Spirometric prediction equations and the relationship between metabolic syndrome and spirometric parameters from an island in Fujian, China

Pulmonary Function in Metabolic Syndrome: A Meta-Analysis

Background: This study aims to systematically evaluate the association between metabolic syndrome (MS) and pulmonary function through meta-analysis. Methods: Electronic databases, including PubMed, Embase, Web of Science, and Cochrane Library, were systematically searched to obtain articles associated with MS and lung function published before December 31, 2021. According to the including and excluding criteria, certain studies were obtained and data were extracted. The Newcastle Ottawa Scale was used to evaluate the quality of the studies. A pooled standardized mean difference (SMD) was calculated by means of random-effects meta-analysis. Different effect models were used according to the heterogeneity. Meta-regression and sensitivity analyses were performed to examine the possible sources of heterogeneity. The Begg's funnel plot and Egger's test were used to evaluate publication bias. Analyses were performed using Stata MP, version14.0 (StataCorp LP, College Station, TX, USA). Results: A total of 15 studies, involving 10,285 cases of MS and 25,416 cases of control, were included in this meta-analysis on the relationship between MS and forced vital capacity (FVC). The pooled SMD for FVC was -0.247 (95% CI = -0.327 to -0.2167, P < 0.001) using random effect model, indicating the decrease of FVC in the patients with MS. In the same studies, the pooled SMD for forced expiratory volume in 1 sec (FEV₁) was -0.205 (95% CI = -0.3278 to -0.133, P < 0.001), indicating the decrease of FEV₁ also existed in the MS cases. A total of 13 studies, involving 8167 cases of MS and 19,788 cases of control, were included in this meta-analysis on the relationship between MS and FEV₁/FVC. The pooled SMD for FEV₁/FVC was 0.011 (95% CI = -0.072 to 0.093, P = 0.798) using random effect model, indicating that there was no significant difference between the patients with MS and the control. After introducing the diastolic blood pressure and glycemia into the regression model of the relationship between MS and FVC, the variance of the studies (tau2) decreased from 0.0190 to 0.006694 and 0.007205, which could explain 66.70% and 78.04% of the sources of heterogeneity, and the P values were 0.038 and 0.023. The results suggested that hypertension (diastolic pressure) and hyperglycemia were the factors linked to the heterogeneity among the included studies on both FVC and FEV₁. The Begg's funnel plot and Egger's test both showed no evidence of publication bias. Conclusions: Our results show that FVC and FEV₁ decrease in MS patients, while FEV₁/FVC has no significant difference compared with the control group. It indicates that the patients with MS have restrictive ventilatory functional disturbance. Meta-regression analysis suggests that hypertension (diastolic pressure) and hyperglycemia are the factors linked to the heterogeneity among the included studies on both FVC and FEV₁.

[Prevalence of external respiratory dysfunction in young people]

AIM

To investigate the prevalence of impaired external respiration function (ERF) in young Novosibirsk dwellers.

SUBJECTS AND METHODS

A cross-sectional population-based survey in one of the typical districts of Novosibirsk was conducted at the Research Institute of Internal and Preventive Medicine in 2013-2015. ERF was examined by spirometry in accordance with the guidelines. The best indicators of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio were selected and three reproducible attempts were made to evaluate ERF. Spirometry was carried out in 787 respondents (358 males and 429 females) for the entire period. The results were interpreted according to the guidelines of the European Respiratory Society, the American Thoracic Society, and the Russian Respiratory Society.

RESULTS

The prevalence of a FEV1/FVC of <70% in the total sample was 10.3% (13.4% for men and 7.7% for women; p=0.009); a FEV1 of <80% was 13.9% (14.5% for men and 13.3% for women; p=0.617); a FVC of <80% was 7% (6.1% for men and 7.7% for women; p=0.397). The obstructive type of ventilation disorders (FEV1/FVC <70%, FVC ≥80%) was recorded in 9.4% of the people, the restrictive type (FVC <80%, FEV1/FVC ≥70%) in 6.1%, and the mixed one (FEV1/FVC <70%, FVC <80%) in 0.9%; normal values (FEV1/FVC ≥70% and FVC ≥80%) were seen in 83.6%.

CONCLUSION

Spirometric screening of a young Novosibirsk population demonstrated the incidence of impaired ERF, which is comparable with Russian and foreign data.

Relationship between metabolic syndrome and epicardial fat tissue thickness in patients with chronic obstructive pulmonary disease

OBJECTIVE

An increase in epicardial fat tissue (EFT) thickness was found to be associated with metabolic syndrome (MS) and ischemic heart disease. MS is a comorbidity of chronic obstructive pulmonary disease (COPD) resulting from the accompanying systemic inflammation. The aim of our study was to investigate the usefulness of EFT thickness to predict MS in COPD patients.

METHODS

COPD patients admitted to our clinic during January-December 2014 and healthy controls were included in this prospective case control study. Patients with comorbidities, COPD exacerbation, and malignancies were excluded. Patients and controls were compared in terms of anthropometric measurements, MS-related examination and laboratory findings, pulmonary function tests, and EFT thickness. The correlations between EFT thickness and markers of MS in COPD were evaluated using the Student's t-test and logistic regression analysis.

RESULTS

COPD patients and controls were composed of 82 and 84 individuals, respectively. MS was diagnosed in 31 (37.8%) COPD patients. The EFT thickness was significantly higher in COPD patients than in the controls and was also higher in COPD patients with MS than in those without MS (all p<0.001). Each 1-mm increment of EFT raised the risk of MS two-fold (p=0.011, OR=2.08, 95% CI: 1.18-3.68). Increase in triglyceride level (p=0.004, OR=1.02, 95% CI: 1.01-1.03) and reduction in forced vital capacity (p=0.025, OR=0.26, 95% CI: 0.08-0.84) were found to be associated with increased MS risk. The cut-off value for EFT thickness in the prediction of MS in COPD patients was 6.75 mm (sensitivity: 83%, specificity: 65%).

CONCLUSION

EFT thickness is a non-invasive and easily available parameter, which is valuable in the prediction of increased MS risk in COPD patients. Early diagnosis of patients at risk of MS may help to prevent ischemic heart disease in these patients.