A prospective study of the impact of diabetes mellitus on restrictive and obstructive lung function impairment: The Saku study

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.

Characteristics and Risk of Diabetes in People With Rare Glucose Response Curve During an Oral Glucose Tolerance Test

CONTEXT

Existing differences in persons with lower 30- or 60-minute plasma glucose (PG) levels during 75-g oral glucose tolerance test (OGTT) than fasting PG remain unclear.

OBJECTIVE

To clarify the characteristics of persons whose PG levels decrease after glucose administration during OGTT and their risk of incidence of diabetes in a Japanese general population.

METHODS

In this cohort study, a total of 3995 men and 3500 women (mean age 56.7 years) without diabetes were classified into 3 groups: (1) PG at both 30 and 60 minutes ≥ fasting PG; (2) PG at 30 minutes ≥ fasting PG and PG at 60 minutes < fasting PG; (3) PG at 30 minutes < fasting PG. The characteristics and the risk of diabetes onset were analyzed using ordered logistic regression and Cox proportional hazard regression, respectively.

RESULTS

Among 7495 participants, the numbers of individuals in the group 1, 2, and 3 were 6552, 769, and 174, respectively. The glucose response curve of the group 3 was boat shaped. Group 3 had the youngest age, lowest percentage of men, and best health condition, followed by groups 2 and 1. Among 3897 participants analyzed prospectively, 434 developed diabetes during the mean follow-up period of 5.8 years. The hazard ratio for diabetes onset in the group 2 was 0.30 with reference to the group 1. No-one in group 3 developed diabetes.

CONCLUSION

People with lower 30-minute PG than fasting PG tended to be women, young, healthy, and at low risk of diabetes onset.

GWAS of random glucose in 476,326 individuals provide insights into diabetes pathophysiology, complications and treatment stratification

Conventional measurements of fasting and postprandial blood glucose levels investigated in genome-wide association studies (GWAS) cannot capture the effects of DNA variability on 'around the clock' glucoregulatory processes. Here we show that GWAS meta-analysis of glucose measurements under nonstandardized conditions (random glucose (RG)) in 476,326 individuals of diverse ancestries and without diabetes enables locus discovery and innovative pathophysiological observations. We discovered 120 RG loci represented by 150 distinct signals, including 13 with sex-dimorphic effects, two cross-ancestry and seven rare frequency signals. Of these, 44 loci are new for glycemic traits. Regulatory, glycosylation and metagenomic annotations highlight ileum and colon tissues, indicating an underappreciated role of the gastrointestinal tract in controlling blood glucose. Functional follow-up and molecular dynamics simulations of lower frequency coding variants in glucagon-like peptide-1 receptor (GLP1R), a type 2 diabetes treatment target, reveal that optimal selection of GLP-1R agonist therapy will benefit from tailored genetic stratification. We also provide evidence from Mendelian randomization that lung function is modulated by blood glucose and that pulmonary dysfunction is a diabetes complication. Our investigation yields new insights into the biology of glucose regulation, diabetes complications and pathways for treatment stratification.

Diabetes-related perturbations in the integrity of physiologic barriers

One of the hallmarks of health is the integrity of barriers at the cellular and tissue levels. The two cardinal functions of barriers include preventing access of deleterious elements of the environment (barrier function) while facilitating the transport of essential ions, signaling molecules and nutrients needed to maintain the internal milieu (transport function). There are several cellular and subcellular barriers and some of these barriers can be interrelated. The principal physiologic barriers include blood-retinal barrier, blood-brain barrier, blood-testis barrier, renal glomerular/tubular barrier, intestinal barrier, pulmonary blood-alveolar barrier, blood-placental barrier and skin barrier. Tissue specific barriers are the result of the vasculature, cellular composition of the tissue and extracellular matrix within the tissue. Uncontrolled diabetes and acute hyperglycemia may disrupt the integrity of physiologic barriers, primarily through altering the vascular integrity of the tissues and may well contribute to the clinically recognized complications of diabetes. Although diabetes is a systemic disease, some of the organs display clinically significant deterioration in function while others undergo subclinical changes. The pathophysiology of the disruption of these barriers is not entirely clear but it may be related to diabetes-related cellular stress. Understanding the mechanisms of diabetes related dysfunction of various physiologic barriers might help identifying novel therapeutic targets for reducing clinically significant complications of diabetes.

Ginsenoside Rb1 reduces oxidative/carbonyl stress damage and ameliorates inflammation in the lung of streptozotocin-induced diabetic rats

CONTEXT

Ginsenoside Rb1 (Rb1) is a biologically active component of ginseng [Panax ginseng C.A. Meyer (Araliaceae)].

OBJECTIVE

This study determined the underlying mechanisms of Rb1 treatment that acted on diabetes-injured lungs in diabetic rats.

MATERIALS AND METHODS

Streptozotocin (STZ)-induced diabetic rat model was used. Male Sprague-Dawley (SD) rats were divided into four groups (n = 10): control, Rb1 (20 mg/kg), insulin (15 U/kg to attain the euglycaemic state) and diabetic (untreated). After treatment for six weeks, oxidative stress assay; histological and ultrastructure analyses; TNF-α, TGF-β, IL-1 and IL-6 protein expression analyses; and the detection of apoptosis were performed.

RESULTS

There was decreased activity of SOD (3.53-fold), CAT (2.55-fold) and GSH (1.63-fold) and increased levels of NO (4.47-fold) and MDA (3.86-fold) in the diabetic group from control. Rb1 treatment increased SOD (2.4-fold), CAT (1.9-fold) and GSH (1.29-fold) and decreased the levels of NO (1.76-fold) and MDA (1.51-fold) as compared with diabetic rats. The expression of IL-6 (5.13-fold), IL-1α (2.35-fold), TNF-α (2.35-fold) and TGF-β (2.39-fold) was increased in diabetic rats from control. IL-6 (2.43-fold), IL-1α (2.27-fold), TNF-α (1.68-fold) and TGF-β (2.3-fold) were decreased in the Rb1 treatment group. Diabetes increased the apoptosis rate (2.23-fold vs. control), and Rb1 treatment decreased the apoptosis rate (1.73-fold vs. the diabetic rats). Rb1 and insulin ameliorated lung tissue injury.

DISCUSSION AND CONCLUSIONS

These findings indicate that Rb1 could be useful for mitigating oxidative damage and inflammatory infiltration in the diabetic lung.

Interaction of polycyclic aromatic hydrocarbon exposure and high-fasting plasma glucose on lung function decline in coke oven workers: a cross-lagged panel analysis

Individuals with abnormal fasting plasma glucose (FPG) may be more susceptible to lung diseases associated with environmental pollutants. A cross-sectional survey of 629 workers in 2017 and a panel study of 304 workers from 2014 to 2019 were performed in China. The results showed that elevated total hydroxylated polycyclic aromatic hydrocarbon (ΣOH-PAH) concentration was associated with lower the percentage of predicted forced vital capacity (FVC%) among high-FPG workers (β for the cross-sectional analysis: -1.78%, 95%CI: -2.92%, -0.64%; β for the panel study: -1.10%, 95%CI: -2.19%, -0.02%). The absolute value of the cross-lagged path coefficient from FPG to FVC% (β₂ = -0.096) was significantly greater than that from FVC% to FPG (β₁ = 0.037). Our results suggest that FPG abnormalities may precede the lung function decline induced by PAH exposure and that high-FPG and high ΣOH-PAH levels have an interactive effect on lung function decline.

Multiple Beneficial Effects of Laparoscopic Sleeve Gastrectomy for Patients with Obesity, Type 2 Diabetes Mellitus, and Restrictive Ventilatory Dysfunction

BACKGROUND

Some studies have suggested that bariatric surgery improves pulmonary function in patients with obesity, but whether it alleviates pulmonary ventilation disorders in patients with obesity, type 2 diabetes mellitus (T2DM), and restrictive ventilatory dysfunction(RVD) is unclear. To evaluate the effect of laparoscopic sleeve gastrectomy (LSG) in improving pulmonary ventilation function in patients with obesity, T2DM, and RVD.

METHODS

We studied patients with T2DM and RVD (forced vital capacity (FVC) predicted < 80%, forced expiratory volume in one second/forced vital capacity (FEV1/FVC) > 70%) who underwent LSG from March 2018 to January 2020. Baseline data was recorded and follow-up visits were made at 3, 6, 9, and 12 months after surgery to evaluate glucose, hemoglobin A1c (HbA1c), body mass index (BMI), and pulmonary ventilation function. We used multivariate analyses to assess the remission of RVD (reversion of FVC to ≥80% of the predicted value).

RESULTS

We enrolled 33 patients (mean age 46.9±5.2 years, 21 males). Two patients were lost to follow-up and another patient died. Thirty patients completed follow-up; 24 had remission of RVD (24/33, 72.7%). Multivariate Cox regression analysis showed that lower HbA1c (HR=0.35 (0.16 ~ 0.76), p=0.008), reduced waist size (0.9 (0.83 ~ 0.98), p=0.017), and shorter duration of diabetes (0.67(0.47~0.97), p=0.033) were associated with alleviation of pulmonary ventilation function.

CONCLUSIONS

LSG not only controls the body weight and T2DM; it may also relieve pulmonary ventilation dysfunction in patients with obesity, T2DM, and RVD. The waist size, duration of diabetes, and HbA1c before LSG negatively affect recovery of pulmonary ventilation dysfunction.

Association between Lung Function and New-Onset Diabetes Mellitus in Healthy Individuals after a 6-Year Follow-up

BACKGROUND

We analyzed hemoglobin A1c (HbA1c) levels and various lung function test results in healthy individuals after a 6-year follow-up period to explore the influence of lung function changes on glycemic control.

METHODS

Subjects whose HbA1c levels did not qualify as diabetes mellitus (DM) and who had at least two consecutive lung function tests were selected among the people who visited a health promotion center. Lung function parameters, including forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV/FVC ratio, and forced expiratory flow 25% to 75% (FEF25%-75%), were divided into four groups based on their baseline quantiles. To evaluate future DM onset risk in relation to lung function changes, the correlation between baseline HbA1c levels and changes in lung function parameters after a 6-year follow-up period was analyzed.

RESULTS

Overall, 17,568 individuals were included; 0.9% of the subjects were diagnosed with DM. The individuals included in the quartile with FEV1/FVC ratio values of 78% to 82% had lower risk of DM than those in the quartile with FEV1/FVC ratio values of ≥86% after adjusting for age, sex, and body mass index (P=0.04). Baseline percent predicted FEV1, FVC, FEV1/FVC ratio, and FEF25%-75%, and differences in the FEV1/FVC ratio or FEF25%-75%, showed negative linear correlations with baseline HbA1c levels.

CONCLUSION

Healthy subjects with FEV1/FVC ratio values between 78% and 82% had 40% lower risk for future DM. Smaller differences and lower baseline FEV1/FVC ratio or FEF25%-75% values were associated with higher baseline HbA1c levels. These findings suggest that airflow limitation affects systemic glucose control and that the FEV1/FVC ratio could be one of the factors predicting future DM risk in healthy individuals.

Idiopathic pulmonary fibrosis and diabetes mellitus: a meta-analysis and systematic review

Background

Idiopathic pulmonary fibrosis (IPF) is a chronic diffuse interstitial lung disease, of which the etiology has been poorly understood. Several studies have focused on the relationship between IPF and diabetes mellitus (DM) in the past years but have failed to reach a consensus. This meta-analysis aimed to examine the association between diabetes to IPF.

Methods

We accumulated studies investigating the association between DM and IPF from databases including Medline, Cochrane Library, Embase, Web of Science, and China National Knowledge Infrastructure. RevMan 5.3 and the Newcastle–Ottawa Scale (NOS) were utilized to analyze the data and assess the quality of the included studies. The value of odds ratio (OR) with 95% confidence interval (CI) was used as the measure to estimate the risk of DM in IPF. Heterogeneity was assessed by I² statistics. We also performed subgroup analysis, meta-regression, and Egger’s test for bias analysis.

Results

Nine case–control studies with 5096 IPF patients and 19,095 control subjects were included in the present meta-analysis, which indicated a positive correlation between DM and IPF (OR 1.65, 95% CI 1.30–2.10; P < 0.0001). Meta-regression and subgroup analysis negated the influence of covariates like cigarette smoking, age and gender, but the heterogeneity existed and could not be fully explained.

Conclusion

IPF and DM may be associated, but the causal relationship remains indeterminate till now. Further rigorously designed studies are required to confirm the present findings and investigate the possible mechanisms behind the effect of DM on IPF.

Lung function impairment and cardiometabolic risks among rural adults: implication for an aging society

BACKGROUND

Early detection and prevention of cardiometabolic risk factors in an increasingly aging society are a global public health concern. Maintaining adequate lung function is important for healthy aging. Few studies exist on lung function impairment and decline in primary healthcare settings, especially among rural adults with cardiometabolic risks. This study aimed to explore the prevalence of impaired lung function and its association with cardiometabolic risks among rural adults.

METHODS

A community-based, cross-sectional study was conducted between March and December 2019 in western coastal Yunlin County, Taiwan. The lung function test was measured by spirometry, based on the American Thoracic Society recommendations. Three lung function parameters were obstructive lung impairment, restrictive lung impairment, and mixed lung impairment. Restrictive, obstructive, and mixed type lung function was categorized as impaired. Cardiometabolic risk factors and metabolic syndrome were based on the national standard and include five abnormal biomarkers, including abdominal obesity, blood pressure, fasting plasma glucose, triglycerides, and decreased high-density cholesterol levels.

RESULTS

The median age of the 1653 (92.9%) participants with complete data was 66 years (interquartile range: 55 to 75 years). The prevalence of impaired lung function was 37%, including 31.7% restrictive, 2.5% obstructive, and 2.7% mixed type. Adults with impaired lung function (86% restrictive type) engaged more in smoking and betel nut chewing, ate fewer vegetables and fruit, and drank less water compared to the normal lung function group. After adjusting for potential confounding variables, multivariate logistic regression analysis showed that cardiometabolic risk factors were independently associated with restrictive lung impairment, while cigarette smoking (OR = 2.27, 95% CI = 1.14-4.53) and betel nut chewing (OR = 2.33, 95% CI = 1.09-5.01) were significantly associated with the obstructive type of lung impairment.

CONCLUSIONS

A high prevalence of restrictive lung impairment, cardiometabolic risks, and unhealthy lifestyles among rural adults were found in this study. For adults with cardiometabolic risks in rural areas, initiating lifestyle modifications with culture-tailored programs to improve lung function should be an important issue for clinicians and primary healthcare providers.

Repetitive Ozone Exposures and Evaluation of Pulmonary Inflammation and Remodeling in Diabetic Mouse Strains

BACKGROUND

Epidemiological studies support the hypothesis that diabetes alters pulmonary responses to air pollutants like ozone (O 3 ). The mechanism(s) underlying these associations and potential links among diabetes, O 3 , and lung inflammation and remodeling are currently unknown.

OBJECTIVES

The goal was to determine whether pulmonary responses to repetitive ozone exposures are exacerbated in murine strains that are hyperglycemic and insulin resistant.

METHODS

Normoglycemic and insulin-sensitive C57BL/6J mice; hyperglycemic, but mildly insulin-resistant, KK mice; and hyperglycemic and markedly insulin-resistant KKAy mice were used for ozone exposure studies. All animals were exposed to filtered air (FA) or repetitive ozone (0.5  ppm O 3 , 4 h/d, for 13 consecutive weekdays). Tissue analysis was performed 24 h following the final exposure. This analysis included bronchoalveolar lavage (BAL) for cell and fluid analysis, and tissue for pathology, immunohistology, mRNA, and hydroxyproline.

RESULTS

Following repetitive O 3 exposure, higher bronchoalveolar lavage fluid inflammatory cells were observed in all mice (KKAy > KK > C 57 BL / 6 ), with a notable influx of neutrophils and eosinophils in KK and KKAy mice. Although the lungs of O 3 -exposed C57BL/6J and KK mice had minimal centriacinar histological changes without fibrosis, the lungs of O 3 -exposed KKAy mice contained marked epithelial hyperplasia in proximal alveolar ducts and adjacent alveoli with associated centriacinar fibrosis. Fibrosis in O 3 -exposed KKAy lungs was confirmed with immunohistochemistry, tissue hydroxyproline content, and tissue mRNA expression of fibrosis-associated genes (Ccl11, Il13, and Mmp12). Immunofluorescence staining and confocal microscopy revealed alterations in the structure and composition of the airway and alveolar epithelium in regions of fibrosis.

DISCUSSION

Our results demonstrate that in diabetic animal strains repetitive ambient ozone exposure led to early and exaggerated pulmonary inflammation and remodeling. Changes in distal and interstitial airspaces and the activation of Th2 inflammatory and profibrotic pathways in experimental animals provide a preliminary, mechanistic framework to support the emerging epidemiological associations among air pollution, diabetes, and lung disease. https://doi.org/10.1289/EHP7255.

[Pulmonary insufficiency in acute stroke: risk factors and mechanisms of development]

Various degrees of pulmonary insufficiency (PI) (PaO₂ ≤60 mm Hg, SaO₂ ≤90%) are diagnosed in most of patients with severe acute stroke (AS). Frequency and severity of PI positively correlates with the severity of AS. PI worsens patient's condition, prolongs the hospitalization period, and increases the probability of fatal outcome. Early clinical signs of PI may be undiagnosed due to the severity of stroke and thus not treated. The initiating pathogenic mechanism of PI is stress-related activation of sympathetic nervous system (SNS) and systemic immunosuppression. In severe stroke with mass effect, the rapid and significant increase in intracranial pressure may additionally activate the SNS. Risk factors of PI include older age, previous pulmonary disease, prolonged supine position, respiratory muscle dysfunction, apnea, and concomitant somatic diseases. Decompensation of somatic diseases leads to multiple stage reactions with facilitation of functional and morphologic changes in the pulmonary system, hypoxemia and hypoxia, promotes infectious complications and multiple organ failure and worsens neurological outcome. Diagnosis and treatment of PI in AS decreases mortality and improves rehabilitation prognosis.

Bidirectional relationship between diabetes and pulmonary function: a systematic review and meta-analysis

AIM

Evidence of the lungs being a target organ of diabetes-related pathophysiology is increasing, and decreased pulmonary function increases the risk of diabetes after adjusting for demographic and metabolic factors. This systematic review and meta-analysis evaluates the bidirectional relationship between diabetes and pulmonary function.

METHODS

MEDLINE, Embase, The Cochrane Library and Web of Science databases were searched, and all studies describing this bidirectional relationship were identified. Two reviewers independently extracted study characteristics and assessed the risk of bias.

RESULTS

A total of 93 studies were included in the meta-analysis. The pooled weighted mean difference (WMD) between diabetes patients and non-diabetic participants for forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) were -5.65% and -5.91%, respectively, of predicted values. Diabetes-related microvascular complications and poor glycaemic control were associated with poorer pulmonary function in those with diabetes. In addition, diabetes was associated with a restrictive spirometry pattern (RSP) in both cross-sectional studies [odds ratio (OR): 2.88, 95% confidence interval (CI): 2.18-3.81, I² = 0.0%] and prospective cohort studies [hazard ratio (HR): 1.57, 95% CI: 1.04-2.36]. In five longitudinal studies, the conclusions were inconsistent as to whether or not diabetes accelerates pulmonary function decline. However, every 10% decrease in baseline predicted FVC value was associated with a 13% higher risk of incident diabetes (HR: 1.13, 95% CI: 1.09-1.17, I² = 0.0%).

CONCLUSION

There is a bidirectional relationship between diabetes and pulmonary function. However, further investigations into whether dynamic changes in glycaemic levels before and shortly after diabetes onset mediate the deleterious effects on pulmonary function, or vice versa, are now required.

Relationship between pulmonary function and albuminuria in type 2 diabetic patients with preserved renal function

BACKGROUND

Albuminuria is the early manifestation of the pathogenesis of diabetic nephropathy (DN). The current study was to investigate the relationship of pulmonary function with albuminuria in type 2 diabetic patients with preserved renal function to evaluate the role of pulmonary function in the early stage of DN.

METHODS

A total of 326 patients with type 2 diabetes mellitus (T2DM) including 270 without albuminuria and 56 with albuminuria, and 265 non-diabetic patients were enrolled. The patients' general information, and the parameters of pulmonary function, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, total lung capacity (TLC), diffusion capacity for carbon monoxide of lung (DLCO) were compared between T2DM and control groups, as well as T2DM patients with and without albuminuria groups. All pulmonary function parameters were expressed as a percentage of those predicted (%pred). Logistic regression models were constructed to test the association of albuminuria and pulmonary function.

RESULTS

The values of FVC%pred, FEV1%pred, TLC%pred and DLCO%pred were lower, and the proportion of subjects with FVC%pred < 80, FEV1%pred < 80, and DLCOc%pred < 80 was higher in T2DM subjects than controls (all P < 0.05). Subgroup analysis of diabetic patients showed that the values of FVC%pred, FEV1%pred, TLC%pred, and DLCOc%pred (97.18 ± 13.45, 93.95 ± 14.51, 90.64 ± 9.97, 87.27 ± 13.13, respectively) were significantly lower in T2DM subjects with albuminuria than those without albuminuria (103.94 ± 14.12, 99.20 ± 14.25, 93.79 ± 10.36, 92.62 ± 13.45, all P < 0.05). There was a significantly negative correlation between the urine albumin-to-creatinine ratio (UACR) and DLCOc%pred (r = - 0.143, P = 0.010) in spearman linear correlation test. In logistic regression analysis, the FVC%pred (OR 0.965, 95%CI 0.944-0.988), FEV1%pred (OR 0.975, 95%CI 0.954-0.996), and DLCOc%pred (OR 0.974, 95%CI 0.951-0.998) were independently associated with albuminuria after adjustments for smoking index, duration, HbA1c, FBG, and TG.

CONCLUSION

Our results demonstrated albuminuria is associated with a restrictive pulmonary function as well as pulmonary diffusion function in T2DM with preserved renal function, which remind us to be alert of the pulmonary function decline even in the early stage of DN.

Diabetes Mellitus Contributes to Idiopathic Pulmonary Fibrosis: A Review From Clinical Appearance to Possible Pathogenesis

Diabetes mellitus is a systematic metabolic disease characterized by persistent hyperglycemia, which complications often involve multiple organs and systems including vessels, kidneys, retinas, and nervous system. Idiopathic pulmonary fibrosis is a chronic, progressive, fibrotic disease with usual interstitial pneumonia patterns. With in-depth research, diabetic related lung injury has been confirmed, and the lung is also considered as one of the targeted organs of diabetes, which mainly manifests as the pulmonary fibrosis. Based on that, this review discusses the association between diabetes mellitus and idiopathic pulmonary fibrosis from clinical findings to possible mechanisms.

Pre- and postoperative respiratory muscle strength, body mass index and fasting glucose profile of patients with type 2 diabetes mellitus submitted to metabolic surgery

Abstract Introduction: The lung is considered a target organ in diabetes mellitus as a consequence of alterations secondary to chronic hyperglycemia that compromise respiratory muscle strength. Metabolic surgery for improving diabetes mellitus has beneficial effects on weight loss and glucose metabolism. Objective: The objective of this study was to evaluate the respiratory muscle strength, assessed by MIP and MEP, body mass index (BMI) and fasting glucose profile of patients with type 2 diabetes mellitus before and after metabolic surgery without gastric resection. Method: Seventeen patients with type 2 diabetes mellitus participated in the study. The participants had a mean age of 44.8 ± 11.81 years. Results: The results showed a significant decrease of MEP values in the immediate postoperative period when compared to the preoperative period (p=0.001), while no significant results were obtained for MIP. Regarding BMI and fasting glucose, significant weight loss and a significant reduction in fasting glucose levels were observed in the late postoperative period (p=0.006 and p=0.007, respectively). Conclusion: The MIP and MEP were reestablished and satisfactory results were obtained for BMI and fasting glucose in the late postoperative period. Further studies are needed to monitor patients in the pre- and postoperative period of metabolic surgery, identifying complications and acting on the care and recovery of these patients.

Pulmonary Pathology Among Patients with Type 2 Diabetes Mellitus: An Updated Systematic Review and Meta-analysis

BACKGROUND

Restrictive lung pathology was reported in the previous meta-analysis among patients with Type 2 Diabetes mellitus (T2DM) which is date back to 2010.

OBJECTIVE

To see the effect of T2DM on pulmonary functions through updated systematic review and meta-analysis.

DATA SOURCE

PubMed.

STUDY ELIGIBILITY CRITERIA

English language case-control or cross-sectional studies, published between 1 January 2010 to 31 August 2018.

PARTICIPANTS AND INTERVENTION

T2DM and non-diabetic subjects were compared for at least one of the pulmonary function variables i.e. Forced expiratory volume in 1st second (FEV1), % FEV1, Forced vital capacity (FVC), % FVC and % FEV1/FVC.

STUDY APPRAISAL AND SYNTHESIS METHODS

Methodological quality of the study was assessed using Newcastle-Ottawa Quality Assessment Scale. Meta-analysis was done using Review Manager 5.3 (RevMan 5.3) and meta-regression was conducted using R statistical software.

RESULTS

We selected 22 articles that met our inclusion and exclusion criteria. Results reveal that among patients with T2DM all variables were reduced except %FEV1/FVC which shows statistically nonsignificant results with P=0.46. This confirms that T2DM patients have a restrictive type of lung pathology.

LIMITATION

Only articles from the PubMed database were included. Conclusion and Implications of Key Findings: This review affirms the existing evidence of restrictive pathology among patients with T2DM. The future study could be conducted to see the effect of various rehabilitation protocols on pulmonary function among patients with T2DM.

Hyperuricemia predicts the risk for developing hypertension independent of alcohol drinking status in men and women: the Saku study

Hyperuricemia has been reported to be a risk factor for hypertension, but this association may be affected by alcohol consumption. This study aimed to investigate whether hyperuricemia remains a risk factor for hypertension after eliminating the effect of alcohol consumption. This study comprised 7848 participants (4247 men and 3601 women) aged 30-74 years without hypertension who had undergone a medical checkup between April 2008 and March 2009 at Saku Central Hospital, Nagano Prefecture, Japan. Hyperuricemia was defined as uric acid >7.0 mg/dl in men, ≥6.0 mg/dl in women, and/or receiving treatment for hyperuricemia or gout. The incidence of hypertension was defined as the first diagnoses of blood pressure ≥140/≥ 90 mmHg and/or initiations of antihypertensive drug treatment. Multivariable-adjusted hazard ratios (HRs) of hyperuricemia for the incidence of hypertension after adjustment for and classification by alcohol consumption were estimated using the Cox proportional hazard model. During a mean of 4.0 years of follow-up, 1679 individuals developed hypertension. After adjustment for alcohol consumption, the HRs (95% confidence interval) associated with hyperuricemia were 1.37 (1.19-1.58) in men and 1.54 (1.14-2.06) in women. Among nondrinkers, the HR was 1.29 (0.94-1.78) in men with hyperuricemia compared with men without, and the corresponding HR was 1.57 (1.11-2.22) in women. The corresponding HR was 1.88 (1.27-2.86) in all participants with baseline blood pressure <120/80 mmHg. The interactions between hyperuricemia and sex (P = 0.534) and between drinking and sex (P = 0.713) were not significant. In conclusion, hyperuricemia predicts the risk for developing hypertension independent of alcohol drinking status.

Fasting Blood Glucose Predicts Incidence of Hypertension Independent of HbA1c Levels and Insulin Resistance in Middle-Aged Japanese: The Saku Study

BACKGROUND

Relationships between blood glucose (BG) levels and insulin action, and incidence of hypertension have not been well known epidemiologically. This study aimed to investigate the association between indices of diabetes and the incidence of hypertension and compare the predictive powers of these indices in middle-aged Japanese.

METHODS

This 5-year cohort study included 2,210 Japanese aged 30-64 years without hypertension. Hazard ratios of high fasting blood glucose (FBG) levels, high post-loaded BG levels, high glycated hemoglobin (HbA1c) levels, insulin resistance (defined by homeostasis model assessment of insulin resistance [HOMA-IR]) and impaired insulin secretion at baseline for the incidence of hypertension were estimated using multivariable-adjusted Cox proportional hazard models. Hypertension was defined as blood pressure ≥ 140/90 mm Hg or receiving antihypertensive treatment.

RESULTS

During the follow-up, 456 participants developed hypertension. After adjustment for HbA1c and HOMA-IR, FBG was independently and significantly associated with hypertension. The hazard ratio of participants with FBG ≥ 7.0 mmol/l was 1.79 compared with those with FBG < 5.6 mmol/l. Even among those with HbA1c < 6.5%, HOMA-IR < 2.5, body mass index < 25 kg/m2, age < 55 years old, blood pressure < 130/80 mm Hg or non- and moderate drinking, the results were similar. High 120-minute BG level and impaired insulin secretion did not increase the risk for hypertension.

CONCLUSIONS

FBG was a predictable index for future incidence of hypertension in middle-aged Japanese men and women. This is the first study comparing predictive powers of indices of diabetes for the incidence of hypertension.

Diabetic lung, an underrated complication from restrictive functional pattern to pulmonary hypertension

In patients with type 1 and type 2 diabetes mellitus (DM), respiratory function abnormalities have been reported with regard to lung volumes, pulmonary diffusing capacity, control of ventilation, bronchomotor tone, and neuroadrenergic bronchial innervation. Indeed, the decrease in lung volumes and the impairment of diffusing capacity might have important clinical implications. Furthermore, there is an increasing evidence of a link between DM and pulmonary hypertension (PH) related to an involvement of the pulmonary vascular structures. These findings support the view of the lung as target organ in DM. In this paper, we briefly describe the main derangements of the respiratory system in DM and the inherent mechanisms.

Reactive Carbonyl Species: Diabetic Complication in the Heart and Lungs

Abnormal chemical reactions in hyperglycemia alter normal metabolic processes in diabetes, which is a key process in the production of reactive carbonyls species (RCS). Increasing the concentration of RCS may result in carbonyl/oxidative stress in both the diabetic heart and lung. Ryanodine receptors (RyRs) not only play a key role in heart contraction, including rhythmic contraction and relaxation of the heart, but they are also important for controlling the airway smooth muscle. RCS modifies RyRs, resulting in RyRs dysfunction, which is involved in important mechanisms in diabetic complications. Very little is known about the mechanistic relationship between the heart and lung in diabetes. This review highlights new findings on the pathophysiological mechanisms and discusses potential approaches to treatment for these complications.

The association between glycemic control and lung function impairment in individuals with diabetes: the Saku study

Aim

Though diabetes is a risk factor for lung function impairment, whether the glycemic control level affects lung function in individuals with diabetes remains unclear. The present study aimed to assess the association between glycemic control level and restrictive or obstructive lung function impairment in individuals with diabetes.

Methods

This cross-sectional study included 1028 individuals with diabetes, aged 40-69 years, who underwent a medical checkup between April 2008 and March 2014. Hemoglobin A1c (HbA1c) was categorized as  < 6.9%, 7.0-7.9%, and  ≥ 8.0%. Restrictive and obstructive lung function impairment was defined by a forced vital capacity (FVC) < 80% predicted and a forced expiratory volume in 1 s to FVC ratio < 0.70.

Results

Of the participants, 8.7% and 6.3% were classified as having restrictive and obstructive lung function impairment, respectively. The multivariable-adjusted odds ratios and 95% confidence intervals for restrictive lung function impairment were 1.43 (0.84-2.42) in individuals with HbA1c 7.0-7.9%, and 2.42 (1.38-4.26) in individuals with HbA1c ≥ 8.0%, compared with those who had HbA1c < 6.9% (p for trend = 0.002). In contrast, glycemic control level was not associated with obstructive lung function impairment (p for trend = 0.749).

Conclusions

Poor glycemic control was associated with restrictive lung function impairment in individuals with diabetes. Good glycemic control would be important to minimize restrictive lung function impairment in individuals with diabetes.