著者

楠原 慶子

雑誌

東京女子大学紀要論集

巻号頁・発行日

vol.48, no.1, pp.53-64, 0000

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健康な運動習慣のない若年女性31名を対象に,身体組成,筋量,筋厚と骨密度との関係を考察した結果,以下のことが明かとなった.1.身長は全身骨量および腰椎(L2-L4),大腿骨測定部位3箇所(大腿骨頸部,Ward's三角,大転子部)の骨量と相関関係が認められた.また体重は全身骨量と高い相関関係であった.2.体重から体脂肪量を除いた除脂肪体重(FFM)は一部(左大転子部)を除いて,すべての測定部位の骨量,骨密度との間に相関関係が認められた.一方,脂肪に関する指標と(体脂肪量,体脂肪率(%FAT))骨量,骨密度は,%FATとWard's三角部の骨密度に負の相関関係が認められたほかは,有意な関係はなかった.3.除脂肪体重と臍部(腹直筋)筋厚には,高い相関関係が観察された.4.臍部(腹直筋)筋厚は各測定部位の骨密度と有意な相関関係であったのに対して,臍部皮下脂肪厚はいずれの骨密度とも相関はなかった.5.握力と左右大腿骨頸部骨密度には正の相関関係が認められたのに対して,背筋力はいずれの骨密度測定部位とも相関関係は認められなかった.6.運動習慣のない若年女性における骨状態の評価には,除脂肪体重および,臍部筋厚が指標として有効であることが明かとなった.It has been shown in recent studies that bone mineral density (BMD) correlated with fat free mass (FFM) or fat mass (FM) in women. It seems that BMD is influenced by muscle volume, however little is known about the relationship between BMD and muscle thickness distribution. Therefore the purpose of this study was to examine correlations between BMD and muscle thickness of the limbs and the trunk. Thirty-one young female subjects (mean age; 18.9+1.1 yrs, height; 159.5+3.5cm, weight; 51.6+4.0kg) were used as subjects. BMD in the lumber spine (L2-L4) and femoral necks of both limbs were measured using dual energy X-ray absorptiometry (Norland Inc.). Body composition was estimated by standard underwater weighing techniques and corrected for residual volume. Percent body fat of the subjects determined from this method ranged from 18.8-32.8%. Muscle thickness taken from the mid-belly of the forearm muscles, biceps brachii, triceps brachii, quadriceps, tibialis anterior, abdominal and subscapular were determined by B-mode ultrasonograghy. Correlate level was set at p<0.05. As shown in previous studies, the present study also demonstrated correlations between body weight and lumber spine (r=0.38, p<0.05) as well as the right and left femoral necks (=0.38, 0.45, respectively). FFM showed significant correlations with muscle thickness of abdominal muscle (r=0.66, p<0.001), quadriceps (r=0.41), and tibialis anterior (r=0.48), but not with the forearm muscle (r=0.30), biceps brachii (r=0.17), triceps brachii (r=0.19), and subscapular (r=0.02). Significant correlations were found between lumber spine and muscle thickness of the abdominal (r=0.45), and between femoral necks (both right and left) and muscle thickness of the quadriceps (r=0.38, 0.42), and abdominal muscle (r=0.60, 0.52). FM did not correlate with BMD in this study. These results would suggest that BMD is influenced by muscle thickness and muscle thickness distribution is an important factor for the relationship between BMD and FFM in young women.