Energy requirements in hospitalized elderly people.

OBJECTIVES: To estimate energy intake and energy expenditure (EE) in elderly hospitalized patients recovering from an acute illness. DESIGN: Cross-sectional evaluation of the disparity between energy intake and expenditure. PARTICIPANTS: Ninety geriatric patients (mean age+/-standard deviation 79.7+/-7.5) admitted to acute care or rehabilitation units. MEASUREMENTS: Patients' energy intake and resting EE (REE) were measured over a 3-day period. Blood samples were taken to determine C-reactive protein (CRP), creatinine, and albumin concentrations and to check renal function. RESULTS: Energy intake was higher than REE by a factor of 1.29, but it was lower than the energy requirement. Energy intake, adjusted for differences in body weight, was independent of sex, highest in those who were malnourished (defined as a body mass index (BMI) <21), and lowest in patients who scored poorly on the Mini-Mental State Examination. Energy intake and REE were independent of plasma CRP, creatinine, and albumin concentrations, as well as the initial diagnosis. REE was similar in men and women, at 18.8 kcal/kg per day. REE was 21.4 kcal/kg per day in patients with a BMI of 21 or less and 18.4 kcal/kg per day in those with a BMI greater than 21 kg/m2. The Harris-Benedict equation accurately predicted mean REE. CONCLUSION: The mean REE of the geriatric patients studied was 18.8 kcal/kg per day, whereas energy intake was just sufficient to cover minimal requirements. Thus, hospitalized elderly patients are likely to benefit from higher calorie intake.

Are elderly hospitalized patients getting enough protein?

OBJECTIVES: To determine the protein requirements of elderly hospitalized patients. DESIGN: Cross-sectional evaluation of nitrogen balance. SETTING: Short-stay geriatric ward or rehabilitation care unit. PARTICIPANTS: Thirty-six elderly hospitalized patients (aged 65-99) admitted to short-stay and rehabilitation care units. MEASUREMENTS: Resting energy expenditure and nitrogen balance were determined under usual and spontaneous energy and protein intake after subjects were clinically stable (3-5 days after admission). All items consumed over a 3-day period were weighed to determine energy and protein intake. RESULTS: Energy (23.5+/-6.3 kcal/kg per day) and protein (0.99+/-0.24 g/kg per day) intake were similar in men and women, and nitrogen balance was neutral (0.37+/-2.6 g/day; P=.41 vs a neutral nitrogen balance, i.e., 0 g/d). Half of the patients had a positive nitrogen balance. Plasma C-reactive protein, renal function, nutritional status, and initial diagnosis had no influence on nitrogen balance. In contrast, energy and protein intakes correlated positively with nitrogen balance. Linear regression analysis suggested that an elderly hospitalized patient with an energy intake of 1.31 times resting energy expenditure or greater appears to require a minimum protein intake of 1.06+/-0.28 g/kg per day. CONCLUSION: Mean protein intake to reach a neutral nitrogen balance in elderly hospitalized patients is 1.06+/-0.28 g/kg per day, which is higher than current recommendations for healthy elderly people. Safe protein intake (that would be adequate to ensure that 95% of patients remain in positive nitrogen balance) is difficult to establish.