title: Abdominal obesity is an independent predictor of serum 25-hydroxyvitamin D deficiency in adults with cerebral palsy.
abstract: BACKGROUND
  Individuals with cerebral palsy (CP) are at risk for nutritional insufficiency. The purpose of the study was to examine the vitamin D status of adults with CP, and to evaluate the association between vitamin D and functional level, age, race, and anthropometric indicators of adiposity.
  
  
  METHODS
  Serum vitamin D levels, BMI, waist circumference (WC), and functional level (measured by Gross Motor Function Classification System (GMFCS)) were examined in 112 adults with CP. Vitamin D status was assessed by serum 25-hydroxyvitamin D level (25(OH)D). The influence of motor impairment and adiposity on 25(OH)D were assessed using general linear modeling and logistic regression, with age, sex, race, and season as covariates.
  
  
  RESULTS
  Mean vitamin D was 28.1 ± 16.0 ng/ml. Only 45% of subjects had optimal levels of 25(OH)D, 21% were insufficient and 34% were deficient. Overweight or obesity was prevalent (52%), as was abdominal obesity in men (23.5% at 102 cm cutoff) and women (31.1% at 88 cm cutoff). There was a robust association between the indicator of visceral adiposity (WC) and 25(OH)D level (p <0.001), even after controlling for age, sex, race, season, and GMFCS. According to sex-specific WC cutoffs, the odds of being deficient in vitamin D increase by a factor of 3.5 (95% CI 1.12-11.0) for abdominal obesity. GMFCS was not associated with 25(OH)D.
  
  
  CONCLUSIONS
  Adults with CP are at risk for low vitamin D levels and overweight/obesity. Waist circumference is a strong independent predictor for low vitamin D levels.
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Michigan Health Systems, 325 E. Eisenhower Parkway, Suite 300, Ann Arbor, Michigan 48108, USA.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Peterson
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Michigan Health Systems, 325 E. Eisenhower Parkway, Suite 300, Ann Arbor, Michigan 48108, USA.
authors.forename: Heidi J
authors.initials: HJ
authors.lastname: Haapala
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Michigan Health Systems, 325 E. Eisenhower Parkway, Suite 300, Ann Arbor, Michigan 48108, USA.
authors.forename: Ashish
authors.initials: A
authors.lastname: Chaddha
authors.affiliation: Department of Physical Medicine and Rehabilitation, University of Michigan Health Systems, 325 E. Eisenhower Parkway, Suite 300, Ann Arbor, Michigan 48108, USA.
authors.forename: Edward A
authors.initials: EA
authors.lastname: Hurvitz
keywords: 25-hydroxyvitamin D; Cerebral palsy; Motor function; Visceral adiposity