From Insult to Injury: Exploring the Associations Between Severe Malnutrition in Childhood, Rehabilitation Weight Gain and Adult Adiposity in a Prospective Cohort Study

The relationships between severe malnutrition (SM), rehabilitation weight gain, and cardiometabolic risk in adult survivors have not been fully elucidated. We utilised a previously collected data set to explore these associations in a cohort of adults who were hospitalised for SM as children from 1963 to 1995. We studied 278 adult SM survivors: 60% male; median age (IQR) 26.5(11.3) years; mean BMI 23.6(5.2) kg/m²). Children's minimum weight-for-age z scores after hospitalisation (minWAZ) were analysed against adiposity as adults in sex-disaggregated regression models. Higher minWAZ was associated with greater adult waist circumference (mean difference:1.8 cm, 95%CI 0.7, 2.9, p = 0.001), fat mass (difference:2.4 kg, 95%CI 0.17,1.06, p = 0.007) and android fat mass (difference:0.19 kg, 95%CI 0.09, 0.29, p < 0.001) in bivariate analyses. Approximately 13% of the effect of minWAZ on adult fat mass was mediated by rehabilitation weight gain in g/kg/day (Sobel's p = 0.053). In male and not female adult survivors, rehabilitation weight gain > 12.9 g/kg/day was associated with greater adult fat mass (difference:5 kg, 95%CI 2, 9, p = 0.006) and android fat (difference:0.5 kg, 95%CI 0.1, 0.8, p = 0.006). Female sex was the strongest predictor of adult fat mass (difference:12.7 kg, 95%CI 9.6, 15.7, p < 0.001) and android fat mass (difference:0.9 kg, 95%CI 0.6, 1.2 p < 0.001) and adult age the strongest predictor of adult waist circumference (difference:0.67 cm, 95%CI 0.39, 0.94, p < 0.001). Faster rehabilitation weight gain as an independent, causal risk factor for adiposity in male SM survivors requires further exploration and more modest weight gain targets may contribute to reducing their risk of adult cardiometabolic disease.