Association between non-high density lipoprotein-cholesterol fractions and presence of allostatic load among industrial workers

Non-high density lipoprotein-cholesterol (non-HDL-C) fraction is the total cholesterol (TC) minus HDL-C. It is not a routinely reported component of lipid profile and is used in lipoprotein lowering therapy and prediction of coronary artery disease, target organ damage and atherosclerosis. Allostatic load (AL) is an imbalance between repetitive chronic exposure to stress and adaptive response. The present study investigates the association between non-HDL-C and its fractions (non-HDL-C/HDL-C, non-HDL-C/TC, non-HDL-C/ triglyceride [TG] and non-HDL-C/low-density lipoprotein-cholesterol [LDL-C]) and the presence of AL to determine, which fractions of non-HDL-C predict the diagnostic accuracy and optimal cut points. The study design is cross-sectional and data were collected from 169 male industrial workers. AL was measured using neuroendocrine (cortisol and dehydroepiandrosterone sulphate), cardiovascular (systolic blood pressure, diastolic blood pressure and heart rate), metabolic (TC, TG, HDL-C and LDL-C) and anthropometric (waist-hip ratio and body mass index) factors. The fractions of non-HDL-C/HDL-C, nonHDL-C/TC, non-HDL-C/TG and non-HDL-C/LDL-C were calculated using non-HDL-C, HDL-C, TC, TG and LDL-C values. About 43.2% and 56.8% of workers had low and high AL, respectively. The non-HDL-C and its fractions such as non-HDL-C/HDL-C, non-HDL-C/TC and non-HDL-C/LDL-C were significantly increased in the high AL group. Stepwise regression analysis was used to examine the association between non-HDL-C fractions and AL. The fractions of non-HDL-C (b = 0.785, P = 0.001), non-HDL-C/TC (b = −0.336, P = 0.001) and nonHDL-C/LDL-C (b = 0.295, P = 0.001) influenced AL by 38.6%. The AUC with 95% CI in the high AL group was as follows: non-HDL-C 0.766 (0.696–0.837, P = 0.001); non-HDL-C/HDL-C 0.638 (0.555–0.721, P = 0.002); nonHDL-C/TC 0.635 (0.552–0.712, P = 0.003) and non-HDL-C/LDL-C 0.520 (0.433–0.607, P = 0.657). Non-HDL-C and its fractions were more precisely predicted in the high AL category of workers than in the low AL category. Non-HDL-C predicted the most precisely, followed by non-HDL-C/HDL-C, non-HDL-C/TC, non-HDL-C/ LDL-C and non-HDL-C/TG. According to the present study, non-HDL-C and its fractions such as non-HDL-C/HDL-C, nonHDL-C/TC and non-HDL-C/LDL-C should be considered regular lipid profiles and could be used as biomarkers to reduce the risk of AL.