Energy intake and energy expenditure in prepubertal males with asthma.

This study aimed to measure energy intake (EI) and total energy expenditure (TEE) of asthmatic males and to validate diet history as a method of estimating their energy requirements. EI was assessed by dietary history and TEE by the heart-rate monitoring method in a group of asthmatic and nonasthmatic males. Resting energy expenditure (REE) adjusted for fat-free mass was higher in asthmatic than in nonasthmatic males (5,037 versus 4,839 kJ x day(-1), p<0.05). TEE (93+/-1.8 versus 8.4+/-1.4 MJ x day(-1), respectively; p=NS) and EI (9.2+/-15 versus 8.8+/-15 MJ x day(-1), respectively, p=NS) were not statistically different in asthmatic and nonasthmatic male. EI was not statistically different from TEE in both groups of males. Asthmatic males showed an acceptable agreement between TEE and EI at the individual level (range of agreement: -3.2 to 2.9 MJ x day(-1)), and a good agreement at the group level (95% confidence interval for the bias, - 1.1 to 0.8 MJ x day(-1)). Males with mild-to-moderate asthma have a higher metabolic activity per unit fat-free mass than nonasthmatic males. This increased requirement is apparently well compensated by an adequate energy intake. Diet history is a suitable method for estimating energy requirements in males with mild-to-moderate asthma.

Total energy expenditure and patterns of activity in 8-10-year-old obese and nonobese children.

Total energy expenditure (TEE) and patterns of activity were measured by means of a heart rate (HR)-monitoring method in a group of 8-10-year-old children including 13 obese children (weight, 46 +/- 10 kg; fat mass: 32 +/- 9%) and 16 nonobese children (weight, 31 +/- 5 kg; fat mass, 18 +/- 5%). Time for sleeping was not statistically different in the two groups of children (596 +/- 33 vs. 582 +/- 43 min; p = NS). Obese children spent more time doing sedentary activities (400 +/- 129 vs. 295 +/- 127 min; p < 0.05) and less time in nonsedentary activities (449 +/- 126 vs. 563 +/- 135 min; p < 0.05) than nonobese children. Time spent in moderate or vigorous activity-i.e., time spent at a HR between 50% of the maximal O2 uptake (peak VO2) and 70% peak VO2 (moderate) and at a HR > or = 70% peak VO2 (vigorous)-was not statistically different in obese and nonobese children (88 +/- 69 vs. 52 +/- 35 min and 20 +/- 21 vs. 16 +/- 13 min, respectively; p = NS). TEE was significantly higher in the obese group than in the nonobese group (9.46 +/- 1.40 vs. 7.51 +/- 1.67 MJ/day; p < 0.01). The energy expenditure for physical activity (plus thermogenesis) was significantly higher in the obese children (3.98 +/- 1.30 vs. 2.94 +/- 1.39 MJ/day; p < 0.05). The proportion of TEE daily devoted to physical activity (plus thermogenesis) was not significantly different in the two groups, as shown by the ratio between TEE and the postabsorptive metabolic rate (PMR): 1.72 +/- 0.25 obese vs 1.61 +/- 0.28 non-obese. In conclusion, in free-living conditions obese children have a higher TEE than do nonobese children, despite the greater time devoted to sedentary activities. The higher energy cost to perform weight-bearing activities as well as the higher absolute PMR of obese children help explain this apparent paradox.

Daily energy expenditure in free-living conditions in obese and non-obese children: comparison of doubly labelled water (2H2(18)O) method and heart-rate monitoring.

OBJECTIVE: To compare the heart-rate monitoring with the doubly labelled water (2H2(18)O) method to estimate total daily energy expenditure in obese and non-obese children. DESIGN: Cross sectional study of obese and normal weight children. SUBJECTS: 13 prepubertal children: six obese (4M, 2F, 9.1 +/- 1.5 years, 47.3 +/- 9.7 kg) and seven non-obese (3M, 4F, 9.3 +/- 0.6 years, 31.8 +/- 3.2 kg). MEASUREMENTS: Total daily energy expenditure was assessed by means of the doubly labelled water method (TEEDLW) and of heart-rate monitoring (TEEHR). RESULTS: TEEHR was significantly (P < 0.05) higher than TEEDLW in obese children (9.47 +/- 0.84 MJ/d vs 8.99 +/- 0.63 MJ/d) whereas it was not different in non-obese children (8.43 +/- 2.02 MJ/d vs 8.42 +/- 2.30 MJ/d, P = NS). The difference of TEE assessed by HR monitoring in the obese group averaged 6.2 +/- 4.7%. At the individual level, the degree of agreement (difference between TEEHR and TEEDLW +/- 2s.d.) was low both in obese (-0.36, 1.32 MJ/d) and in non-obese children (-1.30, 1.34 MJ/d). At the group level, the agreement between the two methods was good in nonobese children (95% c.i. for the bias:-0.59, 0.63 MJ/d) but not in obese children (0.04, 0.92 MJ/d). Duration of sleep and energy expenditure during resting and physical activity were not significantly different in the two groups. Patterns of heart-rate (or derived energy expenditure) during the day-time were similar in obese and non-obese children. CONCLUSION: The HR monitoring technique provides an estimation of TEE close to that assessed by the DLW method in non-obese prepubertal children. In comparison with DLW, the HR monitoring method yields a greater TEE value in obese children.

Assessment of the DQB1-DQA1 complete genotype allows best prediction for IDDM.

OBJECTIVE: To analyze the HLA-DQ (human leukocyte antigen) genetic association with insulin-dependent diabetes mellitus (IDDM) patients of the Northeast Italian population. RESEARCH DESIGN AND METHODS: Fifty-one IDDM patients and 52 healthy control subjects were molecularly typed for DQB1 and DQA1 loci by using allele-specific oligonucleotide probes and polymerase chain reaction amplified genomic DNA. DNA enzyme immunoassay was used to assess allele specificities. RESULTS: IDDM status strongly correlated with DQB1 alleles carrying a non-aspartic acid (non-Asp) residue in position 57 of DQ beta-chain and DQA1 alleles with an arginine (Arg) residue in position 52 of DQ alpha-chain. Individuals with two DQB1 (non-Asp) alleles and two DQA1(Arg) alleles had the highest relative risk for disease: they constituted approximately 40% of IDDM patients compared with 0% of control subjects. Heterozygosis at either residue 57 of DQB1 or residue 52 of DQA1 was sufficient to abrogate statistical significance for disease association, although 47% of IDDM patients were included in these two groups compared with 21% of normal control subjects. On the other hand, the presence of two DQB1 alleles with Asp in position 57 was sufficient to confer resistance to disease irrespective of the DQA1 genotype. CONCLUSIONS: The results demonstrate that the complete HLA-DQ genotype, more than a single DQB1 or DQA1 locus, should be determined to estimate the highest risk for disease. Screening a population for preventive purposes and/or early signs of IDDM should then take advantage of this result, and "susceptible homozygous" individuals should be followed very closely and considered the first group of choice for possible new therapeutic trials.

Elevated energy expenditure and reduced energy intake in obese prepubertal children: paradox of poor dietary reliability in obesity?

The purpose of this study was to assess the validity of two common methods used to assess energy intake. A 3-day weighed dietary record and a dietary history were collected and compared with the total daily energy expenditure (TEE) assessed by the heart rate method in a group of 12 obese and 12 nonobese prepubertal children (mean age 9.3 +/- 1.1 years vs 9.3 +/- 0.4 years). The TEE value was higher in obese than in nonobese children (9.89 +/- 1.08 vs 8.13 +/- 1.39 MJ/day; p < 0.01). Energy intake assessed by the dietary record was significantly lower than TEE in the obese children (7.06 +/- 0.98 MJ/day; p < 0.001) but comparable to TEE in the nonobese children (8.03 +/- 0.99 MJ/day; p = not significant). Energy intake assessed by diet history was lower than TEE in the obese children (8.37 +/- 1.35 MJ/day, p < 0.05) but close to TEE in the nonobese children (8.64 +/- 1.54 MJ/day, p = not significant). These results suggest that obese children underreport food intake and that the dietary record and the diet history are not valid means of assessing energy intake in obese prepubertal children.

Energy expenditure during walking and running in obese and nonobese prepubertal children.

We measured body composition and energy expenditure during walking and running on a treadmill in 40 prepubertal children: 23 obese children (9.3 +/- 1.1 years of age; 46 +/- 10 kg (mean +/- SD)) and 17 nonobese matched control children (9.2 +/- 0.6 years of age; 30 +/- 5 kg). Energy expenditure was assessed by indirect calorimetry with a standard open-circuit method. At the same speed of exercise, the energy expenditure was significantly (p < 0.01) greater in obese than in control children, in both boys and girls. Expressed per kilogram of body weight or per kilogram of fat-free mass, the energy expenditure was comparable in the two groups. Obese children had a significantly (p < 0.01) larger pulmonary ventilatory response to exercise than did control children. Heart rate was comparable in boys and girls combined but significantly higher (p < 0.05) in obese subjects, if boys and girls were analyzed separately. These data indicate that walking and running are energetically more expensive for obese children than for children of normal body weight. The knowledge of these energy costs could be useful in devising a physical activity program to be used in the treatment of obese children.

Effect of weight loss on resting energy expenditure in obese prepubertal children.

To assess the effect of weight loss on resting metabolic rate (RMR), the energy expenditure of eight obese prepubertal children (age 9 +/- 1 years; weight 48.7 +/- 9.1 kg; BMI 25.3 +/- 3.9) and of 14 age-matched children of normal body weight (age 9 +/- 1 years; weight 28.8 +/- 5.6 kg; BMI 16.5 +/- 1.7) was measured by indirect calorimetry. The obese children were reinvestigated after a mean weight loss of 5.4 +/- 1.2 kg induced by a six-months mixed hypocaloric diet. Before slimming, the obese group showed a higher daily energy intake than the control group (10.40 +/- 3.45 MJ/day vs 7.97 +/- 2.02 MJ/day respectively; P less than 0.05) but a similar value was observed per unit fat-free mass (FFM) (0.315 +/- 0.032 MJ/kgFFM/day vs 0.329 +/- 0.041 MJ/kgFFM/day respectively). The average RMR of the obese children was greater than that of the control group (5217 +/- 531 kJ/day vs 4477 +/- 506 kJ/day) but similar after adjusting for FFM (4728 +/- 3102 kJ/day vs 4899 +/- 3102 kJ/day). Weight loss resulted in a reduction in RMR (5217 +/- 531 kJ/day vs 4874 +/- 820 kJ/day), each kg of weight loss being accompanied by a decrease of RMR of 64 kJ (15.3 kcal) per day. The changes in RMR induced by weight loss paralleled the changes in FFM. No difference was found in average RQ in obese children vs controls (0.85 +/- 0.03 vs 0.87 +/- 0.03 respectively) and in the obese children before and after weight loss (0.87 +/- 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Basal energy expenditure in obese and normal weight schoolchildren.

The present study was performed using indirect calorimetry to test the hypothesis of a reduction of the basal energy expenditure in obese prepubertal children. The obese and control children studied were comparable regarding age, height and fat-free mass (FFM). Total weight and body fat percentage were significantly greater in the obese children. Plasma insulin and glucagon concentrations were significantly higher in obese than in control children. In the two groups of children the basal metabolic rates (BMRs) were comparable in both absolute values and values adjusted for FFM, age and gender utilizing the multiple regression analysis. The most important variable to predict BMR was FFM, followed by age. BMR was significantly correlated with FFM, both for obese and control children, and also when the two groups were combined. In conclusion, our data do not support the idea that a child's obesity is maintained by increased metabolic efficiency at least in basal conditions.

Assessment of autonomic functions in insulin-dependent diabetic children and adolescents.

Autonomic function has been studied in 30 insulin-dependent diabetic children and adolescents, through five cardiovascular tests. A significant difference between the diabetic and the control subjects was found in heart rate variations after deep breathing and after standing. Fifty percent of our patients showed an altered response to one or more cardiovascular tests. Although clinical manifestations of autonomic dysfunction are not frequent in young insulin-dependent patients, early signs of functional alterations are detectable in a high percentage of them.