Association of metabolic score for insulin resistance and its 6-year change with incident type 2 diabetes mellitus.

Background: The evidence for the association between metabolic score for insulin resistance (METS-IR) and type 2 diabetes mellitus (T2DM) is limited. We aimed to explore the association of METS-IR and its 6-year change with risk of incident T2DM in a rural Chinese population.

Methods: We analyzed data for 12 107 participants (mean age 50.48 years). A Cox proportional-hazard model was used to estimate the association of METS-IR with incident T2DM by using hazard ratios (HRs) and 95% confidence intervals (CIs); a logistic regression model was used to assess the association of 6-year METS-IR change with incident T2DM by using odds ratios (ORs) and 95% CIs. We used subgroup analyses of the association of METS-IR and its 6-year change with incident T2DM by sex, age, and baseline fasting plasma glucose (FPG) level as well as restricted cubic splines to describe the dose-response association.

Results: The association of METS-IR and 6-year METS-IR change with incident T2DM was significant (per SD unit increase: HR = 1.80, 95% CI: 1.60-2.02 for METS-IR, OR = 1.42, 95% CI: 1.28-1.57 and OR = 1.59, 95% CI: 1.44-1.76 for relative and absolute METS-IR change). The significant association remained on subgroup analyses by sex, age, and baseline FPG level. Dose-response analysis demonstrated that the probability of incident T2DM was significantly increased with increasing METS-IR and 6-year METS-IR change.

Conclusions: Increased METS-IR and 6-year METS-IR change were positively associated with risk of incident T2DM in a rural Chinese population. METS-IR may be a vital indicator for identifying T2DM.