Influence of dietary cholesterol on metabolic syndrome risk in middle-aged Korean adults: using the Korean Genome and Epidemiology Study (KoGES).

Background: The association between dietary cholesterol and metabolic diseases remains controversial. However, the majority of studies focus on egg intake, and there is a limitation in the availability of prospective cohort studies. Our study examined the association between dietary cholesterol and the incidence risk of metabolic syndrome (MetS) in middle aged adults using large prospective cohort study in Republic of Korea.

Methods: The Health Examinees cohort from the Korean Genome and Epidemiology Study was used from baseline to follow-up. Dietary cholesterol intake was assessed by the validated semi-quantitative food frequency questionnaire. Participants were classified as quintile groups according to adjusted dietary cholesterol for total energy intake. MetS was defined as more than 3 of the 5 components of MetS. Hazard ratio (HR) and 95% confidence intervals (CI) for MetS were evaluated by multivariable cox regression analyses.

Results: Of the total 40,578 participants, metabolic syndrome developed in 4,172 (10.28%) individuals during an average follow-up period of approximately 4.76 years. Dietary cholesterol did not exhibit a significant association with the risk of MetS after adjusting for potential confounding factors, but a trend was observed indicating an increased risk with higher intake (p for trend = 0.044). Among the components of MetS, the incidence risk of high waist circumference (HR: 1.164, 95% CI: 1.049-1.290), high blood pressure (HR: 1.188, 95% CI: 1.075-1.313), high serum triglyceride (HR: 1.132, 95% CI: 1.044-1.227) and high fasting blood glucose (HR: 1.217, 95% CI: 1.132-1.308) in the group that consumed the highest dietary cholesterol intake was increased compared with the group that consumed the lowest dietary cholesterol intake. Dose-response relationship suggested a positive linear association between dietary cholesterol intake and the risk of high waist circumference (p-linearity = 0.004), blood pressure (p-linearity = 0.012), and triglycerides (p-linearity = 0.005).

Conclusion: This study suggests a positive association between dietary cholesterol intake and the risk of MetS and its components (abdominal obesity, hypertension, hypertriglyceridemia, and hyperglycemia) in middle-aged Korean adults.