Dietary Inflammatory Index, cardiovascular health, and long-term outcomes in hypertension: external validation in a Chinese percutaneous coronary intervention cohort
Background Hypertension frequently coexists with poor cardiovascular health (CVH), yet whether the inflammatory potential of habitual diet, captured by the Dietary Inflammatory Index (DII), relates to CVH and to subsequent adverse cardiovascular events in this population remains unclear. Methods A discovery analysis was performed in 12,376 hypertensive adults from NHANES (2005–2018), with suboptimal CVH defined as a Life’s Essential 8 (LE8) score < 80. External validation used a single-center retrospective cohort of 1,053 Chinese hypertensive patients who underwent percutaneous coronary intervention (PCI); because an LE8 ≥ 80 is rarely attained in this high-risk secondary-prevention population, suboptimal CVH was defined as LE8 < 60. Multivariable logistic regression, restricted cubic spline, subgroup, and mediation analyses examined the DII–CVH association in both cohorts; NHANES analyses incorporated complex survey design weights. In the PCI cohort, Cox proportional-hazards models assessed the associations of DII and LE8 with major adverse cardiovascular events (MACE), all-cause mortality, recurrent myocardial infarction (MI), and repeat revascularization. Results In NHANES, higher DII was independently associated with suboptimal CVH [fully adjusted odds ratio (OR) 1.39, 95% confidence interval (CI) 1.30–1.50; OR 3.84, 95% CI 2.67–5.52 for the highest versus lowest DII tertile], with a linear dose–response. A consistent association was observed in the PCI cohort: each one-unit increase in DII conferred 29% higher odds of suboptimal CVH (fully adjusted OR 1.29, 95% CI 1.19–1.39; OR 2.99, 95% CI 2.11–4.22 for the highest versus lowest tertile), with a linear dose–response. DII independently predicted MACE [hazard ratio (HR) 1.19, 95% CI 1.10–1.28], recurrent MI (HR 1.24, 95% CI 1.10–1.39), repeat revascularization (HR 1.14, 95% CI 1.02–1.28), and all-cause mortality (HR 1.19, 95% CI 1.04–1.35). Conclusion Higher dietary inflammatory potential is linearly associated with poorer CVH across two demographically and clinically distinct hypertensive cohorts and predicts adverse cardiovascular events in patients with established coronary disease, warranting prospective evaluation.