Leptin and adiponectin are two major adipocytokines reported to be associated with type 2 diabetes. However, it is unknown whether their associations with the risk of incident type 2 diabetes are independent of visceral adiposity and liver fat in a prospective cohort study. We included 787 Japanese men aged 28 to 77 years without type 2 diabetes at baseline. The subjects were classified into four groups based on leptin-adiponectin profile at baseline, with the median concentration value as the cut-off point (median levels of leptin and adiponectin were 4.8 ng/dL and 5.7 µg/mL, respectively): low-high, low-low, high-high, and high-low group. Visceral fat was measured by computed tomography (CT) as intra-abdominal fat area at the umbilicus level. Liver fat was assessed by liver-to-spleen attenuation ratio measured by CT. Type 2 diabetes was diagnosed as fasting plasma glucose level ≥126 mg/dL, HbA1c ≥6.5%, or taking oral hypoglycemic medications or insulin. Cox proportional hazard models were used to estimate hazard ratios (HR) for developing type 2 diabetes. During 5215 person-years of follow-up, 72 subjects developed type 2 diabetes. Incidence rates of type 2 diabetes per 1000 person-years were 3.2, 9.2, 18.6, and 26.1 for the low-high, low-low, high-high, and high-low group, respectively. After adjustment for age, smoking status, alcohol consumption, regular physical activity, family history of diabetes, visceral fat, and liver fat, multiple-adjusted HRs (95% CI) of incident type 2 diabetes were 1.87 (0.63-5.50), 2.90 (1.02-8.21), and 3.41 (1.23-9.47) for the low-low, high-high, and high-low group compared with the low-high group. In conclusion, leptin and adiponectin were associated with incident type 2 diabetes independent of both visceral fat and liver fat.
I. Shibata: None. W. Y. Fujimoto: None. E. J. Boyko: None. T. Hayashi: None. M. Shibata: None. K. K. Sato: None. S. Uehara: None. N. Nishida: None. K. Okamura: None. Y. Yuyama: None. H. Koh: None. Y. Hikita: None.