title: High prevalence of severe vitamin D deficiency in combined antiretroviral therapy-naive and successfully treated Swiss HIV patients.
abstract: OBJECTIVE
  To evaluate the prevalence of 25-hydroxyvitamin D [25(OH)D] deficiency in HIV-positive patients, a population at risk for osteoporosis.
  
  
  METHODS
  Retrospective assessment of vitamin D levels by season and initiation of combined antiretroviral therapy (cART).
  
  
  METHODS
  25(OH)D was measured in 211 HIV-positive patients: samples were taken before initiation of cART from February to April or from August to October as well as 12 (same season) and 18 months (alternate season) after starting cART. 1,25-Dihydroxyvitamin D [1,25(OH)2D] was measured in a subset of 74 patients. Multivariable analyses included season, sex, age, ethnicity, BMI, intravenous drug use (IDU), renal function, time since HIV diagnosis, previous AIDS, CD4 cell count and cART, in particular nonnucleoside reverse transcriptase inhibitor (NNRTI) and tenofovir (TDF) use.
  
  
  RESULTS
  At baseline, median 25(OH)D levels were 37 (interquartile range 20-49) nmol/l in spring and 57 (39-74) nmol/l in the fall; 25(OH)D deficiency less than 30 nmol/l was more prevalent in spring (42%) than in fall (14%), but remained unchanged regardless of cART exposure. In multivariable analysis, 25(OH)D levels were higher in white patients and those with a longer time since HIV diagnosis and lower in springtime measurements and in those with active IDU and NNRTI use. 1-Hydroxylation rates were significantly higher in patients with low 25(OH)D. Hepatitis C seropositivity, previous AIDS and higher CD4 cell counts correlated with lower 1,25(OH)2D levels, whereas BMI and TDF use were associated with higher levels. In TDF-treated patients, higher 1,25(OH)2D correlated with increases in serum alkaline phosphatase.
  
  
  CONCLUSIONS
  Based on the high rate of vitamin D deficiency in HIV-positive patients, systematic screening with consideration of seasonality is warranted. The impact of NNRTIs on 25(OH)D and TDF on 1,25(OH)2D needs further attention.
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, Department of Medicine, University Hospital of Zurich, Zurich, Switzerland. Nicolas.Mueller@usz.ch
authors.forename: Nicolas J
authors.initials: NJ
authors.lastname: Mueller
authors.forename: Christoph A
authors.initials: CA
authors.lastname: Fux
authors.forename: Bruno
authors.initials: B
authors.lastname: Ledergerber
authors.forename: Luigia
authors.initials: L
authors.lastname: Elzi
authors.forename: Patrick
authors.initials: P
authors.lastname: Schmid
authors.forename: Thanh
authors.initials: T
authors.lastname: Dang
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Magenta
authors.forename: Alexandra
authors.initials: A
authors.lastname: Calmy
authors.forename: Athanasios
authors.initials: A
authors.lastname: Vergopoulos
authors.forename: Heike A
authors.initials: HA
authors.lastname: Bischoff-Ferrari
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood*; D023241:Antiretroviral Therapy, Highly Active; D015897:Comorbidity; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology; D015497:HIV-1; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000097:blood* / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013557:Switzerland / Q000453:epidemiology; D014807:Vitamin D / Q000097:blood* / Q000627:therapeutic use; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology*
chemical_list: D014807:Vitamin D; D000469:Alkaline Phosphatase