Sex Differences in the Associations among Insulin Resistance Indexes with Metabolic Syndrome: A Large Cross-Sectional Study

Abstract

Purpose: Metabolic syndrome (MetS) is closely related to insulin resistance (IR), and the sex differences have not been fully explored. This study was aimed to investigate the sex differences in the associations among IR indexes with MetS in a large population.

Methods: A total of 60,799 participants were enrolled in the current study. MetS was defined using the National Cholesterol Education Program Adult Treatment Panel III criteria. The following IR indexes were evaluated: triglyceride-glucose (TyG) index, TyG-waist circumference (TyG-WC), TyG-waist to height ratio (TyG-WHtR), TyG-body mass index (TyG-BMI), triglyceride to high-density lipoprotein cholesterol (TG/HDL-C), and metabolic score for IR (MetS-IR). Factors associated with MetS were examined using logistic regressions. The receiver operating characteristic curves were used to evaluate the predictive value of the IR indexes for MetS.

Results: The prevalence of MetS was 11.8% (n = 4097) for males and 5.4% (n = 1390) for females and increased with age in both subgroups. The IR index levels of male patients were higher than female patients (all p < 0.001). The IR indexes were independent risk factors for MetS except for TyG-WHtR and TG/HDL-C in female patients. TyG had the greatest area under the curve (AUC) (AUC, 0.930; 95% CI, 0.928-0.933; p < 0.001) in the male patients and TyG-WHtR (AUC, 0.916; 95% CI, 0.913-0.920; p < 0.001) in the female patients. The AUCs of 6 IR indexes combination were 0.960 (95% CI, 0.957-0.962; p < 0.001) and 0.962 (95% CI, 0.959-0.964; p < 0.001), with the sensitivities of 91.29% and 90.94%, the specificities of 88.27% and 89.51% in male and female groups, respectively.

Conclusions: The IR index levels are higher in male than female patients. In IR indexes, TyG has the highest AUC in male patients and TyG-WHtR in female patients. The combination of IR indexes improved diagnostic efficiency compared with a single parameter. Moreover, the IR indexes are independently associated with MetS except for TyG-WHtR and TG/HDL-C in female patients. Our findings indicate that the multi-index association of IR indexes may play a potential role in MetS diagnosis, and understanding the sex differences in risk factors for MetS may help doctors properly implement more individualized prevention strategies.

Figure 1

Flow chart of the study populations.

Figure 2

Prevalence of MetS by gender according to the age group. MetS: metabolic syndrome.

Figure 3

Comparisons of IR indexes by gender. IR: insulin resistance; MetS: metabolic syndrome; TyG: triglyceride-glucose; BMI: body mass index; WC: waist circumference; WHtR: waist-to-height ratio; TG: triglyceride; HDL-C: high-density lipoprotein cholesterol; MetS-IR: metabolic score for insulin resistance.

Figure 4

The ROC curve analyses for the IR indexes among (a) males and (b) females. ROC: receiver operating characteristic; IR: insulin resistance; TyG: triglyceride-glucose; BMI: body mass index; WC: waist circumference; WHtR: waist-to-height ratio; TG: triglyceride; HDL-C: high-density lipoprotein cholesterol; MetS-IR: metabolic score for insulin resistance.