Background: Hormone administration to elderly individuals can increase lean body mass (LBM) and decrease fat, but interactive effects of growth hormone (GH) and sex corticosteroids and their influence on strength and endurance are unknown. Objective: The purpose of this study was to evaluate the effects of recombinant human GH or sex corticosteroids on body composition, strength, endurance, and adverse outcomes in aged persons. Design, setting, and participants: This was a 26‐week randomized, double‐blind, placebo‐controlled parallelgroup trial in healthy, ambulatory, community‐dwelling US women (n = 57) and men (n = 74) aged 65 to 88 years recruited between June 1992 and July 1998. Interventions: Participants were randomized to receive GH (starting dose, 30 μg/kg, reduced to 20 μg/kg, subcutaneously 3 times/wk) + sex corticosteroids (women: transdermal estradiol, 100 μg/day, plus oral medroxyprogesterone acetate, 10 mg/day, during the last 10 days of each 28‐day cycle [HRT]; men: testosterone enanthate, biweekly intramuscular injections of 100 mg) (n = 35); GH + placebo sex corticosteroid (n = 30); sex corticosteroid + placebo GH (n = 35); or placebo GH + placebo sex corticosteroid (n = 31) in a 2 × 2 factorial design. Main outcome measures: Lean body mass, fat mass, muscle strength, maximum oxygen uptake (VO2 max) during treadmill test, and adverse effects. Results: In women, LBM increased by 0.4 kg with placebo, 1.2 kg with HRT (p = .09), 1.0 kg with GH (p = .001), and 2.1 kg with GH + HRT (p < .001). Fat mass decreased significantly in the GH and GH + HRT groups. In men, LBM increased by 0.1 kg with placebo, 1.4 kg with testosterone (p = .06), 3.1 kg with GH (p < .001), and 4.3 kg with GH + testosterone (p < .001). Fat mass decreased significantly with GH and GH + testosterone. Women's strength decreased in the placebo group and increased nonsignificantly with HRT (p = .09), GH (p = .29), and GH + HRT (p = .14). Men's strength also did not increase significantly, except for a marginally significant increase of 13.5 kg with GH + testosterone (p = .05). Women's VO2 max declined by 0.4 mL/min/kg in the placebo and HRT groups but increased with GH (p = .07) and GH + HRT (p = .06). Men's VO2 max declined by 1.2 mL/min/kg with placebo and by 0.4 mL/min/kg with testosterone (p = .49) but increased with GH (p = .11) and with GH + testosterone (p < .001). Changes in strength (r = .355; p < .001) and in VO2 max (r = .320; p = .002) were directly related to changes in LBM. Edema was significantly more common in women taking GH (39% versus 0%) and GH + HRT (38% versus 0%). Carpal tunnel symptoms were more common in men taking GH + testosterone (32% versus 0%) and arthralgias were more common in men taking GH (41% versus 0%). Diabetes or glucose intolerance occurred in 18 GH‐treated men versus 7 not receiving GH (p = .006). Conclusions: In this study, GH with or without sex corticosteroids in healthy, aged women and men increased LBM and decreased fat mass. Sex corticosteroid + GH increased muscle strength marginally and V...

Background/purpose: The mechanical properties of human skin are known to change with ageing, rendering skin less resistant to friction and shear forces, as well as more vulnerable to wounds. Until now, only few and contradictory results on the age‐dependent friction properties of skin have been reported. This study has investigated in detail the influence of age on the friction of human skin against textiles. Methods: In vivo skin‐friction measurements on a force plate were combined with skin analyses concerning elasticity, hydration, pH value and sebum content. Thirty‐two young and 28 aged persons rubbed their volar forearm in a reciprocating motion against various textiles on the force plate, using defined normal loads and sliding velocities, representing clinically relevant contact conditions. Results: Mean friction coefficients ranged from 0.30 ± 0.04 (polytetrafluoroethylene) to 0.43 ± 0.04 (cotton/polyester). No significant differences in the friction properties of skin were found between the age groups despite skin elasticity being significantly lower in the aged persons. Skin hydration was significantly higher in the elderly, whereas no significant differences were observed in either skin pH value or sebum content. Conclusion: Adhesion is usually assumed to be the dominant factor in skin friction, but our observations imply that deformation is also an important factor in the friction of aged skin. In the elderly, lower skin elasticity and skin turgor are associated with more pronounced skin tissue displacements and greater shear forces during frictional contact, emphasizing the importance of friction reduction in wound‐prevention programmes.

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.

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