Beaune B, Blonc S, Fellmann N, Bedu M, Coudert J
Laboratoire de Physiologie-Biologie du Sport, Faculté de Médecine, Université d'Auvergne, Clermont-Ferrand, France.
Eur J Appl Physiol Occup Physiol. 1997;76(1):98-102. doi: 10.1007/s004210050219.
The aim of the study was to determine if a decrease in serum insulin-like growth factor I (Igf-I) levels under marginal malnutrition is responsible for the lower physical performance of girls of a low socio-economic status (LSES). Girls were selected after physical examination (Tanner's stage 1) and anthropometric measurements (height, body mass or mb, body mass index or BMI = mb height2). Lean body mass mb,1 was measured after skinfold thickness determination; serum IGE-I, by radioimmunoassay; maximal O2 consumption, (VO2max), directly during incremental exercise up to exhaustion; and maximal aerobic power (Wmax), using the force-velocity test. LSES girls (n = 31) had been malnourished in the past and, currently, were suffering from marginal malnutrition: they were smaller (135.2 +/- 5.5 vs 146.1 +/- 4.3 cm), lighter (31.7 +/- 3.9 vs 37.6 +/- 5.0 kg), exhibited a lower mb,1 (24.2 +/- 2.5 vs 27.5 +/- 3.0 kg) but same BMI compared with HSES (high socio-economic status) girls (n = 32). Igf-I levels (27.7 +/- 7.9 vs 34.1 +/- 6.5 nmol.1(-1), VO2max (45.26 +/- 4.72 vs 50.74 +/- 6.02 ml. min-1.kg-1 LBM) and Wmax (6.00 +/- 1.15 vs 8.70 +/- 1.53 W.kg-1 mb,1 were lower in LSES girls. Moreover, the differences in every parameter were not the consequence of the younger age (10.8 +/- 0.9 vs 11.2 +/- 0.6 years) of the LSES girls. Our results provide evidence that the lower Wmax of undernourished prepubertal girls was partly the consequence of alterations in muscle function at the qualitative level, as a result of a decrease in Igf-I levels. Conversely, under normal nutritional conditions, anthropometric characteristics only are explicatory factors for physical performances.
本研究的目的是确定在边缘性营养不良情况下血清胰岛素样生长因子I（Igf-I）水平的降低是否是导致社会经济地位低下（LSES）女孩体能较低的原因。在进行体格检查（坦纳第一期）和人体测量（身高、体重或mb、体重指数或BMI = mb/身高²）后挑选女孩。在测定皮褶厚度后测量瘦体重mb,1；通过放射免疫测定法测定血清IGE-I；在递增运动直至力竭期间直接测量最大耗氧量（VO2max）；使用力-速度测试测量最大有氧功率（Wmax）。LSES女孩（n = 31）过去曾营养不良，目前正遭受边缘性营养不良：与社会经济地位高（HSES）的女孩（n = 32）相比，她们身材更矮小（135.2±5.5 vs 146.1±4.3厘米）、体重更轻（31.7±3.9 vs 37.6±5.0千克）、mb,1更低（24.2±2.5 vs 27.5±3.0千克），但BMI相同。LSES女孩的Igf-I水平（27.7±7.9 vs 34.1±6.5纳摩尔·升⁻¹）、VO2max（45.26±4.72 vs 50.74±6.02毫升·分钟⁻¹·千克⁻¹瘦体重）和Wmax（6.00±1.15 vs 8.70±1.53瓦·千克⁻¹ mb,1）更低。此外，每个参数的差异并非LSES女孩年龄较小（10.8±0.9 vs 11.2±0.6岁）所致。我们的结果表明，营养不良的青春期前女孩较低的Wmax部分是由于Igf-I水平降低导致肌肉功能在质量水平上发生改变的结果。相反，在正常营养条件下，人体测量特征仅是体能表现的解释因素。
