Safety of metformin in patients with chronic obstructive pulmonary disease and type 2 diabetes mellitus

Relationship between glycemic control and chronic obstructive pulmonary disease in patients with type 2 diabetes: A nested case-control study

AIMS

To evaluate the relationship between glycemic control and plasma glycated hemoglobin (HbA1c) levels in patients with type 2 diabetes mellitus (T2D) and the risk of chronic obstructive pulmonary disease (COPD).

METHODS

We conducted a population-based, retrospective, nested, case-control study involving 124,876 patients with DM2 from the Canary Islands, Spain. From the cohort, we selected all COPD cases and, for each case, five control subjects who were COPD free. We analyzed the association between glycemic control, HbA1c level and incident COPD.

RESULTS

A total of 1320 incidence cases of COPD (1.06%) were identified and matched individually with 6600 controls according to age and sex. After multivariate adjustment, the COPD risk increased among patients with poor glycemic control compared to patients with good glycemic control [HbA1c levels <7% (53 mmol/mol)] (OR 1.18; 95% CI: 1.03-1.36). In comparison with patients exhibiting HbA1c levels <7% (53 mmol/mol), the risk of COPD was higher among people with HbA1c levels of 7-8% (53-64 mmol/mol) (OR 1.24; 95% CI: 1.05-1.47) and 8-9% (64-75 mmol/mol) (OR 1.31; 95% CI: 1.04-1.66).

CONCLUSIONS

Poor glycemic control reveals a weak association with increased risk of COPD in T2D patients.

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.

Effects of metformin use on total mortality in patients with type 2 diabetes and chronic obstructive pulmonary disease: A matched-subject design

BACKGROUNDS

Few studies have investigated the therapeutic effects of metformin in patients with type 2 diabetes mellitus (T2DM) and chronic obstructive pulmonary disease (COPD). We compared the risk of all-cause mortality between metformin users and nonusers.

METHODS

We conducted a retrospective cohort study for patients with T2DM and COPD who were enrolled between January 1, 2000 and June 30, 2012. Individuals with exacerbated symptoms who were hospitalized or sent to the emergency department (ED) were identified as having exacerbated COPD; outpatient claims were identified as having stable COPD. A total of 40,597 metformin users and 39,529 nonusers comprised the cohort of stable COPD; 14,001 metformin users and 21,613 nonusers comprised the cohort of exacerbated COPD. Users and nonusers were matched using propensity score (1:1). Our primary outcome was all-cause mortality.

RESULTS

A total of 19,505 metformin users were matched to 19,505 nonusers in the cohort of diabetes with stable COPD. The mean follow-up time was 3.91 years. All-cause mortality was reported in 1326 and 1609 metformin users and nonusers, respectively. After multivariate adjustment, metformin users had lower risk of mortality (adjusted hazard ratio [aHR] = 0.84, p < 0.0001). Metformin users had significantly lower risk of noncardiovascular death (aHR = 0.86, p = 0.0008). A total of 7721 metformin users were matched to 7721 nonusers in the cohort of diabetes with exacerbated COPD. The mean follow-up time was 3.18 years. All-cause mortality was reported in 1567 and 1865 metformin users and nonusers, respectively. After multivariate adjustment, metformin users had significantly lower risk of mortality (aHR = 0.89, p = 0.002) and cardiovascular death (aHR = 0.70, p = 0.01).

CONCLUSION

This large-series, nationwide cohort study demonstrated that metformin use could significantly lower the risk of all-cause mortality in patients with T2DM and either stable or exacerbated COPD.

Telomere and its role in the aging pathways: telomere shortening, cell senescence and mitochondria dysfunction

Aging is a biological process characterized by a progressive functional decline in tissues and organs, which eventually leads to mortality. Telomeres, the repetitive DNA repeat sequences at the end of linear eukaryotic chromosomes protecting chromosome ends from degradation and illegitimate recombination, play a crucial role in cell fate and aging. Due to the mechanism of replication, telomeres shorten as cells proliferate, which consequently contributes to cellular senescence and mitochondrial dysfunction. Cells are the basic unit of organismal structure and function, and mitochondria are the powerhouse and metabolic center of cells. Therefore, cellular senescence and mitochondrial dysfunction would result in tissue or organ degeneration and dysfunction followed by somatic aging through multiple pathways. In this review, we summarized the main mechanisms of cellular senescence, mitochondrial malfunction and aging triggered by telomere attrition. Understanding the molecular mechanisms involved in the aging process may elicit new strategies for improving health and extending lifespan.

Inhalational supplementation of metformin butyrate: A strategy for prevention and cure of various pulmonary disorders

The management of chronic lung diseases such as cancer, asthma, COPD and pulmonary hypertension remains unsatisfactory till date, and several strategies are being tried to control the same. Metformin, a popular anti-diabetic drug has shown promising effects in pre-clinical studies and has been subject to several trials in patients with debilitating pulmonary diseases. However, the clinical evidence for the use of metformin in these conditions is disappointing. Recent observations suggest that metformin use in diabetic patients is associated with an increase in butyrate-producing bacteria in the gut microbiome. Butyrate, similar to metformin, shows beneficial effects in pathological conditions found in pulmonary diseases. Further, the pharmacokinetic data of metformin suggests that metformin is predominantly concentrated in the gut, even after absorption. Butyrate, on the other hand, has a short half-life and thus oral supplementation of butyrate and metformin is unlikely to result in high concentrations of these drugs in the lung. In this paper, we review the pre-clinical studies of metformin and butyrate pertaining to pathologies commonly encountered in chronic lung diseases and underscore the need to administer these drugs directly to the lung via the inhalational route.

Lactate Levels with Chronic Metformin Use: A Narrative Review

Metformin has been associated with lactic acidosis. Lactate levels are not commonly tested in clinical practice, and it is unclear to what extent metformin would typically increase lactate levels with chronic use. The aim of this review was to determine whether regular monitoring of the plasma lactate level would be beneficial in avoiding lactate accumulation and, ultimately, minimising the incidence of lactic acidosis in metformin-treated patients.A comprehensive search of PubMed, Embase, Web of Science, Cochrane and International Pharmaceutical Abstracts databases covering the period up to 30 May 2017 was performed. Search terms included combinations of terms and keywords, including "metformin", "lactate", "lactic acid" and "lactic acidosis". Cases series of lactic acidosis or metformin-associated lactic acidosis were excluded.Of 1539 potentially relevant articles, a total of 52 reported lactate levels from routine/regular pathological tests in metformin users. The studies were subdivided into four themes, regarding metformin usage and the reported lactate levels in patients who: (1) did not have contraindications to the use of metformin; (2) had contraindications, or renal impairment but without other contraindications; (3) exercised; or (4) also received any nucleoside reverse transcriptase inhibitor. Studies have reported that metformin treatment could increase lactate level of users. However, most results showed that the lactate level remained in the normal range.No definitive conclusions on the benefits of regular lactate monitoring in patients taking metformin can be made. Future research on larger populations focusing on the measurement of lactate levels with continuous metformin use is warranted.

Geroprotectors as a therapeutic strategy for COPD - where are we now?

Although current therapies in chronic obstructive pulmonary disease (COPD) improve the quality of life, they do not satisfactorily reduce disease progression or mortality. There are still many gaps in knowledge about the cellular, molecular, and genetic mechanisms contributing to pathobiology of this disease. However, increasing evidence suggests that accelerated aging, chronic systemic inflammation, and oxidative stress play major roles in pathogenesis in COPD, thus opening new opportunities in therapy. Therefore, the aim of our review was to describe and discuss some of the most widely used therapeutics that affect the root cause of aging and oxidative stress (metformin, melatonin, sirolimus, statins, vitamin D, and testosterone) in context of COPD therapy.

Pharmacology and therapeutic implications of current drugs for type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a global epidemic that poses a major challenge to health-care systems. Improving metabolic control to approach normal glycaemia (where practical) greatly benefits long-term prognoses and justifies early, effective, sustained and safety-conscious intervention. Improvements in the understanding of the complex pathogenesis of T2DM have underpinned the development of glucose-lowering therapies with complementary mechanisms of action, which have expanded treatment options and facilitated individualized management strategies. Over the past decade, several new classes of glucose-lowering agents have been licensed, including glucagon-like peptide 1 receptor (GLP-1R) agonists, dipeptidyl peptidase 4 (DPP-4) inhibitors and sodium/glucose cotransporter 2 (SGLT2) inhibitors. These agents can be used individually or in combination with well-established treatments such as biguanides, sulfonylureas and thiazolidinediones. Although novel agents have potential advantages including low risk of hypoglycaemia and help with weight control, long-term safety has yet to be established. In this Review, we assess the pharmacokinetics, pharmacodynamics and safety profiles, including cardiovascular safety, of currently available therapies for management of hyperglycaemia in patients with T2DM within the context of disease pathogenesis and natural history. In addition, we briefly describe treatment algorithms for patients with T2DM and lessons from present therapies to inform the development of future therapies.

A history of diabetes but not hyperglycaemia during exacerbation of obstructive lung disease has impact on long-term mortality: a prospective, observational cohort study

OBJECTIVE

Hyperglycaemia is very common during exacerbations of asthma and chronic obstructive pulmonary disease (COPD). However, its clinical significance is not clear. The objective of the present study was to assess whether exacerbation-associated hyperglycaemia affects long-term mortality in these patients.

DESIGN

A prospective, observational cohort study.

SETTING

A single hospital in eastern Finland.

PARTICIPANTS

153 consecutive patients who were hospitalised due to mild to moderate obstructive lung disease exacerbation (110 with asthma and 43 with COPD) and who survived at least 30 days.

INTERVENTIONS

Plasma glucose levels were recorded seven times during the first day on the ward. Several possible confounders were also recorded. The median follow-up time was 6 years and 2 months.

RESULTS

During the follow-up, 57 (37%) of the patients died. Previously diagnosed diabetes was strongly associated with elevated mortality (adjusted HR (aHR) 3.03 (1.28 to 7.18). The highest fasting glucose value (aHR 1.10 (1.01 to 1.20) per 1 mmol/L) and the highest postprandial glucose value ((aHR 1.07 (1.00 to 1.16)) were also associated with late mortality. However, the associations between highest glucose values and mortality vanished when the diagnosis of diabetes was included in the same model. Within the patients without diabetes, neither fasting (aHR 0.92 (0.42 to 2.02)) nor postprandial ((aHR 1.04 (0.50 to 2.12)) hyperglycaemia was associated with late mortality. There were no statistically significant differences in the underlying causes of death between the patients with and without diabetes.

CONCLUSION

A history of diabetes but not hyperglycaemia during exacerbation of obstructive lung disease has impact on long-term mortality.