The integrated concentration of cortisone is reduced in obese children.

We evaluated the possibility that there is enhanced conversion of cortisol (F) to cortisone (E) in obese children. IC-E was measured from 15 lean children aged 12.7 +/- 2.2 years, body mass index Z-score (BMI-SD) = -0.35 +/- 0.82, IC-F = 197 +/- 70 nM/l and 9 obese children aged 12.3 +/- 3.2 years, BMI-SD = + 4.7 +/- 2.1, IC-F = 149 +/- 53 nM/l. IC-E was higher in lean children 76 +/- 25 nM/l compared to obese 60 +/- 11 nM/l (p < 0.04). There was no difference in the ratio of IC-E/IC-F between lean 0.40 +/- 0.10 and obese subjects 0.42 +/- 0.09 (p < 0.06). IC-E was directly correlated with IC-F: IC-E = 0.25 x IC-F + 26 (n = 24, r2 = 0.57, p < 0.0001). In a multiple regression model (overall r2 = 0.32, p < 0.02), IC-E was related to BMI-SD inversely (p < 0.0054) and influenced as well by interaction of BMI-SD with sex (p < 0.043), IC-E being lower in boys with increasing body mass. In childhood, obesity is associated with decreased plasma IC-E and IC-F levels, the ratio of IC-E/IC-F is independent of body mass. Reduced IC-E levels in obese children are most likely due to the impact of body mass on IC-F.