Commentary: games people play--birthweight.
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Anthropology↗
Biomedical subjects
Jonathan Wells
Publications and source records attributed to Jonathan Wells.
Gastrostomy feeding in cerebral palsy: too much of a good thing?
Gastrostomy tube (GT) feeding in children with cerebral palsy (CP) is associated with significant increases in weight gain and, potentially, with overfeeding. This study aimed to measure energy balance and body composition in children with CP who were fed either orally or by GT. Forty children (27 males, 13 females; median age 8y 6mo; range 1y 4mo-18y 11mo) with spastic quadriplegic CP, of whom 22 were gastrostomy-fed and 18 orally-fed, underwent anthropometry, indirect calorimetry, and total energy expenditure determination (doubly-labelled water method). Total body water content (estimated by the 18O dilution method) was used to determine body composition. The Gross Motor Function Classification System (GMFCS) was used to determine the degree of motor impairment. GMFCS levels ranged from I to V; in the gastrostomy group 19 out of 22 were Level V and two out of 22 were Level IV. Within the orally-fed group, 11 out of 18 were Level V and four out of 18 were Level IV. Resting metabolic rate and total energy expenditure of the gastrostomy-fed children were lower but they had a significantly larger triceps skinfold thickness (p=0.01) and fat mass index (p=0.02) than the orally-fed children. Both groups had consistently higher body-fat content and lower fat-free (i.e. muscle and bone) content than the reference population of age- and sex-matched children without disabilities. This study has demonstrated the relatively low energy expenditure and high body-fat content of children with severe CP and highlighted the potential risk of overfeeding with available enteral feeds administered via GT.
Adolescent↗
Exploration of the contribution of biobehavioral variables to the energy expenditure of preterm infants.
Variation in energy expended by preterm infants may be due to infant maturity and history of resolved acute lung disease (respiratory distress syndrome [RDS]) as well as growth, caloric intake, and activity. Indirect calorimetry was used in this exploratory, short-term longitudinal study to estimate energy expenditure (EE) from measures of inspired and expired O2 and CO2. The sample included 35 assessments for 10 preterm infants (5 with and 5 without RDS history). Lung disease history (resolved RDS, no RDS diagnosis), weight gain (g/d) from the day on which birth weight had been regained to the study day, mean activity level, the number of the assessment (1-6), and the interaction of lung disease history and time were included in a linear mixed model for repeated measures. Time was an index of postconceptional and postnatal age; all 3 were highly correlated. Because of high correlation with weight gain, caloric intake was not included in the analytic model. Lung disease history, mean activity level, and time were significant contributors to EE. A more precise measure of medical status than absence or presence of lung disease history, evenly spaced repetitions of EE assessment, and exploration of contexts in which the infants exhibit a higher activity level are needed in a replication study with a larger sample.
Acute Disease↗
Anthropometry and body composition of 18 year old men according to duration of breast feeding: birth cohort study from Brazil.
OBJECTIVE: To assess the association between duration of breast feeding and measures of adiposity in adolescence. DESIGN: Population based birth cohort study. SETTING: Pelotas, a city of 320 000 inhabitants in a relatively developed area in southern Brazil. PARTICIPANTS: All newborn infants in the city's hospitals were enrolled in 1982; 78.8% (2250) of all male participants were located at age 18 years when enrolling in the national army. MAIN OUTCOME MEASURES: Weight, height, sitting height, subscapular and triceps skinfolds, and body composition (body fat, lean mass). RESULTS: Neither the duration of total breast feeding nor that of predominant breast feeding (breast milk plus non-nutritive fluids) showed consistent associations with anthropometric or body composition indices. After adjustment for confounding factors, the only significant associations were a greater than 50% reduction in obesity among participants breast fed for three to five months compared with all other breastfeeding categories (P = 0.007) and a linear decreasing trend in obesity with increasing duration of predominant breast feeding (P = 0.03). Similar significant effects were not observed for other measures of adiposity. Borderline direct associations also occurred between total duration of breast feeding and adult height (P = 0.06). CONCLUSIONS: The significant reduction in obesity among children breast fed for three to five months is difficult to interpret, as no a priori hypothesis existed regarding a protective effect of intermediate duration of breast feeding. The findings indicate that, in this population, breast feeding has no marked protective effect against adolescent adiposity.
Adipose Tissue↗
Programming of lean body mass: a link between birth weight, obesity, and cardiovascular disease?
BACKGROUND: A high birth weight has been suggested to increase the later risk of obesity, as measured by body mass index, but, paradoxically, to decrease the later propensity to cardiovascular disease. Programming of more lean tissue rather than fat mass by a high birth weight might explain this paradox and also explain the association of birth weight with later body mass index. This concept has been inadequately tested. OBJECTIVE: The objective was to test the hypothesis that a high birth weight programs a greater proportion of lean mass in children and adolescents. DESIGN: Body fat mass and fat-free mass were assessed by both skinfold-thickness measurement and bioelectrical impedance analysis in adolescents aged 13-16 y (n = 78) who were part of a study that investigated the early origins of cardiovascular disease. Body composition was assessed by dual-energy X-ray absorptiometry in a separate group of younger children. RESULTS: An increase in birth weight of 1 SD was significantly associated with a 0.9-1.4-kg (2-3%) increase in fat-free mass in adolescents but not with an increase in fat mass. This association was independent of age, sex, height, pubertal stage, socioeconomic status, and physical activity. Similar observations were made in younger children. CONCLUSIONS: Our data support the hypothesis that fetal growth, measured by birth weight, programs lean mass later in life. Our observations may therefore explain the association of birth weight with body mass index and have implications for the early origins of both obesity and cardiovascular disease.
Absorptiometry, Photon↗
Do centrioles generate a polar ejection force?
A microtubule-dependent polar ejection force that pushes chromosomes away from spindle poles during prometaphase is observed in animal cells but not in the cells of higher plants. Elongating microtubules and kinesin-like motor molecules have been proposed as possible causes, but neither accounts for all the data. In the hypothesis proposed here a polar ejection force is generated by centrioles, which are found in animals but not in higher plants. Centrioles consist of nine microtubule triplets arranged like the blades of a tiny turbine. Instead of viewing centrioles through the spectacles of molecular reductionism and neo-Darwinism, this hypothesis assumes that they are holistically designed to be turbines. Orthogonally oriented centriolar turbines could generate oscillations in spindle microtubules that resemble the motion produced by a laboratory vortexer. The result would be a microtubule-mediated ejection force tending to move chromosomes away from the spindle axis and the poles. A rise in intracellular calcium at the onset of anaphase could regulate the polar ejection force by shutting down the centriolar turbines, but defective regulation could result in an excessive force that contributes to the chromosomal instability characteristic of most cancer cells.
Algorithms↗