title: Serum levels and liver store of retinol and their association with night blindness in individuals with class III obesity.
abstract: BACKGROUND
  Studies showed a rise in obesity prevalence in world population and evidences point to a possible association with vitamin A deficiency (VAD). The objective of this study is to assess vitamin A nutritional status through functional [night blindness diagnosis-xerophthalmia (XN)] and biochemical (serum levels and retinol liver store) indicators of class III obesity individuals and its association.
  
  
  METHODS
  We studied 114 patients of both genders with BMI ≥40 kg/m2, candidates to bariatric surgery at Clínica Cirúrgica Carlos Saboya in Rio de Janeiro, Brazil. XN was diagnosed through a standardized interview (WHO and MacLaren and Frigg), and serum levels and retinol liver store were quantified by HPLC-UV with <1.05 μmol/L and < 20 mg/g cutoffs for VAD, respectively.
  
  
  RESULTS
  XN prevalence was 23.8%, and serum levels and retinol liver store inadequacy were 14.0% and 80%, respectively. The association between VAD and XN presence (p = 0.003) was observed with the biochemical indicator and the gold standard, retinol liver store (p = 0.003 and p = 0.018, respectively). Means were 59.3% (sensitivity), 87.4% (specificity), and 80.8% (accuracy) as regards to the XN role in predicting VAD according to the biochemical indicator. As regards to retinol liver store, XN diagnosis presented 48% of sensitivity and 75% of specificity. VAD highest indexes occurred in patients with highest BMI (rs-0.21, p = 0.02). Distribution of XN prevalence was 59.2% according to serum retinol.
  
  
  CONCLUSIONS
  VAD and XN prevalence was high in class III obesity individuals, and the functional indicator for XN diagnosis may be a promising method for diagnosis in this group.
authors.affiliation: Vitamin A Research Group, Universidade Federal do Rio de Janeiro, Rua Dona Mariana, 143/F11, CEP: 22280020, Rio de Janeiro, Rio de Janeiro, Brazil. se.pereira@gmail.com
authors.forename: Silvia Elaine
authors.initials: SE
authors.lastname: Pereira
authors.forename: Carlos José
authors.initials: CJ
authors.lastname: Saboya
authors.forename: Cláudia
authors.initials: C
authors.lastname: Saunders
authors.forename: Andrea
authors.initials: A
authors.lastname: Ramalho
mesh_terms: D000328:Adult; D001938:Brazil / Q000453:epidemiology; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009755:Night Blindness / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism; D009752:Nutritional Status; D009767:Obesity, Morbid / Q000097:blood / Q000453:epidemiology / Q000378:metabolism*; D015995:Prevalence; D014801:Vitamin A / Q000097:blood / Q000378:metabolism*; D014802:Vitamin A Deficiency / Q000150:complications / Q000453:epidemiology* / Q000378:metabolism; D014985:Xerophthalmia / Q000453:epidemiology* / Q000378:metabolism
chemical_list: D014801:Vitamin A