Recherche en gérontologie et en gériatrie

Abstrait

Effects of Catechin-Ingestion and Heat Stress on the Maximum Isometric Force in Knee Extension, the Volume of Quadriceps Muscle, and Serum Thiobarbituric Acid Reactive Substances Level in Healthy Elderly Women

Katsumasa Goto, Hideshi Oda, Noriyasu Ota, Atsuya Watanabe, Hidefumi Kitazawa, Michihito Igaki, Atsushi Suzuki, Akira Shimotoyodome, Tadashi Hase, Takao Sugiura, Yoshinobu Ohira and Toshitada Yoshioka

Background: Sarcopenia, is a major concern for our aged society because sarcopenia is a fundamental cause of frailty and functional disability.

Aim: The effects of catechin-ingestionp and/or heat treatment on the volume in quadriceps muscles, isometric force of knee extension, and serum thiobarbituric acid reactive substances (TBARS) were investigated in healthy elderly women.

Methods: Subjects (71.0 ± 0.7 years old, n=27) were divided into 3 groups; 1) catechin-ingested, 2) heatstressed, and 3) catechin-ingestion with heat stressed (catechin+heat) groups. Subjects in both catechin-ingested and catechin+heat groups daily ingested 350 ml of green tea containing 540 mg of catechin in one hour for 10 weeks. Heat stress was applied on the quadriceps muscles for 8 hours a day and 4 days a week by using two heat- and steam generating sheets.

Results: In catechin+heat group, muscle volume (Pre: 670 ± 38.7 cm2, Post: 676 ± 37.2 cm2) and maximal isometric force (Pre: 25.8 ± 2.5 kg, Post: 27.0 ± 2.5 kg) were significantly increased by the 10-week of treatment (p<0.05), but not in catechin-ingested and heat-stressed groups. The time of Timed-Get-Up-and-Go test (TUG), which is widely used to measure sit-to-stand performance, in both catechin-ingested (Pre: 6.70 ± 0.33 s and Post: 6.19 ± 0.28 s) and catechin+heat (Pre: 6.49 ± 0.30 s and Post: 5.95 ± 0.24 s) groups in catechin-ingested group; was significantly shortened by the treatment (p<0.05). Following 10-week of the treatment, serum TBARS levels in both catechin ingested (Pre: 29.06 ± 1.32 nmol/ml, Post: 24.47 ± 2.30 nmol/ml) and catechin+heat (Pre: 29.84 ± 1.57 nmol/ml, Post: 23.92 ± 0.98 nmol/ml) groups were significantly decreased (p<0.05), but not in heat group.

Conclusions: Evidences suggest that catechin-ingestion with heat stress might improve impaired muscle function of elderly women.