title: Energy expenditure in lean and obese diabetic patients using the doubly labelled water method.
abstract: Obesity is a common problem among Type 2 diabetic patients. To investigate the role of energy expenditure in the maintenance of obesity in diabetic subjects, total energy output was measured during weight stability in 23 diabetic patients: 8 lean, 5 overweight, and 10 obese. Free living total energy expenditure was measured over 14 days using doubly labelled water method, resting metabolic rate by indirect calorimetry, and urinary energy losses were assessed. Total energy output was higher in the obese (13.66 +/- SD 3.18 MJ 24 h-1) than normal weight patients (10.84 +/- 2.02 MJ 24 h-1; p < 0.05); 11.96 +/- 2.51 MJ 24 h-1 in the overweight. None of the lean but four of the obese had total energy output > 16 MJ 24 h-1. Urinary energy losses accounted for only 0.6% of total energy output in lean, 2.8% in overweight, and 3.1% in obese. Resting metabolic rate was significantly higher in obese (7.47 +/- 1.69 MJ 24 h-1) compared to lean (5.87 +/- 1.07; p < 0.05) and resting metabolic rate correlated with lean body mass (r = 0.8, p < 0.001). Thermogenesis plus physical activity was substantial and not lower in the obese (5.77 versus lean 4.97 MJ 24 h-1). The mean ratio of total energy expenditure to resting metabolic rate was in the moderate exercise category and similar in lean (1.87) and obese (1.80). Resting metabolic rate, total energy expenditure, and thermogenesis and physical activity were similar in all three groups when corrected for differences in lean body mass.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Medicine, University of Dundee, Scotland.
authors.forename: P K
authors.initials: PK
authors.lastname: Chong
authors.forename: R T
authors.initials: RT
authors.lastname: Jung
authors.forename: M J
authors.initials: MJ
authors.lastname: Rennie
authors.forename: C M
authors.initials: CM
authors.lastname: Scrimgeour
mesh_terms: D000328:Adult; D001481:Basal Metabolism; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D001833:Body Temperature Regulation; D003903:Deuterium; D003920:Diabetes Mellitus / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D008297:Male; D008875:Middle Aged; D009765:Obesity; D010101:Oxygen Consumption; D010103:Oxygen Isotopes; D012016:Reference Values; D012737:Sex Factors; D013851:Thinness; D014867:Water
chemical_list: D001786:Blood Glucose; D010103:Oxygen Isotopes; D014867:Water; D003903:Deuterium