ENDO: Hormones Linked to Beneficial Effects in Elderly
Mild hypothyroidism associated with longer life; ghrelin supplementation with increased appetite
MONDAY, June 15 (HealthDay News) -- Mild age-associated increases in thyroid-stimulating hormone may be linked with increased longevity, and supplementation with another hormone -- ghrelin -- may benefit frail elderly women with unexplained weight loss, according to two studies presented at the Endocrine Society's 91st Annual Meeting, held from June 10 to 13 in Washington, D.C.
In one study, Martin Surks, M.D., of the Albert Einstein College of Medicine in Bronx, N.Y., and colleagues studied 236 Ashkenazi Jewish centenarians, 434 of their children (median age, 67 years), and 188 of their children's spouses. Because thyroid-stimulating hormone levels between parents and children (but not the children's spouses) were closely related, further analysis showed that two genetic variants were common to both groups, suggesting that mildly elevated levels are associated with a long life.
In a second study, Anne Cappola, M.D., of the University of Pennsylvania School of Medicine in Philadelphia, and colleagues studied the effects of an appetite-stimulating ghrelin infusion versus a placebo infusion in five frail elderly women with unexplained weight loss and five healthy, matched controls. Compared to placebo, they found that ghrelin was associated with a 51 percent increased calorie intake during a meal following the infusion, and that it not only resulted in higher ghrelin blood levels but also higher levels of growth hormone.
"If future studies extend our findings to non-Ashkenazi populations, our data suggest that levothyroxine treatment of the elderly for elevated thyroid-stimulating hormone alone, but not true hypothyroidism, could be harmful," Surks and colleagues conclude.