Body composition assessed by bioelectrical impedance analysis (BIA) and the correlation with plasma insulin-like growth factor I (IGF-I) in normal Japanese subjects and patients with acromegaly and GH deficiency.

Body composition was assessed by bioelectrical impedance analysis (BIA) in 100 Japanese normal adults, 9 patients with acromegaly and 11 patients with growth hormone (GH) deficiency. Body weight (BW) was greater in normal males than in normal females. Percent body fat (BF/BW) was greater in females than in males and was increased with age in both sexes. Percent total body water (TBW/BW) was less in females than in males. Although percent extracellular water (ECW/BW) was not different between both sexes, the ECW/TBW ratio was greater in females than in males. Percent body cell mass (BCM/BW) was lower in females than in males. The patients with acromegaly had a lower percent BF but a higher percent TBW, percent ECW and ECW/TBW ratio than normal subjects, while the patients with GH deficiency had a higher percent BF and ECW/TBW ratio, but lower percent TBW. Percent body cell mass (BCM/BW) was higher in acromegaly and lower in GH deficiency than in normals. There was a negative correlation (r = -0.62) between plasma IGF-I levels and percent BF, whereas a positive correlation (r = 0.51) was found between the plasma IGF-I level and percent BCM. It is suggested, therefore, that body composition is affected by sex and age in normals, and by GH secretion in patients with pituitary dysfunction. Plasma IGF-I levels may be one of the factors responsible for alterations in body composition.