OBJECTIVE The significant roles of brown adipose tissue (BAT) in the regulation of energy expenditure and adiposity are established in small rodents but have been controversial in humans. The objective is to examine the prevalence of metabolically active BAT in healthy adult humans and to clarify the effects of cold exposure and adiposity. RESEARCH DESIGN AND METHODS In vivo 2-[18F]fluoro-2-deoxyglucose (FDG) uptake into adipose tissue was measured in 56 healthy volunteers (31 male and 25 female subjects) aged 23–65 years by positron emission tomography (PET) combined with X-ray computed tomography (CT). RESULTS When exposed to cold (19°C) for 2 h, 17 of 32 younger subjects (aged 23–35 years) and 2 of 24 elderly subjects (aged 38–65 years) showed a substantial FDG uptake into adipose tissue of the supraclavicular and paraspinal regions, whereas they showed no detectable uptake when kept warm (27°C). Histological examinations confirmed the presence of brown adipocytes in these regions. The cold-activated FDG uptake was increased in winter compared with summer (P < 0.001) and was inversely related to BMI (P < 0.001) and total (P < 0.01) and visceral (P < 0.001) fat areas estimated from CT image at the umbilical level. CONCLUSIONS Our findings, being against the conventional view, indicate the high incidence of metabolically active BAT in adult humans and suggest a role in the control of body temperature and adiposity.

Bioelectrical impedance analysis (BIA) is widely used for assessing the total body, and sometimes visceral, fat content. However the reliability of the results remains to be confirmed, especially for their relationship to the blood parameters associated with obesity and metabolic syndrome. We analyzed the relationship between some blood parameters and the body fat content evaluated by standard X-ray computed tomography (CT) and BIA. Fifty-eight male and 52 female healthy subjects (20-72 years old with a body mass index of 16.3-30.6 kg/m2) underwent both CT and BIA. The visceral fat content was consistently higher in the males than females, regardless of the method used. However, the absolute value by BIA was higher than that by CT. The total and visceral fat contents of the females assessed by CT were positively correlated with the blood leptin, glucose, HbA1c and triglyceride levels, and negatively with adiponectin. The total and visceral fat contents of the males were also positively correlated with the leptin, HbA1c, triglyceride, and insulin levels, and negatively with adiponectin and HDL cholesterol. Similar correlations were also found for the males when the fat contents were assessed by BIA. However, apparently different relationships were found for the females when assessed by BIA compared with those by CT. Assessing body fat by BIA may give some results different from those estimated by the standard CT method, particularly for the relationship with obesity-associated blood parameters.

OBJECTIVE The significant roles of brown adipose tissue (BAT) in the regulation of energy expenditure and adiposity are established in small rodents but have been controversial in humans. The objective is to examine the prevalence of metabolically active BAT in healthy adult humans and to clarify the effects of cold exposure and adiposity. RESEARCH DESIGN AND METHODS In vivo 2-[18F]fluoro-2-deoxyglucose (FDG) uptake into adipose tissue was measured in 56 healthy volunteers (31 male and 25 female subjects) aged 23–65 years by positron emission tomography (PET) combined with X-ray computed tomography (CT). RESULTS When exposed to cold (19°C) for 2 h, 17 of 32 younger subjects (aged 23–35 years) and 2 of 24 elderly subjects (aged 38–65 years) showed a substantial FDG uptake into adipose tissue of the supraclavicular and paraspinal regions, whereas they showed no detectable uptake when kept warm (27°C). Histological examinations confirmed the presence of brown adipocytes in these regions. The cold-activated FDG uptake was increased in winter compared with summer (P < 0.001) and was inversely related to BMI (P < 0.001) and total (P < 0.01) and visceral (P < 0.001) fat areas estimated from CT image at the umbilical level. CONCLUSIONS Our findings, being against the conventional view, indicate the high incidence of metabolically active BAT in adult humans and suggest a role in the control of body temperature and adiposity.

新潟市内の保育所, 小・中学校, 高校寮及び大学寮の各給食における, 動脈硬化予防の視点から重視される脂溶性成分, 食物繊維, ミネラルの給与の実態について検討した。1990年1月から3月までに実施された連続30日間または25日間の給食献立について解析を試み, 次のような結果を得た。1) 各給食における脂肪エネルギー比は21.5～29.4%の範囲にあった。2) 給与脂肪酸のバランスは, 保育所給食ではP/S 1.57, n-6/n-3 4.4, 小・中学校給食ではP/S 0.64・0.71, n-6/n-3 6.8・7.1, 高校 (女子)・大学 (男子) 寮給食では, P/S 1.06・1.79, n-6/n-3 6.0・5.8であった。E/PUFAは0.45～0.71であった。給与コレステロール量は, 保育所給食で81mg, 小・中学校給食で91mg・107mg, 高校 (女子)・大学 (男子) 寮給食で343mg・240mgであった。3) 食物繊維給与量は, 保育所給食で5.0g, 小・中学校給食で6.1g・7.3g, 高校 (女子) ら大学 (男子) 寮給食で16.3g・15.1gであった。4) 給与ミネラルのバランスは, 保育所給食から大学寮給食まで, 給食対象の年齢増加に伴い, Ca/Mgが6.87から1.40へ漸減, Na/Kが0.90から1.80へ漸増していた。給与エネルギー当たりの食塩給与量は, 大学寮給食のやや多量を除き, いずれも成人の目標摂取量の範囲にあった。