## 4 Discussion
[20] investigated the association of airflow obstruction with MS in Japanese men. Their dataset consisted of 7189 subjects aged 45-88 years from spirometric lung function tests at medical checkups. The airflow obstruction was divided into two parts (GOLD I and GOLD II-IV) according to GOLD guidelines. The incidence rate of MS was higher in subjects with GOLD II-IV than in those with normal lung function (OR = 1.33 [1.01-1.76]). Additionally, the MS component WC was associated with MS (OR = 1.76 [1.24-2.50]) and BP (OR = 1.37 [1.08-1.74]). [PERSON] et al. [22] evaluated the association between impaired lung function and metabolic risk factors, enrolling 4001 subjects aged \(>\) 18 years in 2001 from the KNHANES dataset. Using multiple linear regression, they analyzed the association of low pulmonary function with MS. They also examined the associations of restrictive lung disease and obstructive lung disease with MS using multiple logistic regression adjusting for WHtR, sex, age, smoking, physical activity, alcohol consumption, and socioeconomic status. WC, SBP, and TG were associated with FVC. They showed that the association of low pulmonary function with MS risk factors and restrictive lung disease (OR = 1.40 [1.01-1.98]) was also related to MS.  
[PERSON] et al. [23] investigated the association between chronic obstructive pulmonary disease (COPD) and MS. Their dataset comprised 1215 subjects aged \(>\) 40 years from the KNHANES in 2001. The prevalence of MS was significantly high among COPD patients in both men and women (33.0% and 48.5% higher, respectively). In men, the risk of COPD (OR = 2.03 [1.08-3.80]) was associated with MS and abdominal obesity (OR = 1.95 [0.93-4.11]). [PERSON] et al. [24] studied the relationship between impaired lung function and MS in adults. Their study assessed 46,514 patients (21,669 men and 24,845 women) aged \(>\) 20 years, recruited from four nationwide MJ Health Screening Centers in Taiwan. The investigators examined associations between lung function test results and MS using multivariate logistic regression. They demonstrated the association between restrictive lung impairment and an increased risk of MS (\(p\) < 0.01, OR = 1.221), adjusting for age, sex, BMI, smoking, alcohol consumption, and physical activity. This study showed results similar to those of previous studies [12-24] regarding the association of MS with anthropometric, blood, urinary, and spirometric factors. Specifically, TG exhibited the strongest association among all parameters in both men and women. With regard to anthropometric factors, WHtR showed the strongest association in both men and women. Concerning blood parameters, GLU showed a strong positive association. With respect to urinary parameters, UPH showed a negative association with MS. Regarding spirometric factors, FEV6 and FVC exhibited negative associations with MS.  
[PERSON] et al. [38] constructed and analyzed the five MS prediction models including the MLP (multilayer perceptron), NB, RF (random forest classification), CT (decision tree), and SVM (support vector machine). As for the AUC, the NB model showed the highest predictive power at 0.690. [PERSON] et al. [47] evaluated and validated T2 DM (type 2 diabetes mellitus) prediction model including lm (linear regression model), Glmnet (regularized generalized linear model), RF, XGBoot (extreme gradient boosting), and LightGBM (light gradient boosting machine) by RMSE, AUC, AUPRC, R\({}^{2}\), and calibration plot. RF showed the best performance according to RMSE. In our study, as for the results of performance analysis and calibration plot, the wrapper_LR model showed the best performance in both men (AUC = 0.868) and women AUC = 0.932), respectively. Overall, our current findings show that anthropometric, blood, urinary, and spirometric factors might be involved in the induction of MS. Specifically, there was increased association of WC and WHtR, and decreased association of TG, UPH, FEV6, and FVC with MS.