Statin, calcium channel blocker and Beta blocker therapy may decrease the incidence of tuberculosis infection in elderly Taiwanese patients with type 2 diabetes

Impact of COVID-19 pandemic responses on tuberculosis incidence: insights from Shantou, China

BACKGROUND

Various measures taken against the COVID-19 pandemic are not only effective in reducing the spread of the disease, but also lead to some unexpected results. This article regarded these measures as an intervention and explored their impact on the incidence of tuberculosis in Shantou, China.

METHODS

The incidence rate and the surveillance data of tuberculosis from January 1st, 2018 to December 31st, 2021 were provided by the Shantou Tuberculosis Prevention and Control Institute. Data were divided into pre-pandemic period (January 1st, 2018 - December 31st, 2019) and pandemic periods (January 1st, 2020 - December 31st, 2021). The Interrupted Time Series (ITS) was used to analyze the trend of tuberculosis incidence prior to and during the COVID-19 epidemic.

RESULTS

The results showed that the incidence of tuberculosis cases in Shantou decreased significantly (p < 0.05) during the pandemic as compared to that prior to the pandemic. Among them, the 45-64 age group and the 65 + age group have statistically significant declines. When patients were stratified by occupation, the unemployed and those working in agriculture reduced the most.

CONCLUSIONS

In response to the pandemic, measures like lockdowns and quarantines seem to have reduced tuberculosis incidence. However, this does not imply a true decrease. Underlying causes for the reduced true incidence need further scrutiny. Findings offer a preliminary exploration of interventions designed for one disease but functioning as unexpected results for another.

Association between statin use and tuberculosis risk in patients with bronchiectasis: a retrospective population-based cohort study in Taiwan

BACKGROUND

Chronic airway diseases have been associated with an increased risk of tuberculosis (TB); however, data in patients with bronchiectasis is limited. Statins have been shown to exhibit anti-inflammatory effects by modulating the inflammatory response. This study investigated whether statin treatment could reduce the risk of TB in patients with bronchiectasis.

METHODS

We conducted a retrospective cohort study using a nationwide population database of patients with bronchiectasis who did or did not receive statin treatment. The defined daily dose (DDD) of statin, current or past statin user and statin exposure time were measured for the impact of statin use. The primary outcome was the incidence of new-onset TB. Considering of potential immortal time bias due to stain exposure time, Cox regression models with time-dependent covariates were employed to estimate HRs with 95% CIs for TB incidence among patients with bronchiectasis.

RESULTS

Patients with bronchiectasis receiving statin treatment had a decreased risk of TB. After adjusting for age, sex, income, comorbidities and Charlson Comorbidity Index, statin users had a 0.59-fold lower risk of TB incidence compared with non-statin users (95% CI 0.40 to 0.88; p=0.0087). Additionally, compared with non-statin users, statin treatment was a protective factor against TB in users with a cumulative DDD greater than 180 per year, with an HR of 0.32 (95% CI 0.12 to 0.87; p=0.0255).

CONCLUSIONS

Statin treatment demonstrated a dose-dependent protective effect and was associated with a reduced risk of TB in patients with bronchiectasis. These findings suggest that statins may play a role in lowering TB risk by modulating airway inflammation in this patient population.

Effect of calcium-channel blockers on the risk of active tuberculosis and mortality: systematic review and meta-analysis

Introduction: Recent studies suggest that calcium channel blockers (CCBs) could reduce the risk of active tuberculosis and improve clinical outcomes. We aimed to synthesize the evidence regarding the effect of CCBs on the risk of developing active tuberculosis and mortality. Methods: We systematically searched for observational studies and clinical trials published in six databases until 31 August 2023, following a PECO/PICO strategy. Results: We included eight observational studies, 4,020,830 patients, among whom 241,761 had diabetes mellitus and 30,397 had active tuberculosis. According to our results, CCBs reduce the risk of developing active tuberculosis by 29% (RR 0.71; 95% CI 0.67-0.75) in patients with and without diabetes mellitus. However, CCBs do not show any benefit in terms of tuberculosis-related mortality (RR 1.00; 95% CI 0.98-1.02). For both outcomes, no statistical heterogeneity was found (I2 = 0, p > 0.10). This protective effect of CCBs on the risk of active tuberculosis remained independent of the type of patient (with diabetes mellitus vs. general population) or the class of CCB administered (DHP-CCB vs. non-DHP-CCB) (test for subgroup differences I2 = 0, p > 0.10). However, this beneficial effect was more significant among the general population (RR 0.70; 95% CI 0.66-0.74) compared to patients with diabetes mellitus (RR 0.72; 95% CI 0.61-0.86) and among those patients treated with DHP-CCBs (RR 0.69; 95% CI 0.63-0.74) compared to patients treated with non-DHP-CCBs (RR 0.72; 95% CI 0.67-0.78). Conclusion: CCBs may reduce the risk of active TB in patients with diabetes and the general population. On the contrary, CCBs do not seem to have a protective effect on tuberculosis-related mortality. However, more evidence is still needed. We recommend developing clinical trials to verify these findings, including more diverse populations. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=352129].

Host-directed therapy against mycobacterium tuberculosis infections with diabetes mellitus

Tuberculosis (TB) is caused by the bacterial pathogen Mycobacterium tuberculosis (MTB) and is one of the principal reasons for mortality and morbidity worldwide. Currently, recommended anti-tuberculosis drugs include isoniazid, rifampicin, ethambutol, and pyrazinamide. TB treatment is lengthy and inflicted with severe side-effects, including reduced patient compliance with treatment and promotion of drug-resistant strains. TB is also prone to other concomitant diseases such as diabetes and HIV. These drug-resistant and complex co-morbid characteristics increase the complexity of treating MTB. Host-directed therapy (HDT), which effectively eliminates MTB and minimizes inflammatory tissue damage, primarily by targeting the immune system, is currently an attractive complementary approach. The drugs used for HDT are repositioned drugs in actual clinical practice with relative safety and efficacy assurance. HDT is a potentially effective therapeutic intervention for the treatment of MTB and diabetic MTB, and can compensate for the shortcomings of current TB therapies, including the reduction of drug resistance and modulation of immune response. Here, we summarize the state-of-the-art roles and mechanisms of HDT in immune modulation and treatment of MTB, with a special focus on the role of HDT in diabetic MTB, to emphasize the potential of HDT in controlling MTB infection.

Repositioning of HMG-CoA Reductase Inhibitors as Adjuvants in the Modulation of Efflux Pump-Mediated Bacterial and Tumor Resistance

Efflux pump (EP)-mediated multidrug resistance (MDR) seems ubiquitous in bacterial infections and neoplastic diseases. The diversity and lack of specificity of these efflux mechanisms raise a great obstacle in developing drugs that modulate efflux pumps. Since developing novel chemotherapeutic drugs requires large investments, drug repurposing offers a new approach that can provide alternatives as adjuvants in treating resistant microbial infections and progressive cancerous diseases. Hydroxy-methyl-glutaryl coenzyme-A (HMG-CoA) reductase inhibitors, also known as statins, are promising agents in this respect. Originally, statins were used in the therapy of dyslipidemia and for the prevention of cardiovascular diseases; however, extensive research has recently been performed to elucidate the functions of statins in bacterial infections and cancers. The mevalonate pathway is essential in the posttranslational modification of proteins related to vital eukaryotic cell functions. In this article, a comparative review is given about the possible role of HMG-CoA reductase inhibitors in managing diseases of bacterial and neoplastic origin. Molecular research and clinical studies have proven the justification of statins in this field. Further well-designed clinical trials are urged to clarify the significance of the contribution of statins to the lower risk of disease progression in bacterial infections and cancerous diseases.

A united model for diagnosing pulmonary tuberculosis with random forest and artificial neural network

Background: Pulmonary tuberculosis (PTB) is a chronic infectious disease and is the most common type of TB. Although the sputum smear test is a gold standard for diagnosing PTB, the method has numerous limitations, including low sensitivity, low specificity, and insufficient samples.

Methods: The present study aimed to identify specific biomarkers of PTB and construct a model for diagnosing PTB by combining random forest (RF) and artificial neural network (ANN) algorithms. Two publicly available cohorts of TB, namely, the GSE83456 (training) and GSE42834 (validation) cohorts, were retrieved from the Gene Expression Omnibus (GEO) database. A total of 45 and 61 differentially expressed genes (DEGs) were identified between the PTB and control samples, respectively, by screening the GSE83456 cohort. An RF classifier was used for identifying specific biomarkers, following which an ANN-based classification model was constructed for identifying PTB samples. The accuracy of the ANN model was validated using the receiver operating characteristic (ROC) curve. The proportion of 22 types of immunocytes in the PTB samples was measured using the CIBERSORT algorithm, and the correlations between the immunocytes were determined.

Results: Differential analysis revealed that 11 and 22 DEGs were upregulated and downregulated, respectively, and 11 biomarkers specific to PTB were identified by the RF classifier. The weights of these biomarkers were determined and an ANN-based classification model was subsequently constructed. The model exhibited outstanding performance, as revealed by the area under the curve (AUC), which was 1.000 for the training cohort. The AUC of the validation cohort was 0.946, which further confirmed the accuracy of the model.

Conclusion: Altogether, the present study successfully identified specific genetic biomarkers of PTB and constructed a highly accurate model for the diagnosis of PTB based on blood samples. The model developed herein can serve as a reliable reference for the early detection of PTB and provide novel perspectives into the pathogenesis of PTB.

Incidence and prevalence of pulmonary tuberculosis among patients with type 2 diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

The epidemic of type 2 diabetes mellitus (T2DM) poses a great challenge to pulmonary tuberculosis (PTB) control. However, the incidence and prevalence of PTB among T2DM patients has not been fully determined. This meta-analysis aimed to provide the estimation on the global incidence and prevalence of PTB among T2DM patients (T2DM-PTB).

METHODS

Online databases including Web of Science, PubMed, China National Knowledge Infrastructure and Cochrane Library were searched for all relevant studies that reported the incidence or prevalence of T2DM-PTB through 31 January 2022. Pooled incidence and prevalence of T2DM-PTB with 95% confidence interval (CI) was estimated by the random-effect model. All statistical analyses were performed using R software.

RESULTS

A total of 24 studies (14 cohort studies, 10 cross-sectional studies) were included. The pooled incidence and prevalence of T2DM-PTB were 129.89 per 100,000 person-years (95% confidence interval (CI): 97.55-172.95) and 511.19 per 100,000 (95% CI: 375.94-695.09), respectively. Subgroup analyses identified that the incidence of T2DM-PTB was significantly higher in Asia (187.20 per 100,000 person-years, 95% CI: 147.76-237.17), in countries with a high TB burden (172.04 per 100,000 person-years, 95% CI: 122.98-240.68) and in studies whose data collection ended before 2011 (219.81 per 100,000 person-years, 95% CI: 176.15-274.28), but lower in studies using International Classification of Diseases-10 codes (73.75 per 100,000 person-years, 95% CI: 40.92-132.91). The prevalence of T2DM-PTB was significantly higher in countries with a high TB burden (692.15 per 100,000, 95% CI: 468.75-1022.04), but lower in Europe (105.01 per 100,000, 95% CI: 72.55-151.98).

CONCLUSIONS

This systematic review and meta-analysis suggests high global incidence and prevalence of PTB among T2DM patients, underlining the necessity of more preventive interventions among T2DM patients especially in countries with a high TB-burden. Key messagesA total of 24 studies (14 cohort studies, 10 cross-sectional studies) containing 2,569,451 T2DM patients were included in this meta-analysis.The pooled incidence and prevalence of T2DM-PTB are 129.89 per 100,000 person-years (95% CI: 97.55-172.95) and 511.19 per 100,000 (95% CI: 375.94-695.09) respectively.The incidence of T2DM-PTB was significantly higher in Asia, in countries with a high TB burden and in studies whose data collection ended before 2011, but lower in studies using International Classification of Diseases-10 codes.The prevalence of T2DM-PTB was significantly higher in countries with a high TB-burden, but lower in Europe.

Host-directed therapies in pulmonary tuberculosis: Updates on anti-inflammatory drugs

Tuberculosis (TB) is a lethal disease and remains one of the top ten causes of mortality by an infectious disease worldwide. It can also result in significant morbidity related to persistent inflammation and tissue damage. Pulmonary TB treatment depends on the prolonged use of multiple drugs ranging from 6 months for drug-susceptible TB to 6–20 months in cases of multi-drug resistant disease, with limited patient tolerance resulting from side effects. Treatment success rates remain low and thus represent a barrier to TB control. Adjunct host-directed therapy (HDT) is an emerging strategy in TB treatment that aims to target the host immune response to Mycobacterium tuberculosis in addition to antimycobacterial drugs. Combined multi-drug treatment with HDT could potentially result in more effective therapies by shortening treatment duration, improving cure success rates and reducing residual tissue damage. This review explores the rationale and challenges to the development and implementation of HDTs through a succinct report of the medications that have completed or are currently being evaluated in ongoing clinical trials.

Further insights into to the role of statins against active tuberculosis: systematic review and meta-analysis

OBJECTIVES

Tuberculosis is a major cause of global morbidity and mortality. Statins could be associated with a lower risk of some infectious diseases, including tuberculosis. Statins could reduce the risk of latent tuberculosis infection and active tuberculosis, acting as an adjuvant in treating tuberculosis. This study aimed to determine if statins reduce the risk of active tuberculosis.

METHODS

We systematically analyzed 8 databases from inception to December 2021. We included articles without language restriction if they met our inclusion and exclusion criteria and the PECO strategy (Population: adults without active pulmonary tuberculosis; Exposure: treatment with any statin; Comparator: no use of statins; Outcome: active tuberculosis). Odds Ratios (ORs) with 95% confidence intervals (CIs) were pooled using random- effects models regardless of heterogeneity quantified by Cochran's Q and I² statistics. We performed subgroup analyses according to the participants' diabetic status and follow-up length (≤10 years or >10 years).

RESULTS

Twelve articles reporting observational studies involving 3.038.043 participants, including at least 32.668 cases of active tuberculosis. Eight reported retrospective cohort studies, three nested case-control study, and one was a case control study.According to our meta-analysis, statins may reduce the risk of active tuberculosis, in the general population (OR 0.66; 95% CI, 0.54-0.81), in non-diabetic (OR 0.66; 95% CI, 0.54-0.80) and in diabetic patients (OR 0.65; 95% CI, 0.49-0.87). This protective effect did not differ according to the participants' diabetic status nor follow-up length (test for subgroup differences I²=0). We found significant clinical and methodological heterogeneity. Similarly, the forest plot, and the I² and Chi² statistics suggested considerable statistical heterogeneity (I²=95%, p<0.05, respectively). Of the 12 included studies, 9 were at low risk of bias and 3 were at high risk of bias. Similarly, according to the funnel plot, it is very likely that there are important publication biases.

CONCLUSION

Statin use may significantly reduce the risk of tuberculosis in the general population, diabetic and non-diabetic patients. Nevertheless, caution should be exercised when interpreting these conclusions, due to the quality of the evidence, the heterogeneity of the studies, the presence of bias, and the difficulty in extrapolating these results to populations of other races and ethnicities.

Recent Advances in Host-Directed Therapies for Tuberculosis and Malaria

Tuberculosis (TB), caused by the bacterium Mycobacterium tuberculosis, and malaria, caused by parasites from the Plasmodium genus, are two of the major causes of death due to infectious diseases in the world. Both diseases are treatable with drugs that have microbicidal properties against each of the etiologic agents. However, problems related to treatment compliance by patients and emergence of drug resistant microorganisms have been a major problem for combating TB and malaria. This factor is further complicated by the absence of highly effective vaccines that can prevent the infection with either M. tuberculosis or Plasmodium. However, certain host biological processes have been found to play a role in the promotion of infection or in the pathogenesis of each disease. These processes can be targeted by host-directed therapies (HDTs), which can be administered in conjunction with the standard drug treatments for each pathogen, aiming to accelerate their elimination or to minimize detrimental side effects resulting from exacerbated inflammation. In this review we discuss potential new targets for the development of HDTs revealed by recent advances in the knowledge of host-pathogen interaction biology, and present an overview of strategies that have been tested in vivo, either in experimental models or in patients.

Targeting Molecular Inflammatory Pathways in Granuloma as Host-Directed Therapies for Tuberculosis

Globally, more than 10 million people developed active tuberculosis (TB), with 1.4 million deaths in 2020. In addition, the emergence of drug-resistant strains in many regions of the world threatens national TB control programs. This requires an understanding of host-pathogen interactions and finding novel treatments including host-directed therapies (HDTs) is of utter importance to tackle the TB epidemic. Mycobacterium tuberculosis (Mtb), the causative agent for TB, mainly infects the lungs causing inflammatory processes leading to immune activation and the development and formation of granulomas. During TB disease progression, the mononuclear inflammatory cell infiltrates which form the central structure of granulomas undergo cellular changes to form epithelioid cells, multinucleated giant cells and foamy macrophages. Granulomas further contain neutrophils, NK cells, dendritic cells and an outer layer composed of T and B lymphocytes and fibroblasts. This complex granulomatous host response can be modulated by Mtb to induce pathological changes damaging host lung tissues ultimately benefiting the persistence and survival of Mtb within host macrophages. The development of cavities is likely to enhance inter-host transmission and caseum could facilitate the dissemination of Mtb to other organs inducing disease progression. This review explores host targets and molecular pathways in the inflammatory granuloma host immune response that may be beneficial as target candidates for HDTs against TB.

Statin use and impact on tuberculosis risk

Introduction: Tuberculosis, a chronic infection caused by Mycobacterium tuberculosis (MTB), is one of the 10 leading causes of death in the world. The current treatment is a combination antimicrobial therapy administered for 6-9 months. It is important to find therapeutic strategy to shorten the treatment during and strengthen the host immune response against MTB.Areas covered: There is evidence that MTB uses cholesterol in the host macrophage to infect and survive inside the host macrophage. Statins inhibit the synthesis of cholesterol and aid in reducing the levels of cholesterol in human, which have been associated with better outcome in infectious diseases. In this narrative review, we discuss recent studies that investigated the effects of statins on the prevention or treatment of TB infection.Expert opinion: The evaluation of the published evidence suggests that statins may be beneficial in the treatment of patients with TB infections. Future studies may focus not only on the beneficial effects of statins, but also on distinguishing the effects of different statins.

Use of Calcium Channel Blockers and Risk of Active Tuberculosis Disease: A Population-Based Analysis

Calcium channel blockers (CCBs) are known to reduce the availability of iron-an important mineral for intracellular pathogens. Nonetheless, whether the use of CCBs modifies the risk of active tuberculosis in the clinical setting remains unclear. To determine whether CCBs may modify the risk of active tuberculosis disease, we conducted a nested case-control study using the National Health Insurance Research Database of Taiwan between January 1999 and December 2011. Conditional logistic regression and disease risk score adjustment were used to calculate the risk of active tuberculosis disease associated with CCB use. Subgroup analyses investigated the effect of different types of CCBs and potential effect modification in different subpopulations. A total of 8164 new active tuberculosis cases and 816 400 controls were examined. Use of CCBs was associated with a 32% decrease in the risk of active tuberculosis (relative risk [RR], 0.68 [95% CI, 0.58-0.78]) after adjustment with disease risk score. Compared with nonuse of CCBs, the use of dihydropyridine CCBs was associated with a lower risk of tuberculosis (RR, 0.63 [95% CI, 0.53-0.79]) than nondihydropyridine CCBs (RR, 0.73 [95% CI, 0.57-0.94]). In contrast, use of β-blockers (RR, 0.99 [95% CI, 0.83-1.12]) or loop diuretics (RR, 0.88 [95% CI, 0.62-1.26]) was not associated with lower risk of tuberculosis. In subgroup analyses, the risk of tuberculosis associated with the use of CCBs was similar among patients with heart failure or cerebrovascular diseases. Our study confirms that use of dihydropyridine CCBs decreases the risk of active tuberculosis.

α-Glucosidase Inhibitor Can Effectively Inhibit the Risk of Tuberculosis in Patients with Diabetes: A Nested Case-Control Study

Diabetes mellitus (DM) and tuberculosis (TB) are major public health and economic burdens. DM increases Mycobacterium tuberculosis (M.tb) infection rates and treatment durations. This study evaluated the relationship between five classes of oral DM medications and TB infection risk in DM patients. We used longitudinal records from the Taiwan Longitudinal Health Insurance Research Database. DM patients were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 250 and A code A181. TB patients were identified using ICD-9-CM code 010.x-017.x. Oral DM medications were divided into five classes: sulfonylureas, biguanides, meglitinides, α-glucosidase inhibitors (AGIs), and thiazolidinediones. Users were classified as nonusers, low-concentration users, and high-concentration users. The incidence rate ratio (IRR) was derived using multivariate Poisson regression to calculate the relative risk of TB infection. DM patients using low- and high-concentration AGIs had significantly lower TB infection risks compared with nonusers. The IRRs of the sulfonylureas and AGI users were [CI] 0.693-0.948) and (95% CI 0.651-0.995), respectively. The other four classes of medications exhibited no significant effect on TB infection risk in DM patients. Furthermore, DM patients using high-concentration AGIs had a significantly lower TB infection risk compared with those using low-concentration AGIs (IRR 0.918, 95% CI: 0.854-0.987). We noted a dose-response relationship in the effects of DM medications on TB risk. Accordingly, we suggest that DM patients use AGIs to benefit from their protective effect on TB infection risk.

Statin Use May Be Associated With Reduced Active Tuberculosis Infection: A Meta-Analysis of Observational Studies

Background: Tuberculosis remains one of the leading causes of mortality among the infectious diseases, while statins were suggested to confer anti-infective efficacy in experimental studies. We aimed to evaluate the association between statin use and tuberculosis infection in a meta-analysis.

Method: Relevant studies were obtained via systematically search of PubMed and Embase databases. A random or a fixed effect model was applied to pool the results according to the heterogeneity among the included studies. Subgroup analyses according to the gender and diabetic status of the participants were performed. We assessed the quality of evidence with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Results: Nine observational studies were included. Significant heterogeneity was detected among the studies (p for Cochrane's Q test <0.001, I² = 93%). The GRADE approach showed generally low quality of evidence. Pooled results showed that statin use was associated with reduced active tuberculosis infection (risk ratio [RR]: 0.60, 95% confidence interval [CI]: 0.45 to 0.75, p < 0.001). Subgroup analyses showed that the negative association between statin use and active tuberculosis infection was consistent in men (RR: 0.63, p = 0.01) and women (RR: 0.58, p < 0.001), in participants with (RR: 0.63, p = 0.02) and without diabetes (RR: 0.50, p < 0.001), in retrospective cohort studies (RR: 0.56, p = 0.02), prospective cohort studies (RR: 0.76, p = 0.03), nested case-controls studies (RR: 0.57, p < 0.001), and case-control studies (RR: 0.60, p < 0.001), and in studies with statin used defined as any use within 1 year (RR: 0.59, p < 0.001) or during follow-up (RR: 0.61, p < 0.001). Significant publication bias was detected (p for Egger's regression test = 0.046). Subsequent “trim and fill” analyses retrieved an unpublished study to generate symmetrical funnel plots, and meta-analysis incorporating this study did not significantly affect the results (RR: 0.72, 95% CI: 0.68 to 0.76, p < 0.001).

Conclusions: Statin use may be associated with reduced active tuberculosis infection. Randomized controlled trials (RCTs) are needed to confirm the potential preventative role of statin use on tuberculosis infection.

Anti-tuberculous Effects of Statin Therapy: A Review of Literature

Tuberculosis (TB) is a chronic infection caused by Mycobacterium tuberculosis (M. TB). It is transmitted through respiratory droplets. Increased cholesterol level is a predisposing factor for TB. M. TB uses cholesterol in the host macrophage membranes to bind and enter the macrophages. Statins are the drugs that are prescribed to hyperlipidemic patients to maintain their lipid levels in the normal range, thereby reducing the risk of stroke and cardiovascular events. Moreover, statins aid in reducing the levels of cholesterol in human macrophages. Therefore, a reduction in the membrane cholesterol minimizes the entry of TB pathogen inside macrophages. Furthermore, acting as vitamin D3 analogs and positively influencing pancreatic beta-cell function in a chronic diabetic state, statins minimize the occurrence of M. TB infection among diabetic population as well. This review aims to provide a comprehensive detail of all in vitro, in vivo, and retrospective studies that investigated the effects of statins in relation to the prevention or treatment of TB infection.

Effects of host-directed therapies on the pathology of tuberculosis

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), has co-evolved with the human immune system and utilizes multiple strategies to persist within infected cells, to hijack several immune mechanisms, and to cause severe pathology and tissue damage in the host. This delays the efficacy of current antibiotic therapy and contributes to the evolution of multi-drug-resistant strains. These challenges led to the development of the novel approach in TB treatment that involves therapeutic targeting of host immune response to control disease pathogenesis and pathogen growth, namely, host-directed therapies (HDTs). Such HDT approaches can (1) enhance the effect of antibiotics, (2) shorten treatment duration for any clinical form of TB, (3) promote development of immunological memory that could protect against relapse, and (4) ameliorate the immunopathology including matrix destruction and fibrosis associated with TB. In this review we discuss TB-HDT candidates shown to be of clinical relevance that thus could be developed to reduce pathology, tissue damage, and subsequent impairment of pulmonary function. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Statin use and risk of tuberculosis: a systemic review of observational studies

OBJECTIVES

Statin intake may be linked with a lower risk of several infectious diseases, including tuberculosis, which is an important cause of mortality worldwide. The aim of this study was to investigate the definite impacts of statins on the risk of tuberculosis (TB) in diabetic patients and in the general population.

METHODS

Four databases were thoroughly searched from inception up to July 2019. Articles in any language were included if they assessed and clarified statin intake, presented the risk of TB in diabetes mellitus (DM) patients or the general population, and reported odds ratios (ORs), relative risks (RRs), or hazard ratios (HRs) or contained data for relevant calculation. RRs with 95% confidence intervals (CIs) were pooled using random-effects models regardless of heterogeneity quantified by Cochran's Q and I² statistics.

RESULTS

Six articles reporting observational studies involving 2 073 968 patients were included. Four reported cohort studies, one a nested case-control study, and one was an abstract. Statin use significantly reduced the risk of TB in DM patients by 22% (pooled RR 0.78, 95% CI 0.63-0.95), with severe heterogeneity (I² = 76.1%). Statin intake also significantly decreased the risk of TB in the general population by 40% (pooled RR 0.60, 95% CI 0.50-0.71), with severe heterogeneity (I² = 57.7%).

CONCLUSIONS

Statin use is related to a considerably lower risk of TB in both DM patients and the general population. However, these conclusions should be interpreted with caution given the possible remaining confounding, and call for large-size and multicenter randomized controlled studies in the future.

Changes in Host Response to Mycobacterium tuberculosis Infection Associated With Type 2 Diabetes: Beyond Hyperglycemia

Tuberculosis (TB) remains as the first cause of death among infectious diseases worldwide. Global incidence of tuberculosis is in part coincident with incidence of type 2 diabetes (T2D). Incidence of T2D is recognized as a high-risk factor that may contribute to tuberculosis dissemination. However, mechanisms which favor infection under T2D are just starting to emerge. Here, we first discuss the evidences that are available to support a metabolic connection between TB and T2D. Then, we analyze the evidences of metabolic changes which occur during T2D gathered thus far for its influence on susceptibility to M. tuberculosis infection and TB progression, such as hyperglycemia, increase of 1AC levels, increase of triglycerides levels, reduction of HDL-cholesterol levels, increased concentration of lipoproteins, and modification of the activity of some hormones related to the control of metabolic homeostasis. Finally, we recognize possible advantages of metabolic management of immunity to develop new strategies for treatment, diagnosis, and prevention of tuberculosis.

Use of lipid-lowering agents is not associated with improved outcomes for tuberculosis patients on standard-course therapy: A population-based cohort study

Objectives

Animal and ex vitro studies suggested lipid-lowering agents (LLAs) may be used as an adjunct to standard anti- tuberculosis (TB) treatment. No human study has been conducted to date. Using the Taiwan National Health Insurance Research Database (NHIRD), the current population-based cohort study sought to examine the association between use of LLAs and outcomes of patients with pulmonary TB receiving anti-TB treatment.

Methods

Using a NHIRD from 2003 to 2010, this population-based cohort study retrospectively examined the association between LLAs (statins or fibrates) and the outcomes of patients with pulmonary TB receiving anti-TB treatment.

Results

A total of 1452 adult patients newly diagnosed with pulmonary TB during the study period were identified and compared with 5808 matched patients. In the LAA cohort, 1258 received statin, and 295 received fibrate. Compared with patients who did not take LLA, patients who took oral LLAs had similar incidence of treatment completion at 9, 12, and 24 months.

Conclusions

Neither statins nor fibrates provide clinical benefit superior to that achieved with standard anti-tuberculosis treatment. Future clinical trials should investigate the effects of statins and fibrates on short-course standard anti-TB therapy.

Potential Effect of Statins on Mycobacterium tuberculosis Infection

Tuberculosis is one of the 10 leading causes of death in the world. The current treatment is based on a combination of antimicrobials administered for six months. It is essential to find therapeutic agents with which the treatment time can be shortened and strengthen the host immune response against Mycobacterium tuberculosis. M. tuberculosis needs cholesterol to infect and survive inside the host, but the progression of the infection depends to a large extent on the capacity of the immune response to contain the infection. Statins inhibit the synthesis of cholesterol and have pleiotropic effects on the immune system, which have been associated with better results in the treatment of several infectious diseases. Recently, it has been reported that cells treated with statins are more resistant to M. tuberculosis infection, and they have even been proposed as adjuvants in the treatment of M. tuberculosis infection. The aim of this review is to summarize the immunopathogenesis of tuberculosis and its mechanisms of evasion and to compile the available scientific information on the effect of statins in the treatment of tuberculosis.

Metformin use is associated with a low risk of tuberculosis among newly diagnosed diabetes mellitus patients with normal renal function: A nationwide cohort study with validated diagnostic criteria

Human studies on the use of metformin as host-directed therapy (HDT) for tuberculosis (TB) are rare. We performed a nationwide cohort study to evaluate the effect of metformin on mitigating the risk of active TB among patients with diabetes mellitus (DM). Among newly diagnosed DM patients identified in the Taiwan National Health Insurance Research Database, metformin users, defined on the basis of >90 cumulative defined daily doses within 1 year, and propensity-score-matched metformin nonusers were selected. The primary outcome was incident TB, identified using diagnostic criteria validated by real patient data at a medical center. Independent predictors were investigated using Cox regression analysis. Similar analysis was performed in a subpopulation without a history of hypertensive nephropathy and renal replacement therapy. A total of 88,866 metformin users and 88,866 propensity-score-matched nonusers were selected. Validation results showed that the TB diagnostic criteria had a sensitivity of 99.13% and specificity of 99.90%. During follow-up, 707 metformin users and 807 nonusers developed active TB. Metformin use was independently associated with a lower risk of incident TB (hazard ratio [HR]: 0.84 [0.74-0.96]). TB risk was lower in high-dose metformin users than in low-dose users (HR: 0.83 [0.72-0.97]). The effect of metformin remained when analysis was restricted in the subpopulation without renal function impairment. Newly diagnosed diabetic patients without contraindication should receive metformin as an anti-diabetic medication, with potential additional benefit against TB.

Calcium Ion Channels: Roles in Infection and Sepsis Mechanisms of Calcium Channel Blocker Benefits in Immunocompromised Patients at Risk for Infection

Immunosuppression may occur for a number of reasons related to an individual's frailty, debility, disease or from therapeutic iatrogenic intervention or misadventure. A large percentage of morbidity and mortality in immunodeficient populations is related to an inadequate response to infectious agents with slow response to antibiotics, enhancements of antibiotic resistance in populations, and markedly increased prevalence of acute inflammatory response, septic and infection related death. Given known relationships between intracellular calcium ion concentrations and cytotoxicity and cellular death, we looked at currently available data linking blockade of calcium ion channels and potential decrease in expression of sepsis among immunosuppressed patients. Notable are relationships between calcium, calcium channel, vitamin D mechanisms associated with sepsis and demonstration of antibiotic-resistant pathogens that may utilize channels sensitive to calcium channel blocker. We note that sepsis shock syndrome represents loss of regulation of inflammatory response to infection and that vitamin D, parathyroid hormone, fibroblast growth factor, and klotho interact with sepsis defense mechanisms in which movement of calcium and phosphorus are part of the process. Given these observations we consider that further investigation of the effect of relatively inexpensive calcium channel blockade agents of infections in immunosuppressed populations might be worthwhile.

Electroconvulsive Therapy and Risk of Dementia-A Nationwide Cohort Study in Taiwan

Background: Electroconvulsive therapy (ECT) is an effective treatment for schizophrenia, bipolar disorder, and major depressive disorder, and a temporary memory loss may occur after ECT. However, the association between ECT in patients with schizophrenia, bipolar disorder, and major depressive disorder, and the risk of dementia is yet to be examined. Objective: This study aimed to clarify as to whether ECT is associated with the risk of dementia after ECT in patients with schizophrenia, bipolar disorder, and major depressive disorder, using Taiwan's National Health Insurance Research Database (NHIRD). Methods: A total of 3,796 enrolled participants (schizophrenia, 46.68%; bipolar disorder, 11.77%; and major depressive disorder, 41.55%) with 994 patients who had received ECT and 2,982 controls matched for sex and age, between January 1, and December 31, 2000, were selected from the NHIRD. After adjusting for confounding factors, Fine and Gray's survival analysis was used to compare the risk of developing dementia during the 10 years of follow-up. Results: Of the study patients, 45 (4.53%) of them developed dementia when compared to 149 (5.0%) in the control group. Fine and Gray's survival analysis revealed that the study patients were not associated with an increased risk of dementia [hazard ratio (HR) = 0.612, 95% confidence interval (CI) = 0.438-1.854, P = 0.325]. After adjusting for sex, age, monthly income, urbanization level, geographic region, and comorbidities, the adjusted HR was 0.633 (95% CI = 0.448 - 1.895, P = 0.304). Conclusion: This study supports that ECT was not associated with the increased risk of dementia in patients with schizophrenia, bipolar disorder, and major depressive disorder, using the NHIRD.

The Risk of TB in Patients With Type 2 Diabetes Initiating Metformin vs Sulfonylurea Treatment

BACKGROUND

Metformin and the sulfonylureas are common initial antidiabetic agents; the former has demonstrated anti-TB action in in vitro and animal studies. The comparative effect of metformin vs the sulfonylureas on TB risk in patients with type 2 diabetes mellitus (T2DM) remains unclear.

METHODS

In this retrospective cohort study, patients without chronic kidney disease who received a T2DM diagnosis during 2003 to 2013 were identified from the Taiwan National Health Insurance Research Database. Participants with ≥ 2 years of follow-up were reviewed and observed for TB until December 2013. Patients receiving metformin ≥ 60 cumulative defined daily dose (cDDD) and sulfonylureas < 15 cDDD in the initial 2 years were defined as metformin majors; it was the inverse for sulfonylurea majors. The two groups were matched 1:1 by propensity score and compared for TB risk by multivariate Cox regression analysis.

RESULTS

Among 40,179 patients with T2DM, 263 acquired TB (0.65%) over a mean follow-up of 6.1 years. In multivariate analysis, the initial 2-year dosage of metformin, but not that of the sulfonylureas, was an independent predictor of TB (60-cDDD increase (adjusted hazard ratio [HR], 0.931; 95% CI, 0.877-0.990) after adjustment by cofactors, including adapted diabetes complication severity index. Metformin majors had a significantly lower TB risk than that of sulfonylurea majors before and after matching (HR, 0.477; 95% CI, 0.268-0.850 and HR, 0.337; 95% CI, 0.169-0.673; matched pairs, n = 3,161). Compared with the reference group (initial 2-year metformin < 60 cDDD), metformin treatment showed a dose-dependent association with TB risk (60-219 cDDD; HR, 0.860; 95% CI, 0.637-1.161; 220-479 cDDD, HR, 0.706; 95% CI, 0.485-1.028; ≥ 480 cDDD, HR, 0.319; 95% CI, 0.118-0.863).

CONCLUSIONS

Metformin use in the initial 2 years was associated with a decreased risk of TB, and metformin users had a reduced risk compared with their sulfonylurea comparators.

Potential effect of ezetimibe against Mycobacterium tuberculosis infection in type II diabetes

BACKGROUND AND OBJECTIVE

Tuberculosis (TB) risk might be increased in patients with diabetes by factors other than hyperglycaemia, such as dyslipidaemia. Host lipids are essential energy sources used by mycobacteria to persist in a latent TB state. A potential therapy targeting cholesterol catabolism of mycobacteria has been proposed, but the potential of cholesterol-lowering drugs as anti-TB therapy is unclear. The purpose of this study was to determine the effects of ezetimibe, a 2-azetidinone cholesterol absorption inhibitor, on intracellular mycobacteria survival and dormancy.

METHODS

Intracellular mycobacteria survival was determined by measurements of ATP activity and colony-formation units (CFUs). Gene expression profiles of hypoxia-induced dormant Mycobacterium tuberculosis (Mtb) were analysed by real-time PCR. Flow cytometry and microscopy analysis were used to measure the lipid loads of human macrophages with or without ezetimibe treatment. QuantiFERON-TB Gold In-Tube (QFT-G-IT) assays were performed to diagnose latent TB infection. The levels of intracellular cholesterol/ triglyceride were measured by an enzymatic fluorometric method.

RESULTS

Ezetimibe was capable of effectively lowering intracellular growth of Mtb and hypoxia-induced dormant Mtb. There was a significant decrease in Mtb growth in leucocytes from ezetimibe-treated patients with diabetes in terms of ATP levels of intracellular mycobacteria and CFU formation. Also, patients receiving ezetimibe therapy had a lower prevalence of latent TB and had lower intracellular lipid contents.

CONCLUSION

Ezetimibe, which is a currently marketed drug, could hold promise as an adjunctive, host-directed therapy for TB.

Association between statins and infections among patients with diabetes: a cohort and prescription sequence symmetry analysis

Purpose

A previous meta‐analysis of randomized trials did not confirm findings from observational studies that suggested that statins reduce the risk of infection. However, animal experiments indicate that statins may be more effective in reducing the risk and/or the severity of infection among patients with diabetes. Hence, we evaluated the effect of statins on antibiotic prescriptions (a proxy for infections) among patients with drug‐treated type 2 diabetes using two confounding‐reducing observational designs.

Methods

We conducted a prescription sequence symmetry analysis and a cohort study using the IADB.nl pharmacy prescription database. For the prescription sequence symmetry analysis, a sequence ratio was calculated. The matched cohort study, comparing the time to first antibiotic prescription between periods that statins are initiated and non‐use periods, was analyzed using stratified Cox regression.

Results

Prescription sequence symmetry analysis of 4684 patients with drug‐treated type 2 diabetes resulted in an adjusted sequence ratio of 0.86 (95% confidence interval [CI]: 0.81 to 0.91). Corresponding figures for the cohort analysis comparing 9852 statin‐initiation with 4928 non‐use periods showed similar results (adjusted hazard ratio: 0.88, 95%CI: 0.83 to 0.95).

Conclusions

These findings suggest that statins are associated with a reduced risk of infections among patients with drug‐treated type 2 diabetes. © 2016 The Authors. Pharmacoepidemiology and Drug Safety Published by John Wiley & Sons Ltd.

Association of tuberculosis and diabetes Mellitus: an analysis of 1000 consecutively admitted cases in a tertiary care hospital of North India

INTRODUCTION

The association of Tuberculosis and Diabetes Mellitus is a cause of concern for the health sector. The coexistence of these two highly prevalent diseases has made the already existing treatments very complex. This issue is of particular significance to developing countries like India that bear a significant burden of these two diseases.

METHODS

Retrospective analysis of 1000 consecutively admitted patients in a tertiary care hospital were analyzed for the coexistence of Tuberculosis and Diabetes Mellitus.

RESULTS

The study found that a significant proportion of diabetic patients had coexistent tuberculosis (65.5%). Rural population was predominantly affected in both the genders. The study observed that the coexistence of these two conditions increased with advanced age.

CONCLUSION

The coexistence of Diabetes Mellitus with Tuberculosis needs to identified early and adequately addressed. The rural population needs to be educated about these two conditions and seek timely medical care.