Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vitamin D deficiency and insufficiency are often unappreciated in men. This cross-sectional period-prevalence study was conducted in private practice between November 20, 2008 and January 22, 2009 at latitude N 40, 46 minutes. HIV-infected men presenting for routine care without clinical disease or use of medications known to interfere with vitamin D metabolism were evaluated. Current receipt protease inhibitor (PI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) were determined. Vitamin D deficiency was defined as 25-[OH] D less than 50 nmol/L, severe deficiency as less than 25 nmol/L, and insufficiency as greater than 50 nmol/L but less than 75 nmol/L. Sixty-two men, median CD4 count 541 cells per microliter, 85.5% viral load less than 200 copies per milliliter, were evaluated. A total of 30.7% were receiving a NNRTI and 59.7% a PI; 41.9% were vitamin D-deficient (11.3% severe deficiency), 33.9% insufficient, and 24.2% sufficient, p = < 0.0001. Median vitamin D: 42.4 versus 64.9 nmol/L NNRTI and PI recipients, respectively, p = 0.0017. Percentage deficient: 73.7 (14/19) NNRTI versus 29.7 (11/37) PI recipients, p = 0.0017 OR 6.62 (95% confidence interval [CI] 1.91-22.89). Tobacco use correlated with severe deficiency, p = 0.032. In conclusion, vitamin D deficiency and insufficiency were highly prevalent in these urban men irrespective of stable viral suppression. NNRTI receipt and tobacco use may be associated with lower vitamin D levels and greater risk of deficiency, and severe deficiency, respectively.
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PMID:Highly prevalent vitamin D deficiency and insufficiency in an urban cohort of HIV-infected men under care. 2037 37

In a retrospective case series study, medical records were evaluated for all male patients infected with human immunodeficiency virus (HIV) diagnosed over a one-year period with foot fractures (n = 30) confirmed by magnetic resonance imaging at a Los Angeles outpatient private practice rheumatology clinic. Proportionally more patients had received tenofovir prefracture (17 [57%]) than those who had not (13 [43%]). At fracture diagnosis, these two groups were similar in median age (49 versus 48 years), HIV-1 RNA (both 1.7 log(10) copies/mL), CD4 count (300 versus 364/mm(3)), time between HIV diagnosis and foot fracture (both 17 years), family history of degenerative bone disease (24% versus 23%), prevalence of malabsorption syndrome, renal failure, calcium deficiency, or vitamin D deficiency, and concurrent use of bisphosphonates, calcitonin, and diuretics. However, more tenofovir-treated patients had osteoporosis (35% versus 8%), stress-type fractures (53% versus 31%), concurrent fractures (12% versus 0%), wasting syndrome (29% versus 15%), truncal obesity (18% versus 8%), smoked cigarettes (more than one pack/day for more than one year; 35% versus 8%), dual energy X-ray absorptiometry (DEXA) T scores < -2.4 (denoting osteoporosis) at the femur (24% versus 9%) and spine (47% versus 36%), and had received protease inhibitors (71% versus 46%), non-nucleoside reverse transcriptase inhibitors (24% versus 0%), prednisone (24% versus 0%), testosterone (47% versus 23%), and teriparatide (29% versus 8%). Median time from tenofovir initiation until fracture was 2.57 (range 1.17-5.69) years. In conclusion, more foot fractures were observed in tenofovir-treated patients than in non-tenofovir-treated patients with HIV infection. Comorbidities and/or coadministered drugs may have been contributory.
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PMID:Characteristics of foot fractures in HIV-infected patients previously treated with tenofovir versus non-tenofovir-containing highly active antiretroviral therapy. 2209 7

Hypovitaminosis D is a very common disorder, regarding both Western and developing countries. A growing amount of data over the last years have shown vitamin D deficiency to be high prevalent among HIV-positive subjects. In addition to "classic" risk factors, such as female sex, low dietary intake, dark skin pigmentation and low sun exposure, HIV-related factors, including immune activation and antiretroviral adverse effects, may affect vitamin D status. Even if both protease inhibitors and non-nucleoside reverse transcriptase inhibitors have been associated with low vitamin D levels, available evidences have failed to univocally associate hypovitaminosis D with specific antiretroviral class effects. Low vitamin D is known to have a negative impact not only on bone health, but also on neurocognitive, metabolic, cardiovascular and immune functions. Similarly to the general population, several studies conducted on HIV-infected subjects have associated hypovitaminosis D with a greater risk of developing osteopenia/osteoporosis and fragility fractures. Analogously, vitamin D deficiency has been described as an independent risk factor for cardiovascular disease and metabolic disorders, such as insulin resistance and type 2 diabetes mellitus. Last EACS guidelines suggest to screen for hypovitaminosis D every HIV-positive subject having a history of bone disease, chronic kidney disease or other known risk factors for vitamin D deficiency. Vitamin D repletion is recommended when 25-hydroxyvitamin D levels are below 10 ng/ml. Furthermore, it may be indicated in presence of 25OHD values between 10 and 30 ng/ml, if associated with osteoporosis, osteomalacia or increased parathyroid hormone levels. The optimal repletion and maintenance dosing regimens remain to be established, as well as the impact of vitamin D supplementation in preventing comorbidities.
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PMID:Vitamin D deficiency in HIV infection: an underestimated and undertreated epidemic. 2369 Jan 92

Vitamin D deficiency in HIV infection has attracted much interest. The best known clinical outcomes of vitamin D deficiency are rickets (children) and osteomalacia (adults). Several non-skeletal disorders have also been linked to suboptimal vitamin D levels in the general population. The prevalence of vitamin D deficiency varies widely (6-100%) across diverse patient populations, with no evidence that it is higher in HIV-positive versus noninfected adults. Vitamin D deficiency may blunt immune restoration and exacerbate HIV complications (e.g. opportunistic infections, poor perinatal outcomes, wasting, HIV disease progression, AIDS events, and death). The nonnucleoside reverse transcriptase inhibitor efavirenz was associated with a relatively high risk of vitamin D deficiency; nevirapine, etravirine, and rilpivirine were noted to have less or no impact on vitamin D versus efavirenz in the limited data available. Protease inhibitors have either no or a low association with vitamin D deficiency. Nucleoside/nucleotide reverse transcriptase inhibitors (with the possible exception of zidovudine) also did not appear to be associated with vitamin D deficiency. Management of vitamin D deficiency in HIV-positive adults has not been rigorously evaluated; some guidelines recommend more vitamin D supplementation for HIV-positive adults on antiretrovirals versus the general population (e.g. 2-3 times higher vitamin D daily intake for the age group; loading dose up to 10,000 IU/day for 8-10 weeks and a maintenance dose of 800-2,000 IU/day). In conclusion, although vitamin D deficiency in HIV-positive adults can be prevalent, current evidence for its causes and impact is relatively weak. More data, particularly from large, controlled, long-term trials, regarding the benefits of correcting vitamin D levels in HIV-positive adults are needed.
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PMID:Vitamin D deficiency in HIV: a shadow on long-term management? 2475 52

Tuberculosis (TB) is a major global health problem. Patients with TB have a high rate of vitamin D deficiency, both at diagnosis and during the course of treatment with anti-tuberculosis drugs. Although data on the efficacy of vitamin D supplementation on Mycobacterium tuberculosis (Mtb) clearance is uncertain from randomized controlled trials (RCTs), vitamin D enhances the expression of the anti-microbial peptide human cathelicidin (hCAP18) in cultured macrophages in vitro. One possible explanation for the mixed (primarily negative) results of RCTs examining vitamin D treatment in TB infection is that anti-TB drugs given to enrolled subjects may impact actions of vitamin D to enhance cathelicidin in macrophages. To address this hypothesis, human macrophage-like monocytic (THP-1) cells were treated with varying doses of first-line anti-tuberculosis drugs in the presence of the active form of vitamin D, 1N1,25-dihydroxyvitamin D3 (1,25(OH)2D3). The expression of hCAP18 was determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). 1,25(OH)2D3 strongly induced expression of hCAP18 mRNA in THP-1 cells (fold-change from control). The combination of the standard 4-drug TB therapy (isoniazid, rifampicin, pyrazinamide and ethambutol) in the cultured THP-1 cells demonstrated a significant decrease of hCAP18 mRNA at the dosage of 10 ug/mL. In 31 subjects with newly diagnosed drug-sensitive TB randomized to either high-dose vitamin D3 (1.2 million IU over 8 weeks, n=13) versus placebo (n=18), there was no change from baseline to week 8 in hCAP18 mRNA levels in peripheral blood mononuclear cells or in plasma concentrations of LL-37, the protein product of hCAP18.These data suggest that first-line anti-TB drugs may alter the vitamin D-dependent increase in hCAP18 and LL-37 human macrophages.
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PMID:The Effects of First-Line Anti-Tuberculosis Drugs on the Actions of Vitamin D in Human Macrophages. 2811 15