The Association between the Triglyceride-Glucose Index and the Incidence Risk of Parkinson's Disease: A Nationwide...

We aimed to investigate the associations of the triglyceride-glucose index, which measures insulin resistance, and the incidence of Parkinson's disease.

Our study used the Health Screening Cohort database of the National Health Insurance Service of South Korea (2002-2019). We included 310,021 participants who had no previous history of Parkinson's disease and for whom more than 3 triglyceride-glucose index measurements were available. A diagnosis of Parkinson's disease was determined via the International Classification of Diseases Tenth edition (G20) with a specific reimbursement code for rare intractable diseases and a history of prescriptions for anti-Parkinsonism drugs.

During a median of 9.64 years (interquartile range 8.72-10.53), 4,587 individuals (1.5%) had Parkinson's disease. Based on a multivariable time-dependent Cox proportional hazards model, a per-unit increase in triglyceride-glucose index score was associated with a significantly increased risk of Parkinson's disease (hazard ratio [HR]: 1.062; 95% confidence interval [CI] 1.007-1.119). In a sensitivity analysis, the triglyceride-glucose index was associated with the incidence of Parkinson's disease in a non-diabetes mellitus cohort (HR: 1.093; 95% CI 1.025-1.165), but not in the diabetes mellitus cohort (HR: 0.990; 95% CI 0.902-1.087). In a restricted cubic spline analysis, the association between the triglyceride-glucose index and the incidence risk of Parkinson's disease showed a nonlinear increasing (J-shaped) trend.

Our study demonstrated that higher triglyceride-glucose index scores were associated with the incidence of Parkinson's disease in the general population, particularly in a nondiabetic mellitus cohort.