Objective: Both increased serum levels of low-density lipoprotein cholesterol (LDLC) and metabolic syndrome (MetS) are associated with obesity and have been established to be risk factors of cardiovascular disease. However, studies on the relationship between LDLC and MetS have been limited.
Methods: Cross-sectional (n=3,871) and longitudinal (n=2,558) associations between LDLC and MetS were examined in a Japanese health screening population.
Results: The odds ratio (OR) [95% confidence interval (CI)] of coexisting MetS for each one SD increase in the LDLC level was 1.25 [1.12-1.40] (p<0.001) adjusted for body mass index (BMI) and other confounding covariates and 1.12 [0.97-1.28] (p=0.119) adjusted for numerical values of the components of MetS and other confounding covariates. The similarly adjusted ORs [95% CIs] for the highest quartile of LDLC (Q4) compared with the lowest quartile (Q1) were 1.76 [1.22-2.54] (p=0.002) and 1.46 (0.93-2.30) (p=0.101), respectively. The hazard ratio (HR) [95% CI] for developing MetS for each one SD increase in the LDLC level was 1.24 [1.10-1.40] (p<0.001) adjusted for BMI and other confounding covariates and 1.19 [1.05-1.34] (p=0.006) adjusted for the pre-existing dichotomous five components of MetS and other confounding covariates. The similarly adjusted HRs [95% CIs] for developing MetS for Q4 compared with Q1 were 1.71 [1.17-2.51] (p=0.006) and 1.61 [1.08-2.40] (p=0.020), respectively.
Conclusion: The LDLC level is associated with coexisting MetS and functions as a predictor of the development of MetS, independent of BMI or the pre-existing components of MetS, in a Japanese health screening population.