Remnant cholesterol and two decades risk of incident hypertension: a prospective cohort study and meta-analysis

Whether high remnant cholesterol (RC) is associated with an increased risk of incident hypertension, independent of its well-known risk factors, in the general population remains unclear. We followed 5264 participants (3312 women; mean age 39.1 years) from Tehran Lipid and Glucose Study. RC was calculated as total cholesterol minus the sum of the high- and low-density lipoprotein-cholesterol. Hypertension was defined as systolic blood pressure (SBP) ≥ 140 mmHg, or diastolic blood pressure (DBP) ≥ 90 mmHg, or using anti-hypertensive medications. Multivariable Cox proportional hazards regression models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). In a random-effects meta-analysis we combined our results with six previous studies. In our cohort study, during a median follow-up of 12.4 years, 2189 events of hypertension occurred. Accordingly, in multivariable analyses, the association between RC and hypertension reached non-significant after adjusting for baseline SBP and DBP as covariates in both continuous (per 1-SD increase: 1.00 (0.91-1.10)) and categorical analyses (Q4 vs. Q1: 1.02 (0.85-1.22) (P for trend = 0.343)). However, in the meta-analysis, elevated RC was significantly associated with hypertension (pooled 11 effect-sizes, 1.30 (1.14-1.48); I² = 99.80; N = 7 studies (6 studies used calculated RC); 2,559,478 participants). In subgroup analyses of meta-analysis, this association was generally more pronounced among individuals with lower baseline risk. In conclusion, in our cohort study, elevated RC was not significantly associated with higher risk of incident hypertension in the presence of large set of confounders, including baseline SBP and DBP levels. We investigated the association between remnant cholesterol and risk of hypertension through a prospective study and meta-analysis. In our cohort study, the association between RC and hypertension was not independent of baseline SBP and DBP levels among Iranian adults. However, the meta-analysis revealed a significant association, albeit with substantial heterogeneity.