Paper # 750 
Assessment of Vitamin D Levels among HIV-infected Persons in the Study to Understand the Natural History of HIV/AIDS in the Era of Effective Therapy: SUN Study
Christine Dao1, P Patel1, S Pals1, T Bush1, F Rhame2, T Overton3, E Kojic4, K Wood5, J Brooks1, and the SUN Study Investigators
1CDC, Atlanta, GA, US; 2Abbott-Northwestern Hosp, Minneapolis, MN, US; 3Washington Univ in St Louis, Sch of Med, MO, US; 4The Miriam Hosp, Providence, RI, US; and 5Cerner Corp, Vienna, VA, US
Background: Vitamin D insufficiency as assessed by levels
of serum 25-hydroxyvitamin D (25[OH]D), which is activated and converted to 1,25-dihydroxyvitamin
D (1,25[OH]D) in the kidneys, is highly prevalent in the general U.S. adult population and has been associated with many chronic illnesses that commonly affect
persons with HIV. Like anti-epileptics, efavirenz may induce hepatic catabolism
of 25(OH)D via the cytochrome P450 system resulting in vitamin D insufficiency.
We explored 25(OH)D levels and associated factors for insufficiency in an adult
HIV cohort.
Methods: We examined baseline data from the SUN
Study, a prospective observational cohort of 700 HIV-infected adults enrolled
at clinics in 4 U.S. cities from March 2004-June 2006. We reviewed behavioral, clinical
(including bone mineral density [BMD]), and laboratory data (including 25(OH)D),
and estimated ultraviolet (UV) exposure from National Weather Service data. Using
multivariable logistic regression, we examined risk factors for 25(OH)D insufficiency
defined as <30 ng/mL.
Results: Among 672 participants with baseline serum 25(OH)D
determinations who were not receiving vitamin D supplements (median age 41
years, 77% male, 30% black and 10% Hispanic, median CD4 count 471 cells/mm3,
74% with HIV RNA viral loads <400 copies/mL), 71.6% (95% confidence
interval [CI] 68.1 to 74.9) were 25(OH)D insufficient. In multivariable
analysis, black race (adjusted odds ratio [aOR] = 4.50, 95%CI 2.59 to 7.85), Hispanic
ethnicity (aOR = 2.78, 95%CI 1.31 to 5.90), lower UV exposure (aOR = 1.28, 95%CI
1.17 to 1.40), hypertension (aOR = 1.88, 95%CI 1.10 to 3.22), lack of exercise
(aOR = 3.14, 95%CI 1.80 to 5.47), and efavirenz exposure (aOR = 1.98, 95%CI 1.18
to 3.34) were independently associated with 25(OH)D insufficiency. Renal
insufficiency (aOR for GFR <90 mL/min/1.73m2 = 0.55, 95%CI 0.36
to 0.83) and ritonavir exposure (aOR = 0.56, 95%CI 0.35 to 0.89) were
associated with lower odds of 25(OH)D insufficiency. We observed no association
between 25(OH)D insufficiency and gender, age, or BMD.
Conclusions: Nearly three-fourths of HIV-infected adults
in this contemporary cohort were 25(OH)D insufficient. The observed associations
of 25(OH)D insufficiency with renal insufficiency, and with ritonavir and
efavirenz exposures are consistent with both HIV-related and therapy-mediated
alterations in vitamin D metabolism. Calcium and vitamin D supplementation to
prevent osteomalacia might be warranted for persons using efavirenz.
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