type:Article

体脂肪は, 皮下, 内臓周囲, 筋中などに分布している。そこで近赤外分光法により, 身体各部位の体密度を推定し, 局部脂肪分布として評価することを検討した。対象は, 肥満外来患者105名である。近赤外分光法はFUTREX 6100 (ケット科学) を用い, 6波長の各周波数でOptical Density (OD値) を計測し, 体密度を算出した。なお, ヒトの身体j局部の体密度を求めるにあたり, 基礎実験として, 脂肪含有量が異なる豚肉の近赤外線のOD値を求めた。次に豚肉の各部位について密度を実測して, 6波長のOD値と密度の実測値の重回帰分析から, 密度を算出する式を求めた。身体局所として測定した部位は, 上腕二頭筋, 上腕三頭筋, 臍横部, 肩甲骨下縁, 大腿部, 下腿部の6ヶ所であった。全身の体脂肪率はタニタ製TBF511にて測定した。女性の上腕三頭筋, 下腿部の局所体密度は男性の体密度に比べ有意に低い値を示した。上腕二頭筋, 上腕三頭筋, 下腿部においてBMI≧35の群でBMI<35の群より局所体密度は有意に低い値を示した。上腕二頭筋, 上腕三頭筋, 下腿部の局所体密度はBMIとの有意な負の相関を示した。以上より, ヒトの局所体密度すなわち体組成の評価においては, 新たに近赤外分光法が応用できる可能性が示唆された。

The body fat is distributed subcutaneously, periviscerally, and intramusculary. We conducted a study on estimation of the body densities in various regions of the human body by the near-infrared reference methods, and we evaluated these values as indicators of the local fat distribution in the body. Our study subjects were 105 obese patients who received regular treatment at our outpatient clinic. By the near-infrared reflectance methods carried out using FUTREX 6100, 6-wavelength optical densities were measured, and the body fat densities were calculated based on a reference curve obtained using pork which had different fat contents. The measurement was taken for the following six body regions: the biceps brachii muscle, the triceps muscle of the arm, the transverse part of the naval, the inferior margin of the scapula, the anterior surface of the femur, and the leg. The whole body fat ratio was measured with TANITA TBF511. The local body fat densities in the triceps muscles of the arm and the leg of female patients were significantly lower than those of the male patients. The local body fat densities in the biceps brachii muscle, the triceps muscle of the arm, and the leg were significantly lower for the BMI≧35 group than for the BMI<35 group. Significant negative correlations between the local body fat densities in the biceps branii muscle, the triceps muscle of the arm and the leg and BMI were observed. There was significant a negative correlation between the blood leptin concentration and the local body fat densities in the femur and the leg. The aforementioned findings suggested that it would be possible to newly apply the near-infrared reflectance methods in the evaluation of the human local body fat densities, that is, local body composition.