Metabolic Syndrome is Associated with Lower Plasma Levels of Desacyl Ghrelin and Total Ghrelin in Asymptomatic Middle-aged Korean Men

BACKGROUND: Desacyl ghrelin is acylated by ghrelin O-acyltransferase (GOAT) and converted to acyl ghrelin. To date, little is known about the relationship among the levels of these two forms of ghrelin, GOAT level, and insulin resistance in Asian individuals. The purpose of this study was to determine the relationship between insulin resistance and the levels of plasma acyl ghrelin, desacyl ghrelin, and GOAT in asymptomatic middle-aged Korean men. METHODS: This cross-sectional study evaluated 78 asymptomatic middle-aged Korean men with metabolic syndrome (MS). We examined the correlation between the plasma levels of acyl ghrelin, desacyl ghrelin, and GOAT and sociodemographic, dietary, anthropometric, and metabolic parameters, as well as the association between insulin resistance and plasma levels of acyl ghrelin, desacyl ghrelin, and GOAT. RESULTS: The levels of desacyl ghrelin and total ghrelin were significantly lower in the MS group than in the non-MS group (P<0.017, P=0.01, respectively). HOMA-IR values showed a significant negative correlation with desacyl ghrelin (r=−0.271, P=0.017) and total ghrelin (r=−0.271, P=0.016) levels. Acyl ghrelin and GOAT were not significantly correlated with HOMA-IR, and no correlation was found between the plasma levels of the two ghrelin types and GOAT. CONCLUSION: The plasma levels of desacyl ghrelin and total ghrelin in middle-aged Korean men with MS were lower than in those without MS. A significant negative correlation was observed between desacyl ghrelin level and HOMA-IR; however, no correlation was found between plasma levels of acyl ghrelin and GOAT and HOMA-IR.