Pioglitazone and Risk of Chronic Obstructive Pulmonary Disease in Patients with Type 2 Diabetes Mellitus: A Retrospective Cohort Study

Pioglitazone and asthma: a review of current evidence

OBJECTIVE

This review aims to present existing evidence on the impact of pioglitazone, a thiazolidinedione class anti-diabetic drug, on asthma control and lung function, providing a comprehensive understanding of its potential as a treatment for asthma.

DATA SOURCES

The review draws upon data from preclinical animal studies and clinical trials investigating the effects of pioglitazone on asthma, focusing on its role in reducing airway inflammation, hyperreactivity, and remodeling, and its impact on pulmonary function.

STUDY SELECTIONS

Relevant studies were selected based on their examination of pioglitazone's therapeutic effects in asthma, including both animal models and clinical trials involving human asthma patients.

RESULTS

Animal studies have suggested that pioglitazone could alleviate inflammation, airway hyperreactivity, and airway remodeling, thereby improving pulmonary function in asthma. However, clinical trials have not demonstrated significant therapeutic benefits, with minimal improvements observed in asthma control and lung function, and the presence of notable side effects.

CONCLUSION

Despite promising preclinical data, the efficacy of pioglitazone in treating human asthma remains unproven, with safety concerns and limited clinical benefits observed in trials. Further research is needed to assess the safety and effectiveness of pioglitazone in asthma treatment and to explore its impact on other inflammatory mechanisms.

Causal relationship between type 2 diabetes and common respiratory system diseases: a two-sample Mendelian randomization analysis

Background

Type 2 diabetes (T2D) frequently co-occurs with respiratory system diseases such as chronic obstructive pulmonary disease (COPD), bronchial asthma, lung cancer, interstitial lung disease, and pulmonary tuberculosis. Although a potential association is noted between these conditions, the available research is limited.

Objective

To investigate the causal relationship between patients with T2D and respiratory system diseases using two-sample Mendelian randomization analysis.

Methods

Causal relationships were inferred using a two-sample Mendelian randomization (MR) analysis based on publicly available genome-wide association studies. We employed the variance inverse-weighted method as the primary analytical approach based on three key assumptions underlying MR analysis. To bolster the robustness and reliability of our results, we utilized MR Egger's intercept test to detect potential pleiotropy, Cochran's Q test to assess heterogeneity, funnel plots to visualize potential bias, and "leave-one-out" sensitivity analysis to ensure that our findings were not unduly influenced by any single genetic variant.

Result

The inverse variance weighted (IVW) analysis indicated a causal relationship between T2D and COPD [Odds Ratio (OR) = 0.87; 95% Confidence Interval (CI) = 0.82-0.96; p < 0.05]. No significant heterogeneity or pleiotropy were observed through their respective tests (p > 0.05), and the statistical power calculations indicated that the results were reliable. The IVW analysis showed a negative causal relationship between T2D and bronchial asthma [OR = 0.85; 95% CI = 0.81-0.89; p < 0.05]. However, the IVW under the random-effects model indicated heterogeneity (p < 0.05), suggesting instability in the results and requiring cautious interpretation. The study found a positive causal relationship between T2D and pulmonary tuberculosis (OR = 1.24, 95% CI = 1.05-1.45, p < 0.05). However, they exhibited pleiotropy (p < 0.05), indicating their instability. No correlation between T2D and interstitial lung disease or lung cancer was observed.

Conclusion

T2D is negatively associated with COPD, suggesting that T2D may reduce the risk of developing COPD. A negative causal relationship between T2D and bronchial asthma has been observed, but the results exhibit heterogeneity. There is a positive causal relationship between T2D and pulmonary tuberculosis, yet the findings suggest the presence of pleiotropy. No significant causal relationship between T2D and lung cancer or interstitial lung disease was observed.

Hyperglycaemia and Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) may coexist with type 2 diabetes mellitus (T2DM). Patients with COPD have an increased risk of developing T2DM compared with a control but, on the other side, hyperglycaemia and DM have been associated with reduced predicted levels of lung function. The mechanistic relationships between these two diseases are complicated, multifaceted, and little understood, yet they can impact treatment strategy. The potential risks and benefits for patients with T2DM treated with pulmonary drugs and the potential pulmonary risks and benefits for patients with COPD when taking antidiabetic drugs should always be considered. The interaction between the presence and/or treatment of COPD, risk of infection, presence and/or treatment of T2DM and risk of acute exacerbations of COPD (AECOPDs) can be represented as a vicious circle; however, several strategies may help to break this circle. The most effective approach to simultaneously treating T2DM and COPD is to interfere with the shared inflammatory substrate, thus targeting both lung inflammation (COPD) and vascular inflammation (DM). In any case, it is always crucial to establish glycaemic management since the reduction in lung function found in people with diabetes might decrease the threshold for clinical manifestations of COPD. In this article, we examine possible connections between COPD and T2DM as well as pharmacological strategies that could focus on these connections.

PPARG stimulation restored lung mRNA expression of core clock, inflammation- and metabolism-related genes disrupted by reversed feeding in male mice

The circadian rhythm system regulates lung function as well as local and systemic inflammations. The alteration of this rhythm might be induced by a change in the eating rhythm. Peroxisome proliferator-activated receptor gamma (PPARG) is a key molecule involved in circadian rhythm regulation, lung functions, and metabolic processes. We described the effect of the PPARG agonist pioglitazone (PZ) on the diurnal mRNA expression profile of core circadian clock genes (Arntl, Clock, Nr1d1, Cry1, Cry2, Per1, and Per2) and metabolism- and inflammation-related genes (Nfe2l2, Pparg, Rela, and Cxcl5) in the male murine lung disrupted by reversed feeding (RF). In mice, RF disrupted the diurnal expression pattern of core clock genes. It decreased Nfe2l2 and Pparg and increased Rela and Cxcl5 expression in lung tissue. There were elevated levels of IL-6, TNF-alpha, total cells, macrophages, and lymphocyte counts in bronchoalveolar lavage (BAL) with a significant increase in vascular congestion and cellular infiltrates in male mouse lung tissue. Administration of PZ regained the diurnal clock gene expression, increased Nfe2l2 and Pparg expression, and reduced Rela, Cxcl5 expression and IL-6, TNF-alpha, and cellularity in BAL. PZ administration at 7 p.m. was more efficient than at 7 a.m.

Cardiovascular diseases or type 2 diabetes mellitus and chronic airway diseases: mutual pharmacological interferences

Chronic airway diseases (CAD), mainly asthma and chronic obstructive pulmonary disease (COPD), are frequently associated with different comorbidities. Among them, cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) pose problems for the simultaneous treatment of CAD and comorbidity. Indeed, there is evidence that some drugs used to treat CAD negatively affect comorbidity, and, conversely, some drugs used to treat comorbidity may aggravate CAD. However, there is also growing evidence of some beneficial effects of CAD drugs on comorbidities and, conversely, of the ability of some of those used to treat comorbidity to reduce the severity of lung disease. In this narrative review, we first describe the potential cardiovascular risks and benefits for patients using drugs to treat CAD and the potential lung risks and benefits for patients using drugs to treat CVD. Then, we illustrate the possible negative and positive effects on T2DM of drugs used to treat CAD and the potential negative and positive impact on CAD of drugs used to treat T2DM. The frequency with which CAD and CVD or T2DM are associated requires not only considering the effect that drugs used for one disease condition may have on the other but also providing an opportunity to develop therapies that simultaneously favorably impact both diseases.

Pharmacological reversal of post-transcriptional alterations implicated in alcohol-induced alveolar macrophage dysfunction

Alcohol use disorders (AUD) cause alveolar macrophage (AM) immune dysfunction and increase risk of lung infections. Excessive alcohol use causes AM oxidative stress, which impairs AM phagocytosis and pathogen clearance from the alveolar space. Alcohol induces expression of NADPH oxidases (Noxes), primary sources of oxidative stress in AM. In contrast, alcohol decreases AM peroxisome proliferator-activated receptor gamma (PPARγ), a critical regulator of AM immune function. To explore the underlying molecular mechanisms for these effects of alcohol, we hypothesized that ethanol promotes CCAAT/enhancer-binding protein beta (C/EBPβ)-mediated suppression of Nox-related microRNAs (miRs), in turn enhancing AM Nox expression, oxidative stress, and phagocytic dysfunction. We also hypothesized that PPARγ activation with pioglitazone (PIO) would reverse alcohol-induced C/EBPβ expression and attenuate AM oxidative stress and phagocytic dysfunction. Cells from the mouse AM cell line (MH-S) were exposed to ethanol in vitro or primary AM were isolated from mice fed ethanol in vivo. Ethanol enhanced C/EBPβ expression, decreased Nox 1-related miR-1264 and Nox 2-related miR-107 levels, and increased Nox1, Nox2, and Nox 4 expression in MH-S cells in vitro and mouse AM in vivo. These alcohol-induced AM derangements were abrogated by loss of C/EBPβ, overexpression of miRs-1264 or -107, or PIO treatment. These findings identify C/EBPβ and Nox-related miRs as novel therapeutic targets for PPARγ ligands, which could provide a translatable strategy to mitigate susceptibility to lung infections in people with a history of AUD. These studies further clarify the molecular underpinnings for a previous clinical trial using short-term PIO treatment to improve AM immunity in AUD individuals.

Pioglitazone Has a Null Association with Inflammatory Bowel Disease in Patients with Type 2 Diabetes Mellitus

Pioglitazone shows potential benefits in inflammatory bowel disease (IBD) in preclinical studies, but its effect in humans has not been researched. We used a nationwide database of Taiwan's National Health Insurance to investigate whether pioglitazone might affect IBD risk. We enrolled 12,763 ever users and 12,763 never users matched on a propensity score from patients who had a new diagnosis of type 2 diabetes mellitus between 1999 and 2008. The patients were alive on 1 January 2009, and they were followed up for a new diagnosis of IBD until 31 December 2011. Propensity score-weighted hazard ratios were estimated, and the interactions between pioglitazone and major risk factors of IBD (i.e., psoriasis, arthropathies, dorsopathies, chronic obstructive pulmonary disease/tobacco abuse, and any of the above) and metformin were investigated. At the end of the follow-up, 113 ever users and 139 never users were diagnosed with IBD. When compared to never users, the hazard ratio for ever users was 0.809 (95% confidence interval: 0.631-1.037); and none of the hazard ratios for ever users categorized by tertiles of cumulative duration and cumulative dose reached statistical significance. No interactions with major risk factors or metformin were observed. Our findings suggested a null effect of pioglitazone on IBD.

Pioglitazone and breast cancer risk in female patients with type 2 diabetes mellitus: a retrospective cohort analysis

Background

Whether pioglitazone may affect breast cancer risk in female diabetes patients is not conclusive and has not been investigated in the Asian populations.

Methods

The reimbursement database of Taiwan’s National Health Insurance was used to enroll an unmatched cohort and a propensity score-matched cohort of ever users and never users of pioglitazone in female patients with newly diagnosed type 2 diabetes during 1999–2008. The patients were alive on January 1, 2009 and were followed up for breast cancer incidence until December 31, 2011. Cox regression was used to estimate hazard ratios for ever users and tertiles of cumulative duration of pioglitazone therapy versus never users, and for cumulative duration of pioglitazone therapy treated as a continuous variable. Three models were created for the unmatched cohort and the matched cohort, respectively: 1) without adjustment for covariates; 2) after adjustment for covariates that differed with statistical significance (P-value < 0.05) between ever users and never users; and 3) after adjustment for all covariates.

Results

There were 174,233 never users and 6926 ever users in the unmatched cohort; and 6926 never users and 6926 ever users in the matched cohort. After a median follow-up of 2.8 years, the numbers of incident breast cancer were 1044 in never users and 35 in ever users in the unmatched cohort and were 41 and 35, respectively, in the matched cohort. Hazard ratios suggested a null association between pioglitazone and breast cancer in all three models in either the unmatched cohort or the matched cohort. The overall hazard ratio after adjustment for all covariates was 0.758 (95% confidence interval: 0.539–1.065) in the unmatched cohort and was 0.824 (95% confidence interval: 0.524–1.296) in the matched cohort. None of the hazard ratios for the tertiles of cumulative duration of pioglitazone therapy and for the cumulative duration being treated as a continuous variable were statistically significant.

Conclusions

This study suggests a null association between pioglitazone and breast cancer risk in female patients with type 2 diabetes mellitus. However, because of the small breast cancer cases and the limited follow-up time, further studies are warranted to confirm our findings.