title: Impact of brown adipose tissue on body fatness and glucose metabolism in healthy humans.
abstract: BACKGROUND
  Brown adipose tissue (BAT) is involved in the regulation of whole-body energy expenditure and adiposity. Some clinical studies have reported an association between BAT and blood glucose in humans.
  
  
  OBJECTIVE
  To examine the impact of BAT on glucose metabolism, independent of that of body fatness, age and sex in healthy adult humans.
  
  
  METHODS
  Two hundred and sixty healthy volunteers (184 males and 76 females, 20-72 years old) underwent fluorodeoxyglucose-positron emission tomography and computed tomography after 2 h of cold exposure to assess maximal BAT activity. Blood parameters including glucose, HbA1c and low-density lipoprotein (LDL)/high-density lipoprotein-cholesterol were measured by conventional methods, and body fatness was estimated from body mass index (BMI), body fat mass and abdominal fat area. The impact of BAT on body fatness and blood parameters was determined by logistic regression with the use of univariate and multivariate models.
  
  
  RESULTS
  Cold-activated BAT was detected in 125 (48%) out of 260 subjects. When compared with subjects without detectable BAT, those with detectable BAT were younger and showed lower adiposity-related parameters such as the BMI, body fat mass and abdominal fat area. Although blood parameters were within the normal range in the two subject groups, HbA1c, total cholesterol and LDL-cholesterol were significantly lower in the BAT-positive group. Blood glucose also tended to be lower in the BAT-positive group. Logistic regression demonstrated that BAT, in addition to age and sex, was independently associated with BMI, body fat mass, and abdominal visceral and subcutaneous fat areas. For blood parameters, multivariate analysis after adjustment for age, sex and body fatness revealed that BAT was a significantly independent determinant of glucose and HbA1c.
  
  
  CONCLUSIONS
  BAT, independent of age, sex and body fatness, has a significant impact on glucose metabolism in adult healthy humans.
authors.affiliation: Department of Nutrition, School of Nursing and Nutrition, Tenshi College, Sapporo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Matsushita
authors.affiliation: Laboratory of Histology and Cytology, Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yoneshiro
authors.affiliation: Department of Food and Nutrition, Hakodate Junior College, Hakodate, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Aita
authors.affiliation: LSI Sapporo Clinic, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kameya
authors.affiliation: LSI Sapporo Clinic, Sapporo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sugie
authors.affiliation: Department of Nutrition, School of Nursing and Nutrition, Tenshi College, Sapporo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Saito
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D002001:Adipose Tissue, Brown / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000502:physiology; D050154:Adiposity / Q000502:physiology*; D000328:Adult; D000368:Aged; D001823:Body Composition; D003080:Cold Temperature; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18; D005947:Glucose; D006442:Glycated Hemoglobin; D019275:Radiopharmaceuticals; C517652:hemoglobin A1c protein, human