Parent cardiometabolic risk factors and child BMI and obesity incidence in Malaysia: a prospective cohort study (Preprint)

BACKGROUND Risk factors for obesity prevalence can help target treatment, but less is known about risk factors for obesity incidence which may be distinct and more pertinent for preventing excessive weight gain. OBJECTIVE To explore factors associated with child/adolescent BMI and childhood obesity incidence over 5 years in Malaysia including parental cardiometabolic risk, socio-demographic and baseline child BMI. METHODS Longitudinal data on 1768 children (aged 6-14 years) and parents were drawn from a Malaysian cohort and followed up after 5 years. Multilevel models estimated associations between parent cardiometabolic risk factors (overweight/obesity, central obesity, hypertension, hyperglycaemia), socio-demographics (ethnicity, employment, education) and child BMI z-score at follow-up, adjusting for baseline and potential confounders. Associations with five-year child obesity incidence were explored using logistic multilevel models. RESULTS Obesity prevalence was stable (16-17%) and average annual obesity incidence ranged from 2.2% for 6-10 years (childhood) to 1.2% for 11-14 years (adolescence). Higher baseline BMI z-score was associated with a higher follow-up BMI z score in childhood (0.60; 95% CI: 0.55, 0.65) and adolescence (0.76; 95% CI: 0.70, 0.82). Associations were smaller with maternal overweight/obesity and childhood BMI (overweight: 0.16; 95% CI: -0.03, 0.36, obesity: 0.41; 95% CI: 0.20, 0.61), and paternal overweight/obesity and adolescent BMI (overweight: 0.22; 95% CI: 0.01, 0.43, obesity: 0.16; 95% CI: -0.10, 0.41). Five-year obesity incidence in adolescence was associated with parental obesity (paternal OR= 4.37; maternal OR= 3.38). There were no marked associations with parental hypertension/hyperglycaemia or socio-demographics. CONCLUSIONS Parental overweight/obesity was prospectively associated with higher child BMI and obesity incidence, but the largest follow-up BMIs were among children with a higher baseline BMI. Early childhood, rather than parent cardiometabolic risk, maybe a better target for obesity prevention.