Body composition analysis by dual-energy X-ray absorptiometry in young preschool children.

BACKGROUND/OBJECTIVES: Dual-energy X-ray absorptiometry (DXA) is considered a specific method for measuring body composition to assess obesity and osteoporosis, although few studies have been conducted in preschool children. The aim of this study was to provide sex - and age-specific references for bone mineral density (BMD), bone mineral content (BMC), fat mass (FM) and fat-free mass (FFM) normative data for children aged 2 to <6 years. SUBJECTS/METHODS: One hundred and eighty seven healthy white children from Buenos Aires City suburbs, Argentina, were studied by the Lunar DPX-L DXA, pediatric software: BMC less head (g), BMD (g/cm2), FM (%) and FFM (g). RESULTS: BMD and BMC increased significantly with age (P<0.0001), but only BMD was significantly different between boys and girls of similar age, being greater for boys (P=0.013). FM was not significantly different among the various age groups of boys and girls. However, the FFM/height was higher in boys and the BMC/FFM was higher in girls. The Z-scores and centile curves were derived separately for each sex and age. Q-Q detrended plots and LMS curves produced robust, unbiased fits that generated references for the 3rd, 50th and 97th percentiles for BMD, BMC, FM and FFM data, respectively. CONCLUSIONS: These DXA scans add to the scarcity of accurate measurements of body composition of white young children. The data analyses provided greater accuracy, particularly at the upper and lower ends of the distribution, which is important in clinical settings for identification of children with impaired body composition.

Dietas desequilibradas en niños preescolares: estudio en un jardín integral de la provincia de Buenos Aires, Argentina / Imbalance diets in preschool children: study in a day-care center in the Province of Buenos Aires, Argentina

The purpose of this study was to investigate the impact of low fat diets in children aged 2 to 5. Eighty two children (40 females and 42 males) attending a school cafeteria (Province of Buenos Aires, Argentina), in a cross sectional study, were evaluated. Body weight (W), height (H) and body composition (BC) by bioimpedance were recorded. The anthropometric raw data were processed as Z-score of the weight-for-age (WEZ) and of the height-for-age (HAZ). Serum insulin-like growth factor 1 (IGF-1) and Zinc/haemoglobin ratio (Zn/Hb) were also measured. Results showed that 73.2 per cent of children were adequate (A) according WEZ, 13.4 per cent were lean (L) and 13.4 per cent overweight (O). 8.5 per cent presented simultaneously impairment in WEZ and HAZ. Body fat percentage and energy metabolism were higher in O than in L and A (p < 0.05). Serum IGF-1's children--aged 4 to 5 years--with HAZ deficit were low than adequate HAZ ones. No statistical differences in Zn/Hb ratio between A, L and O were found. This cross sectional study suggests metabolic disorders in young children attending school cafeterias. These conclusions will allow to design balanced diets in order to optimize the resources, promote optimal growth and development and prevent adult diseases through dietary practices in childhood.

Incomplete carbohydrate absorption from fruit juice consumption after acute diarrhea.

We carried out a double-blind, randomized study in 60 children with acute diarrhea to determine their capacity to tolerate commonly consumed fruit juices. Feedings of juice with high fructose/glucose ratios and sorbitol resulted in incomplete carbohydrate absorption and recurrence of diarrhea during the phase immediately after improvement of the illness.

Growth deceleration and bone metabolism in nutritional dwarfing rats.

Nutritional status as well as energy and protein intake are critical regulators of IGF-1 and IGFBP-3 and contribute to the modulation of bone remodeling and formation. The purpose of this study was to investigate on an experimental model with nutritional dwarfing (ND), whether the alterations on body growth velocity, energy metabolism and body composition could affect serum concentrations of IGF-1 and IGFBP-3 and bone (tibiae and mandible) histology and histomorphometry. Twenty-one male weanling Wistar rats (body weight = 38.20 +/- 0.94 g) were randomized to three groups: seven of them were killed at day = 0 (CO, n = 7); control (C, n = 7); and experimental 80 (E80, n = 7). During 4 weeks, C was fed ad libitum with a 1:1 carbohydrate to fat diet. E80 was being underfed with the same diet by 80% and the following parameters were measured: weight (Wt) for length (L) ratio z-score; oxygen consumption (VO2); body composition (BC) by EM-SCAN SA 3000. At t = 28, E80 and C were killed. Serum IGF-1 and IGFBP-3 and bone histology and histomorphometry were performed on C0, E80 and C. E80 showed Wt for L z-score between lean and adequate, a decrease in VO2 according to body proportions, a BC of a delayed puberty individual, IGF-1 and IGFBP-3 decreased by 56 and 53%, respectively. Tibiae's hematopoyetic and adipose bone marrow areas were combined, with sealing trabeculae on metaphyseal areas. This study suggests that there is a relationship among growth deceleration in ND rats and structural alterations on tibiae.

Lipid profile in congenital adrenal hyperplasia.

Glucocorticoids have been reported to exert a marked effect on lipoprotein metabolism. Several studies have shown a potential risk of hyperlipidemia in patients under long-term glucocorticoid therapy. Current management of patients with congenital adrenal hyperplasia (CAH) includes the use of glucocorticoids to attenuate the increased production of undesirable adrenal hormones. A case-control study was designed to compare the serum lipid profiles of 14 patients with CAH under glucocorticoid therapy and 14 normal controls and to determine the characteristics of the profiles. A total of 9 patients (64.3%) had serum total cholesterol (TC) greater than 4.4 mmol/L (170 mg/dL), compared with 6 individuals in the control group (42.3%). Nine patients with CAH (64.3%) had serum triglycerides (TGs) more than 1.0 mmol/L (90 mg/dL), compared with only 2 in the control group (14.3%). Similarly, the mean serum TG was higher in the CAH group versus the controls, 1.33 mmol/L (118 mg/dL) versus 0.75 mmol/L (67 mg/dL), respectively. Serum low-density lipoprotein, (LDL-C) and high-density, lipoprotein (HDL-C) cholesterol were determined in 13 children with CAH and in the 14 controls. Nine CAH patients (69.2%) and 8 controls (57%) had LDL-C greater than 2.8 mmol/L (<110 mg/dL). For HDL-C, 2 children with CAH (15.4%) and 4 controls (28.6%) had levels less than 0.9 mmol/L (35 mg/dL). There were no significant differences for the cholesterol index, 0.24 for the controls and 0.22 for the CAH group. In the CAH group, the mean serum TG level and the percentage of individuals with TGs greater than 1.0 mmol/L were statistically significant compared with the controls. The mean serum TC and LDL-C, as well as the percentage of subjects with levels over the cutoff point, although slightly higher in the CAH group, were of no statistical significance. The results of this pilot study suggest that long-term glucocorticoid therapy in patients with CAH may induce abnormalities in the serum lipid profile characterized mainly by an increment in serum TGs.

Low dosages of exogenous growth hormone and its effect on growth in an animal model of suboptimal nutrition.

In a previous study, weight gain, insulin growth factor-1 (IGF-1) and insulin growth factor binding protein-3 (IGFBP-3) were increased in rats fed suboptimal levels of energy and administered 0.1 mg/100 g of body weight of recombinant human growth hormone (rhGH). Our objective was to determine whether these anabolic effects were still obtained with lower dosages of rhGH in similarly fed rats. Three groups of male, prepubertal Sprague-Dawley rats were administered rhGH and three groups of similar rats were given normal saline solution daily (0.05 mg/100 g of body weight subcutaneously). All rats were fed a balanced 1:1 carbohydrate:fat ratio diet for 4 wk. Restricted rats within each treatment were pair fed 80% and 60% ad libitum. Daily body weight, food intake, and efficiency were recorded. After 4 wk, serum IGF-1 and IGFBP-3, body fat, fat-free mass, and total body water were determined. Total weight gain and serum IGFBP-3 were significantly higher, with a tendency for increased body fat, in rats treated with rhGH and fed at 60% ad libitum. However, within each treatment, energy restriction caused decreased body fat and total body water. These results suggest that lower dosages of rhGH provide anabolic effects during suboptimal energy intake.

Consequences of incomplete carbohydrate absorption from fruit juice consumption in infants.

BACKGROUND: Most infants consume fruit juices by 6 months of age. However, fruit juices containing sorbitol may be associated with carbohydrate malabsorption without clinical symptoms. We hypothesized that increased physical activity and metabolic rate may be associated with carbohydrate malabsorption. METHODS: Physical activity and metabolic rate were determined in 14 healthy infants ([mean +/- SD] age, 5.1 +/- 0.8 months; weight, 7.8 +/- 1.1 kg; length, 67 +/- 4.2 cm; and body fat, 26% +/- 5%) for 3 hours in a respiratory chamber. Seven were fed pear juice, and the other 7 were fed white grape juice (120 mL) after a 2-hour fast. Pear juice contains sorbitol and a high fructose-glucose ratio, whereas white grape juice is sorbitol free and has a low fructose-glucose ratio. Carbohydrate absorption was determined by breath hydrogen gas analysis. The study was double-blinded. RESULTS: When compared with the infants without carbohydrate malabsorption (peak breath hydrogen level < 20 ppm above baseline), 5 of the 7 infants fed pear juice and 2 of the 7 infants fed white grape juice exhibited carbohydrate malabsorption (peak breath hydrogen level > or = 20 ppm above baseline; P < .01). These infants also exhibited both increased physical activity (P < .001) and metabolic rate (P < .05) after juice consumption in comparison with infants with normal carbohydrate absorption. When grouped according to the type of juice consumed, only infants fed pear juice exhibited increases in physical activity (P < .01). CONCLUSIONS: Carbohydrate malabsorption is associated with increased physical activity and metabolic rate in infants. Most of the infants who had carbohydrate malabsorption consumed pear juice. Therefore, fruit juices containing sorbitol and high levels of fructose may not be optimal for young infants.

Intrauterine growth retardation and long-term effects on growth.

The authors present intrauterine growth retardation (IUGR) as an entity with significant prevalence, morbidity, and mortality. They discuss short-term and long-term sequelae, and particularly emphasize long-term growth disabilities. The authors review the most important trials with human growth hormone that have been carried out recently to maximize the growth and final height potential of children affected with IUGR. They also highlight the most recent advances in the field of fetal growth, with special attention to genetic and endocrine factors. Finally, the authors discuss in detail epidemiological and clinical evidence of the causes of IUGR in relation to several adult onset disorders.

Comprehensive assessment of the components of energy expenditure in infants using a new infant respiratory chamber.

BACKGROUND: Current methods for energy expenditure (EE) measurements in term infants do not include simultaneous measurements of basal and sleeping metabolic rates (BMR and SMR) or a measure of physical activity (PA). Furthermore, prediction equations for calculating EE are not appropriate for use in infants with metabolic disorders. OBJECTIVE: To develop and utilize a new infant respiratory chamber for simultaneous measurements of EE (kJ/d), preprandial BMR (kJ/d), SMR (kJ/d) and an index of PA (oscillations/min/kg body weight) in infants with a variety of metabolic disorders, for up to four hours in a hospital setting, while allowing parental interaction in a comfortable environment. METHODS: We obtained simultaneous measurements of EE, BMR, SMR and PA in 21 infants (66+/-73 days of age, 4.5+/-1.7 kg body weight, 55+/-8 cm in length and 16+/-7% body fat) using our new infant respiratory chamber. Six of these infants were healthy, seven had thyroid dysfunction, five were HIV-exposed, one had AIDS, one had intrauterine and postnatal growth retardation and one was a hypothermic preterm infant. Energy expenditure, BMR and SMR were extrapolated for 24 hours. Body composition was estimated by skin-fold thickness, using age-appropriate formulae. Basal metabolic rate obtained with the infant respiratory chamber was compared to BMR that was calculated using the appropriate World Health Organization (WHO) equations. RESULTS: In all infants both extrapolated 24-hour EE and BMR correlated with fat-free mass (r = 0.89, p<0.01 and r = 0.88, p<0.01 respectively). Twenty-four hour EE also correlated with PA (r = 0.52, p<0.05). The HIV-exposed infants had higher BMR (p<0.05) than that calculated by the appropriate WHO equation. We found that the caloric requirements for the infant with growth retardation were underestimated based on the infant's weight and age. CONCLUSIONS: The infant respiratory chamber can measure all of the main components of EE. Some of the results obtained differed significantly from those obtained by the WHO equations; therefore, the new infant respiratory chamber is necessary for estimating EE in infants with metabolic and growth disorders.

Nutritional management of regurgitation in infants.

Infantile regurgitation is a frequently occurring problem. Throughout the world, anxious parents are imploring physicians to eliminate their infant's regurgitation. General practitioners, pediatricians and pediatric gastroenterologists strive to alleviate infantile regurgitation and its related parental stress. In this paper we define the scope of the problem and analyze the optimal, cost-efficient management approach to simple regurgitation in infants. The intent of this paper is to disseminate this information to practicing physicians and other health care professionals in an attempt to minimize the impact of this annoying problem of infancy and to eliminate confusion and expensive diagnostic tests and use of sub-optimal treatment modalities. Parental reassurance and dietary management by feeding thickened formula are important components in managing regurgitation in infants while maintaining optimal nutritional intake for adequate growth and development.

Comparison of several equations and derivation of a new equation for calculating basal metabolic rate in obese children.

OBJECTIVES: To compare basal metabolic rate (BMR) calculated by the Harris-Benedict, Ravussin, Cunningham, World Health Organization (WHO) and Schofield equations to BMR determined in an obese pediatric population. The second objective is to derive a new equation, based on measured BMR in obese children, for calculating BMR in obese pediatric patients. METHODS: The study included 110 (50 male/60 female) healthy obese subjects (BMI > 28) (11.7 +/- 2.8 years, 73 +/- 27 kg, 152 +/- 14 cm and 38 +/- 6% fat) who had preprandial BMR determined by indirect calorimetry. These results were compared to BMR calculated with the five above mentioned equations. Fat-free mass was determined by bioelectrical impedance and body composition was calculated using the appropriate equation. The age groups analyzed were as follows: males 3 to 10 and 11 to 18 years old; females 3 to 10 and 11 to 18 years old. A new equation was derived by stepwise multiple regression analysis using 100 randomly selected subjects from our test group and tested using the remaining 10 subjects. RESULTS: Basal metabolic rate calculated by the Ravussin and Cunningham equations in all subgroups was lower (p < 0.05) than measured BMR. Basal metabolic rate calculated by the Harris-Benedict equation was lower (p < 0.05) than measured BMR in male populations ages 3 to 10, 11 to 18, and in the entire cohort. Measured BMR was overestimated by the Harris-Benedict equation (p < 0.05) in females 11 to 18 years old; by the WHO equation (p < 0.05) in both male and females 3 to 10 years old and by the Schofield equation (p < 0.05) in males 11 to 18 years old. In comparison to measured BMR, the WHO equation appeared to be the most accurate for estimating BMR in males and females 11 to 18 years old. However, BMR calculating using our new equation in the 10 test subjects was similar to measured BMR. CONCLUSIONS: The WHO equation was the most accurate of the prediction equations studied. However, our new prediction equation may be more appropriate for calculating BMR in an obese pediatric population.

Dynamics of ionized magnesium and ionized calcium during recovery from diabetic ketoacidosis managed with conventional treatment.

Serial measurements of ionized magnesium (iMg), ionized calcium (iCa) and pH performed during the management of diabetic ketoacidosis (DKA) in a 10 9/12-year-old female showed a progressive decrease in iMg and iCa to subnormal values which inversely correlated with the increase of pH, suggesting a state of depletion of these cations during conventional DKA management.

Effects of exogenous recombinant human growth hormone on an animal model of suboptimal nutrition.

BACKGROUND: Nutritional dwarfing, a form of suboptimal nutrition, has been identified as a frequent cause of short stature and delayed sexual development in children. Retarded growth is an adaptive response to suboptimal nutrition. OBJECTIVE: To assess whether recombinant human growth hormone (rhGH) may promote growth during various levels of suboptimal nutrition. METHODS: Using a previously developed rat model of suboptimal nutrition, six groups of rats (six rats/group) were fed a balanced 1:1 carbohydrate:fat ratio diet for 4 weeks. Three of the groups were administered daily injections of rhGH (0.1 mg/100 g BW) subcutaneously in the back while the other three groups were kept as controls and were given similar dosages of normal saline solution (NSS). Restricted rats within each treatment group were pair fed 80 and 60% of the ad-libitum rats intake. Daily intake of the 80 and 60% fed groups were determined based on the intake of the ad-libitum fed groups. Serum IGF-I and insulin were determined after 4 weeks of dietary treatment by radioimmunoassay while IGFBP-3 was determined by an immunoradiometric assay. Body composition was assessed in all rats by carcass analysis. RESULTS: After 4 weeks, total weight gain and tail growth were higher (p < 0.05) in the rhGH treated group at 80 and 60% of-libitum energy intake. Serum levels of IGF-I and IGFBP-3 were higher (p < 0.05) in rhGH treated rats fed at 60% of ad-libitum. In comparison to the NSS groups, administration of rhGH in rats fed ad-libitum increased total body water. Energy restriction caused decreased fat percentage (p < 0.05) in both rhGH and NSS groups without differences among treated groups. CONCLUSION: These results suggest that the anabolic effects of rhGH may overcome mild to moderate energy restriction.

Response to nutritional and growth hormone treatment in progeria.

Hutchinson-Gilford progeria syndrome (HGPS) is a rare condition with an unknown molecular defect. Patients with HGP progressively develop failure to thrive (FTT), alopecia, loss of subcutaneous fat, scleroderma, stiffening of various joints, and severe atherosclerosis. The median life span is 13 years, and the main cause of death is cardiovascular complications. There are few reports of endocrine and metabolic studies because of the rarity of this condition, and the response to long-term growth hormone (GH) treatment has not been described. We report the results of endocrine and metabolic studies performed to investigate the etiology of growth failure in five patients with HGP. Additionally, the response to nutritional therapy (NT) and GH treatment in three of these patients is presented. Our results suggest that elevated GH levels are characteristic of this disease and that an elevated basal metabolic rate (BMR) could be the cause of the FTT seen in HGP. Nonaggressive NT slightly improved weight gain and growth velocity (GV). Combined NT and GH treatment in three patients improved the GV, increased the levels of growth factors, and paradoxically resulted in decreased BMRs. However, the response to these therapies decreased over time and did not seem to prevent the progression of atherosclerotic disease.

Carbohydrate absorption from one serving of fruit juice in young children: age and carbohydrate composition effects.

OBJECTIVES: To test the hypotheses that: the efficiency of carbohydrate absorption in childhood increases with age, and decreased carbohydrate absorption occurs more frequently with juices containing more fructose than glucose and/or sorbitol than with juices which contain equal amounts of fructose and glucose and are sorbitol-free. METHODS: One hundred and four healthy children were recruited from the Ambulatory Center at Maimonides Children's Center. They were assigned to one of three age groups: approximately 1, 3 and 5 years of age. Each child received one age-specific dose (by randomization) of one of four juices: a) pear juice which contains fructose in excess to glucose and a large amount of sorbitol; b) apple juice which is similar to pear juice in its fructose to glucose ratio but contains four times less sorbitol than pear juice; c) white grape juice or d) purple grape juice both of which contain equal amounts of fructose and glucose and are sorbitol-free. Breath hydrogen excretion (BH2) was utilized as the index of carbohydrate absorption. It was measured in fasting children and at 30-minute intervals for 3 hours after drinking the single serving of juice. Multiple breath hydrogen related parameters were quantified and results were expressed as: BH2 peak, area under the curve, and degree of carbohydrate malabsorption. After the test, parents completed a questionnaire and recorded signs and symptoms of intestinal malabsorption for 24 hours. RESULTS: Pear juice related BH2 levels were significantly higher among children 1 and 3 years of age as compared to the levels achieved after the other juices. Apple juice related BH2 levels were significantly higher only among the youngest age group of children. There was no significant difference in carbohydrate absorption among the 5 year old children regardless of the juice consumed. Incomplete carbohydrate absorption (BH2 peak above 20 ppm) occurred more frequently after pear juice consumption (84%) than after apple juice (41%) or grape juice (white 20%, purple 24%) [p < 0.05]. Further outcome measures of BH2 excretion did not elicit differences beyond those detected by the above-mentioned parameters. Parents reported diarrhea in six children after pear juice, two after apple juice and two after purple grape juice and these children had the highest BH2 levels in their respective groups. No other symptoms were reported. CONCLUSIONS: The data show that the efficiency of carbohydrate absorption of one age-specific serving of juice increases with advancing age of children. Decreased carbohydrate absorption occurs more often after ingestion of juices that contain more sorbitol, a nonabsorbable sugar and higher concentrations of fructose over glucose than after ingestion of juices which lack sorbitol and contain equal amounts of fructose and glucose.

Evaluation of differential effects of carbohydrate and fat intake on weight gain, serum IGF-1 and erythrocyte Na+K+ATPase activity in suboptimal nutrition in rats.

OBJECTIVE: Suboptimal nutrition leads to growth delay, frequently without over clinical or biochemical signs. We hypothesize that changes in serum IFG-1 and erythrocyte sodium-potassium ATPase activity (ENKA) may be indices of suboptimal nutrition. METHODS: Male Sprague-Dawley rats were pair-fed for 4 weeks with balanced diets of different carbohydrate (CHO) to fat (FAT) ratios (3:1, 2:1, and 1:1) and three levels of energy intake (ad-libitum, 80%, and 60%), corrected for actual body weight). Daily weight gain and weekly tail growth were monitored while ENKA, serum total protein, T3, insulin and IGF-1 were measured after four weeks. Refeeding experiments were also performed with the 3:1 and 1:1 CHO:FAT diets, including 4 weeks of dietary restriction and one week of ad-libitum feeding. RESULTS: Weight gain, tail growth, and IGF-1 decreased (p < 0.05) in all groups after 1 week of dietary restriction. A decrease in ENKA (p < 0.05) was found in rats that consumed 60% of ad-libitum energy intake only after 4 weeks. At the end of dietary treatment, weight gain was higher (p < 0.05) in rats fed the 3:1 CHO:FAT diet. In contrast, when energy was restricted to 80% or 60% of ad-libitum intake, rats fed the 1:1 CHO:FAT diet gained more weight (p < 0.05) compared to the 3:1 and 2:1 CHO:FAT diets. After 1 week of refeeding body weight, tail growth and ENKA returned to control values while serum IGF-1 levels remained depressed. CONCLUSIONS: Acute nutritional changes are clearly detected by a reduction of serum IGF-1 while ENKA may be a useful index for assessing chronic suboptimal nutrition.

Considerations about dietary fat restrictions for children.

Expert panels recommend reduction of dietary fat and cholesterol, because excessive fat intake may lead to known health hazards. However, there are no data demonstrating beneficial effects of such diets starting in childhood for all children, including those with normal serum cholesterol levels. Dietary restrictions in early life may not necessarily induce a long-lasting decrease in blood cholesterol levels in children persisting into adulthood or reduce disease incidence. On the other hand, the result of such diets may be suboptimal growth and development. Furthermore, low fat diets may lower high density lipoprotein cholesterol levels and not specifically low density lipoprotein cholesterol. In addition, low serum cholesterol levels may be associated with increased mortality, including deaths due to accidents, which is most important in children. Recently, increased attention has been drawn to the association between short stature and/or nutritional status and deficiencies in intrauterine and early life with coronary artery disease in adulthood. Also, the problems of associated psychological consequences, family conflicts and cost should not be ignored while implementing a low fat diet. In this review, we discuss the controversies on dietary fat restrictions for children.