Effects Of Physical Training On Intramuscular Fat Parameter For Elderly Individuals Requiring Nursing Care

Abstract

Fat depot within muscles, known as intramuscular fat (IMF), has been related with insulin resistance and physical dysfunction. It is suggested that elderly individuals requiring nursing care may have excessive IMF depot due to advancing of aging as well as lower physical activity. Physical training would be a representative intervention to improve both muscle functions and preserving physical capacity. PURPOSE: The purpose of this study was to quantify the effects of physical training on intramuscular fat parameter in elderly individuals requiring nursing care. METHODS: 19 elderly individuals requiring nursing care (Ex group; 10 women and 9 men, 78 ± 8 years) and 16 healthy elderly without nursing care (Cont group; 10 women and 6 men, 76 ± 7 years) participated in this study. Ex group need nursing care while they could do almost all activities of daily living. They performed physical training consisting of resistive exercises, stretching, and aerobic exercises as a part of rehabilitation once or twice a week for a 6-month period. B-mode transverse ultrasonographic images were taken from rectus femoris (RF) and biceps femoris (BF) of the mid-thigh before and after a 6-month physical training period. Echo intensity as an index of IMF was calculated. RESULTS: After the training, echo intensity of RF and BF was significantly lower compared with before (RF, 80.6 ± 10.0 a.u. to 72.5 ± 14.0 a.u.; BF, 63.1 ± 11.4 a.u. to 57.9 ± 12.0 a.u., p < 0.05), suggesting IMF could be decreased as a result of training. In the Cont group, echo intensity was significantly increased in RF (75.9 ± 7.6 a.u. to 83.8 ± 11.5 a.u., p < 0.05); however, no change in BF (65.2 ± 7.8 a.u. to 70.1 ± 8.9 a.u., p = 0.07). The relative change of echo intensity was significantly difference between Ex group and Cont group in RF (Ex group, −9.8 ± 16.2%; Cont group, 10.8 ± 14.1%, p < 0.05) and BF (Ex group, −6.9 ± 18.5%; Cont group, 8.4 ± 14.5%, p < 0.05). CONCLUSIONS: Physical training decreases IMF in two different thigh muscles of elderly individuals requiring nursing care. This result suggests that change in muscle quality is earlier than we expect in elderly individuals requiring nursing care.