left kidney was generally bigger than the right kidney (P < 0.01). Results suggest that the normal pattern of renal length reported by other studies is inadequate for Nigerian black population.