Tenth categories of total and HDL cholesterol fail to independently predict death risk in middle-aged Turkish adults

Abstract

Objective: The aim of this study was to delineate in detail the longitudinal association of total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) levels with overall mortality in middle-aged partici pants of the biennial Turkish Adult Risk Factor study.Methods: Baseline lipid variables were analyzed in sex-specific deciles. A baseline age of 45 to 84 years as an inclusion criterion led to the enrollment of 2121 men and women. Cox regression analyses were performed. Results: Deaths were recorded in 237 and 306 women and men, respectively, during a mean 8.85 +/- 4.4 years of follow-up. Afte r adjustment for age, smoking status, lipid-lowering and antihypertensive drug usage, prevalent diabetes, and coronary heart disease, and using the lowest decile as referent, neither TC (p trend=0.94 and 0.96, respectively), nor HDL-C categories (p trend=0.20 and 0.31, respectively) were significantly predictive of mortality in either gender. TC deciles exhibited a gender difference insofar as hazard ratios in females tended to be reciprocal to those in males in deciles 2 through 5. Conclusion: The findings on TC deciles may be attributed to a comparatively higher death rate in the female (compared with male) bottom decile, reflecting the autoimmune process-induced elevated risk in the lowest decile. Observations on HDLC confirmed presumed pro-inflammatory conversion in levels >50 mg/dL. These results have important clinical implications.