Effect of vitamin D supplementation in type 2 diabetes patients with pulmonary tuberculosis

Prevalence of vitamin D deficiency and the effect of vitamin D3 supplementation on response to anti-tuberculosis therapy in patients with extrapulmonary tuberculosis

BACKGROUND

We aimed to assess serum 25-hydroxyvitamin D3 (25(OH)D3) concentrations in extrapulmonary tuberculosis (EPTB) patients and to evaluate the effect of vitamin D3 supplementation on their treatment course.

METHODS

Serum 25(OH)D3concentrations were measured in 47 newly diagnosed EPTB patients and 42 controls. Vitamin D-deficient EPTB patients were randomly assigned to receive 50,000 IU of vitamin D3 (cholecalciferol) orally once a week for 6 weeks (total 300,000 IU), followed by maintenance doses of 1000 IU a day besides anti-TB drugs or the first line anti-TB treatment only. Follow up serum 25(OH)D3 concentrations were measured after 3 months of starting vitamin D3 supplementation. Both groups were evaluated for clinical, laboratory, and radiological outcomes after treatment.

RESULTS

Serum 25(OH)D3 concentrations were significantly lower among TB cases (17.1 ± 5.5 nmol/L) compared to healthy controls (51.8 ± 27.3 nmol/L), and vitamin D deficiency was observed in all EPTB patients (n = 47). Patients in VD3 supplementation group had significantly higher weight gain and serum albumin level at 2 months and end of treatment, higher hemoglobin concentration at the end of treatment, significantly lower CRP and ESR at 2 months and at the end of treatment. In cases with TB pleurisy, a significant higher rate of full resolution of pleural fluid after 6 months of anti-TB treatment and shorter treatment duration were noted compared to the other group.

CONCLUSIONS

Vitamin D deficiency is prevalent in EPTB patients, in whom, vitamin D supplementation is a useful adjunctive therapy to anti-TB drugs and improves treatment course.

Shedding light on vitamin D in tuberculosis: A comprehensive review of clinical trials and discrepancies

Over the past few decades, there has been extensive research on the use of vitamin D as an adjunctive therapy in the treatment and prevention of tuberculosis. In vitro studies have provided valuable insights into the mechanisms by which vitamin D activates the immune response to combat Mycobacterium tuberculosis. These encouraging findings have spurred clinical investigations globally to assess the effectiveness of vitamin D as a preventive measure and as an adjunctive treatment for tuberculosis. However, the results from these clinical studies have been contradictory, with some demonstrating clear efficacy while others report only modest or no activity. In this review, we aim to analyze the clinical studies on vitamin D and examine the possible discrepancies observed in their outcomes.

Tuberculosis and malnutrition: The European perspective

Tuberculosis (TB) is a leading infectious cause of death worldwide, despite ongoing efforts to limit its incidence and mortality. Although the European Region has made gains in TB incidence and mortality, it now contends with increasing numbers of multidrug- and rifampicin-resistant tuberculosis (MDR/RR-TB). Malnutrition is a major contributor to the burden of TB and may also be directly caused or enhanced by the onset of TB. The presence of malnutrition may worsen TB and MDR/RR-TB related treatment outcomes and contribute to growing TB drug-resistance. Preventing and treating all forms of malnutrition is an important tool to limit the spread of TB worldwide and improve TB outcomes and treatment efficacy. We carried out a scoping review of the existing evidence that addresses malnutrition in the context of TB. Our review found malnutrition increased the risk of developing TB in high-burden settings and increased the likelihood of developing unfavorable treatment outcomes, including treatment failure, loss to follow-up, and death. The potential impact of nutritional care and improved nutritional status on patient prognosis was more difficult to evaluate due to heterogeneity of patient populations, treatment protocols, and treatment durations and goals. High-quality trials that consider malnutrition as a major risk factor and relevant treatment target when designing effective strategies to limit TB spread and mortality are needed to inform evidence-based practice. In TB patients, we suggest that widespread and regular nutritional screening, assessment, and counselling, has the potential to increase effectiveness of TB management strategies and improve patient quality of life, overall outcomes, and survival.

Preparation and Evaluation of Low-Dose Calcitriol Dry Powder Inhalation as Host-Directed Adjunct Therapy for Tuberculosis

Background

It is unclear whether Vitamin D is efficacious as a host-directed therapy (HDT) for patients of tuberculosis (TB). We investigated pulmonary delivery of the active metabolite of Vitamin D₃, i.e., 1, 25-dihydroxy vitamin D₃ (calcitriol) in a mouse model of infection with Mycobacterium tuberculosis (Mtb).

Methods

We optimized a spray drying process to prepare a dry powder inhalation (DPI) of calcitriol using a Quality by Design (QbD) approach. We then compared outcomes when Mtb-infected mice were treated with inhaled calcitriol at 5 ng/kg as a stand-alone intervention versus DPI as adjunct to standard oral anti-tuberculosis therapy (ATT).

Results

The DPI with or without concomitant ATT markedly improved the morphology of the lungs and mitigated histopathology in both the lungs and the spleens. The number of nodular lesions on the lung surface decreased from 43.7 ± 3.1 to 22.5 ± 3.9 with the DPI alone and to 9.8 ± 2.5 with DPI + ATT. However, no statistically significant induction of host antimicrobial peptide cathelicidin or reduction in bacterial burden was seen with the DPI alone. DPI + ATT did not significantly reduce the bacterial burden in the lungs compared to ATT alone.

Conclusions

We concluded that HDT using the low dose calcitriol DPI contributed markedly to mitigation of pathology, but higher dose may be required to evoke significant induction of bactericidal host response and bactericidal activity in the lung.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11095-022-03360-5.

Effect of Vitamin D Supplementation in Type 2 Diabetes Patients with Tuberculosis: A Systematic Review

BACKGROUND

Diabetes mellitus (DM) and tuberculosis (TB) have been recognized as reemerging epidemics, especially in developing countries. Among all the risk factors, diabetes causes immunosuppression, increasing the risk of active TB three times. Vitamin D has been found as a link between DM-TB co-morbidity.

OBJECTIVE

Vitamin D affects the immune response, suppresses Mycobacterium tuberculosis (Mtb) growth, and affects insulin secretion. The present systematic review determines the effect of vitamin D supplementation on clinical and therapeutic outcomes of DM-TB patients.

METHOD

A comprehensive literature search was carried out in PubMed, Cochrane, Web of Science, and Scopus database to determine eligible studies from inception to January 2021. Out of the 639 articles retrieved, three randomized controlled trials (RCTs) were included in the systematic review.

RESULT

The effect of vitamin D3 or oral cholecalciferol supplementation was assessed on outcomes, such as duration to sputum smear conversion, TB scores improvement, change in glycemic parameters, including HbA1c, FBS, and PLBS, and laboratory parameters, such as Hb, ESR, and CRP. Duration of sputum smear conversion was decreased by two weeks in the vitamin D3 supplemented group in two studies. TB score improvement and changes in glycemic parameters were inclined towards supplemented group; however, they were not significant.

CONCLUSION

The overall effect of vitamin D3 supplementation on TB patients with DM was not significant. Further studies are required in the future examining the effect of supplementation on outcomes in this population.

The effect of a structured clinical algorithm on glycemic control in patients with combined tuberculosis and diabetes in Indonesia: A randomized trial

AIMS

Diabetes mellitus (DM) is associated with worse tuberculosis (TB) treatment outcomes, especially among those with poor glycemic control. We examined whether a structured clinical algorithm could improve glycemic control in TB patients with DM.

METHODS

In an open label randomized trial, TB-DM patients were randomized to scheduled counselling, glucose monitoring, and adjustment of medication using a structured clinical algorithm (intervention arm) or routine DM management (control arm), with glycated hemoglobin (HbA1c) at month 6 as the primary end point.

RESULTS

We randomized 150 pulmonary TB-DM patients (92% culture positive, 51.3% male, mean age 53 years). Baseline mean HbA1c was 11.0% in the intervention arm (n = 76) and 11.6% in the control arm (n = 74). At 6 months, HbA1c had decreased more in the intervention arm compared with the control arm (a difference of 1.82% HbA1c, 95% CI 0.82-2.83, p < 0.001). Five patients were hospitalized in the intervention arm and seven in the control arm. There was more hypoglycemia (35.0% vs 11.8%; p = 0.002) in the intervention arm. Two deaths occurred in the intervention arm, one due to cardiorespiratory failure and one because of suspected septic shock and multiorgan failure.

CONCLUSION

Regular monitoring and algorithmic adjustment of DM treatment led to improved glycemic control.

The effect of micro-nutrients on malnutrition, immunity and therapeutic effect in patients with pulmonary tuberculosis: A systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

Micro-nutrients are closely related to pulmonary tuberculosis (PTB). Most patients with PTB suffer from micro-nutrients deficiency. We aimed to evaluate the efficacy of micro-nutrients support on clinical therapy and chronic inflammation in patients with PTB.

METHODS

We searched Pubmed, Springer link, Web of Science, Cochrane, Wan Fang and CNKI databases for randomised controlled trials (RCTs). The patients with anti-TB treatments were divided into two groups, the control group with nutritional advice or placebo, and the experimental group with micro-nutrients support for more than 2 weeks. Two reviewers conducted data extraction and quality assessment of the studies independently, and ReviewManager 5.2 software was used to input and analyse the data. The dichotomous variable was expressed in the risk ratios (RRS) and 95% CI, the continuous data were expressed in the mean difference (MD) and 95% CI, and the heterogeneity of subgroup was evaluated by I (Kerantzas and Jacobs, Jr., 2017) [2] test.

RESULTS

A total of 13 trials (2847 participants) were included. First, micro-nutrients improved sputum smears or culture negative conversion rates (OR 0.16 0.03-0.77, 2.29; MD -2.36, -4.72~-0.01, z = 1.97). Meanwhile, micro-nutrients support increased lymphocytes and decreased leukocytes, neutrophils, CRP and ESR (MD 0.20, 0.06-0.35, z = 2.78; MD -0.42, -0.65~-0.18, z = 3.48; MD -0.66, -1.12~-0.20, z = 2.82). However it had not impact on body weight, MUAC, haemoglobin, albumin or monocytes (p > 0.05).

CONCLUSION

Micro-nutrients support can reduce chronic inflammation and improve sputum smears or culture conversions to contribute to anti-TB treatment.

Effectiveness of vitamin D supplementation on the outcome of pulmonary tuberculosis treatment in adults: a meta-analysis of randomized controlled trials

Supplemental Digital Content is available in the text

Background:

Tuberculosis (TB) is one of the most debilitating diseases worldwide. Current studies have shown that vitamin D plays a significant role in host immune defense against Mycobacterium tuberculosis, but clinical trials reported inconsistent results. Therefore, we systematically reviewed the literature to investigate whether vitamin D supplementation could improve the effect of anti-TB therapy.

Methods:

We systematically searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials from their inception to February 8th, 2019 for randomized controlled trials on vitamin D supplementation in patients with pulmonary TB receiving anti-TB therapy. The primary outcomes were time to sputum culture and smear conversion and proportion of participants with negative sputum culture. The secondary outcomes were clinical response to treatment and adverse events. A random-effects model was used to pool studies. Data were analyzed using RevMan 5.3 software.

Results:

Five studies with a total of 1126 participants were included in our meta-analysis. Vitamin D supplementation did not shorten the time to sputum culture and smear conversion (hazard ratio [HR] 1.04, 95% confidence interval [CI] 0.89–1.23, P = 0.60; HR 1.15, 95% CI 0.93–1.41, P = 0.20, respectively) and did not lead to an increase in the proportion of participants with negative sputum culture (relative risk [RR] 1.04, 95% CI 0.97–1.11, P = 0.32). However, it reduced the time to sputum culture conversion in the sub-group of participants with TaqI tt genotype (HR 8.09, 95% CI 1.39–47.09, P = 0.02) and improved the multidrug-resistant (MDR) TB sputum culture conversion rate (RR 2.40, 95% CI 1.11–5.18, P = 0.03). There was no influence on secondary outcomes.

Conclusions:

Vitamin D supplementation had no beneficial effect on anti-TB treatment, but it reduced the time to sputum culture conversion in participants with tt genotype of the TaqI vitamin D receptor gene polymorphism and improved the MDR TB sputum culture conversion rate.

Vitamin D Supplementation in Overweight/obese Asian Indian Women with Prediabetes Reduces Glycemic Measures and Truncal Subcutaneous Fat: A 78 Weeks Randomized Placebo-Controlled Trial (PREVENT-WIN Trial)

Vitamin D deficiency may contribute to etiology of type 2 diabetes in Asian Indians. The objectives of this study was to evaluate effect of vitamin D supplementation on glycemic profile and body composition in prediabetic and vitamin D deficient overweight/obese Asian Indian women. In this open-label randomized placebo-controlled trial (78 weeks duration), 121 females (aged 20-60 years) with prediabetes and vitamin D deficiency were randomly allocated in intervention (n, 61) and placebo (n, 60) groups. The primary outcome variables were fasting blood glucose (FBG), 2-h blood glucose post OGTT (2-h BG), hemoglobin A1c (HbA1C), and reversal to normoglycemia. In Intention-to-treat analysis, at the end of intervention, we observed significant decrease in FBG [-5.0 (-12.6-2.4), p = 0.04], 2-h blood glucose post OGTT [-11(-49.3-26.9), p = 0.02], hemoglobin A1c [-0.41 (5.89, 6.55), p = 0.05] and increase in 25(OH) D [7.5 (-6.0-20.9), p = 0.002] levels in intervention as compared to the placebo group. Changes in glycemic category based on FBG were as follows; intervention group: normal FBG, 58.6%; impaired fasting glucose (IFG), 39%; and type 2 diabetes mellitus (T2DM), 2.4%; placebo group: normal FBG, 48.8%; IFG, 46.3%; and T2DM, 4.9%. Changes in category of 2-hour glucose post OGTT after intervention were as follows; intervention group: normal glucose tolerance (NGT) 51.2% and prediabetes, 48.8%; placebo group: NGT, 43.9%; prediabetes, 53.7% and T2DM, 2.4%. After intervention, subscapular skinfold (visit Ist compared to visit IIIrd) and suprailiac skinfold (visit IInd compared to visit IIIrd) were significantly lower in intervention group vs. control group. In conclusion, we observed significant reduction in FBG, 2-hour glucose post OGTT, HbA1c, and truncal subcutaneous fat and reversal to normoglycemia in overweight/obese prediabetic vitamin D deficient Asian Indian women after 78 weeks of vitamin D supplementation.

Effectiveness of micronutrients supplement in patients with active tuberculosis on treatment: Systematic review/Meta-analysis

BACKGROUND

Multiple researchers have suggested the influence of micronutrients in the cure and survival of tuberculosis.

OBJECTIVE

To determine the effectiveness of micronutrients in the cure and treatment of pulmonary tuberculosis.

METHODS

Systematic search of randomized controlled trials (RCTs) in databases of people under treatment for active pulmonary tuberculosis, that must have received oral micronutrients for at least four weeks compared with placebo. The synthesis of the variables was shown in standardized mean difference (MD) and/or risk difference (RD). The random effects model was used and was reported in forest plot of the estimates of the effect with a 95 % CI.

RESULTS

Sixteen of 246 studies were included, in total 4398 people. Zinc showed (RD, 0.04; 95 % CI, 0.00-0.08) in mortality, increases muscle mass index (MD, 1.20; 95 % CI, 0.04-2.36) and gains weight (MD, 3.10; 95 % CI, 0.66-5.54). Zinc plus vitamin A increases the weight (MD, 3.10; 95 % CI, 2.78-3.42), improving karnofsky scale (MD, 2.50; 95 % CI, 2.22-2.78). Additionally, vitamin D accelerate the sputum conversión time (RD, 0.38; 95 % CI, 0.03-0.73). Hemoglobin (Hb) with vitamin A and zinc achieves statistically significant changes (MD, 0.69; 95 % CI, 0.28-1.09) and (MD, 0.52; 95 % CI, 0.21-0.83) and reduces area of cavitations in chest X-ray (MD, -0.33; 95 % CI, -0.60--0.06).

CONCLUSIONS

The consumption of micronutrients could achieve weight gain, hemoglobin, accelerated sputum conversion and improvement in quality of life. There are no changes in mortality that may be attributable to the suboptimal dose, larger studies are suggested with adequate doses.

Calcitriol enhances pyrazinamide treatment of murine tuberculosis

Background:

Tuberculosis is a leading cause of morbidity and mortality in humans worldwide. There is an urgent need for new and effective drugs to treat tuberculosis and shorten the duration of tuberculosis therapy. 1, 25-dihydroxy vitamin D₃ (1,25 (OH)₂D₃) has been reported to have a synergistic effect with pyrazinamide (PZA) in killing tubercle bacilli in vitro. The addition of 1,25 (OH)₂D₃ to standard tuberculosis treatment should benefit patients if the adjunctive drug has a synergistic effect in vivo. Thus, in this study, calcitriol (bioactive 1,25 (OH)₂D₃) was administered to mice undergoing treatment for Mycobacterium tuberculosis (M.tb) infection with PZA, a first-line anti-tuberculosis drug, to determine whether vitamin D3 enhances the therapeutic effect.

Methods:

C57BL/6 female mice were infected with the M.tb H37Rv strain through aerosol exposure. Calcitriol and PZA, either alone or in combination, were orally administered to the M.tb infected mice. The effect of calcitriol on PZA activity was determined by evaluating the bacterial burden and analyzing the histopathological lesions in the lungs and spleen. To investigate the expression of inflammatory cytokines and anti-microbial peptide genes, we determined the transcriptional levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), mouse β-defensin-2 (mBD2), and cathelicidin LL-37 through real-time quantitative polymerase chain reaction. The protein levels of IFN-γ were detected by enzyme-linked immunosorbent assay. Differences between groups were analyzed with independent samples t-test or one-way analysis of variance.

Results:

Calcitriol alone had little effect on tuberculosis infection, whereas PZA, compared with saline control treatment, decreased the bacterial burden (spleens: PZA vs. saline, 4.82 ± 0.22 vs. 5.22 ± 0.40 Log₁₀ colony-forming units [CFU]/gram, t = 2.13, P < 0.05; lungs: PZA vs. saline, 5.55 ± 0.15 vs. 6.83 ± 0.46 Log₁₀ CFU/gram, t = 6.56, P < 0.01) and pathological lesions in the lungs. Simultaneous administration of calcitriol with PZA, compared with PZA alone, decreased the bacterial load (spleen: calcitriol + PZA vs. PZA, 4.37 ± 0.13 vs. 4.82 ± 0.22 Log₁₀ CFU/gram, t = 4.36, P < 0.01; lung: calcitriol + PZA vs. PZA, 5.03 ± 0.32 vs. 5.55 ± 0.15 Log₁₀ CFU/gram, t = 3.58, P < 0.01) and attenuated the lung lesions (gross pathological score: calcitriol + PZA vs. PZA, 3.25 ± 0.50 vs. 2.50 ± 0.58, t = 1.96, P < 0.05; affected area of total lung area: calcitriol + PZA vs. PZA, 30.75% ± 6.50% vs. 21.55% ± 2.99%, t = 2.66, P < 0.05). Further studies demonstrated calcitriol significantly increased the expression of anti-inflammatory cytokine IL-4 but suppressed production of the pro-inflammatory cytokine IFN-γ (IL-4: calcitriol vs. saline, 5.69 ± 0.50 vs. 2.80 ± 0.56 fold of control, t = 6.74, P < 0.01; IFN-γ: calcitriol vs. saline, 1.36 ± 0.11 vs. 4.13 ± 0.83 fold of control, t = 5.77, P < 0.01). In addition, calcitriol alone or in combination with PZA significantly enhanced the transcriptional level of anti-microbial peptides (cathelicidin LL-37: calcitriol vs. saline, 10.59 ± 1.03 vs. 2.80 ± 0.90 fold of control, t = 9.85, P < 0.01; mBD2: calcitriol vs. saline, 7.92 ± 0.62 vs. 1.79 ± 0.45 fold of control, t = 13.82, P < 0.01), whereas PZA exerted a negative effect on anti-microbial peptide gene expression.

Conclusions:

Calcitriol as adjunctive treatment can result in beneficial treatment outcomes in M.tb infection by suppressing the inflammatory response and up-regulating the expression of anti-microbial peptides. These results indicate the feasibility of using calcitriol adjunctively with standard chemotherapy for the treatment of M.tb infection.

Efeitos contrastantes da vitamina D sobre a resposta imune inata e adquirida e seu impacto na recuperação da tuberculose

A vitamina D é um hormônio essencial para o organismo, podendo ser obtida da dieta ou, principalmente, gerada pela pele após exposição à luz solar ultravioleta B. Na sua forma ativa (1,25(OH)2D) ela controla a absorção de cálcio e fósforo do intestino para a corrente sanguínea e participa de diversos processos celulares e fisiológicos. A ligação da 1,25(OH)2D ao receptor da vitamina D (VDR) presente em diversas células, como as células do sistema imunológico, induz a transcrição de genes que podem, por exemplo, modular a resposta imune inata e adquirida. A deficiência de vitamina D ou do VDR é associada a problemas de saúde como desordens esqueléticas, hipertensão, doenças cardiovasculares, diabetes mellitus, dislipidemias, doenças autoimunes e doenças infecciosas. Neste sentido, a suplementação com vitamina D tem sido proposta como uma possível medida preventiva, podendo ser aplicada em muitas patologias, em especial na tuberculose. Principal causa de morte por um único agente infeccioso, a tuberculose é responsável por cerca de 1,3 milhões de óbitos por ano no mundo. Publicações recentes apontam efeitos diversos da vitamina D na resposta imune inata e adquirida. A 1,25(OH)2D3 na presença do interferon (IFN)-γ é capaz de aumentar a atividade bactericida do macrófago contra o M. tuberculosis, aumentando a produção de peptídios antimicrobianos e estimulando a autofagia, favorecendo assim a lise de bacilos localizados em fagossomos. Por outro lado, a vitamina D em linfócitos T mostra efeito tolerogênico que favorece o controle de respostas inflamatórias excessivas. Neste trabalho de revisão são apresentados estudos recentes envolvendo efeitos da vitamina D na resposta imune inata e adquirida. Além disso, considerações sobre deficiência de vitamina D e maior risco de contrair tuberculose, e efeitos contrastantes da suplementação com vitamina D na prevenção e tratamento da TB, são discutidos.

Clinical Management of Drug-resistant Mycobacterium tuberculosis Strains: Pathogen-targeted Versus Host-directed Treatment Approaches

Background:

Despite exerted efforts to control and treat Mycobacterium tuberculosis (MTB) strains, Tuberculosis (TB) remains a public health menace. The emergence of complex drug-resistant profiles, such as multi-drug resistant and extensively drug-resistant MTB strains, emphasizes the need for early diagnosis of resistant cases, shorter treatment options, and effective medical interventions.

Objective:

Solutions for better clinical management of drug-resistant cases are either pathogencentered (novel chemotherapy agents) or host-directed approaches (modulating host immune response to prevent MTB invasion and pathogenesis).

Results:

Despite the overall potentiality of several chemotherapy agents, it is feared that their effectiveness could be challenged by sequential pathogen adaptation tactics. On the contrary, host-directed therapy options might offer a long-term conceivable solution.

Conclusion:

This review discusses the main suggestions proposed so far to resolve the clinical challenges associated with drug resistance, in the context of TB. These suggestions include novel drug delivery approaches that could optimize treatment outcome and increase patients’ compliance to the treatment.

Efficacy of Vitamin D supplementation in achieving an early Sputum Conversion in Smear positive Pulmonary Tuberculosis

Objective:

To determine the efficacy of Vitamin D supplementation in achieving an early sputum conversion in vitamin D deficient smear positive pulmonary tuberculosis patients.

Methods:

This randomized clinical trial was done at Mayo hospital Lahore from November 2015 to August 2016. One hundred twenty patients with sputum smear positive pulmonary tuberculosis were selected and randomized to Group-A (taking anti-tuberculous therapy (ATT) only) and Group-B (taking ATT with Vitamin D supplementation). Four doses of100,000 IU of Vitamin D injection intramuscularly were given after every 14 days during intensive-phase. Sputum examination was repeated at 2^nd, 4^th, 6^th, 8^th, 10^th and 12^th weeks. Efficacy of treatment in terms of early sputum conversion between both groups was tested using Chi square and independent sample t-test was applied to compare mean values of serum vitamin D before and after treatment. P-value ≤ 0.05 was considered as significant.

Results:

The mean age of patients was 37.18±6.81 years in Group-A and 39.02±7.56 years in Group-B. There were 63 (52.50%) males and 57 (47.50%) females. The mean serum Vitamin D was 17.07±1.44 in Group-A and 17.23±2.37 in Group-B at baseline and at 12th week, the levels were 21.77±2.23 in Group-A and 29.24±0.72 in Group-B. In Group-A, 7 (11.7%) patients showed positive sputum examination and in Group-B, only one (1.7%) patient had positive sputum examination at 12^th week. The difference was statistically significant (p-value= 0.028).

Conclusion:

Four doses of intramuscular vitamin D given after every 14 days corrected vitamin D deficiency and improved the rate of sputum smear conversion in patients of pulmonary tuberculosis.

Influence of vitamin D deficiency on T cell subsets and related indices during spinal tuberculosis

The present study investigated the effects of vitamin D deficiency on T cell subsets in patients with spinal tuberculosis. In addition, the influence of vitamin D deficiency was investigated on the expression of cytokines IL-1β, IL-6 and TNF-α in intervertebral disc lesions of patients. One hundred and seventeen patients with spinal tuberculosis who received operative treatment in the Department of Orthopedics in Wuhan City Third Hospital from March 2012 to March 2015 were collected. The patients were divided depending upon vitamin D content into the control group (64 cases, vitamin D content <25 nmol/l) and experimental group (53 cases, vitamin D content >50 nmol/l). Immunofluorescence method was applied to determine the content of T cell subsets in both groups of patients. Intervertebral disc lesion tissues of two groups of patients were obtained during surgery then treated with HE staining and immunohistochemical staining. The values of average optical density obtained under light microscope were observed as the expression quantities of IL-1β, IL-6 and TNF-α, to explore the relationship between vitamin D and the expression of cytokines. When vitamin D is lacking, the expression of T lymphocyte subsets in patients with spinal tuberculosis significantly decreased. Compared with experimental group, the difference was statistically significant (P<0.05). Further, the expression of cytokines IL-1β, IL-6 and TNF-α in intervertebral disc lesion tissues of patients with spinal tuberculosis were significantly higher than those of patients with spinal tuberculosis whose vitamin D content was normal (P<0.05). In the control group, vitamin D content was negatively correlated with the expression of IL-1β, IL-6 and TNF-α. The expression of T lymphocyte subsets in patients with vitamin D deficiency was significantly reduced, and the immune function decreased. The expression of IL-1β, IL-6 and TNF-α in lesions were significantly higher than those of patients with normal vitamin D content. In addition, the lower the content of vitamin D was, the more active the expression of inflammatory factors were, which was not conducive to the recovery of tuberculosis lesions.

The Effect of Improved Serum 25-Hydroxyvitamin D Status on Glycemic Control in Diabetic Patients: A Meta-Analysis

BACKGROUND

Type 2 diabetes is a global health concern, with an increased prevalence and high cost of treatment.

OBJECTIVE

The aim of this systematic review and meta-analysis was to determine the effect of vitamin D supplementation and improved vitamin D status on glycemia and insulin resistance in type 2 diabetic patients.

DATA SOURCE

We searched PUBMED/Medline, Cumulative Index to Nursing and Allied Health, and Cochrane Library (until January 2017).

STUDY SELECTION

Prospective clinical trials were selected evaluating the impact of vitamin D supplementation on glycosylated hemoglobin (HbA1c), serum fasting plasma glucose (FPG), and homeostatic model assessment of insulin resistance (HOMA-IR) in diabetic patients.

DATA EXTRACTION AND SYNTHESIS

We used a random-effects model to synthesize quantitative data, followed by a leave-one-out method for sensitivity analysis. The systematic review registration was CRD42017059555. From a total of 844 entries identified via literature search, 24 controlled trials (1528 individuals diagnosed with type 2 diabetes) were included. The meta-analysis indicated a significant reduction in HbA1c [mean difference: -0.30%; 95% confidence interval (CI): -0.45 to -0.15, P < 0.001], FPG [mean difference: -4.9 mg/dL (-0.27 mmol/L); 95% CI: -8.1 to -1.6 (-0.45 to -0.09 mmol/L), P = 0.003], and HOMA-IR (mean difference: -0.66; 95% CI: -1.06 to -0.26, P = 0.001) following vitamin D supplementation and significant increase in serum 25-hydroxyvitamin D levels [overall increase of 17 ± 2.4 ng/mL (42 ± 6 nmol/L)].

CONCLUSIONS

Vitamin D supplementation, a minimum dose of 100 µg/d (4000 IU/d), may significantly reduce serum FPG, HbA1c, and HOMA-IR index, and helps to control glycemic response and improve insulin sensitivity in type 2 diabetic patients.

High glucose induces O-GlcNAc glycosylation of the vitamin D receptor (VDR) in THP1 cells and in human macrophages derived from monocytes

Chronic hyperglycemia increases the carbon flux through the hexosamine pathway, allowing the accumulation of UDP-GlcNAc. UDP-GlcNAc is the sugar donor for the enzyme-mediated protein glycosylation event known as OGlcNAcylation. This posttranslational modification targets several transcription factors implicated in glucose toxicity, insulin resistance, and diabetes. Vitamin D plays an important role in glucose homeostasis and insulin secretion through transcriptional mechanisms mediated by its receptor (VDR). Vitamin D deficiency has been associated with higher susceptibility to bacterial diseases in diabetic patients. However, it has not been explored whether VDR is subject to OGlcNAcylation or whether high glucose affects its transcriptional or biological activities. The aim of this study was to evaluate the effect of hyperglycemia on VDR OGlcNAcylation and its effects on vitamin D-mediated transcription. We predicted potential OGlcNAcylation sites using free software. Our results showed that hyperglycemia (30 mM) induces the OGlcNAcylation of VDR in THP1 cells and in human macrophages derived from monocytes (MDM). This condition did not hamper the vitamin D-dependent activation of LL-37 gene expression, and even did not impair the macrophage bactericidal activity. Our study provides new insight into vitamin D receptor posttranslational modification that may have relevance on the physiological responses of long-term hyperglycemia.

The Effects of First-Line Anti-Tuberculosis Drugs on the Actions of Vitamin D in Human Macrophages

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.

Association between tuberculosis, diabetes and 25 hydroxyvitamin D in Tanzania: a longitudinal case control study

Background

Vitamin D level is inversely associated with tuberculosis (TB) and diabetes (DM). Vitamin D could be a mediator in the association between TB and DM. We examined the associations between vitamin D, TB and DM.

Methods

Consecutive adults with TB and sex- and age-matched volunteers were included in a case-control study in Dar es Salaam, Tanzania. Glycemia and total vitamin D (25(OH)D) were measured at enrolment and after TB treatment in cases. The association between low 25(OH)D (<75 nmol/l) and TB was evaluated by logistic regression adjusted for age, sex, body mass index, socioeconomic status, sunshine hours, HIV and an interaction between low 25(OH)D and hyperglycemia.

Results

The prevalence of low 25(OH)D was similar in TB patients and controls (25.8 % versus 31.0 %; p = 0.22). In the subgroup of patients with persistent hyperglycemia (i.e. likely true diabetic patients), the proportion of patients with low 25(OH)D tended to be greater in TB patients (50 % versus 29.7 %; p = 0.20). The effect modification by persistent hyperglycemia persisted in the multivariate analysis (p_interaction = 0.01).

Conclusions

Low 25(OH)D may increase TB risk in patients with underlying DM. Trials should examine if this association is causal and whether adjunct vitamin D therapy is beneficial in this population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1960-x) contains supplementary material, which is available to authorized users.

Effects of vitamin D supplementation on glycated haemoglobin and fasting glucose levels in hypertensive patients: a randomized controlled trial

AIM

To investigate the efficacy of vitamin D supplementation on glycaemic control.

METHODS

The Styrian Vitamin D Hypertension Trial was a single-centre, double-blind, placebo-controlled study conducted between 2011 and 2014 at the Medical University of Graz, Austria. We enrolled 200 people with arterial hypertension and 25-hydroxyvitamin D [25(OH)D] concentrations <30 ng/mL. Study participants were randomized to receive either 2800 IU of vitamin D or placebo per day for 8 weeks. The present study was a post hoc analysis that incorporated an analysis of covariance (ancova) approach, while adjusting for baseline differences.

RESULTS

A total of 185 participants [mean ± standard deviation age, 60.1 ± 11.3 years; 47% women; mean 25(OH)D 21.2 ± 5.6 ng/mL, mean glycated haemoglobin (HbA1c) 44.8 ± 11.8 mmol/mol and mean body mass index 30.4 ± 5.4 kg/m(2) ] completed the trial. ancova showed a mean treatment effect [95% confidence interval (CI)] on HbA1c of -3.52 (-6.7 to -0.34) mmol/mol (p = .045). There was no difference in fasting glucose -4.7 mg/dL (95% CI -16.3 to 6.9; p = .426).

CONCLUSIONS

Vitamin D supplementation in obese hypertensive patients with low 25(OH)D reduces HbA1c levels. This finding warrants further investigation into potential vitamin D effects on glucose homeostasis.

Nutritional supplements for people being treated for active tuberculosis

BACKGROUND

Tuberculosis and malnutrition are linked in a complex relationship. Tuberculosis may cause undernutrition through increased metabolic demands and decreased intake, and nutritional deficiencies may worsen the disease, or delay recovery by depressing important immune functions. At present, there is no evidence-based nutritional guidance for adults and children being treated for tuberculosis.

OBJECTIVES

To assess the effects of oral nutritional supplements in people being treated with antituberculous drug therapy for active tuberculosis.

SEARCH METHODS

We searched the Cochrane Infectious Disease Group Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL; Issue 1, 2016), MEDLINE (from 1946 to 4 February 2016), EMBASE (from 1980 to 4 February 2016), LILACS (from 1982 to 4 February 2016), the metaRegister of Controlled Trials (mRCT), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), and the Indian Journal of Tuberculosis up to 4 February 2016, and checked the reference lists of all included studies.

SELECTION CRITERIA

Randomized controlled trials that compared any oral nutritional supplement given for at least four weeks with no nutritional intervention, placebo, or dietary advice only for people being treated for active tuberculosis. The primary outcomes of interest were all-cause death, and cure at six and 12 months.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, and extracted data and assessed the risk of bias in the included trials. We presented the results as risk ratios (RR) for dichotomous variables, and mean differences (MD) for continuous variables, with 95% confidence intervals (CIs). Where appropriate, we pooled data from trials with similar interventions and outcomes. We assessed the quality of the evidence using the Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Thirty-five trials, including 8283 participants, met the inclusion criteria of this review. Macronutrient supplementationSix trials assessed the provision of free food, or high-energy supplements. Only two trials measured total dietary intake, and in both trials the intervention increased calorie consumption compared to controls.The available trials were too small to reliably prove or exclude clinically important benefits on mortality (RR 0.34, 95% CI 0.10 to 1.20; four trials, 567 participants, very low quality evidence), cure (RR 0.91, 95% CI 0.59 to 1.41; one trial, 102 participants, very low quality evidence), or treatment completion (data not pooled; two trials, 365 participants, very low quality evidence).Supplementation probably produces a modest increase in weight gain during treatment for active tuberculosis, although this was not seen consistently across all trials (data not pooled; five trials, 883 participants, moderate quality evidence). Two small studies provide some evidence that quality of life may also be improved but the trials were too small to have much confidence in the result (data not pooled; two trials, 134 participants, low quality evidence). Micronutrient supplementationSix trials assessed multi-micronutrient supplementation in doses up to 10 times the dietary reference intake, and 18 trials assessed single or dual micronutrient supplementation.Routine multi-micronutrient supplementation may have little or no effect on mortality in HIV-negative people with tuberculosis (RR 0.86, 95% CI 0.46 to 1.6; four trials, 1219 participants, low quality evidence), or HIV-positive people who are not taking antiretroviral therapy (RR 0.92, 95% CI 0.69 to 1.23; three trials, 1429 participants, moderate quality evidence). There is insufficient evidence to know if supplementation improves cure (no trials), treatment completion (RR 0.99, 95% CI 0.95 to 1.04; one trial, 302 participants, very low quality evidence), or the proportion of people who remain sputum positive during the first eight weeks (RR 0.92, 95% CI 0.63 to 1.35; two trials, 1020 participants, very low quality evidence). However, supplementation may have little or no effect on weight gain during treatment (data not pooled; five trials, 2940 participants, low quality evidence), and no studies have assessed the effect on quality of life.Plasma levels of vitamin A appear to increase following initiation of tuberculosis treatment regardless of supplementation. In contrast, supplementation probably does improve plasma levels of zinc, vitamin D, vitamin E, and selenium, but this has not been shown to have clinically important benefits. Of note, despite multiple studies of vitamin D supplementation in different doses, statistically significant benefits on sputum conversion have not been demonstrated.

AUTHORS' CONCLUSIONS

There is currently insufficient research to know whether routinely providing free food, or energy supplements improves tuberculosis treatment outcomes, but it probably improves weight gain in some settings.Although blood levels of some vitamins may be low in people starting treatment for active tuberculosis, there is currently no reliable evidence that routinely supplementing above recommended daily amounts has clinical benefits.

New tricks for old dogs: countering antibiotic resistance in tuberculosis with host-directed therapeutics

Despite the availability of Mycobacterium tuberculosis (Mtb) drugs for over 50 years, tuberculosis (TB) remains at pandemic levels. New drugs are urgently needed for resistant strains, shortening duration of treatment, and targeting different stages of the disease, especially for treatment during human immunodeficiency virus co-infection. One solution to the conundrum that antibiotics kill the bacillus yet select for resistance is to target the host rather than the pathogen. Here, we discuss recent progress in so-called 'host-directed therapeutics' (HDTs), focusing on two general mechanistic strategies: (i) HDTs that disrupt Mtb pathogenesis in macrophages and (ii) immunomodulatory HDTs that facilitate protective immune responses that kill Mtb or reduce deleterious responses that exacerbate disease. HDTs hold significant promise as adjunctive therapies in that they are less likely to engender resistance, will likely have efficacy against antibiotic-resistant strains, and may have activity against non-replicating Mtb. However, TB is a complex and variegated disease, and human populations exhibit significant diversity in their immune responses to it, which presents a complicated landscape for HDTs to navigate. Nevertheless, we suggest that a detailed mechanistic understanding of drug action, together with careful selection of disease stage targets and dosing strategies may overcome such limitations and allow the development of HDTs as effective adjunctive treatment options for TB.

High-dose vitamin D3 in adults with pulmonary tuberculosis: a double-blind randomized controlled trial

BACKGROUND

Tuberculosis, including multidrug-resistant tuberculosis (MDR-TB), is a major global health problem. Individuals with tuberculosis disease commonly exhibit vitamin D deficiency, which may adversely affect immunity and the response to therapy.

OBJECTIVE

We determined whether adjunctive high-dose vitamin D3 supplementation improves outcomes in individuals with pulmonary tuberculosis disease.

DESIGN

The study was a double-blind, randomized, placebo-controlled, intent-to-treat trial in 199 individuals with pulmonary tuberculosis disease in Tbilisi, Georgia. Subjects were randomly assigned to receive oral vitamin D3 [50,000 IUs (1.25 mg) thrice weekly for 8 wk and 50,000 IU every other week for 8 wk] or a placebo concomitant with standard first-line antituberculosis drugs. The primary outcome was the time for the conversion of a Mycobacterium tuberculosis (Mtb) sputum culture to negative.

RESULTS

Baseline characteristics between groups were similar. Most subjects (74%) were vitamin D deficient (plasma 25-hydroxyvitamin D [25(OH)D] concentration <50 nmol/L). With vitamin D3, plasma 25(OH)D concentrations peaked at ∼250 nmol/L by 8 wk and decreased to ∼125 nmol/L at week 16. Adverse events and plasma calcium concentrations were similar between groups. In 192 subjects with culture-confirmed tuberculosis, an adjusted efficacy analysis showed similar median culture-conversion times between vitamin D3 and placebo groups [29 and 27 d, respectively; HR: 0.86; 95% CI: 0.63, 1.18; P = 0.33). Eight-week culture-conversion rates were also similar (84.0% and 82.1% for vitamin D3 and placebo, respectively; P = 0.99).

CONCLUSION

A high-dose vitamin D3 regimen safely corrected vitamin D deficiency but did not improve the rate of sputum Mtb clearance over 16 wk in this pulmonary tuberculosis cohort. This trial was registered at clinicaltrials.gov at NCT00918086.

The interaction effects of aerobic exercise training and vitamin D supplementation on plasma lipid profiles and insulin resistance in ovariectomized rats

Purpose

The purpose of this study was to determine the interaction effects of aerobic exercise training and vitamin D supplementation on indices of obesity and plasma lipid profiles in ovariectomized (OVX) rats.

Methods

Forty female Wistar rats were divided into 5 groups: aerobic training (3 days/week for 8 weeks; AT; n = 8), aerobic training and vitamin D supplementation (OVX + AT + Vit D; n = 8), vitamin D supplementation (OVX + Vit D; n = 8), ovariectomized control (OVX + C, n = 8) and SHAM (n = 8). After blood sampling, visceral fat was taken from the abdominal cavity and weighed immediately. Data was statistically analyzed by One-way ANOVA and Repeated measure ANOVA tests with a 0.05 significance level.

Results

Body weight, visceral fat, BMI and food intake decreased significantly in OVX + AT + Vit D (P < 0.001); whereas these variables increased significantly in OVX + C (P < 0.001) and SHAM (P < 0.023) groups. At the end of two-months of follow-up, we observed significant differences in TC, TG, HDL-C, LDL-C, glucose, insulin, and HOMA-IR in all groups.

Conclusion

It seems that aerobic training with vitamin D, due to the involvement of muscle mass and exposure to dynamic pressure on the bones and muscles, increased energy expenditure, stimulated insulin exudation and glucose homeostasis, decreased insulin resistance and improved the lipid profile in ovariectomized rats.

Impact of vitamin D on infectious disease

BACKGROUND

Observational studies have linked vitamin D status and infectious disease. This association is supported by the presence of the vitamin D receptor and CYP27B1 in immune cells. This review aims to consolidate data from clinical trials that used vitamin D for the treatment or prevention of infectious disease.

METHODS

The authors searched the term "(vitamin D OR ergocalciferol OR cholecalciferol OR vitamin D2 OR vitamin D3 OR calcitriol) AND (infection OR tuberculosis OR sepsis OR pneumonia)" with limits preset to manuscripts published in English and with human subjects. They identified controlled trials that measured infectious outcomes (eg, incidence and severity of disease, time to disease resolution or recurrence, measures of clinical improvement, mortality). Studies that used analog, topical or micronutrient formulations of vitamin D, assessed only vitamin D status or lacked a comparison group were excluded. The references from eligible manuscripts and from 2 recent reviews were scanned for additional manuscripts.

RESULTS

One thousand two hundred eighty-four manuscripts were identified with our search terms, with 60 papers still eligible after review of the title and abstract. Full review of these papers, their references and 2 related reviews yielded 38 manuscripts.

CONCLUSIONS

Although some prospective studies show positive results regarding vitamin D on infectious disease, several robust studies are negative. Factors such as high variability between studies, the difference in individual responsiveness to vitamin D and study designs that do not primarily investigate infectious outcomes may mask the effects of vitamin D on infections.

Effect of vitamin D supplementation on glycemic control in patients with type 2 diabetes: a systematic review of interventional studies

Background

Diabetes and vitamin D deficiency are global epidemics. Researchers have long been exploring the role of potentially modifiable factors to manage type 2 diabetes. We conducted a systematic review of prospective studies and randomized controlled trials that involved vitamin D supplementation and specifically intended to study glycemic outcomes related to type 2 diabetes.

Methods

Two authors independently searched Medline and PubMed for longitudinal studies that had assessed the effect of vitamin D supplements on glycemic control, insulin resistance and beta-cell dysfunction in patients with diabetes.

Results

Seventeen randomized control trials and seven longitudinal studies with a minimum follow-up of one month were included.

Results of the various short-term studies (follow up ≤ 3 months) suggested that vitamin D supplementation had a positive impact on glycemic control and metabolic parameters such as insulin resistance and beta cell dysfunction. However, the evidence was weak due to the low methodological quality of the studies. There was no significant effect on HbA1c, beta cell function and insulin resistance in the long-term studies (follow up > 3 months). There existed heterogeneity in the methodology of the studies, inclusion criteria, mode of supplementation of vitamin D and the duration of follow up.

Conclusions

Current evidence based on randomized controlled trials and longitudinal studies do not support the notion that vitamin D supplementation can improve hyperglycemia, beta cell secretion or insulin sensitivity in patients with type 2 diabetes. Large-scale trials with proper study design, optimal vitamin D supplementation and longer follow up need to be conducted.

Vitamin D Status, Receptor Gene Polymorphisms, and Supplementation on Tuberculosis: A Systematic Review of Case-Control Studies and Randomized Controlled Trials

OBJECTIVE

To investigate the impacts of vitamin D status, supplementation and vitamin D receptor (VDR) gene polymorphisms on tuberculosis (TB).

METHODS

We conducted a systematic review of published studies pertaining to case-control and randomized-control trials from 2002 to 2014 using the PubMed database.

RESULTS AND CONCLUSION

Individuals with TB have lower vitamin D status than healthy individuals. Some VDR gene polymorphisms are associated with increased susceptibility to TB while others may not. Supplementation with vitamin D leads to improved clinical outcomes. However, further studies with a larger patient population and different ethnicities are needed to confirm these effects.

Status of vitamin D, antimicrobial peptide cathelicidin and T helper-associated cytokines in patients with diabetes mellitus and pulmonary tuberculosis

Pulmonary tuberculosis (PTB) is a high burden infectious disease in China. The immune function is damaged in patients with diabetes mellitus (DM) who are easy to infect with Mycobacterium tuberculosis (Mtb). The growth of Mtb has been shown to be restrained following the administration of vitamin D and antimicrobial peptide cathelicidin (LL-37); however, the effect in patients with DM and PTB remains unclear. Vitamin D can regulate the immune system through Vitamin D receptors expressed in T helper (Th) cells. The aim of the present study was to analyze the status and correlations of vitamin D, LL-37 and Th-associated cytokines in patients with PTB or PTB with DM (DMPTB). Serum 25-hydroxyvitamin D₃ [25(OH)D₃] levels were measured by liquid chromatography-tandem mass spectrometry, while plasma LL-37 levels were analyzed using a solid-phase enzyme-linked immunosorbent assay. Flow cytometry was used to analyze the levels of Th cytokines, including Th1-associated IFN-γ, Th2-associated IL-4 and Th17-associated IL-17. The results revealed that patients with PTB and DMPTB were vitamin D deficient or had insufficient vitamin D levels. Furthermore, the levels of LL-37, IFN-γ, IL-4 and IL-17 were higher in the PTB and DMPTB groups when compared with the normal controls. These results indicated that vitamin D supplementation is necessary for PTB and DMPTB patients. In addition, LL-37, IFN-γ and IL-17 may be diagnostic indexes that become elevated in the compensatory response caused by Mtb infection. Vitamin D can regulate the immune status in patients suffering from PTB.

Clinical review: Effect of vitamin D3 supplementation on improving glucose homeostasis and preventing diabetes: a systematic review and meta-analysis

CONTEXT

Observational studies report consistent associations between low vitamin D concentration and increased glycemia and risk of type 2 diabetes, but results of randomized controlled trials (RCTs) are mixed.

OBJECTIVE

The objective of the study was to systematically review RCTs that report on the effects of vitamin D supplementation on glucose homeostasis or diabetes prevention.

DATA SOURCES

Sources of data for the study were MEDLINE, EMBASE, SCOPUS, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Technology Assessment, and Science Citation Index from inception to June 2013.

STUDY SELECTION

Study selection was trials that compared vitamin D3 supplementation with placebo or a non-vitamin D supplement in adults with normal glucose tolerance, prediabetes, or type 2 diabetes.

DATA EXTRACTION AND SYNTHESIS

Two reviewers collected data and assessed trial quality using the Cochrane Risk of Bias tool. Random-effects models were used to estimate mean differences (MDs) and odds ratios. The main outcomes of interest were homeostasis model assessment of insulin resistance, homeostasis model assessment of β-cell function, hemoglobin A1c levels, fasting blood glucose, incident diabetes, and adverse events.

DATA SYNTHESIS

Thirty-five trials (43 407 patients) with variable risk of bias were included. Vitamin D had no significant effects on insulin resistance [homeostasis model assessment of insulin resistance: MD -0.04; 95% confidence interval (CI) -0.30 to 0.22, I-squared statistic (I(2)) = 45%], insulin secretion (homeostasis model of β-cell function: MD 1.64; 95% CI -25.94 to 29.22, I(2) = 40%), or hemoglobin A1c (MD -0.05%; 95% CI -0.12 to 0.03, I(2) = 55%) compared with controls. Four RCTs reported on the progression to new diabetes and found no effect of vitamin D (odds ratio 1.02; 95% CI 0.94 to 1.10, I(2) = 0%). Adverse events were rare, and there was no evidence of publication bias.

CONCLUSIONS

Evidence from available trials shows no effect of vitamin D3 supplementation on glucose homeostasis or diabetes prevention. Definitive conclusions may be limited in the context of the moderate degree of heterogeneity, variable risk of bias, and short-term follow-up duration of the available evidence to date.

Host-directed therapeutics for tuberculosis: can we harness the host?

Treatment of tuberculosis (TB) remains challenging, with lengthy treatment durations and complex drug regimens that are toxic and difficult to administer. Similar to the vast majority of antibiotics, drugs for Mycobacterium tuberculosis are directed against microbial targets. Although more effective drugs that target the bacterium may lead to faster cure of patients, it is possible that a biological limit will be reached that can be overcome only by adopting a fundamentally new treatment approach. TB regimens might be improved by including agents that target host pathways. Recent work on host-pathogen interactions, host immunity, and host-directed interventions suggests that supplementing anti-TB therapy with host modulators may lead to shorter treatment times, a reduction in lung damage caused by the disease, and a lower risk of relapse or reinfection. We undertook this review to identify molecular pathways of the host that may be amenable to modulation by small molecules for the treatment of TB. Although several approaches to augmenting standard TB treatment have been proposed, only a few have been explored in detail or advanced to preclinical and clinical studies. Our review focuses on molecular targets and inhibitory small molecules that function within the macrophage or other myeloid cells, on host inflammatory pathways, or at the level of TB-induced lung pathology.

Correlation of vitamin D, bone mineral density and parathyroid hormone levels in adults with low bone density

BACKGROUND

Bone mineral densiy (BMD) is known to be affected by serum 25-hydroxyvitamin D (25(OH) D) levels, intact parathyroid hormone (iPTH) levels. Indian data pertinent to above observation is scant. Our study aimed to investigate the relationships between serum 25-hydroxyvitamin D (25(OH) D) levels, intact parathyroid hormone (iPTH) levels and bone mineral density (BMD) in a cohort of Indian patients.

MATERIALS AND METHODS

Adults with or without fragility fractures with low BMD at the hip or lumbar spine were evaluated clinically along with laboratory investigations. T-scores of the hip and spine were derived from BMD-DEXA (dual-energy X-ray absorptiometry). Multivariate regression models were used to investigate the relationships between serum 25(OH) D, iPTH and BMD.

RESULTS

Total of 102 patients (male:female = 38:64) with a mean age of 62.5 ± 6.4 years were included in the study. Forty-four patients had osteopenia. Osteoporosis was present in 58 patients. The mean values for serum 25(OH) D and iPTH levels were 21.3 ± 0.5 ng/ml and 53.1 ± 22.3 pg/ml, respectively. In 84.3% of patients, serum 25(OH) D levels were below 30 ng/ml (Normal = 30-74 ng/ml), confirming vitamin D deficiency. There was no association between 25(OH) D levels and BMD at the hip or lumbar spine (P = 0.473 and 0.353, respectively). Both at the hip and lumbar spine; iPTH levels, male gender, body mass index (BMI) and age were found to be significant predictors of BMD. Patients with higher BMI had significantly lower BMD and T-score. At levels <30 ng/ml, 25(OH) D was negatively associated with iPTH (P = 0.041).

CONCLUSION

Among our cohort of patients with low BMD, no direct relationship between serum 25(OH) D levels and BMD was observed. However, a negative correlation between iPTH and 25(OH) D at serum 25(OH) D concentrations <30 ng/ml. Serum iPTH levels showed a significant negative association with BMD at the hip and lumbar spine. Our findings underscore the critical role of parathyroid hormone in bone metabolism and health.