Effects of GH and/or Sex Steroid Administration on Abdominal Subcutaneous and Visceral Fat in Healthy Aged Women and Men

• Published in: The journal of clinical endocrinology and metabolism Vol. 86; no. 8; pp. 3604 - 3610
• Main Authors: Münzer, Thomas, Harman, S. Mitchell, Hees, Paul, Shapiro, Ed, Christmas, Colleen, Bellantoni, Michele F., Stevens, Thomas E., O’Connor, Kieran G., Pabst, Katherine M., St. Clair, Carol, Sorkin, John D., Blackman, Marc R.
• Format: Journal Article
• Language: English
• Published: Endocrine Society 01-08-2001
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jcem.86.8.7773

Aging is associated with reduced GH, IGF-I, and sex steroid axis
activity and with increased abdominal fat. We employed a randomized,
double-masked, placebo-controlled, noncross-over design to study the
effects of 6 months of administration of GH alone (20 μg/kg BW), sex
hormone alone (hormone replacement therapy in women, testosterone
enanthate in men), or GH + sex hormone on total abdominal area,
abdominal sc fat, and visceral fat in 110 healthy women (n=
46) and men (n = 64), 65–88 yr old (mean, 72 yr). GH
administration increased IGF-I levels in women (P =
0.05) and men (P = 0.0001), with the increment in
IGF-I levels being higher in men (P = 0.05). Sex
steroid administration increased levels of estrogen and testosterone in
women and men, respectively (P = 0.05). In women,
neither GH, hormone replacement therapy, nor GH + hormone replacement
therapy altered total abdominal area, sc fat, or visceral fat
significantly. In contrast, in men, administration of GH and GH +
testosterone enanthate decreased total abdominal area by 3.9% and
3.8%, respectively, within group and vs. placebo
(P = 0.05). Within-group comparisons revealed that
sc fat decreased by 10% (P = 0.01) after GH, and
by 14% (P = 0.0005) after GH + testosterone
enanthate. Compared with placebo, sc fat decreased by 14%
(P = 0.05) after GH, by 7% (P=
0.05) after testosterone enanthate, and by 16%
(P = 0.0005) after GH + testosterone enanthate.
Compared with placebo, visceral fat did not decrease significantly
after administration of GH, testosterone enanthate, or GH +
testosterone enanthate. These data suggest that in healthy older
individuals, GH and/or sex hormone administration elicits a sexually
dimorphic response on sc abdominal fat. The generally proportionate
reductions we observed in sc and visceral fat, after 6 months of GH
administration in healthy aged men, contrast with the disproportionate
reduction of visceral fat reported after a similar period of GH
treatment of nonelderly GH deficient men and women. Whether longer term
administration of GH or testosterone enanthate, alone or in
combination, will reduce abdominal fat distribution-related
cardiovascular risk in healthy older men remains to be
elucidated.