title: Association between bullous pemphigoid and hypovitaminosis D in older inpatients: Results from a case-control study.
abstract: OBJECTIVE
  To compare serum vitamin D status in older inpatients with bullous pemphigoid (BP) and matched inpatients without BP, and to examine whether hypovitaminosis D, a high comorbidity burden or their combination were associated with BP.
  
  
  METHODS
  This prospective case-control study was performed from November 2012 to February 2014. A total of 90 consecutive older inpatients (31 consecutive inpatients with a de novo diagnosis of active BP, and 59 matched controls without BP) were recruited in the Department of Dermatology of Angers University Hospital, France. Hypovitaminosis D was defined as serum 25-hydroxyvitamin D (25OHD) concentration<50nmol/L. Age, gender, functional level, sun exposure, season, comorbidity burden and cognitive performance were used as covariates.
  
  
  RESULTS
  There was no significant difference between older inpatients with and without BP. Fully adjusted logistic regression showed a significant association between BP and hypovitaminosis D (odds ratio [OR]=3.7, P=0.046). The analysis of interaction between hypovitaminosis D and comorbidity burden showed that only the association of both was significantly associated with PB (OR=3.1, P=0.042).
  
  
  CONCLUSIONS
  BP was significantly associated with hypovitaminosis D solely in patients with a high comorbidity burden among the older in-patients studied. This result suggests a complex interplay between hypovitaminosis D and BP, explaining the mixed results reported previously in the literature.
authors.affiliation: Department of Dermatology, UNAM, Angers University Hospital, Angers, France.
authors.forename: M E
authors.initials: ME
authors.lastname: Sarre
authors.affiliation: Department of Neuroscience, Division of Geriatric Medicine, UPRES EA 4638, UNAM, Angers University Hospital, Angers, France; Robarts Research Institute, Department of Medical Biophysics, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Annweiler
authors.affiliation: Division of Rheumatology, UNAM, Angers University Hospital, Angers, France.
authors.forename: E
authors.initials: E
authors.lastname: Legrand
authors.affiliation: Department of Dermatology, UNAM, Angers University Hospital, Angers, France.
authors.forename: L
authors.initials: L
authors.lastname: Martin
authors.affiliation: Department of Medicine, Division of Geriatric Medicine, Sir Mortimer B. Davis - Jewish General Hospital and Lady Davis Institute for Medical Research, McGill University, Montreal, Quebec, Canada; Dr. Joseph Kaufmann Chair in Geriatric Medicine, Faculty of Medicine, McGill University, Montreal, Quebec, Canada; Centre of Excellence on Aging and Chronic Diseases of McGill integrated University Health Network, Quebec, Canada. Electronic address: olivier.beauchet@mcgill.ca.
authors.forename: O
authors.initials: O
authors.lastname: Beauchet
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015897:Comorbidity; D005260:Female; D005602:France; D006801:Humans; D007297:Inpatients; D016015:Logistic Models; D008297:Male; D010391:Pemphigoid, Bullous / Q000453:epidemiology*; D011446:Prospective Studies; D012621:Seasons; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000453:epidemiology*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: Aged, 80 and over; Bullous pemphigoid; Hypovitaminosis; Vitamin D