Low bone mineral density is found in low weight female youth with avoidant/restrictive food intake disorder and associated with higher PYY levels

BackgroundAvoidant/restrictive food intake disorder (ARFID) is a restrictive eating disorder commonly associated with medical complications of undernutrition and low weight. In adolescence, a critical time for bone accrual, the impact of ARFID on bone health is uncertain. We aimed to study bone health in low-weight females with ARFID, as well as the association between peptide YY (PYY), an anorexigenic hormone with a role in regulation of bone metabolism, and bone mineral density (BMD) in these individuals. We hypothesized that BMD would be lower in low-weight females with ARFID than healthy controls (HC), and that PYY levels would be negatively associated with BMD.MethodsWe performed a cross-sectional study in 14 adolescent low-weight females with ARFID and 20 HC 10-23 years old. We assessed BMD (total body, total body less head and lumbar spine) using dual x-ray absorptiometry (DXA) and assessed fasting total PYY concentration in blood.ResultsTotal body BMD Z-scores were significantly lower in ARFID than in HC (- 1.41 & PLUSMN; 0.28 vs. - 0.50 & PLUSMN; 0.25, p = 0.021). Mean PYY levels trended higher in ARFID vs. HC (98.18 & PLUSMN; 13.55 pg/ml vs. 71.40 & PLUSMN; 5.61 pg/ml, p = 0.055). In multivariate analysis within the ARFID group, PYY was negatively associated with lumbar BMD adjusted for age (& beta; = -0.481, p = 0.032).ConclusionOur findings suggest that female adolescents with low-weight ARFID may have lower BMD than healthy controls and that higher PYY levels may be associated with lower BMD at some, but not all, sites in ARFID. Further research with larger samples will be important to investigate whether high PYY drives bone loss in ARFID. Plain English summaryAvoidant/restrictive food Intake disorder (ARFID) is a condition characterized by lack of interest in eating/food, sensory sensitivity and/or fear of aversive consequences of eating. It is associated with low weight and undernutrition, which can lead to medical complications. Specifically, low weight in patients with ARFID raises concerns of impaired bone health. In this study, we compared bone mineral density (BMD), a measure of bone health, in 14 low-weight females with ARFID and 20 healthy females 10-23 years old. We also examined the association between BMD and peptide YY (PYY), a hormone that induces satiety and inhibits bone formation. A strong negative association between bone health and PYY was previously reported in females with anorexia nervosa. Thus, we hypothesized a similar association in low weight females with ARFID. We found that BMD may be lower in low-weight females with ARFID than in healthy females and that higher PYY levels are associated with lower BMD at some but not all sites. We concluded that bone health may be a concern in low-weight females with ARFID. This finding is important as low BMD raises concerns for increased fracture risk, which in turn could have a detrimental effect on quality of life.