title: Visceral fat is a strong predictor of insulin resistance regardless of cardiorespiratory fitness in non-diabetic people.
abstract: Abdominal adiposity and low cardiorespiratory fitness are associated with insulin resistance in people with impaired glucose tolerance and type 2 diabetes. However, little is known about which factor precedes insulin resistance in people with impaired glucose tolerance and type 2 diabetes, and which is the stronger predictor of insulin resistance in non-diabetic people. The purpose of this study was to examine the relationship between insulin resistance and cardiorespiratory fitness, visceral fat, and subcutaneous fat in non-diabetic people. Subjects included 87 men and 77 women aged 30-72 y (mean+/-SD, 51.3+/-12.3 y). Cardiorespiratory fitness was assessed by measuring the maximal oxygen uptake (VO2max) in a progressive continuous test to exhaustion on a cycle ergometer. The visceral and subcutaneous fat areas were measured by magnetic resonance imaging. The homeostasis model assessment of insulin resistance (HOMA-R) was calculated from the fasting concentrations of glucose and insulin. Stepwise multiple linear regression analysis revealed that visceral and subcutaneous fat were significant correlates of HOMA-R, explaining 24% and 6% of the variance, respectively, whereas sex, age, and VO2max were not significant independent determinants. Abdominal fat deposition rather than cardiorespiratory fitness is a significant predictor of insulin resistance in non-diabetic people; visceral fat is the most important factor.
authors.affiliation: Consolidated Research Institute for Advanced Science and Medical Care, Waseda University, Tokyo, Japan. chiyoko@suou.waseda.jp
authors.forename: Chiyoko
authors.initials: C
authors.lastname: Usui
authors.forename: Meiko
authors.initials: M
authors.lastname: Asaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawano
authors.forename: Tomoko
authors.initials: T
authors.lastname: Aoyama
authors.forename: Toshimichi
authors.initials: T
authors.lastname: Ishijima
authors.forename: Shizuo
authors.initials: S
authors.lastname: Sakamoto
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Higuchi
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001786:Blood Glucose; D001823:Body Composition; D002320:Cardiovascular Physiological Phenomena; D003920:Diabetes Mellitus; D005080:Exercise Test / Q000379:methods; D005215:Fasting; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat / Q000033:anatomy & histology / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010809:Physical Fitness / Q000502:physiology*; D012143:Respiratory Physiological Phenomena
chemical_list: D001786:Blood Glucose; D007328:Insulin