Diabetes risks and outcomes in chronic obstructive pulmonary disease patients: Two nationwide population-based retrospective cohort studies

COPD and T2DM: a Mendelian randomization study

Introduction

Type 2 diabetes (T2DM) stands as a global chronic illness, exerting a profound impact on health due to its complications and generating a significant economic burden. Recently, observational studies have pointed toward a potential link between Chronic Obstructive Pulmonary Disease (COPD) and T2DM. To elucidate this causal connection, we employed the Mendelian randomization analysis.

Method

Our study involved a two-sample Mendelian randomization (MR) analysis on COPD and T2DM. Additionally, tests for heterogeneity and horizontal pleiotropy were performed.

Results

For the MR analysis, 26 independent single nucleotides polymorphisms (SNPs) with strong associations to COPD were chosen as instrumental variables. Our findings suggest a pronounced causal relationship between COPD and T2DM. Specifically, COPD emerges as a risk factor for T2DM, with an odds ratio (OR) of 1.06 and a 95% confidence interval ranging from 1.01 to 1.11 (P = 0.006). Notably, all results were devoid of any heterogeneity or pleiotropy.

Conclusion

The MR analysis underscores a significant causal relationship between COPD and T2DM, highlighting COPD as a prominent risk factor for T2DM.

Association of Sodium-Glucose Cotransporter 2 Inhibitor vs Dipeptidyl Peptidase-4 Inhibitor Use With Risk of Incident Obstructive Airway Disease and Exacerbation Events Among Patients With Type 2 Diabetes in Hong Kong

IMPORTANCE

Patients with diabetes are at higher risk for obstructive airway disease (OAD). In recent meta-analyses of post hoc analyses of cardiorenal trials, sodium-glucose cotransporter 2 inhibitors (SGLT2Is) were suggested to reduce the risk of OAD adverse events. However, a clinical investigation of this association is warranted.

OBJECTIVE

This study aimed to investigate the association of SGLT2I use vs dipeptidyl peptidase-4 inhibitor (DPP4I) use with OAD incidence and exacerbation events in patients with type 2 diabetes.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective population-based cohort study used electronic health data from a territory-wide electronic medical database in Hong Kong. Data were collected for patients with type 2 diabetes who were prescribed SGLT2Is or DPP4Is between January 1, 2015, and December 31, 2018. Patients were followed for a median of 2.2 years between January 1, 2015, and December 31, 2020. A prevalent new-user design was adopted to match patients based on previous exposure to the study drugs. Propensity score matching was used to balance baseline characteristics.

EXPOSURES

Patients with type 2 diabetes using SGLT2Is (exposure of interest) or DPP4Is (active comparator).

MAIN OUTCOMES AND MEASURES

The main outcomes were the first incidence of OAD and the count of OAD exacerbations. The risk of incident OAD was estimated using a Cox proportional hazards regression model. The rate of exacerbations was estimated using zero-inflated Poisson regression. Statistical analysis was performed on November 13, 2022.

RESULTS

This study included 30 385 patients. The propensity score-matched non-OAD cohort (incidence analysis) consisted of 5696 SGLT2I users and 22 784 DPP4I users, while the matched OAD cohort (exacerbations analysis) comprised 381 SGLT2I users and 1524 DPP4I users. At baseline, 56% of patients in the non-OAD cohort were men and the mean (SD) age was 61.2 (9.9) years; 51% of patients in the OAD cohort were men and the mean age was 62.2 (10.8) years. Compared with DPP4I use, SGLT2I use was associated with a lower risk of incident OAD (hazard ratio, 0.65 [95% CI, 0.54-0.79]; P < .001) and a lower rate of exacerbations (rate ratio, 0.54 [95% CI, 0.36-0.83]; P = .01). The associations were consistent in sex subgroup analysis.

CONCLUSIONS AND RELEVANCE

The findings of this retrospective cohort study of patients with type 2 diabetes in Hong Kong suggest that SGLT2I use was associated with a reduced risk of incident OAD and a lower rate of exacerbations in a clinical setting compared with DPP4I use. These findings further suggest that SGLT2Is may provide additional protective effects against OAD for patients with type 2 diabetes and that further investigation is warranted.

Reduced lung function predicts risk of incident type 2 diabetes: insights from a meta-analysis of prospective studies

Epidemiological studies have repeatedly investigated the association between reduced pulmonary function and incident type 2 diabetes mellitus (T2DM). However, the results have been inconsistent. This meta-analysis aimed to clarify this association with prospective cohort studies. We searched PubMed, Web of Science (ISI), and Google Scholar for all studies (in English) reporting reduced lung function with a risk of T2DM. The measures of lung function included percentage of forced vital capacity for predicted values (FVC_%pre), percentage of forced expiratory volume in the first second after expiration for predicted values (FEV_1%pre) and FEV₁-to-FVC ratio%. Summary risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using fixed-effects or random-effects meta-analyses. A total of 5,480 incident T2DM patients among 88,799 individuals were identified from nine prospective cohort studies. Compared to the highest category of FVC_%pre and FEV_1%pre, the lowest category of FVC_%pre and FEV_1%pre were significantly associated with increased incident T2DM risk (FVC_%pre: RR = 1.49, 95% CI: 1.39-1.59; FEV_1%pre: RR = 1.52, 95% CI: 1.42-1.62). However, no significant relationship was found between the FEV₁/FVC ratio and incident T2DM risk (RR = 1.01, 95% CI: 0.91-1.13). Current evidence suggests that restrictive rather than obstructive impairment of lung function is significantly associated with the incidence of T2DM. Further research is warranted to explore potential mediators of this relationship.

Analysis of prevalence and prognosis of type 2 diabetes mellitus in patients with acute exacerbation of COPD

BACKGROUND

For patients with acute exacerbation of COPD (AECOPD), type 2 diabetes mellitus (T2DM) as comorbidity have poor outcomes. However, data on the impact of previously diagnosed and new- diagnosed T2DM in such a patient population is lacking.

METHODS

Inpatients diagnosed with AECOPD in the department of Pulmonary and Critical Care Medicine of The First Hospital of China Medical University during 2011-2017 were enrolled. Data on demography, prevalence of type 2 DM, other comorbidities, hospital stays and laboratory tests (including arterial partial pressure of oxygen [PaO2]) results were recorded. Results were compared with AECOPD patients having previously diagnosed and new-diagnosed type 2 diabetes. Markers associated with development of type 2 DM and the prognosis of AECOPD patients were identified.

RESULTS

Of the 196 patients enrolled in this study, the overall prevalence of T2DM was 26%. The PaO2 in the newly diagnosed T2DM group was considerably lower versus non-diabetic group. The T2DM group had a longer hospital stay and higher troponin level versus the non-diabetic group. AECOPD patients with T2DM were found to be correlated with hypertension. Age, need for assisted ventilation, increased troponin, and elevated fasting blood glucose on admission were risk factors for death in hospitalized AECOPD patients.

CONCLUSIONS

AECOPD patients had a higher prevalence of T2DM than the general population; T2DM comorbidity caused lower PaO2, longer hospital stays, and increased troponin. Poor blood glucose control may increase the risk of death in AECOPD patients.

Effects of Pitavastatin, Atorvastatin, and Rosuvastatin on the Risk of New-Onset Diabetes Mellitus: A Single-Center Cohort Study

Statins constitute the mainstay treatment for atherosclerotic cardiovascular disease, which is associated with the risk of new-onset diabetes mellitus (NODM). However, the effects of individual statins on the risk of NODM remain unclear. We recruited 48,941 patients taking one of the three interested statins in a tertiary hospital between 2006 and 2018. Among them, 8337 non-diabetic patients taking moderate-intensity statins (2 mg/day pitavastatin, 10 mg/day atorvastatin, and 10 mg/day rosuvastatin) were included. The pitavastatin group had a higher probability of being NODM-free than the atorvastatin and rosuvastatin groups during the 4-year follow-up (log-rank test: p = 0.038). A subgroup analysis revealed that rosuvastatin had a significantly higher risk of NODM than pitavastatin among patients with coronary artery disease (CAD) (adjusted HR [aHR], 1.47, 95% confidence interval [CI], 1.05–2.05, p = 0.025), hypertension (aHR, 1.26, 95% CI, 1.00–1.59, p = 0.047), or chronic obstructive pulmonary disease (COPD) (aHR, 1.74, 95% CI, 1.02–2.94, p = 0.04). We concluded that compared with rosuvastatin, reduced diabetogenic effects of pitavastatin were observed among patients treated with moderate-intensity statin who had hypertension, COPD, or CAD. Additional studies are required to prove the effects of different statins on the risk of NODM.

Respiratory outcomes of metformin use in patients with type 2 diabetes and chronic obstructive pulmonary disease

Few studies investigated the respiratory outcomes of metformin use in patients with coexistent type 2 diabetes mellitus (T2DM) and chronic obstructive pulmonary disease (COPD). We want to compare the long-term respiratory endpoints of metformin use and nonuse in patients with T2DM and COPD. This retrospective cohort study enrolled patients with T2DM and COPD from Taiwan’s National Health Insurance Program between January 1, 2000, and December 31, 2012. Main outcomes were hospitalized bacterial pneumonia, hospitalization for COPD, noninvasive positive pressure ventilation (NIPPV), invasive mechanical ventilation (IMV), and lung cancer. In total, 20,644 propensity score-matched metformin users and nonusers were assessed. The adjusted hazard ratios (95% confidence intervals) of metformin use relative to nonuse for bacterial pneumonia, hospitalization for COPD, NIPPV, IMV, and lung cancer were 1.17 (1.11–1.23), 1.34 (1.26–1.43), 0.99 (0.89–1.10), 1.10 (1.03–1.17), and 1.12 (0.96–1.30). Metformin use also exhibited significant dose–response relationship with respect to the risks of bacterial pneumonia, hospitalization for COPD and IMV. Consistent results were found in the sensitivity test. This nationwide cohort study demonstrated that in patients with T2DM and COPD, metformin use was associated with higher risks of pneumonia, hospitalization for COPD, and IMV. If patients with COPD use metformin, vigilance with regard to their pulmonary condition may be required.

Chronic obstructive pulmonary disease, lung function and risk of type 2 diabetes: a systematic review and meta-analysis of cohort studies

Background

The association between chronic obstructive pulmonary disease (COPD), lung function and risk of type 2 diabetes mellitus (T2DM) remains controversial. We performed a meta-analysis to clarify this issue.

Methods

The PubMed and EMBASE databases were searched. Cohort studies on COPD, lung function and risk of T2DM in adults were included. A random effects model was adopted to calculate the summary risk ratio (RR) and 95% confidence interval (CI). Dose-response analysis was conducted where possible.

Results

A total of 13 eligible cohort studies involving 307,335 incident T2DM cases and 7,683,784 individuals were included. The risk of T2DM was significantly higher in patients with COPD than those without COPD (RR = 1.25, 95% CI 1.16–1.34). Compared to the highest category of percentage forced vital capacity (FVC%), the lowest category of FVC% was associated with a higher risk of T2DM (RR = 1.43, 95% CI 1.33–1.53). Similarly, the summary RR of T2DM for the lowest versus highest category of percentage forced expiratory volume in 1 s (FEV1%) was 1.49 (95% CI 1.39–1.60). Significant linear associations of FVC% and FEV1% with risk of T2DM were found (P_{non-linearity} > 0.05); the RR of T2DM was 0.88 (95% CI 0.82–0.95) and 0.87 (95% CI 0.81–0.94) per 10% increase in FVC% and FEV1%, respectively. There was a non-significant relationship between the FEV1/FVC ratio and the risk of T2DM.

Conclusions

Both COPD and impaired lung function, especially restricted ventilation dysfunction, could increase the risk of T2DM. However, these findings should be interpreted with caution due to the limited number of studies, and need to be validated by future studies.

Do Benefits Outweigh Risks for Corticosteroid Therapy in Acute Exacerbation of Chronic Obstructive Pulmonary Disease in People with Diabetes Mellitus?

Chronic obstructive pulmonary disease (COPD) and diabetes mellitus (DM) are chronic health conditions with significant impacts on quality and extent of life. People with COPD and DM appear to have worse outcomes in each of the comorbid conditions. Treatment with corticosteroids in acute exacerbation of COPD (AECOPD) has been shown to reduce treatment failure and exacerbation relapse, and to shorten length of hospital stay, but not to affect the inexorable gradual worsening of lung function. Treatment with corticosteroids can lead to a wide spectrum of side effects and complications, including worsening hyperglycemia and deterioration of diabetes control in those with pre-existing DM. The relationship between COPD and DM is rather complex and accumulating evidence indicates a distinct phenotype of the comorbid state. Several randomized controlled trials on corticosteroid treatment in AECOPD excluded people with DM or did not report on outcomes in this subgroup. As such, the perceived benefits of corticosteroids in AECOPD in people with DM have not been validated. In people with COPD and DM, the detrimental side effects of corticosteroids are guaranteed, while the benefits are not confirmed and only presumed based on extrapolation from the general COPD population. Therefore, the potential for harm when prescribing corticosteroids for AECOPD in people with DM cannot be excluded.

Screening for comorbidities in COPD

Due to growing recognition of comorbidities, COPD is no longer considered a disease affecting only the respiratory system. Its management now entails the early diagnosis and treatment of comorbidities. However, although many studies have examined the impact of comorbidities on the evolution of COPD and patients' quality of life, very few have explored the means to systematically identify and manage them. The aims of this article are to summarise the state of current knowledge about comorbidities associated with COPD and to propose a possible screening protocol in the outpatient setting, emphasising the areas needing further research.

Diabetes Mellitus and Chronic Obstructive Pulmonary Disease: An Overview

Chronic obstructive pulmonary disease (COPD) is a common disease with an increasing prevalence, characterised by persistent respiratory symptoms and airflow limitation. Apart from cigarette smoking, certain occupational and environmental exposures, low socioeconomic status and genetic factors may contribute to the pathogenesis of COPD. Comorbidities, e. g. diabetes mellitus (DM), can negatively affect quality of life, COPD outcomes and cardiovascular risk. The present narrative review considers the potential links between COPD and DM, such as systemic inflammation, oxidative stress, hypoxaemia and hyperglycaemia. The effects of antidiabetic drugs on lung function and COPD outcomes, as well as the possibility of common therapeutic modalities are also briefly considered. Further research is needed in this field to elucidate these relationships as well as their potential clinical implications in daily practice.

The impact of comorbidities on mortality among men and women with COPD: report from the OLIN COPD study

BACKGROUND

Comorbidities probably contribute to the increased mortality observed among subjects with chronic obstructive pulmonary disease (COPD), but sex differences in the prognostic impact of comorbidities have rarely been evaluated in population-based studies. The aim of this study was to evaluate the impact of common comorbidities, cardiovascular disease (CVD), diabetes mellitus (DM), and anxiety/depression (A/D), on mortality among men and women with and without airway obstruction in a population-based study.

METHODS

All subjects with airway obstruction [forced expiratory volume in 1 second (FEV₁)/(forced) vital capacity ((F)VC) <0.70, n = 993] were, together with age- and sex-matched referents, identified after examinations of population-based cohorts in 2002-2004. Spirometric groups: normal lung function (NLF) and COPD (post-bronchodilator FEV₁/(F)VC <0.70) and additionally, LLN-COPD (FEV₁/(F)VC <lower limit of normal). Mortality data was collected until December 2015.

RESULTS

In COPD, the prevalence of CVD and DM was higher in men, whereas the prevalence of A/D was higher in women. The cumulative mortality was significantly higher in COPD than NLF, and higher in men than women in both groups. Among women with COPD, CVD and A/D but not DM increased the risk of death independent of age, body mass index, smoking habits, and disease severity, whereas among men DM and A/D but not CVD increased the risk for death. When the LLN criterion was applied, the pattern was similar.

CONCLUSION

There were sex-dependent differences regarding the impact of comorbidities on prognosis in COPD. Even though the prevalence of CVD was higher in men, the impact of CVD on mortality was higher in women, and despite higher prevalence of A/D in women, the impact on mortality was similar in both sexes. The reviews of this paper are available via the supplemental material section.

Incidence of type II diabetes in chronic obstructive pulmonary disease: a nested case-control study

We investigated the incidence of type II diabetes mellitus (T2DM) among people with COPD and whether exposure to inhaled corticosteroid (ICS) and exacerbation status was associated with T2DM. This descriptive cohort study used primary care data from the Clinical Practice Research Datalink (CPRD). The patient cohort included people with a diagnosis of COPD and previous smoking history registered at a CPRD practice between January 2010 and December 2016. We determined incidence rates by age, gender and deprivation. Using a nested case-control design-where cases and controls are drawn from the cohort population-we matched 1:5 with patients by age, gender and GP practice and estimated odds of T2DM using logistic regression (adjusting for smoking status, deprivation, BMI, hypertension, coronary heart disease and heart failure). We identified 220,971 COPD patients; mean age at COPD diagnosis was 66 years (SD 12) and 54% were male. The incidence rate of T2DM in COPD patients was 1.26 per 100 patient years (95% CI: 1.24-1.28) and was higher among men (1.32 vs 1.18 among women). The adjusted odds ratio for T2DM was 1.47 (95% CI: 1.36-1.60) among frequent exacerbators (≥2 treated exacerbations per year) compared to infrequent exacerbators and the odds ratio for patients receiving high-dose ICS (>800 mcg budesonide equivalent dose) was 1.73 (95% CI 1.65-1.82) compared to patients receiving no ICS therapy. Incidence of T2DM among COPD patients is high and exposure to ICS and frequent exacerbations are associated with a higher risk of T2DM among patients with COPD.

Female-specific risk factors associated with risk of ACO (asthma COPD overlap) in aboriginal people

Objective: Sex differences in incidence, susceptibility and severity of many chronic respiratory diseases have been long recognized. Asthma-COPD Overlap (ACO) is newly recognized disease with its management guidelines reported in 2015. The objective of this analysis is to identify the female-specific risk factors associated with ACO in Aboriginal people.Methods: The Aboriginal Peoples Survey 2012 (N = 28,410) is the fourth cycle of a national cross-sectional survey representative of the First Nations living off reserve, Metis and Inuit. The 2012 APS collected information on employment, education, health status, housing, family background and income. Survey Logistic Regression was used to identify the significant risk factors for ACO in the multivariate analysis.Results: The prevalence of ACO was 1.65% and 3.53% in males and females, respectively. The following factors were significantly associated with increased risk of ACO in both males and females: increased age, living in Quebec, living in a rented dwelling and dwelling in need of major repairs. However, four factors including marital status (being widowed, separated, or divorced), smoking status (being a current daily smoker), having a diagnosis of diabetes and working 40 h and over a week were significantly associated with increased risk of ACO in females not males.Conclusion:The results of our study may offer useful evidence for future development of female-specific prevention and public health intervention programs in aboriginal communities to reduce the burden of ACO.

Metformin use mitigates the adverse prognostic effect of diabetes mellitus in chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

Among patients with chronic obstructive pulmonary disease (COPD), diabetes mellitus (DM) is a common comorbidity and is probably associated with increased systemic inflammation and worse prognosis. Metformin, with its pleiotropic anti-inflammatory and antioxidant actions, may offer theoretical benefits in COPD patients with DM. Thus, this study aimed to investigate the effects of DM and metformin use on mortality in the clinical trajectory of COPD.

METHODS

This was a retrospective cohort study comprising patients with spirometry-confirmed COPD and an age of ≥40 years from 2008 to 2014. The primary outcome of interest was all-cause mortality. We evaluated the effects of DM on mortality through the clinical course of COPD and we also assessed the impact of metformin use on survival of the COPD population.

RESULTS

Among 4231 COPD patients, 556 (13%) had DM, and these patients had 1.62 times higher hazards of 2-year mortality than those without DM (95% confidence interval [CI], 1.15-2.28) after adjusting for age, gender, COPD stage, comorbidities and prior COPD hospitalization. Over a 2-year period, metformin users had a significantly lower risk of death (hazard ratio, 0.46; 95% CI, 0.23-0.92) compared with non-metformin users in patients with coexistent COPD and DM. Moreover, metformin users had similar survival to COPD patients without DM.

CONCLUSIONS

This study shows that DM is associated with an increased risk of death in COPD patients and metformin use seems to mitigate the hazard. Our findings suggest a potential role of metformin in the management of DM in COPD.

Prevalence and Risk Factors of ACO (Asthma-COPD Overlap) in Aboriginal People

Background and Objective

Aboriginal peoples are at a higher risk of many chronic respiratory diseases compared to the general Canadian population. Patients with asthma-COPD overlap (ACO), a disease newly described in 2015, are associated with frequent exacerbations, rapid decline in lung function, poor quality of life, high mortality, and disproportionate utilization of health-care resources than patients with asthma and COPD alone. The objective was to investigate the prevalence and risk factors of ACO in Aboriginal peoples.

Methods

Data from the 2012 Aboriginal Peoples Survey (APS) were used for this study. The ACO definition was based on the respondent giving positive responses to both of the following questions "Do you/Does (name) have Asthma diagnosed by a health professional?" and "Do you/Does (name) have chronic bronchitis, emphysema or chronic pulmonary obstructive disease or COPD diagnosed by a health professional?" Results. Aboriginal peoples older than 45 years, women, widowed, separated, or divorced, having a total personal income below $20,000 were associated with a significant risk of ACO. Residing in Ontario, being a daily smoker, living in a rented dwelling, dwelling in need of major repairs, having diabetes, and working more than 40 hrs a week were also significantly associated with increased risk of ACO.

Conclusion

The results from this study will provide information to aid the development of prevention and intervention strategies for Aboriginal communities.

Through the Looking Glass: In Vitro Models for Inhalation Toxicology and Interindividual Variability in the Airway

With 7 million deaths reported annually from air pollution alone, it is evident that adverse effects of inhaled toxicant exposures remain a major public health concern in the 21st century. Assessment and characterization of the impacts of air pollutants on human health stems from epidemiological and clinical studies, which have linked both outdoor and indoor air contaminant exposure to adverse pulmonary and cardiovascular health outcomes. Studies in animal models support epidemiological findings and have been critical in identifying systemic effects of environmental chemicals on cognitive abilities, liver disease, and metabolic dysfunction following inhalation exposure. Likewise, traditional monoculture systems have aided in identifying biomarkers of susceptibility to inhaled toxicants and served as a screening platform for safety assessment of pulmonary toxicants. Despite their contributions, in vivo and classic in vitro models have not been able to accurately represent the heterogeneity of the human population and account for interindividual variability in response to inhaled toxicants and susceptibility to the adverse health effects. Development of new technologies that can investigate genetic predisposition, are cost and time efficient, and are ethically sound, will enhance elucidation of mechanisms of inhalation toxicity, and aid in the development of novel pharmaceuticals and/or safety evaluation. This review will describe the classic and novel cell-based inhalation toxicity models and how these emerging technologies can be incorporated into regulatory or nonregulatory testing to address interindividual variability and improve overall human health.