Relationships of decreased lung function with metabolic syndrome and obstructive sleep apnea in Japanese males

The impact of insulin resistance on the association between metabolic syndrome and lung function: the Kangbuk Samsung Health Study

BACKGROUND/OBJECTIVE

Metabolic syndrome (MS) is related to lung dysfunction. However, its impact according to insulin resistance (IR) remains unknown. Therefore, we evaluated whether the relation of MS with lung dysfunction differs by IR.

SUBJECT/METHODS

This cross-sectional study included 114,143 Korean adults (mean age, 39.6 years) with health examinations who were divided into three groups: metabolically healthy (MH), MS without IR, and MS with IR. MS was defined as presence of any MS component, including IR estimated by HOMA-IR ≥ 2.5. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for lung dysfunction were obtained in MS, MS without IR, and MS with IR groups compared with the MH (reference) group.

RESULTS

The prevalence of MS was 50.7%. The percent predicted forced expiratory volume in 1 s (FEV1%) and forced vital capacity (FVC%) showed statistically significant differences between MS with IR and MH and between MS with IR and MS without IR (all P < 0.001). However, those measures did not vary between MH and MS without IR (P = 1.000 and P = 0.711, respectively). Compared to MH, MS was not at risk for FEV1% < 80% (1.103 (0.993-1.224), P = 0.067) or FVC% < 80% (1.011 (0.901-1.136), P = 0.849). However, MS with IR was clearly associated with FEV1% < 80% (1.374 (1.205-1.566) and FVC% < 80% (1.428 (1.237-1.647) (all p < 0.001), though there was no evident association for MS without IR (FEV1%: 1.078 (0.975-1.192, P = 0.142) and FVC%: 1.000 (0.896-1.116, p = 0.998)).

CONCLUSION

The association of MS with lung function can be affected by IR. However, longitudinal follow-up studies are required to validate our findings.

Does intestinal dysbiosis contribute to an aberrant inflammatory response to severe acute respiratory syndrome coronavirus 2 in frail patients?

In a few months, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has become the main health problem worldwide. Epidemiologic studies revealed that populations have different vulnerabilities to SARS-CoV-2. Severe outcomes of the coronavirus disease 2019 (COVID-19) with an increased risk of death are observed in patients with metabolic syndrome, as well as diabetic and heart conditions (frail population). Excessive proinflammatory cytokine storm could be the main cause of increased vulnerability in this frail population. In patients with diabetes and/or heart disease, a low inflammatory state is often associated with gut dysbiosis. The increase amount of microbial metabolites (i.e., trimethylamine N-oxide and lipopolysaccharide), which generate an inflammatory microenvironment, is probably associated with an improved risk of severe illness from COVID-19. Nutritional interventions aimed at restoring the gut microbial balance could represent preventive strategies to protect the frail population from COVID-19. This narrative review presents the possible molecular mechanisms by which intestinal dysbiosis that enhances the inflammatory state could promote the spread of SARS-CoV-2 infection. Some nutritional strategies to counteract inflammation in frail patients are also analyzed.

Metabolic syndrome and lung function in Korean children and adolescents: A cross-sectional study

This study aimed to investigate whether obesity and metabolic syndrome (MetS) are associated with pulmonary function in Korean children and adolescents. Data from the 2009–2011 Korea National Health and Nutrition Examination Survey which is cross-sectional, nationwide, and representative survey were used. Adjusted regression analysis was performed to evaluate the association of obesity and MetS with lung function in children and adolescents. A total of 763 children and adolescents aged 10–18 years were evaluated. We found no significant difference in FEV₁% predicted, FVC% predicted, and FEV₁/FVC ratio among the obesity groups. Subjects with MetS showed a significantly lower FEV₁ predicted (91.54 ± 0.74% vs 94.64 ± 0.73%, P = 0.004), lower FVC% predicted (91.86 ± 0.63% vs 95.20 ± 0.63%, P < 0.001), and lower FEV₁/FVC ratio (76.76 ± 0.43% vs 80.13 ± 0.43%, P < 0.001) than those without MetS. Elevated waist circumference (WC), systolic blood pressure, fasting glucose, and lower high-density lipoprotein cholesterol (HDL-C) were independently associated with lower FEV₁/FVC ratio (all P < 0.05, respectively). Among MetS components, increased WC was the most important factor influencing lower FEV₁/FVC ratio. In conclusion, lung function in MetS patients was significantly lower, and the MetS component was independently associated.

Impact of respiratory function on the progression from metabolically healthy non-overweight to metabolically abnormal phenotype

BACKGROUND AND AIMS

Recent studies identified that metabolically abnormal non-overweight phenotype is a risk factor for cardiovascular diseases. However, only little is known about risk factors for the progression from metabolically healthy non-overweight (MHNO) to metabolically abnormal phenotype. In this study, we investigated the impact of respiratory function on the progression from MHNO to metabolically abnormal phenotype.

METHODS AND RESULTS

In this retrospective cohort study, 8949 (3872 men and 5077 women) individuals with MHNO, who participated in a health-checkup program from 2004 to 2015, were enrolled. Four metabolic factors (high-normal blood pressure or hypertension, impaired fasting glucose or diabetes, hypertriglyceridemia, and low HDL cholesterol concentration) were used to define metabolically healthy (less than two factors) or metabolically abnormal (two or more factors) phenotypes. Respiratory function was measured by spirometry. Over a median 4.0 years of follow-up, 927 participants progressed to metabolically abnormal phenotype. The percentage of FVC for predicted values (HR 0.98, 95% CI 0.93-1.03, p = 0.418) was not associated with the progression to metabolically abnormal phenotype after adjusting for covariates, including age, sex, alcohol consumption, exercise, smoking status, and body mass index, whereas the percentage of FEV₁ for predicted values (%FEV₁) (HR 0.87, 95% CI 0.84-0.91, p < 0.001) and the FEV₁/FVC ratio (HR 0.86, 95% CI 0.78-0.95, p = 0.004) were associated with the progression to metabolically abnormal phenotype.

CONCLUSION

Decrease in respiratory function in terms of %FEV₁ and the FEV₁/FVC ratio is associated with the progression to metabolically abnormal phenotype in individuals with MHNO.

Relationship of hyperlipidemia to comorbidities and lung function in COPD: Results of the COSYCONET cohort

Although hyperlipidemia is common in COPD, its relationship to comorbidities, risk factors and lung function in COPD has not been studied in detail. Using the baseline data of the COSYCONET cohort we addressed this question. Data from 1746 COPD patients (GOLD stage 1-4; mean age 64.6 y, mean FEV1%pred 57%) were evaluated, focusing on the comorbidities hyperlipidemia, diabetes and cardiovascular complex (CVC; including arterial hypertension, cardiac failure, ischemic heart disease). Risk factors comprised age, gender, BMI, and packyears of smoking. The results of linear and logistic regression analyses were implemented into a path analysis model describing the multiple relationships between parameters. Hyperlipidemia (prevalence 42.9%) was associated with lower intrathoracic gas volume (ITGV) and higher forced expiratory volume in 1 second (FEV1) when adjusting for its multiple relationships to risk factors and other comorbidities. These findings were robust in various statistical analyses. The associations between comorbidities and risk factors were in accordance with previous findings, thereby underlining the validity of our data. In conclusion, hyperlipidemia was associated with less hyperinflation and airway obstruction in patients with COPD. This surprising result might be due to different COPD phenotypes in these patients or related to effects of medication.

Long-term administration of angiotensin (1-7) prevents heart and lung dysfunction in a mouse model of type 2 diabetes (db/db) by reducing oxidative stress, inflammation and pathological remodeling

Congestive heart failure is one of the most prevalent and deadly complications of type 2 diabetes that is frequently associated with pulmonary dysfunction. Among many factors that contribute to development and progression of diabetic complications is angiotensin II (Ang2). Activation of pathological arm of renin-angiotensin system results in increased levels of Ang2 and signaling through angiotensin type 1 receptor. This pathway is well recognized for its role in induction of oxidative stress (OS), inflammation, hypertrophy and fibrosis. Angiotensin (1-7) [A(1-7)], through activation of Mas receptor, opposes the actions of Ang2 which can result in the amelioration of diabetic complications; enhancing the overall welfare of diabetic patients. In this study, 8 week-old db/db mice were administered A(1-7) daily via subcutaneous injections. After 16 weeks of treatment, echocardiographic assessment of heart function demonstrated significant improvement in cardiac output, stroke volume and shortening fraction in diabetic animals. A(1-7) also prevented cardiomyocyte hypertrophy, apoptosis, lipid accumulation, and decreased diabetes-induced fibrosis and OS in the heart tissue. Treatment with A(1-7) reduced levels of circulating proinflammatory cytokines that contribute to the low grade inflammation observed in diabetes. In addition, lung pathologies associated with type 2 diabetes, including fibrosis and congestion, were decreased with treatment. OS and macrophage infiltration were also reduced in the lungs after treatment with A(1-7). Long-term administration of A(1-7) to db/db mice is effective in improving heart and lung function in db/db mice. Treatment prevented pathological remodeling of the tissues and reduced OS, fibrosis and inflammation.

Lung function and metabolic syndrome: Findings of National Health and Nutrition Examination Survey 2007–2010

BACKGROUND

Considerable uncertainty remains about obstructive lung function( OLF) in adults with metabolic syndrome (MetS). The aim of the present study was to examine pulmonary function status in adults with and without MetS.

METHODS

We used data from 3109 participants aged ≥20 years of the National Health and Nutrition Examination Survey 2007-2010. Subjects'MetS status was established on the basis of the 2009 harmonizing definition. Participants received spirometry.

RESULTS

After age adjustment, 79.3% (SE 1.1) of participants with MetS had normal lung function, 8.7% (0.9) had restrictive lung function (RLF), 7.1% (0.8) had mild OLF, and 4.8% (0.6) had moderate OLF or worse. Among participants without MetS, these estimates were 78.7% (1.2), 3.9% (0.6), 10.9%(1.1), and 6.4% (0.8), respectively. After multiple adjustment, participants with MetS were more likely to have RLF (adjusted prevalence ratio [aPR] 2.20; 95% confidence interval [CI] 1.67, 2.90) and less likely to have any OLF (aPR 0.73; 95% CI 0.62, 0.86) than those without MetS. Furthermore, participants with MetS had lower mean levels of forced expiratory volume in one second (FEV1), FEV1 % predicted, forced vital capacity (FVC), and FVC % predicted, but a higher FEV1/FVC ratio than participants without MetS. Mean levels of FEV1, FEV1 % predicted, FVC, and FVC % predicted declined significantly, but not the FEV1/FVC ratio, as the number of components increased.

CONCLUSIONS

Compared with adults without MetS, spirometry is more likely to show a restrictive pattern and less likely to show an obstructive pattern among adults with MetS.

Relationship between lung function and metabolic syndrome

Although the link between impaired lung function and cardiovascular events and type 2 diabetes mellitus has been recognized, the association between impaired lung function and metabolic syndrome has not been comprehensively assessed in the United States (U.S.) population. The aim of our study was to explore the association between impaired lung function and metabolic syndrome in a nationally representative sample of men and women. This cross-sectional population-based study included 8602 participants aged 20–65 years in the Third National Health and Nutrition Examination Survey (NHANES III). We examined the relationship between the different features of metabolic syndrome and lung function, including forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1). After adjusting for potential confounders such as age, body mass index, inflammatory factors, medical condition, and smoking status, participants with more components of metabolic syndrome had lower predicted values of FVC and FEV1 (p for trend <0.001 for both). Impaired pulmonary function was also associated with individual components of metabolic syndrome, such as abdominal obesity, high blood pressure, high triglycerides, and low high density lipoprotein (HDL) cholesterol (p<0.05 for all parameters). These results from a nationally representative sample of US adults suggest that a greater number of features of metabolic syndrome is strongly associated with poorer FVC and FEV1. In clinical practice, more comprehensive management strategies to address subjects with metabolic syndrome and impaired lung function need to be developed and investigated.

Early major medical complications after surgical management of obstructive sleep apnea: a retrospective cohort analysis and case series

PURPOSE

The purpose of this study was to determine the frequency and relative risk (RR) of early postoperative major medical complications after surgery for the management of obstructive sleep apnea.

PATIENTS AND METHODS

This was a retrospective cohort analysis of patients who had undergone surgery for the treatment of polysomnogram-confirmed obstructive sleep apnea at 2 hospitals in Pittsburgh, PA, between 1992 and 2013. Early postoperative major medical complications were defined as either a life-threatening complication requiring intensive care unit intervention or death within the immediate hospital course. Standard demographic data, apnea-hypopnea index, Epworth Sleepiness Score, minimum nocturnal oxygen saturation, and body mass index were collected. The 2-tailed independent t test, Fisher exact test, and RR with 95% confidence interval were used.

RESULTS

A total of 267 consecutive patients who underwent surgery for obstructive sleep apnea and met the inclusion criteria were included in this study. A total of 6 patients (6 of 267, 2.2%) had early major medical postoperative complications. When stratified by surgical group (intrapharyngeal vs extrapharyngeal), there were 162 intrapharyngeal patients with 2 complications (1.2%) and 105 extrapharyngeal patients with 4 complications (3.8%). We found no statistically significant difference in frequency (2 of 162 intrapharyngeal patients [1.2%] vs 4 of 105 extrapharyngeal patients [3.8%], P = .17) or RR (3.1; 95% confidence interval, 0.58 to 16.55; P = .1885) between the groups. There were statistically significant differences for mean age, apnea-hypopnea index, Epworth Sleepiness Score, minimum nocturnal oxygen saturation, and body mass index between the surgical groups.

CONCLUSIONS

The overall frequency of early major medical postoperative complications in upper airway surgery for obstructive sleep apnea is low, with no statistically significant difference in frequency and RR between intrapharyngeal and extrapharyngeal surgery. There may, however, be a clinically significance difference in RR possibly because of associated differences in risk factors between the groups.

Predicting the occurrence of oxygenation impairment in patients with type-B acute aortic dissection

Complicated respiratory failure requiring mechanical ventilation in patients with type-B acute aortic dissection (AAD) has been previously reported, and inflammatory reactions have been found to be associated with the occurrence of oxygenation impairment (OI). However, the possibility of predicting the occurrence of OI in patients with type-B AAD has not yet been evaluated. This study was performed to investigate the possibility of predicting the occurrence of OI in type-B AAD. In this study, 79 type-B AAD patients were enrolled to investigate the possibility of predicting the occurrence of OI. OI was defined as Po2/Fio2 ≤ 200. Patient characteristics, type of AAD, vital signs on admission, and the presence of inflammatory reactions obtained on admission day were evaluated. OI occurred in 39 patients (49%) on hospital day 2.5 ± 1.4 on average. Younger age, male gender, nonslender frame (body mass index ≥ 22 kg/m(2)), a relatively high maximum body temperature on the admission day (≥ 36.5°C), DeBakey IIIb type, patent false lumen, and lower Po2/Fio2 on admission were found to be associated with the occurrence of OI. Multivariate analysis revealed that nonslender frame, relatively high body temperature on the admission day, and lower Po2/Fio2 on admission were reliable for predicting the occurrence of oxygen impairment. The occurrence of OI in type-B AAD can be predicted in the clinical setting.