C-reactive protein-triglyceride-glucose index and risk of incident depressive symptoms in older adults: an eight-year follow-up study from ELSA.
Abstract
Background
Depression is a common mental health issue among older adults, yet few studies have explored whether metabolic biomarkers predicting its onset exist. The CRP-TyG index (CTI), combining C-reactive protein and the triglyceride-glucose index, may more effectively capture inflammatory-metabolic dysregulation than either marker alone. However, prospective evidence on the relationship between CTI and depression in aging populations is limited.
Methods
We analyzed data from 2,813 depression-free participants aged ≥ 50 years in ELSA, with follow-up through Wave 8. Baseline CTI was assessed from fasting blood biomarkers, and depressive symptoms were evaluated using the CES-D-8 scale. Cox proportional hazards models were used to estimate hazard ratios (HRs). To assess the potential influence of missing data, multiple-imputation analyses were additionally performed as sensitivity analyses.
Results
During follow-up, 136 participants developed incident depressive symptoms. After full adjustment including BMI, each 1-SD increase in CTI was associated with a higher risk of incident depressive symptoms (HR = 1.253; 95% CI: 1.002-1.479; p = 0.035). Multiple-imputation sensitivity analyses yielded directionally consistent results.
Conclusion
In this nationally representative cohort of adults aged 50 years and older in England, higher baseline CTI was prospectively associated with an increased risk of incident depressive symptoms. CTI may serve as a scalable biomarker for identifying older adults at elevated risk of depressive symptoms.