Background: The triglyceride-glucose (TyG) index is a simple surrogate marker of insulin resistance and is increasingly recognized for its role in cardiometabolic risk assessment. However, little is known about temporal trends in TyG levels among patients with type 2 diabetes mellitus (T2DM), especially across ethnic and demographic subgroups in Southeast Asia. The objective of this study is to examine the trends of the TyG index from 2011 to 2019 among adults with T2DM receiving care in public primary care settings in Malaysia, stratified by age, sex, and ethnicity.
Methods: This retrospective cohort study used registry data from T2DM patients attending government primary care clinics between 2011 and 2019. The TyG index was calculated as ln[fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. Descriptive and regression analyses evaluated overall temporal trends and the trend by sex, age group, and ethnicity across three-time intervals. Restricted cubic spline models assessed potential nonlinear patterns.
Results: A slight but significant decrease in mean TyG index was seen over the study period (P<0.001). Among 161,759 patients, younger individuals had consistently higher TyG values (P<0.001). Both males and females showed a similar modest decline (P<0.001). TyG levels varied by ethnicity (P<0.001), with Malays highest and Chinese lowest. However, the small effect sizes for sex, age, and ethnicity indicate these factors explain only a minor part of the variation in TyG index.
Conclusions: This study found a modest but significant decline in the TyG index among Malaysian adults with T2DM from 2011 to 2019. TyG levels varied by age, ethnicity, and sex, with younger individuals and Malays showing higher values. However, these demographic factors explained only a small part of the variation. Further research is needed to identify other factors and develop targeted interventions to reduce insulin resistance and cardiometabolic risk.
