Comparison of physiological and behavioural nutrition-related factors in people with and without adolescent idiopathic scoliosis, from cohort data at 8 to 20 years

Nutrition-related variables including lower body mass index (BMI), lower bone mineral density (BMD), altered body composition and hormone levels have been reported in adolescent idiopathic scoliosis (AIS). To determine if physiological and behavioural nutrition-related factors differ between people with and without AIS, and to quantify their relationship with AIS, in unbiased cohort sample. BMI, presence of an eating disorder, leptin, adiponectin, BMD, vitamin D, lean mass and fat mass were compared between those with and without AIS at ages 8, 10, 14, 17 and 20 years, and multiple logistic regression was performed between these variables and AIS. Lower total body BMD (median 1.0 g/cm2 vs 1.1 g/cm2, p = 0.03) and lean mass (median 38.8 kg vs 46.0 kg, p = 0.04) at age 20 years were observed in those with AIS compared to those without scoliosis. At age 20, the odds of AIS were 3.23 times higher for adolescents with an eating disorder compared to those with no eating disorder (95%CI[1.02, 8.63)) when adjusted for BMI. Every 1 kg/m2 increase in BMI decreased the odds of AIS by 0.88 times (95%CI[0.76 to 0.98]) after adjusting for eating disorder diagnosis. Lower BMI in mid-adolescence and presence of eating disorder outcomes, lower BMD and lower lean mass in late adolescence were associated with the presence of AIS. Current data do not explain the mechanisms for these associations, but suggest that serum leptin, adiponectin and vitamin D are unlikely to be contributing factors. Conclusive determination of the prevalence of eating disorders in AIS will require further studies with larger sample sizes.