Relation between plasma creatinine and body size.

We studied the relationship between creatinine concentration in plasma and body size in 673 healthy individuals (385 women, 288 men). Weight, height, and skinfold thickness were measured and blood was sampled (after a short fast) for estimations of urea and creatinine in plasma. Lean body mass was calculated according to Durnin and Wormsley (Br J Nutr 1974; 32:77-97). Concentrations of urea and creatinine in plasma were significantly lower in women than in men and were significantly correlated with age in both sexes. For neither sex was there a significant correlation between lean body mass and creatinine concentration, even after we took age into account either by multiple linear-regression analysis or by considering subjects at decade intervals.