Comparing Attained Weight and Weight Velocity During the First 6 Months in Predicting Child Undernutrition And Mortality

Background The first 6 months of life are critical for subsequent risk of undernutrition and mortality. The predictive abilities of attained weight at the end of each month and monthly weight velocity for undernutrition and mortality need to be compared. Objective This study aimed to examine the predictive abilities of different weight metrics during the first 6 months of life in predicting undernutrition and mortality. Methods This study used a cohort of infants in Tanzania. Weight and length were measured monthly from birth to 18 months of age. Three weight metrics during the first 6 months of life were considered as predictors, including attained weight-for-age z-score (WAZ) at the end of each month, monthly change in WAZ, and monthly weight velocity z-score (WVZ). Logistic models were used with undernutrition (at 6 or 12 months) and mortality (over the first 18 months) as outcomes. Area under the curve (AUC) values were compared across metrics. Results For predicting wasting at 6 months, WVZ (AUC = 0.80) had a greater predictive ability than attained WAZ (AUC = 0.76) and change in WAZ (AUC = 0.71) during the second month of life. After 2 months, attained WAZ (AUC: 0.81 to 0.89) had greater predictive abilities than WVZ (AUC: 0.71 to 0.77) and change in WAZ (AUC: 0.65 to 0.67). For predicting stunting at 6 months, attained WAZ (AUC: 0.75 to 0.79) had consistently greater predictive abilities than WVZ (AUC: 0.56 to 0.66) and change in WAZ (AUC: 0.50 to 0.57). The weight metrics had similar abilities in predicting mortality, with the AUC rarely reaching above 0.65. Conclusions Attained weight at the end of each month had greater abilities than monthly weight velocity in the same month in predicting undernutrition. Attained weight remains a useful indicator for identifying infants at greater risk of undernutrition.

Socioeconomic inequalities in children’s weight, height and BMI trajectories in Norway

Studies exploring when social inequalities in body mass index (BMI) and its composites emerge and how these evolve with age are limited. Thus, this study explored parental income and education related inequalities in children’s weight, height, weight velocity and body mass index among Norwegian children from 1 month to 8 years. The study population included 59,927 family/children pairs participating in the Norwegian Mother, Father, and Child Cohort Study. Growth was modelled using the Jenss–Bayley model and linear mixed effects analyses were conducted. Maternal and paternal educational differences in children’s weight and BMI trajectories emerged during infancy, continuing to age 8 years. Parental income-related inequalities in children’s weight were observed from the age of 1 month to 4 years for maternal and up to 1 year for paternal income-related differences but then disappeared. Parental income-related inequalities in child’s BMI were observed from 18 months to 8 years for maternal income, and from 9 months to 8 years for paternal income-related differences. These results suggest that social inequalities in children’s BMI present early in infancy and continue to 8 years of age. The inequalities sometimes differed by indicator of socioeconomic position used. Interventions to combat these inequalities early in life are, thus needed.

Quantification of urinary sodium concentrations in term infants

Background Infants with gastrointestinal conditions and poor weight gain are administered sodium supplementation based on urinary sodium concentrations. However, the reference range of urinary electrolytes is unknown. The aim of this study was to ascertain the normal values of urinary electrolytes in healthy, term infants. Secondary aims were to establish the relationship between urinary electrolytes with weight velocity and feeding practices. Methods Healthy, term (≥37 weeks’ gestation) infants were recruited. Parental questionnaires were completed before discharge and at six weeks. Electrolytes were quantified from a urine sample at six weeks. t-Tests and Mann-Whitney U tests were conducted for parametric and non-parametric electrolytes, respectively. Results A total of 200 infants were recruited before discharge. Twenty-nine follow-up questionnaires and urine samples were returned (nine female; mean gestational age 39 + 6 weeks [SD 9.9 days]; mean birthweight 3350 g [SD 483 g]; 17 breastfed, nine formula and three mixed; mean change in Z score for weight –0.914 [SD 0.814]). Majority (25/29) of infants had urinary sodium <20 mmo/L. Change in Z score for weight was similar between infants with sodium <20 mmol/L and >20 mmol/L ( P = 0.78). All exclusively breastfed infants had sodium <20 mmol/L, however, not statistically dissimilar to formula-fed infants ( P = 0.27). Conclusion Most term infants in this study had urinary sodium values <20 mmol/L with no identified relationship to weight velocity. Lower concentrations of sodium could be not quantified reliably because of the limitations of the analytical method that were used. More evidence is required to identify candidates for sodium supplementation.

The effect of early growth patterns and lung function on the development of childhood asthma: a population based study

BackgroundInfant weight gain is associated with lower lung function and a higher risk of childhood asthma. Detailed individual childhood growth patterns might be better predictors of childhood respiratory morbidity than the difference between two weight and height measurements. We assessed the associations of early childhood growth patterns with lung function and asthma at the age of 10 years and whether the child’s current body mass index (BMI) influenced any association.MethodsWe derived peak height and weight growth velocity, BMI at adiposity peak, and age at adiposity peak from longitudinally measured weight and height data in the first 3 years of life of 4435 children enrolled in a population-based prospective cohort study. At 10 years of age, spirometry was performed and current asthma was assessed by questionnaire. Spirometry outcomes included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC ratio, and forced expiratory flow after exhaling 75% of vital capacity (FEF75).ResultsGreater peak weight velocity was associated with higher FVC but lower FEV1/FVC and FEF75. Greater BMI at adiposity peak was associated with higher FVC and FEV1 but lower FEV1/FVC and FEF75. Greater age at adiposity peak was associated with higher FVC, FEV1, FEV1/FVC and FEF75, particularly in children with a small size at birth, and lower odds of current asthma in boys. The child’s current BMI only explained the associations of peak weight velocity and BMI at adiposity peak with FVC and FEV1. Peak height velocity was not consistently associated with impaired lung function or asthma.ConclusionPeak weight velocity and BMI at adiposity peak were associated with reduced airway patency in relation to lung volume, whereas age at adiposity peak was associated with higher lung function parameters and lower risk of asthma at 10 years, particularly in boys.