The C-reactive protein-triglyceride-glucose index and its obesity-derived indicators predict cardio-renal-metabolic multimorbidity: evidence from the UK biobank and CHARLS.

Background

Cardio-renal-metabolic multimorbidity is defined as the coexistence of cardiovascular disease, type 2 diabetes, and chronic kidney disease. We examined the relationships between C-reactive protein-triglyceride glucose-index and its five obesity derivatives with CRMM incidence and progression.

Methods

We included 374,513 participants from UK Biobank and 6,401 participants from CHARLS. Cox, RCS, and multistate models were used to assess incident CRMM and disease transitions. Predictive performance was evaluated using time-dependent ROC, C-index, NRI, and IDI.

Results

Over 15.98 years of follow-up, 13,315 participants developed CRMM.six indices were positively associated with CRMM risk in UK Biobank.CTI-WC showing the strongest association (HR 1.974, 95% CI 1.943-2.007), followed by CTI-WHtR (HR 1.919, 95% CI 1.890-1.950). Multistate analyses also supported associations with CRMM progression, particularly for transitions from healthy to FCRMD, again strongest for CTI-WC (HR 1.538, 95% CI 1.526-1.550). Adding CTI-derived indices improved prediction, with NRI ranging from 21.161% to 23.929%, IDI from 1.051% to 1.512%, and ΔC-index from 0.029 to 0.038 , suggesting improved risk stratification beyond traditional measures. In CHARLS, associations were directionally consistent but attenuated,likely due to the smaller validation cohort.

Conclusions

CTI-derived obesity-related indices, especially CTI-WC and CTI-WHtR, were associated with CRMM incidence and progression and may improve risk stratification.