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

Abstract

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 microg/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.

Administration of recombinant human GHRH-1,44-amide for 3 months reduces abdominal visceral fat mass and increases physical performance measures in postmenopausal women

“…2 kg, and one reported carpaltunnel syndrome. Such adverse events are consistent with an increase in total body water associated with elevated GH concentrations, as also observed during GH administration (16,17). Clinical cardiac function and fasting glucose concentrations did not change.…”

“…However, only one of these interventions altered body composition significantly (15). In contrast, GH supplementation consistently decreases intraabdominal fat and increases lean body mass in GHdeficient adults (16,17). Whether an inadequate dose and/or frequency of secretagogue administration accounts for the lack of whole-body effects in earlier regimens is not known.…”

The impact of the CAG repeat polymorphism of the androgen receptor gene on muscle and adipose tissues in 20–29-year-old Danish men: Odense Androgen Study

“…The significant impact of CAG n on (SAT thigh and SAT lower trunk ) and lacking impact on deeper adipose tissues (IMAT thigh and VAT) are interesting findings: they may indicate that actions of androgens on male adipose tissues are mainly associated with favorable impacts on subcutaneous compartments. This is in accordance with interventional studies of testosterone replacement therapy, in which subcutaneous compartments diminished (32,33), while only one small, older study reported diminished amounts of VAT (34). The interpretation of cross-sectional data is uncertain, but our study strongly indicates that VAT increases considerably from age 20 to 29 years, and that, on average, VAT is further increased in middle-aged men (21).…”

Body composition, metabolic syndrome and testosterone in ageing men

“…31 More detailed analyses of regional adipose tissue distribution have yielded conflicting reports of the effects of androgens. Older eugonadal (baseline serum testosterone 15.3 nM) men with a mean BMI 26 kg/m 2 treated with intramuscular testosterone for 6 months had a non-significant 10% decrease in subcutaneous abdominal fat area, with no change in visceral or total intraabdominal fat (at the level of L4-L5 on MRI); 56 Body composition, metabolic syndrome and testosterone in ageing men CA Allan et al similarly, transdermal testosterone administered for 24 months to men with median BMI 28 kg/m 2 did not decrease visceral fat on CT examination. 57 Studies of 17-alkylated androgens (oxymetholone and oxandrolone) have shown both preferential loss of truncal FM 34 and an equivalent loss in both the trunk and the appendices.…”