Higher circulating concentrations of insulin , leptin , cholecystokinin and peptide-YY accord with reduced appetite and energy intakes in healthy older adults .
Interventions to reduce circulating levels of these hormones may be beneficial for combatting the anorexia of ageing
Ageing is associated with reduced appetite and energy intakes .
However , the mechanisms underlying this phenomenon are not fully understood .
This systematic review and meta- analysis quantified differences in circulating concentrations of appetite-related hormones between healthy older and younger adults .
Effect of exogenous cholecystokinin (CCK)-8 on food intake and plasma CCK, leptin, and insulin concentrations in older and young adults: evidence for increased CCK activity as a cause of the anorexia of aging.
Healthy aging is associated with reductions in appetite and food intake -- the so-called anorexia of aging , which may predispose to protein-energy malnutrition . One possible cause of the anorexia of aging is an increased satiating effect of cholecystokinin ( CCK ) . To investigate the impact of aging on the satiating effects of CCK , 12 young and 12 older healthy subjects received 25-min iv infusions of saline ( control ) and CCK-8 , 1 ng/kg per min or 3 ng/k per min , on 3 separate days before a test meal . Older subjects ate less than young subjects , and food intake was suppressed 21.6 % by CCK-8 , compared with the control day ( P < 0.05 ) . The suppression of energy intake by CCK-8 in older subjects was twice that in young subjects ( 32 + /- 6 % vs. 16 + /- 6 % SEM , P < 0.05 ) and was related to plasma CCK-8 concentrations , which were higher at baseline ( P < 0.05 ) and increased more during CCK-8 infusions in older than young subjects ( P < 0.01 ) . The extent of suppression of food intake per given rise in plasma CCK-8 concentrations did not differ between the two age groups ( P = 0.35 ) . Endogenous CCK concentrations were higher at baseline in older subjects ( P < 0.001 ) and decreased during the CCK-8 but not control infusions ( P < 0.01 ) , suggesting that CCK suppresses its own release . Plasma leptin concentrations were not affected by CCK infusion , whereas postpr and ial insulin concentrations were lowered and the peak postpr and ial glucose concentration was delayed but not affected by CCK-8 infusion . Because older people retain their sensitivity to the satiating effects of exogenous CCK and plasma endogenous CCK concentrations are higher in older people , increased CCK activity may contribute to the anorexia of aging
Higher circulating concentrations of insulin , leptin , cholecystokinin and peptide-YY accord with reduced appetite and energy intakes in healthy older adults .
Interventions to reduce circulating levels of these hormones may be beneficial for combatting the anorexia of ageing
Ageing is associated with reduced appetite and energy intakes .
However , the mechanisms underlying this phenomenon are not fully understood .
This systematic review and meta- analysis quantified differences in circulating concentrations of appetite-related hormones between healthy older and younger adults .