Integrated concentrations of growth hormone, insulin, C-peptide and prolactin in human obesity.
Twenty-four hour integrated concentrations of growth hormone (IC-GH) were significantly lower in young, obese subjects than in young subjects who were lean. Significant inverse correlations were found between IC-GH and body mass index (BMI) as well as the IC-GH and the 24 hr integrated concentrations of insulin (IC-I) and C-peptide (IC-C) in obese subjects below 30 yr of age. Since IC-GH decreases with age, the effect of obesity on IC-GH could not be demonstrated in the older subjects; a weak inverse correlation (p less than 0.05) between IC-GH and IC-C was found. Prolactin was significantly lower in the older subjects but did not correlate with IC-GH and was similar in lean and obese. Lipid deposition in adipose cells is promoted by high concentrations of insulin as well as low concentrations of growth hormone. We found a significant correlation between the IC-I/IC-GH ratio and BMI of both the young and older subjects. Correlations between these two factors do not necessarily imply a cause and effect relationship. It is plausible, however, that the elevated IC-I/IC-GH of the obese may facilitate their lipid storage and counter their efforts at weight reduction.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001835:Body Weight; D002096:C-Peptide / Q000097:blood*; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism*; D010455:Peptides / Q000097:blood*; D011388:Prolactin / Q000097:blood*
D002096:C-Peptide; D007328:Insulin; D010455:Peptides; D011388:Prolactin; D013006:Growth Hormone