Association of C-reactive protein-triglyceride-glucose index with all-cause and cardiovascular mortality in postmenopausal women

Introduction
Although the C-reactive protein-triglyceride-glucose index (CTI) is associated with various adverse outcomes, its relationship with mortality in postmenopausal women remains unclear.

Material and methods
We analysed data on 5,582 postmenopausal women from the National Health and Nutrition Examination Survey 2001–2010, with mortality follow-up continuing until the end of 2019. C-reactive protein-triglyceride-glucose index was calculated as 0.412 × ln [C-reactive protein (mg/l)] + ln [triglycerides (mg/dl) × fasting plasma glucose (mg/dl))/2]. The Cox proportional hazards model assessed the risk of mortality across CTI levels. We assessed potential nonlinearity with spline analyses and conducted sensitivity analyses.

Results
The mean age of participants was 65.1 ±11.2 years and a mean CTI of 4.2 ±0.6 recorded at baseline. Over a median follow-up of 141 months (~ 11.8 years), 1,846 (33.1%) deaths occurred, including 582 (10.4%) cardiovascular disease (CVD) deaths. An association was observed between increasing CTI values and greater mortality risk in this population. Non-linear analysis identified a CTI threshold at 4.16. Below this value, no significant association with all-cause mortality was found (hazard ratio – HR 0.87, 95% CI: 0.74–1.03); above it, each 1-unit CTI increase raised all-cause mortality risk by 68% (HR 1.68, 95% CI: 1.47–1.92; p < 0.01). Tertile comparisons showed that the highest group/tertile group had significantly increased risks for all-cause (adjusted HR 1.34, 95% CI: 1.19–1.51) and cardiovascular mortality (HR 1.43, 95% CI: 1.16–1.76) compared to the middle tertile. A similar trend was observed for CVD mortality. These associations remained consistent in sensitivity analyses.

Conclusions
Elevated CTI remains independently associated with an increased risk of both all-cause and CVD mortality in postmenopausal women.