OBJECTIVE—Until now, few clinical studies have reported on the association between the indexes of body fat distribution and serum ferritin, an indicator of body iron stores and a putative risk factor for insulin resistance. We investigated the association between serum ferritin concentrations and the indexes of distribution of adipose tissues in the body, such as the visceral fat area (VFA), the subcutaneous fat area (SFA), and the hepatic fat content in Japanese subjects.

RESEARCH DESIGN AND METHODS—A total of 248 Japanese subjects (127 men and 121 postmenopausal women aged 57.8 ± 13.9 years, BMI 25.7 ± 4.6 kg/m²; 140 subjects with type 2 diabetes and 108 nondiabetic subjects) were evaluated. Subjects with a history of alcohol intake were excluded from the study. We measured body height, body weight, and serum ferritin, as well as fasting plasma glucose and plasma insulin concentrations. We estimated insulin resistance by homeostasis model assessment. The fat distribution was evaluated by measuring the VFA and SFA by abdominal computed tomography at the umbilical level. To assess the hepatic fat content, the ratio of the computed tomography attenuation value of the liver to that of the spleen was calculated.

RESULTS—Serum ferritin was significantly correlated with the various indexes of adiposity examined, such as the hepatic fat content (r = −0.280, P < 0.0001), VFA (r = 0.254, P < 0.0001), SFA (r = 0.231, P = 0.0005), and homeostasis model assessment (r = 0.286, P = 0.0008).

CONCLUSIONS—This is the first report to directly demonstrate an association between serum ferritin and VFA and SFA. The results of this study suggest that the serum ferritin concentration may be a useful indicator of systemic fat content and degree of insulin resistance.