The role of different lipid measures for incident hypertension during more than 12 years follow-up: Tehran Lipid and Glucose Study

To examine the associations of different lipid measures and related indices with incident hypertension during a median follow-up of 12.89 years. Fasting levels of total cholesterol (TC), triglycerides (TG), high and low density lipoprotein cholesterol (HDL-C and LDL-C, respectively), and related indices (TC/HDL-C and TG/HDL-C) were determined in 7335 Iranian adults (men=3270) free of hypertension, aged 39.0 [standard deviation (SD):13.2] years. Multivariate Cox proportional hazard regression was applied and lipid parameters were considered either as categorical or continuous variables. During follow-up, 2413 (men=11260) participants experienced hypertension. Using the first quartile as reference, significant trends were found between quartiles of TG, HDL-C, TC/HDL-C, and TG/HDL-C in multivariate models; moreover considering these measures as continuous variables, a 1 SD increase in each of these parameters was significantly associated with risk of incident hypertension; the corresponding hazard ratios and confidence intervals were 1.06(1.02-1.10), 0.94(0.89-0.98), 1.04(1.01-1.09), and 1.04(1.01-1.07), respectively. The association between lipid measures and incident hypertension did not change after excluding lipid lowering drug users and those with type 2 diabetes mellitus and were independent of the baseline categories of blood pressure (P for interaction > 0.08). To take into account the nutrition data, a re-analysis on a subgroup (n=1705), showed that a 1-SD increase in TG and TG/HDL-C were associated with incident hypertension, after adjusting for dietary cofounders [1.15(1.08–1.24) and 1.03(1.01–1.04), respectively].

These findings indicate that TG, TG/HDL-C, and TC/HDL-C were independently associated with higher risk while HDL-C was associated with lower risk of incident hypertension.