Can proopiomelanocortin methylation be used as an early predictor of metabolic syndrome?

OBJECTIVE The objectives of this study were to compare early predictive marker of the metabolic syndrome with proopiomelanocortin (POMC) methylation status and to determine the association among birth weight, ponderal index, and cord blood methylation status. RESEARCH DESIGN AND METHODS We collected pregnancy outcome data from pregnant women, cord blood samples at delivery, and blood from children (7-9 years old; n = 90) through a prospective cohort study at Ewha Womans University, MokDong Hospital (Seoul, Korea), from 2003-2005. POMC methylation was assessed by pyrosequencing. We divided subjects into three groups according to cord blood POMC methylation: the low methylation (<10th percentile), mid-methylation, and high methylation (>90th percentile) groups. We analyzed the association of POMC methylation status at birth with adiposity and metabolic components using ANCOVA and multiple linear regression analysis. RESULTS Birth weights (P = 0.01) and ponderal indices (P = 0.01) in the high POMC methylation group were significantly lower than in the mid-POMC methylation group. In terms of metabolic components of childhood, blood triglycerides (57.97, 67.29 vs. 113.89 mg/dL; P = 0.03, 0.01) and insulin (7.10, 7.64 vs. 10.13 μIU/mL; P = 0.05, 0.02) at childhood were significantly higher in the high POMC methylation group than in the low and mid-POMC methylation group. CONCLUSIONS High POMC methylation in cord blood was associated with lower birth weight, and children with high POMC methylation in cord blood showed higher triglycerides and higher insulin concentrations in blood. Thus, POMC methylation status in cord blood may be an early predictive marker of future metabolic syndrome.