TY - JOUR
T1 - Oral arginine-lysine does not increase growth hormone or insulin-like growth factor-I in old men
AU - Corpas, E.
AU - Blackman, M. R.
AU - Roberson, R.
AU - Scholfield, D.
AU - Harman, S. M.
PY - 1993
Y1 - 1993
N2 - Background. Older adults tend to have reduced growth hormone (GH) secretion and insulin-like growth factor I (IGF-I) levels as well as changes in body composition which are partially reversed by GH injections. Arginine stimulates GH release, and lysine may amplify this response. We investigated whether oral arginine/lysine could be used to increase basal IGF-I and GH levels in non-obese old men (age 69 ± 5 years; mean ± SD) to values similar to those of untreated young men (age 26 ± 4 years). Methods. Two groups of 8 healthy old men were treated with 3 g of arginine plus 3 g of lysine or with placebo capsules twice daily for 14 days. Before and on day 14 of each treatment GH levels were determined in blood samples taken at 20-minute intervals from 2000-0800 h, IGF-I was measured at 0800 h, and a 1 μg/kg GHRH stimulation test was done. Results. At baseline, mean GH peak amplitude (p < .02) and serum IGF-I (p < .0001) were lower, whereas GHRH responses were similar, in old vs young men. Arginine/lysine did not significantly alter spontaneous or GHRH-stimulated GH levels, or serum IGF-I. Arginine absorption was age-independent. The correlation (p < .005) between measured increments in serum arginine and increases in serum GH after a single dose of arginine/lysine was similar in old and young groups. Conclusions. Our data suggest that oral arginine/lysine is not a practical means of chronically enhancing GH secretion in old men.
AB - Background. Older adults tend to have reduced growth hormone (GH) secretion and insulin-like growth factor I (IGF-I) levels as well as changes in body composition which are partially reversed by GH injections. Arginine stimulates GH release, and lysine may amplify this response. We investigated whether oral arginine/lysine could be used to increase basal IGF-I and GH levels in non-obese old men (age 69 ± 5 years; mean ± SD) to values similar to those of untreated young men (age 26 ± 4 years). Methods. Two groups of 8 healthy old men were treated with 3 g of arginine plus 3 g of lysine or with placebo capsules twice daily for 14 days. Before and on day 14 of each treatment GH levels were determined in blood samples taken at 20-minute intervals from 2000-0800 h, IGF-I was measured at 0800 h, and a 1 μg/kg GHRH stimulation test was done. Results. At baseline, mean GH peak amplitude (p < .02) and serum IGF-I (p < .0001) were lower, whereas GHRH responses were similar, in old vs young men. Arginine/lysine did not significantly alter spontaneous or GHRH-stimulated GH levels, or serum IGF-I. Arginine absorption was age-independent. The correlation (p < .005) between measured increments in serum arginine and increases in serum GH after a single dose of arginine/lysine was similar in old and young groups. Conclusions. Our data suggest that oral arginine/lysine is not a practical means of chronically enhancing GH secretion in old men.
UR - http://www.scopus.com/inward/record.url?scp=0027195625&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0027195625&partnerID=8YFLogxK
U2 - 10.1093/geronj/48.4.m128
DO - 10.1093/geronj/48.4.m128
M3 - Article
C2 - 8315224
AN - SCOPUS:0027195625
SN - 0022-1422
VL - 48
SP - M128-M133
JO - Journals of Gerontology
JF - Journals of Gerontology
IS - 4
ER -