Head‑to‑head comparison of four waist-adiposity–glycolipid indices for long‑term prediction of new‑onset hypertension: the NAGALA cohort study

Background Glycolipid dysregulation is linked to vascular damage and hypertension, but routine anthropometric and lipid markers capture only part of cardiometabolic risk. We constructed a novel waist-adiposity index (WAI) that integrates two independent dimensions of central obesity(absolute WHtR and relative WC/BMI) and compared four glycolipid composite indices for long-term hypertension prediction. Methods We analyzed 15,422 adults from the NAGALA community cohort (recruited 1994–2016, mean follow-up 6.05 years). Three indices incorporated WAI (TyG-WAI, MCMI-WAI, WyG-WAI); CMI served as a non-WAI comparator. We performed comprehensive internal validation of WAI across eight domains: known-groups validity, convergent/discriminant validity, time-dependent AUC, incremental predictive value (ΔC-index), restricted cubic spline dose-response, subgroup analyses, sensitivity analyses, and measurement-error propagation. All indices were z-score standardized. Results During follow-up, 780 participants developed hypertension. Three indices (CMI, MCMI-WAI, TyG-WAI) were independently associated with incident hypertension in fully adjusted Cox models (all p < 0.05); WyG-WAI was not. WAI internal validation confirmed: known-groups validity (MetS p < 0.001, overweight p < 0.001), convergent validity (r with WC = 0.600, BMI = 0.357), discriminant validity (r with WHtR = 0.789 > r with BMI = 0.357), 13-year AUC = 0.733 (95% CI 0.703–0.763), a statistically significant likelihood-ratio test for incremental value (p = 0.008) with negligible absolute change in C-index (ΔC-index = −0.00021), linear dose–response (P nonlinear = 0.280), exploratory associations in women (HR = 1.216, p = 0.008) and lean adults (HR = 1.186, p = 0.004), and robustness across four exclusion criteria plus measurement-error propagation (CV = 2.26% for WC ±1 cm error). Conclusions Three of four indices were independently associated with long-term hypertension risk, with distinct nonlinear patterns. WAI demonstrated robust internal validity across eight domains and may serve as a candidate risk-stratification marker. Exploratory subgroup findings in women and lean adults require confirmation in independent cohorts. External validation in independent cohorts is required before clinical application.