Children with cerebral palsy do not achieve healthy physical activity levels

AIM

This study compared daily activity energy expenditure (AEE) in children with cerebral palsy with a control group and investigated whether the children achieved healthy levels of physical activity.

METHODS

We enrolled eight children with bilateral cerebral palsy, from eight to 10 years of age, and a group of controls matched for age and gender. For three days, physical activity was simultaneously measured by accelerometers and self-reports using a diary. The daily AEE results were compared between groups and methods. The number of children that achieved healthy physical activity levels in each group was explored.

RESULTS

Children with cerebral palsy had significantly lower daily AEE, as measured by accelerometers, than the controls, and they did not achieve the healthy moderate to heavy physical activity level defined in the Nordic Nutrition Recommendations. Self-reports using the diaries resulted in an overestimation of physical activity compared with the ankle accelerometer measurements in both groups.

CONCLUSION

Our investigation of physical activity in children with cerebral palsy and controls using accelerometers and a diary found low levels of daily AEE and physical activity, and these results were most prominent in the group with cerebral palsy. The diaries overestimated physical activity in both groups.

Physical capacity, respiratory quotient and energy expenditure during exercise in male patients with schizophrenia compared with healthy controls

BACKGROUND

Despite massive research on weight gain and metabolic complications in schizophrenia there are few studies on energy expenditure and no current data on physical capacity.

AIM

To determine oxygen uptake capacity, respiratory quotient (RQ) and energy expenditure during a submaximal exercise test in patients with schizophrenia and healthy controls.

METHOD

Ten male patients and 10 controls were included. RQ and energy expenditure were investigated with indirect calorimetry during a cycle ergometer test. The submaximal work level was defined by heart rate and perceived exhaustion. Physical capacity was determined from predicted maximal oxygen uptake capacity (VO(2-max)).

RESULTS

The patients exhibited significantly higher RQ on submaximal workloads and lower physical capacity. A significant lower calculated VO(2-max) remained after correction for body weight and fat free mass (FFM). Energy expenditure did not differ on fixed workloads.

CONCLUSION

RQ was rapidly increasing in the patients during exercise indicating a faster transition to carbohydrate oxidation and anaerobic metabolism that also implies a performance closer to maximal oxygen uptake even at submaximal loads. This may restrict the capacity for everyday activity and exercise and thus contribute to the risk for weight gain. Physical capacity was consequently significantly lower in the patients.

Differences in resting energy expenditure and body composition between patients with schizophrenia and healthy controls

OBJECTIVE

A lowered energy metabolism in schizophrenia was reported already in the 1920s. However, these early investigations were case studies without control groups or statistical analysis. In this study the resting energy expenditure (REE) and relevant body composition variables were measured in patients with schizophrenia and healthy controls.

METHOD

REE was determined in 30 patients and 17 controls. The difference between the measured and the expected level for each individual was calculated as DeltaREE. Body composition was assessed with bioelectrical impedance and calliper measurements.

RESULTS

DeltaREE was significantly lower in the patients than in the controls. A decrease was also seen in the non-medicated patients. The patients showed significantly lower percentages of water in fat free-mass and intracellular water.

CONCLUSION

The lowering of REE and body water fractions may suggest a homeostatic aberration in schizophrenia that may be of importance for the understanding of metabolic disturbances observed in the disease.

Inverse relationship between protein intake and plasma free amino acids in healthy men at physical exercise

The effect of a "normal" (n = 8) and "high" (n = 6) protein intake (1 and 2.5 g x kg(-1) x day(-1), respectively) and of exercise on plasma amino acid (AA) concentrations, insulin, and glucagon concentrations was followed throughout a continuous 24-h period in adult male subjects at energy balance after six days on a standardized diet and exercise program. Subjects were fasting from 2100 on day 6 to 1200 on day 7 and then fed 10 identical meals hourly until 2100. Physical exercise was performed (46% maximal oxygen uptake) between 0830 and 1000 (fasting) and in a fed state (1600-1730) on each day. The normal-protein group showed fasting plasma AA concentrations that were higher (P < 0.05) than those for the high-protein group, except for leucine, methionine, and tyrosine. Glutamine, glycine, alanine, taurine, and threonine concentrations were distinctly higher ( approximately 30% or greater) throughout the 24-h period in subjects consuming the normal- vs. the high-protein diets. Exercise appeared to increase, although not profoundly, the plasma concentrations of amino acids except for glutamate, histidine, ornithine, and tryptophan. The profound diet-related differences in plasma AA concentrations are only partially explained by differences in the renal clearance of the amino acids. We speculate on the possible metabolic basis for these findings.

Rates of urea production and hydrolysis and leucine oxidation change linearly over widely varying protein intakes in healthy adults

The quantitative relationships between nitrogen (N) intake, urea production, excretion and amino acid oxidation are currently a matter of debate. Some investigators have proposed that urea production is essentially constant over a wide range of N intakes and that urea hydrolysis is regulated according to the N needs of the organism. We have assessed this proposal by compiling results from four separate experiments in healthy young adults (n = 34) carried out in our laboratories and all at the end of the respective diet periods using an identical 24-h continuous intravenous infusion of [(15)N, (15)N]urea and L-[1-(13)C]leucine. The N intakes were: expt. 1; protein-free diet for 5 d; expt. 2; N at 44 mg N. kg(-1). d(-1) from a balanced L-amino acid mixture for 13 d; expt. 3; N at 161 mg. kg(-1). d(-1) from egg protein for 6 d; expt. 4 -one group received 157 mg. kg(-1). d(-1) and the other 392 mg. kg(-1). d(-1) from milk-protein-based diets for 6 d. Urea production and excretion were linearly correlated with N intake (r = 0.98 and 0.94, respectively; P < 0.01). Urea hydrolysis increased linearly with N intake (r = 0.7; P < 0.05), with considerable variation in the rate among individuals, especially at the N intake of approximately 160 mg N. kg(-1)d(-1). These findings are consistent with the generally accepted view that a control of body N balance is via a regulation of urea production. They do not support the concept that urea hydrolysis is the more important site in the control of body N loss.

Effect of protein intake and physical activity on 24-h pattern and rate of macronutrient utilization

Effects of moderate physical activity (90 min at 45-50% of maximal O2 uptake 2 times daily) and "high" (2.5 g protein. kg-1. day-1, n = 6) or "normal" protein intake (1.0 g protein. kg-1. day-1, n = 8) on the pattern and rate of 24-h macronutrient utilization in healthy adult men were compared after a diet-exercise-adjustment period of 6 days. Energy turnover (ET) was determined by indirect and direct (suit) calorimetry, and "protein oxidation" was determined by a 24-h continuous intravenous infusion of [1-13C]leucine. Subjects were in slight positive energy balance during both studies. Protein contributed to a higher (22 vs. 10%) and carbohydrate (CHO) a lower (33 vs. 58%) proportion of total 24-h ET on the high- vs. normal-protein intake. The highest contribution of fat to ET was seen postexercise during fasting (73 and 61% of ET for high and normal, respectively). With the high-protein diet the subjects were in a positive protein (P < 0.001) and CHO balance (P < 0.05) and a negative fat balance (P < 0.05). The increased ET postexercise was not explained by increased rates of urea production and/or protein synthesis.

An evaluation of dual-energy X-Ray absorptiometry and underwater weighing to estimate body composition by means of carcass analysis in piglets

To evaluate the use of dual-energy X-ray absorptiometry (DXA) and underwater weighing (UWW) for body-composition measurements, the carcasses of eight piglets (12-wk old, 15-22 kg in weight) were dissected into muscle, fat and bone. Thereafter, the components were homogenized and chemically analyzed for fat and bone mineral mass. Body components as measured by DXA correlated closely to the carcass analysis (r = 0.90-1.0). However, DXA still overestimated significantly the bone mineral mass, lean mass and total weight, and underestimated fat mass. The reproducibility of measurements, expressed as the CV for fat mass was 13.5%, whereas for total weight, lean mass and bone mineral mass, the CV was 0.74-1.9%. Fat mass was overestimated by UWW using the equations of Siri or Kraybill (r = 0. 77), but not by the equation of Lohman et al. (r = 0.69). The difference between the estimation of fat by chemical analysis and estimations by DXA and UWW was significantly affected by the amount of water in lean mass and fat-free mass.

The 24-h whole body leucine and urea kinetics at normal and high protein intakes with exercise in healthy adults

In healthy adult men adapted to a diet/exercise regimen for 6 days, the effects of small, frequent meals supplying daily protein intakes of 1 (n = 8) or 2.5 g . kg-1 . day-1 (n = 6) on leucine oxidation, urea production, and whole body protein synthesis (PS) and degradation (PD) have been compared with the use of a 24-h continuous intravenous [13C]leucine and [15N,15N]urea infusion protocol. Two 90-min periods of exercise (approximately 50% maximal O2 consumption) were included during the fasting and the fed periods of the 24-h day. Subjects were determined to be at approximate energy, nitrogen, and leucine balances on both diets. Increased protein intake raised the urea production rate; the absolute rate of urea hydrolysis was the same on both diets. When the first-pass splanchnic uptake of leucine was taken to be 25% of intake, PS was stimulated by feeding (after an overnight fast) at both protein intake levels (P < 0.05 and P < 0.01), whereas PD declined significantly (P < 0.01) at both protein levels. Protein gain at a high protein intake appears to be the result of both a stimulation of PS and a marked decline in PD, whereas at a less generous intake, the gain appears to be a result of a fall in PD with a less evident change in PS. Exercise moderately decreased PS during and/or immediately after exercise at each protein level, and there was a postexercise-induced increase (P < 0.01) in PD, which was more dramatic when feeding was at the higher protein intake level.

Evaluation of modified multicompartment models to calculate body composition in healthy males

Body volume was measured by underwater weighing (UWW) or with a skinfold caliper; bone mineral by dual energy X-ray absorptiometry (DXA); and body water by bioelectrical impedance analysis (BIA) in 22 healthy males. The percentage of water and bone mineral in fat-free mass had a significant effect on the calculated amount of fat using a two-compartment model. A three-compartment model based on field-adapted methods (skinfold thickness + BIA) to calculate body fat, correlated significantly with a more complex four-compartment model (UWW + BIA + DXA) (r = 0.95, p < 0.001). The advantages of three- and four-compartment equations are that they reduce the number of assumptions.

Evaluation of modified multicompartment models to calculate body composition in healthy males

The purpose of this study was to develop flexible and accurate multicompartment equations to calculate body composition and compare the results with methods using common two-compartment equations. Twenty-two healthy male volunteers 22-59 y of age were studied. Body volume was measured by underwater weighing (UWW) or with a skinfold caliper, bone mineral by dual-energy X-ray absorptiometry (DXA), and body water by bioelectrical impedance analysis (BIA). The percentage of water and bone mineral in fat-free mass (FFM) had a significant effect on the difference in percentage fat obtained by the two-compartment model compared with a four-compartment model. FFM density was negatively (r = -0.76, P < 0.001) and percentage water in FFM was positively correlated with age (r = 0.75, P < 0.001). The three-compartment model based on field-adapted methods (skinfold thickness + BIA) to calculate percentage body fat correlated significantly with the more complex four-compartment model (UWW + BIA + DXA; r = 0.95, P < 0.001). The advantages of three- and four-compartment equations are that they compensate for differences in body content of bone mineral and water.

The influence of physical activity on BMR

In addition to factors such as fat free mass, hormonal status, genetics and energy balance, previous physical activity has been shown to influence energy turnover during resting (RMR = resting metabolic rate) or basal conditions (BMR = basal metabolic rate). This article presents data on BMR from elite endurance athletes (4 female and 4 male), at least 39 h after their last training session, in comparison with sedentary nonathletic controls matched for sex and fat free mass (FFM). Comparisons with theoretical calculations of BMR were also made. The athletes were shown to have a significantly higher BMR than was expected from calculations based on body mass (16%, P < 0.05) or body composition (12%, P < 0.05). There were no corresponding differences found in the nonathletic control group. The athletes had a 13% higher (P < 0.001) BMR than controls if related to FFM and 16% (P = 0.001) if related to both FFM and fat mass (FM). The athletes were also found to have 10% lower R-values (P < 0.01) indicating higher fat oxidation. The conformity of these findings with the present literature and the possible mechanisms behind them as well as its influence on theoretical calculations of energy turnover (ET) based on activity factors expressed as multiples of RMR are further discussed.