Paper # 752 
High Prevalence of Severe Vitamin D Deficiency in cART-naļve and Successfully Treated Swiss HIV Patients
N Mueller1, Christoph Fux2, B Ledergerber1, L Elzi3, P Schmid4, T Dang5, L Magenta6, A Calmy7, A Vergopoulos1, H Bischoff-Ferrari1, and Swiss HIV Cohort Study
1Univ Hosp Zurich, Switzerland; 2Univ Hosp Bern, Switzerland; 3Univ Hosp Basel, Switzerland; 4Cantonal Hosp, St Gallen, Switzerland; 5Ctr Hosp Univ Vaudois, Lausanne, Switzerland; 6Ospedale Civico di Lugano, Switzerland; and 7Univ Hosp Geneva, Switzerland
Background: To evaluate the prevalence of 25-hydroxy
vitamin D [25(OH)D] deficiency in HIV+ patients, a population at risk
for osteoporosis.
Methods: Retrospective assessment of serum vitamin D
levels within the Swiss HIV Cohort Study by season (spring vs fall) and
initiation of combined antiretroviral treatment (cART). 25(OH)D was measured in
211 HIV+ patients (75% men, 88% Caucasian, median age 37 years) at 3
consecutive time points: The first sample was taken before initiation of cART,
either from Feb to Apr or from Aug to Oct. Samples 2 and 3 were taken after
starting cART at 12 (same season) and 18 months (alternate season) after the
first sample. 1,25(OH)2D was measured in a subset of 74 patients.
Multivariable analyses included season, gender, age, ethnicity, body mass
index, IDU, renal function, duration since HIV diagnosis, previous AIDS, CD4
cell count, and cART, in particular protease inhibitors vs non-nucleoside
reverse transcriptase inhibitor (NNRTI), as well as tenofovir disoproxil
fumarate (TDF)-use.
Results: At baseline, median 25(OH)D levels were
36.5 (IQR 20.1 to 49.3) nmol/L in spring and 57.4 (38.8 to 74.1) nmol/L in the
fall; 25(OH)D deficiency <30 nmol/L was more prevalent in spring (42%)
than in fall (14%), but remained unchanged after cART initiation. Multivariable
analysis demonstrated a positive correlation of 25(OH)D levels with Caucasian
ethnicity and duration since HIV diagnosis, as well as a negative correlation
with IVDU and NNRTI-use. 1-Hydroxylation rates were significantly higher in
patients with low 25(OH)D. IVDU, previous AIDS, and higher CD4 counts
correlated with lower 1,25(OH)2D; BMI, and TDF-use with higher
1,25(OH)2D 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 NNRTI on 25(OH)D and TDF on 1,25(OH)2D
needs further attention.
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