ABSTRACT
Previous studies have suggested an association of somatotype with body composition and the organ dimensions among individuals and populations. However, the relationship of somatotypes of medical students of Ahmadu Bello University (ABU), Zaria with body composition, organ dimensions and some anthropometric variables has not been evaluated. This cross-sectional study consisted of 350 apparently healthy medical students of ABU, Zaria (175 males and 175 females) aged 18-35 years. Stature, four skinfold sites, body mass, two bone breadths and two girths were measured according to the International Society for the Advancement of Kinanthropometry (ISAK). The body composition variables were computed using the Durnin and Wormersely method and hepatobiliary dimensions were measured with an ultrasound machine. Chi-square test, independent sample t-test, one-way Analysis of variance (ANOVA), somatotype analysis of variance (SANOVA), Pearson's correlation, partial correlation and multiple linear regression were used. P < 0.05 was set at the level of significance. The mean somatoype was 1.61-4.28-3.04 (ectomorphic-mesomorph) for the males and 1.75-4.21-1.96 (balanced mesomorph) for the females and were significantly different (F=30.06, p<0.001). Seven major somatotype categories were found irrespective of the sexes: endomorphic-mesomorph, balanced-mesomorph, ectomorphic-mesomorph, mesomorph-ectomorph, mesomorphic- ectomorph, balanced-ectomorph and central. There was a significant association for male and female subjects based on the somatotype categories (χ2 = 44.87, p < 0.05). The height, body mass index (BMI), body surface area (BSA), skin folds, bone breadth and body composition variables showed significant sexual dimorphism based on the dominant somatotypes (p< 0.05). The BMI, BSA, gall bladder width, common bile duct diameter (CBDD) and body composition variables indicated significant differences according to the age groups in the dominant mesomorphs and xvii ectomorphs (p< 0.05). Dominant endomorphy was positively correlated with some skin folds and body composition variables in both sexes. Mesomorphy correlated positively with upper arm girth, calf girth, BBH and BBF in both sexes. Ectomorphy showed more sparing correlation with other variables, i.e., it showed a significant positive correlation with BBH and BBF in male subjects only. No significant correlations were observed in blood pressure and hepatobiliary dimensions with the dominant somatotypes. Tricep skin fold, subscapular skin fold, and medial calf skin fold were the joint best predictors of percent body fat in both sexes (R2= 0.999). In conclusion, the relationship between dominant somatotypes with body composition, hepatobiliary dimensions and some anthropometric variables have been established.