Beyond the somatopause: growth hormone deficiency in adults over the age of 60 years

Abstract

GH secretion declines by 14% decade of adult life, leading to the suggestion that people over the age of 60 yr are functionally GH deficient. If this is the case, one might not be able to detect a difference in GH secretion between the elderly with documented hypothalamic-pituitary disease and an age-matched control group. We studied GH secretion in 24 patients with hypothalamic-pituitary disease and 24 controls matched for body mass index and age using 24-h GH profiles, arginine stimulation tests, and serum insulin-like growth factor I (IGF-I) levels. The median (range) area under the curve of the GH profile [< 9.6 (< 9.6-20) vs. 18.5 (10.7-74.4) micrograms/L.24 h; P < 0.0001], the median stimulated peak GH response to arginine [< 0.4 (< 0.4-7.7) vs. 8.0 (1.6-37.0) micrograms/L; P < 0.0001], and the median serum IGF-I concentration [102 (< 14-162) vs. 147 (65-255) ng/mL; P = 0.0002] were significantly lower in the patients than in the controls. Fifteen patients showed no evidence of spontaneous or stimulated GH secretion, whereas all controls had evidence of both. The area under the GH curve in the 33 subjects with demonstrable GH secretion correlated significantly with the peak GH response to arginine (r = 0.71; P < 0.0001), but not with serum IGF-I concentration. This study suggests that organic GH deficiency in the elderly is distinct from the decline in GH secretion associated with the aging process. These patients may benefit from GH replacement therapy.

Aspects of Growth Hormone (GH) Replacement in Elderly Patients with GH Deficiency: Data from KIMS

“…All subgroups of patients had an equivalent degree of severe GHD on dynamic testing, as would be expected given the high prevalence of structural pituitary disease and severity of hypopituitarism. Although normal ageing is associated with a decline in spontaneous GH secretion, it is well established that it is possible to diagnose GHD by dynamic testing in older patients using similar criteria to those used in younger patients [23, 24]. …”

“…Third, do older GH-deficient patients demonstrate beneficial effects from GH replacement therapy? Dealing with these in turn, it has been clearly documented that GH responses to both insulin-induced hypoglycaemia and intravenous arginine are decreased in elderly hypopituitary patients compared with age-matched controls [23, 24]. Furthermore, it has been shown that total and regional fat mass are increased in elderly hypopituitary patients compared with elderly control individuals [25].…”

Growth Hormone (GH) Status and Body Composition in Normal Ageing and in Elderly Adults with GH Deficiency

“…In contrast, all of the control participants had detectable GH secretion at some point during the 24-hour profile [15]. When re-evaluated using an ultrasensitive chemiluminescence assay (sensitivity, 0.002 µg/l), GH was measurable in all of the samples obtained during the 24-hour profiles from the controls and the patients [16].…”

Effects of 3-year GH replacement therapy on bone mineral density in younger and elderly adults with adult-onset GH deficiency

“…The elderly GHD adults have lower GH secretion (8) and increased total body fat (9) compared with age-matched healthy subjects, whereas there is little difference in terms of lean mass (9). The results of several studies suggest that GH replacement in elderly GHD patients has approximately similar efficacy as that in younger GHD adults in terms of quality of life, body composition, and serum lipid pattern (10, 11, 12, 13).…”