Type 2 Diabetes and Asthma: Systematic Review of the Bidirectional Relationship

Association of obesity or metabolic syndrome with various allergic diseases: An overview of reviews

The relationship between obesity, metabolic syndrome, related disorders, and various allergic diseases remains unclear. An overview of reviews investigating potential associations between obesity or metabolic syndrome and various allergic diseases was conducted. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched. Systematic reviews and meta-analyses with summary effect size and corresponding 95% confidence intervals for at least one outcome (asthma, atopic dermatitis, and various allergic diseases) were included. This study encompassed 17 systematic review articles and 29 eligible meta-analyses. All included meta-analyses indicated a positive association between obesity/overweight and asthma. Three meta-analyses from one review demonstrated a positive association between obesity/overweight and the risk of atopic dermatitis. However, no meta-analyses focused on the associations between obesity/overweight or metabolic syndrome and allergic rhinitis, allergic conjunctivitis, or other allergic conditions. All included reviews employed poor methodology according to the AMSTAR-2 assessment tools. Our findings suggest that obesity likely increases the risk of asthma. However, evidence for associations with other allergic diseases is limited. Furthermore, no meta-analyses were conducted to assess the relationship between metabolic syndrome and allergic diseases. Further studies are necessary to elucidate the associations between obesity and the full spectrum of allergic diseases.

Asthma Exacerbation Risk in Pregnancy and Postpartum: Assessing the Impact of Gestational Diabetes Mellitus and Other Key Factors

BACKGROUND

Asthma, affecting approximately 13% of pregnancies worldwide, and gestational diabetes mellitus (GDM), present in approximately 14%, are both associated with adverse maternal and perinatal outcomes. This study aims to address a lack of current knowledge about how GDM affects asthma during pregnancy.

OBJECTIVE

To determine whether GDM is associated with an increased risk of asthma exacerbations during pregnancy and the first year postpartum.

METHODS

This retrospective cohort study analyzed electronic health records of pregnant patients with asthma from 2010 to 2023, excluding those with pre-existing diabetes mellitus or concurrent chronic lung diseases. Asthma exacerbations were defined by the need for an oral corticosteroid prescription. Multivariable logistic regression and zero-inflated Poisson regression were used to adjust for age, race, body mass index (BMI), prepregnancy asthma exacerbation history, and insurance status.

RESULTS

Among 10,985 individuals, 1492 had GDM. Patients with GDM were older with higher BMIs. GDM was associated with increased asthma exacerbation risk during pregnancy (adjusted odds ratio [OR] = 1.36, 95% confidence interval [CI]: 1.10-1.67), but not postpartum. Stratified analyses of 4331 individuals with gestational blood glucose measurement showed that each doubling of blood glucose levels doubled the risk of asthma exacerbations during pregnancy (adjusted OR = 2.02, 95% CI: 1.45-2.81). Other factors associated with asthma exacerbation included prepregnancy asthma exacerbations, older age, and Medicaid coverage.

CONCLUSION

The association between GDM and increased risk of asthma exacerbations underscores the need for early, universal screening and effective interventions to improve blood glucose control in pregnant individuals with pre-existing asthma.

Higher prevalence of long COVID observed in cancer survivors: Insights from a US nationwide survey

BACKGROUND

Cancer and cancer treatments can weaken the body's immune system, making cancer patients particularly vulnerable to COVID-19. While evidence suggests that cancer patients may be at increased risk for severe outcomes after COVID-19 infection, there is a lack of population-based studies comparing long COVID prevalence between cancer survivors and non-cancer individuals.

METHODS

We utilized data from the 2022 Behavioral Risk Factor Surveillance System (BRFSS), analyzing a sample of 120,658 U.S. adults who had tested positive for COVID-19. Long COVID was defined as the presence of COVID-19 symptoms lasting three months or longer. The weighted prevalence of long COVID was compared between cancer survivors and non-cancer individuals. Crude and adjusted odds ratios (ORs) with 95 % confidence intervals (CIs) were calculated. Multiple imputation was employed to address missing data on COVID-19 vaccination.

RESULTS

Among 17,362 cancer survivors who tested positive for COVID-19, 4009 reported having long COVID (weighted prevalence = 24.0 %), compared to a weighted prevalence of 21.6 % in non-cancer individuals (p < 0.001). After controlling for covariates and accounting for the complex sampling design, the adjusted OR was 1.17 (95 % CI = 1.06-1.30, p = 0.002). In participants under 45 years old, cancer survivors had a notably higher prevalence of long COVID compared to non-cancer individuals (32.1 % vs. 21.3 %, p < 0.001), with an adjusted OR of 1.33 (95 % CI = 1.07-1.66, p = 0.012). In participants aged 45 and above, the prevalence difference was not significant (22.7 % vs. 21.9 %, p = 0.324), with an adjusted OR of 1.14 (95 % CI = 1.02-1.27, p = 0.024). Regarding the association of COVID-19 vaccination with long COVID, four or more doses were linked to a significant reduced odds of long COVID among cancer survivors (adjusted OR=0.55, 95 %CI = 0.34-0.88, p = 0.013).

CONCLUSIONS

Cancer survivors are observed to have higher odds of developing long COVID, particularly younger survivors. The association of COVID-19 vaccination with long COVID varies between cancer survivors and non-cancer individuals, with cancer survivors requiring more doses to achieve significant reduction in the odds of long COVID.

Prevalence of cardiovascular and other selected diseases among Greenlanders with and without type 2 diabetes

This study aims to estimate the prevalence of cardiovascular disease, kidney disease, and other selected diseases including hypertension, atrial fibrillation, asthma, chronic obstructive lung disease, osteoarthritis, osteoporosis, psoriasis and depression among Greenlanders living in Nuuk with and without type 2 diabetes (T2D). The study was designed as a cross-sectional case-control study based on data from the electronic medical record (EMR) in Greenland. Persons with a registered T2D diagnosis in EMR and residence in Nuuk (N = 435) were included. The prevalence of cardiovascular disease was 17.9% among persons with T2D and significantly higher compared to the control group (10.1%). In addition, our results showed a significantly higher prevalence of ischaemic heart disease, hypertension, heart failure, atrial fibrillation, osteoarthritis and psoriasis among persons with T2D compared to the control group.Our study found a higher prevalence in five out of 10 selected diseases in regularly followed persons with T2D in Nuuk compared to unselected controls. This enlightens the importance of a broad multifaceted approach in combination of changing primary health care to focus on early detection of controllable risk factors and chronic conditions care in Artic Greenland.

A Comprehensive Youth Diabetes Epidemiological Data Set and Web Portal: Resource Development and Case Studies

BACKGROUND

The prevalence of type 2 diabetes mellitus (DM) and pre-diabetes mellitus (pre-DM) has been increasing among youth in recent decades in the United States, prompting an urgent need for understanding and identifying their associated risk factors. Such efforts, however, have been hindered by the lack of easily accessible youth pre-DM/DM data.

OBJECTIVE

We aimed to first build a high-quality, comprehensive epidemiological data set focused on youth pre-DM/DM. Subsequently, we aimed to make these data accessible by creating a user-friendly web portal to share them and the corresponding codes. Through this, we hope to address this significant gap and facilitate youth pre-DM/DM research.

METHODS

Building on data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018, we cleaned and harmonized hundreds of variables relevant to pre-DM/DM (fasting plasma glucose level ≥100 mg/dL or glycated hemoglobin  ≥5.7%) for youth aged 12-19 years (N=15,149). We identified individual factors associated with pre-DM/DM risk using bivariate statistical analyses and predicted pre-DM/DM status using our Ensemble Integration (EI) framework for multidomain machine learning. We then developed a user-friendly web portal named Prediabetes/diabetes in youth Online Dashboard (POND) to share the data and codes.

RESULTS

We extracted 95 variables potentially relevant to pre-DM/DM risk organized into 4 domains (sociodemographic, health status, diet, and other lifestyle behaviors). The bivariate analyses identified 27 significant correlates of pre-DM/DM (P<.001, Bonferroni adjusted), including race or ethnicity, health insurance, BMI, added sugar intake, and screen time. Among these factors, 16 factors were also identified based on the EI methodology (Fisher P of overlap=7.06×10-6). In addition to those, the EI approach identified 11 additional predictive variables, including some known (eg, meat and fruit intake and family income) and less recognized factors (eg, number of rooms in homes). The factors identified in both analyses spanned across all 4 of the domains mentioned. These data and results, as well as other exploratory tools, can be accessed on POND.

CONCLUSIONS

Using NHANES data, we built one of the largest public epidemiological data sets for studying youth pre-DM/DM and identified potential risk factors using complementary analytical approaches. Our results align with the multifactorial nature of pre-DM/DM with correlates across several domains. Also, our data-sharing platform, POND, facilitates a wide range of applications to inform future youth pre-DM/DM studies.

Unraveling the Link between Ιnsulin Resistance and Bronchial Asthma

Evidence from large epidemiological studies has shown that obesity may predispose to increased Th2 inflammation and increase the odds of developing asthma. On the other hand, there is growing evidence suggesting that metabolic dysregulation that occurs with obesity, and more specifically hyperglycemia and insulin resistance, may modify immune cell function and in some degree systemic inflammation. Insulin resistance seldom occurs on its own, and in most cases constitutes a clinical component of metabolic syndrome, along with central obesity and dyslipidemia. Despite that, in some cases, hyperinsulinemia associated with insulin resistance has proven to be a stronger risk factor than body mass in developing asthma. This finding has been supported by recent experimental studies showing that insulin resistance may contribute to airway remodeling, promotion of airway smooth muscle (ASM) contractility and proliferation, increase of airway hyper-responsiveness and release of pro-inflammatory mediators from adipose tissue. All these effects indicate the potential impact of hyperinsulinemia on airway structure and function, suggesting the presence of a specific asthma phenotype with insulin resistance. Epidemiologic studies have found that individuals with severe and uncontrolled asthma have a higher prevalence of glycemic dysfunction, whereas longitudinal studies have linked glycemic dysfunction to an increased risk of asthma exacerbations. Since the components of metabolic syndrome interact with one another so much, it is challenging to identify each one's specific role in asthma. This is why, over the last decade, additional studies have been conducted to determine whether treatment of type 2 diabetes mellitus affects comorbid asthma as shown by the incidence of asthma, asthma control and asthma-related exacerbations. The purpose of this review is to present the mechanism of action, and existing preclinical and clinical data, regarding the effect of insulin resistance in asthma.

Sociodemographic factors, health behavior, parental or workplace smoking, and adult asthma risk in the United States

BACKGROUND

Although several studies have found a link between parental or workplace smoking and asthma risk, particularly in children and adolescents, only a few studies have found this link in adults.

OBJECTIVE

This study aimed to investigate the associations of sociodemographic factors, health behavior, and parental or workplace smoking with adult asthma risk in the United States (US).

METHODS

A secondary data analysis on 874 participants aged 25-45 was performed using data from the 2011-2014 National Survey of Midlife Development in the United States Refresher. Participants were divided into smokers and nonsmokers. Participants were further divided into groups A (a father or mother with a smoking history) and B (others in the house or colleagues in the workplace who had a smoking history).

RESULTS

Findings from the FREQ procedure revealed that sociodemographic (female, black, school or college education, unmarried/divorced, and employed) and lifestyle (no alcohol intake, physically inactive, and obese) and clinical (diabetes and joint disease) factors were significantly associated with one- or more-fold odds of asthma among adult smokers than nonsmokers. Adult smokers in group A, particularly females, those with a high school or college education, physically inactive, and overweight or obese, had a higher risk of asthma than those in group B.

CONCLUSION

Adult smokers' risk of developing asthma is increased in the US by having smoked with their parents, being a woman, being black, having a school or college education, being single or divorced, working, not drinking alcohol, being physically inactive, being obese, having diabetes, and having a joint disease.

Basis of preventive and non-pharmacological interventions in asthma

Asthma is one of the most common atopic disorders in all stages of life. Its etiology is likely due to a complex interaction between genetic, environmental, and lifestyle factors. Due to this, different non-pharmacological interventions can be implemented to reduce or alleviate the symptoms caused by this disease. Thus, the present narrative review aimed to analyze the preventive and non-pharmacological interventions such as physical exercise, physiotherapy, nutritional, ergonutritional, and psychological strategies in asthma treatment. To reach these aims, an extensive narrative review was conducted. The databases used were MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. Asthma is an immune-mediated inflammatory condition characterized by increased responsiveness to bronchoconstrictor stimuli. Different factors have been shown to play an important role in the pathogenesis of asthma, however, the treatments used to reduce its incidence are more controversial. Physical activity is focused on the benefits that aerobic training can provide, while physiotherapy interventions recommend breathing exercises to improve the quality of life of patients. Nutritional interventions are targeted on implement diets that prioritize the consumption of fruits and vegetables and supplementation with antioxidants. Psychological interventions have been proposed as an essential non-pharmacological tool to reduce the emotional problems associated with asthma.

Risk of type 2 diabetes mellitus in adult patients with atopic dermatitis

AIMS

This study aimed to investigate the subsequent risk of type 2 diabetes mellitus (T2D) in adults newly diagnosed with atopic dermatitis (AD).

METHODS

This propensity score-matching cohort study used data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) 2.0 database in South Korea from 2002 to 2015. The adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using a Cox proportional hazards model, for the new onset of T2D (ICD-10 code, E11) in AD patients compared to the matched controls. Subgroup and sensitivity analyses were also conducted.

RESULTS

Each of the 36,692 individuals in the AD group and matched control group was included in the analysis. The risk of T2D in the AD group was significantly higher than that of the matched controls in the adjusted model (adjusted HR 1.44; 95% CI 1.27-1.63, P <.001). The results of subgroup analysis by sex, age, and body mass index were consistent with the results of the primary analysis. Sensitivity analyses using different T2D and/or AD definitions also showed consistent results.

CONCLUSIONS

The significant risk of subsequent T2D in adult AD patients suggested the necessity for efforts to prevent T2D in AD patients.

Facilitating youth diabetes studies with the most comprehensive epidemiological dataset available through a public web portal

The prevalence of type 2 diabetes mellitus (DM) and prediabetes (preDM) is rapidly increasing among youth, posing significant health and economic consequences. To address this growing concern, we created the most comprehensive youth-focused diabetes dataset to date derived from National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2018. The dataset, consisting of 15,149 youth aged 12 to 19 years, encompasses preDM/DM relevant variables from sociodemographic, health status, diet, and other lifestyle behavior domains. An interactive web portal, POND (Prediabetes/diabetes in youth ONline Dashboard), was developed to provide public access to the dataset, allowing users to explore variables potentially associated with youth preDM/DM. Leveraging statistical and machine learning methods, we conducted two case studies, revealing established and lesser-known variables linked to youth preDM/DM. This dataset and portal can facilitate future studies to inform prevention and management strategies for youth prediabetes and diabetes.

TCM as adjunctive therapy improves risks of respiratory hospitalizations in persons with type 2 diabetes: A retrospective cohort study

Patients with type 2 diabetes are at a higher risk of chronic obstructive pulmonary disease (COPD) and asthma than the general population. In addition, emerging evidence suggests that traditional Chinese medicine (TCM) might be beneficial for patients with type 2 diabetes. We investigated whether TCM use was associated with a reduced risk of respiratory hospitalizations in patients with type 2 diabetes. Conducting a retrospective cohort study, we used data retrieved from the NDCMP database. Among 56,035 patients, 5226 were classified as TCM users; 50,809 were classified as TCM nonusers. Both groups were analyzed until the end of 2011 to examine the incidence of respiratory hospitalizations by using a Cox proportional hazards model to evaluate effects of TCM use on respiratory hospitalizations. During the 6-year study follow-up period, the incidence density rates of COPD- and asthma-related hospitalization were estimated to be 13.03 and 4.47 per 10,000 patient-years for TCM nonusers and 10.08 and 3.28 per 10,000 patient-years for TCM users, respectively. The HR of COPD-related hospitalization in TCM users was 0.88 (95% CI = 0.79-0.99); and the HR of asthma-related hospitalization in TCM users was 0.81 (95% CI = 0.66-1.00). Stratified analyses revealed that effects of TCM use were stronger among individuals who had diabetes for <3 years. As a part of Integrative Medicine, our study results demonstrate that TCM use was associated with a significant reduced risk of respiratory hospitalizations, especially in patients with diabetes for <3 years.

Diabetes, insulin resistance, and asthma: a review of potential links

PURPOSE OF REVIEW

Disorders of glucose metabolism, including insulin resistance, prediabetes, and diabetes, have been identified as risk factors for worsened asthma. This review summarizes emerging evidence for their role as modifiable risk factors in asthma, including the potential benefit of diabetes medications on asthma outcomes.

RECENT FINDINGS

Experimental studies show that hyperinsulinemia associated with insulin resistance is associated with airway smooth muscle proliferation and promotes contractility. Epidemiologic studies have identified a higher prevalence of glycemic dysfunction among those with severe and uncontrolled asthma, and longitudinal studies have associated prediabetes and diabetes with higher risk of asthma exacerbations. The potential benefits of thiazolidinediones (TZDs), glucagon-like peptide-1 agonists, and metformin being investigated in asthma, but thus far interventional studies of TZDs have reported null results. On the contrary, observational studies have inconsistently controlled for relevant confounders which leaves conclusions vulnerable to misattribution of relationships due to corelated metabolic disorders, including dyslipidemia.

SUMMARY

Developing evidence suggests that disorders of glucose metabolism may be associated with worsening asthma. However, these conditions arise within a network of obesity-related metabolic diseases that may themselves worsen asthma. Few interventional trials have not identified a benefit, but data have been limited. Additional research is needed to define the potential independent impact of disorders of glucose metabolism in asthma.

Diabetes Mellitus Is Associated with Worse Outcome in Patients Hospitalized for Asthma

BACKGROUND

Asthma is a prevalent disease with a high economic cost. More than 50% of its direct cost relates to asthma hospitalizations. Diabetes mellitus (DM) is a significant comorbidity in asthmatic patients, yet its impact on asthma-related hospitalizations is unknown.

OBJECTIVE

To compare the outcome of asthma-related hospitalizations in patients with and without DM.

METHODS

Using Healthcare Cost and Utilization Project Nationwide Readmissions Database, we analyzed data of all adults with index admission for asthma and with no other chronic pulmonary conditions, and compared outcomes between patients with and without DM. Weighted regression analysis was used to determine the impact of DM on hospitalization outcomes. All multivariate regression models were adjusted for patient demographics, socioeconomic status, and chronic medical comorbidities.

RESULTS

A total of 717,200 asthmatic patients were included, with 202,489 (28.3%) having DM. Diabetic patients were older and had more comorbidities. When hospitalized for asthma, diabetic patients had increased hospital length of stay, cost, and risk for 30-day all-cause and asthma-related readmission. They also had a higher risk for developing nonrespiratory complications during their hospital stay compared with nondiabetic patients. The risk of mortality was similar between the 2 groups.

CONCLUSIONS

Patients hospitalized for asthma with coexisting DM had increased hospital length of stay, cost, and risk for readmission. Interventions are urgently needed to reduce the risk for hospital admission and readmission in patients with coexisting DM and asthma. These interventions would have profound economic and societal impact.

Patients with asthma have a higher risk of rheumatoid arthritis: A systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate whether patients with asthma have a higher risk of incident rheumatoid arthritis (RA) using systematic review and meta-analysis technique.

METHODS

Potentially eligible studies were identified from Medline and EMBASE databases from inception to May 2020 using search strategy that comprised of terms for "Asthma" and "Rheumatoid arthritis". Eligible cohort study must consist of one cohort of patients with asthma and another cohort of individuals without asthma. Then, the study must effect estimates with 95% confidence intervals (95% CIs) comparing incident RA between the groups. Eligible case-control studies must include cases with RA and controls without RA. Then, the study must explore their history of asthma. Odds ratio (OR) with 95% CIs of the association between asthma status and RA must be reported. Point estimates with standard errors were retrieved from each study and were combined together using the generic inverse variance method.

RESULTS

A total of 22,442 articles were identified. After two rounds of independent review by three investigators, six cohort studies and fourteen case-control studies met the eligibility criteria and were included into the meta-analysis. Meta-analysis of cohort studies found that patients with asthma had a significantly higher risk of RA compared with individuals without asthma with the pooled hazard ratio of 1.42 (95% CI, 1.18 - 1.70). Meta-analysis of case-control studies revealed that patients with asthma had a higher risk of RA compared with individuals without asthma with the pooled odds ratio of 1.33 (95%CI, 0.97 - 1.83). Funnel plot for the meta-analysis of case-control studies was asymmetric, suggesting the presence of publication bias.

CONCLUSIONS

This systematic review and meta-analysis found a significant association between asthma and higher risk of incident RA.

Patients with asthma have a higher risk of systemic lupus erythematosus: a systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate the association between asthma and risk of systemic lupus erythematosus (SLE) using systematic review and meta-analysis technique.

METHODS

Potentially eligible studies were identified from Medline and EMBASE databases from inception to March 2020 using search strategy that comprised of terms for "asthma" and "systemic lupus erythematosus." Qualified cohort study must consist of one cohort of patients with asthma and another cohort of individuals without asthma. Then, the study must report relative risk (RR) with 95% confidence intervals (95% CIs) of incident SLE between the two groups. Qualified case-control studies must consist of cases with SLE and controls without SLE. Then, the study must explore their history of asthma. Odds ratio (OR) with 95% CIs of the association between asthma status and SLE must be reported. Point estimates and standard errors were extracted from each study and were combined using the generic inverse variance method.

RESULTS

A total of 21,486 articles were identified. After two rounds of independent review by three investigators, three cohort studies and seven case-control studies met the eligibility criteria and were included into the meta-analysis. Patients with asthma had a significantly higher risk of SLE compared with individuals without asthma with the pooled odds ratio of 1.37 (95% CI 1.14-1.65; I² 67%). Funnel plot was symmetric and did not suggest the presence of publication bias.

CONCLUSIONS

The current study found a significant association between asthma and increased risk of SLE. Key Points • Studies have suggested an elevated risk of systemic lupus erythematosus among patients with asthma; however, the results from existing studies are inconsistent. • This meta-analysis included data from three cohort studies and seven case--control studies. • A significant association between asthma and elevated risk of systemic lupus erythematosus was observed, with the pooled odds ratio of 1.37 (95% CI 1.14-1.65; I² 67%).

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.