Effects of nutritional supplementation on the appetite and energy intake responses to IV cholecystokinin in older adults.

Human aging is associated with a reduction in appetite and food intake. Increased activity of the satiety hormone, cholecystokinin (CCK), may be partly responsible. This study aimed to determine whether an increase in fat and energy intake modifies the suppressive effects of CCK-8 on appetite and energy intake. Fourteen healthy older adults completed three separate dietary periods, a 14-day and a 7-day normal diet (ND; 8272 ± 480 kJ/day; 35% fat), and a 14-day high-fat diet (HFD; 11,642 ± 414 kJ/day; 43% fat), in randomised order. Immediately following each diet, subjects received, in single-blinded fashion, a 30-min intravenous infusion of either CCK-8 (1.5 ng/kg/min) (ND-CCK, HFD-CCK) or 0.9% saline (ND-SAL), the latter following only ND. Plasma CCK concentrations, appetite responses and energy intake at a buffet meal were determined. Energy intake at the buffet meal was higher on the ND-SAL study day (3349 ± 224 kJ), when compared with either ND-CCK (3023 ± 317 kJ) or HFD-CCK (2905 ± 316 kJ). The suppression of energy intake by CCK-8 infusion did not differ between the two diets. We conclude that suppression of energy intake by exogenous CCK-8 does not appear to be attenuated by incorporation of supplemental high-energy, high-fat drinks in the diet of healthy older adults.

Effect of testosterone and a nutritional supplement, alone and in combination, on hospital admissions in undernourished older men and women.

BACKGROUND: In older people, undernutrition is associated with increased hospitalization rates and mortality. Because weight loss in older people often reflects a disproportionate reduction of skeletal muscle, anabolic treatments may be beneficial. OBJECTIVE: Our aim was to evaluate the hypothesis that testosterone treatment and a nutritional supplement have additive benefits. DESIGN: Oral testosterone undecanoate (40 mg daily for women, 80 mg twice daily for men) and an oral nutritional supplement (475 kcal/d) were administered, alone or combined, for 1 y to 49 community-dwelling, undernourished people [Mini Nutritional Assessment score <24 and low body weight (body mass index, in kg/m(2): <22) or recent weight loss (>7.5% over 3 mo)] aged >65 y (mean age: 77 y; 26 women and 23 men). Hospital admissions and other variables were assessed. RESULTS: In subjects receiving combined testosterone and nutritional supplements (n = 11), there were no hospital admissions, whereas there were 9 admissions (2 elective) in 13 subjects in the no-treatment group, 4 in the testosterone-treated group (n = 12), and 5 in the supplement-treated group (n = 13); P = 0.06 with no-treatment compared with combined treatment. When compared with the no-treatment group, the combined-treatment group had significantly fewer subjects admitted to hospital (0 compared with 5, P = 0.03), fewer days in hospital (0 compared with 74, P = 0.041), and a longer time to hospital admission (P = 0.017). CONCLUSIONS: In undernourished older people, combined treatment with testosterone and nutritional supplementation reduced the number of people hospitalized and the duration of hospital admissions, which are important endpoints in this group. Larger, confirmatory studies are now needed. This trial was registered before commencement at clinical trials.gov as NCT00117000.