Assessment of Energy Expenditure by Indirect Calorimetry in Healthy Subjects and Patients with Liver Cirrhosis

Abstract

The reliability of resting energy expenditure (REE) measurements by indirect calorimetry with a ventilated hood was investigated in 50 healthy controls and 10 patients with liver cirrhosis. In each subject basal energy expenditure (BEE) was determined once and REE three times (morning REE1, noon REE2, afternoon REE3). In controls and patients the first 5-minute BEE and first 5-minute REE (controls also second 5-minute REE) were higher than in the remainder of the 30-minute recording. Only the last 20 minutes of recordings were used to calculate BEE (1645 ± 315, mean ± SD, in kilocalories per day), REE1 (1880 ± 365), REE2 (1782 ± 384), and REE3 (1775 ± 316) in controls, and in cirrhotics: BEE (1530 ± 235), REE1 (1714 ± 267), REE2 (1715 ± 238), and REE3 (1779 ± 275). REE was higher than BEE in controls and cirrhotics (p < 0.05). The REE variation coefficient was 5 ± 3% in controls and 5 ± 2% in cirrhotics. No systematic difference between REE1, REE2, and REE3 was found. Energy expenditure predicted by the Harris-Benedict equation differed up to 21% from measured BEE in individual controls; group mean BEE, however, was correctly predicted. In cirrhotics differences between measured and predicted BEE up to 26% occurred, while measured BEE was higher than predicted BEE (p = 0.06). It is concluded that REE can be reliably assessed by indirect calorimetry with a ventilated hood system in controls and patients at any time of the day, when values obtained in the first 10 minutes are deleted. BEE and REE differ considerably in controls as well as in cirrhotic patients, so conditions under which measurements are performed should be standardized. (Journal of Parenteral and Enteral Nutrition 15: 421-425, 1991)