0000000000386347
AUTHOR
Markku Alén
Are skeletal muscle FNDC5 expression and irisin release regulated by exercise and related to health?
Recently, contradictory findings have been reported concerning the function of irisin and its precursor gene, skeletal muscle FNDC5, in energy homeostasis, and the associated regulatory role of exercise and PGC-1α. We therefore evaluated whether muscle FNDC5 mRNA and serum irisin are exercise responsive and whether PGC-1α expression is associated with FNDC5 expression. The male subjects in the study performed single exercises: (1) 1 h low-intensity aerobic exercise (AE) (middle-aged, n= 17), (2) a heavy-intensity resistance exercise (RE) bout (young n= 10, older n= 11) (27 vs. 62 years), (3) long-term 21 weeks endurance exercise (EE) training alone (twice a week, middle-aged, n= 9), or (4) …
Global gene expression profiles in skeletal muscle of monozygotic female twins discordant for hormone replacement therapy
Aging is accompanied by inexorable loss of muscle tissue. One of the underlying causes for this is the massive change in the hormonal milieu of the body. The role of a female sex steroid – estrogen – in these processes is frequently neglected, although the rapid decline in its production coincides with a steep deterioration in muscle performance. We recruited 54- to 62-year-old monozygotic female twin pairs discordant for postmenopausal hormone replacement therapy (HRT, n = 11 pairs; HRT use 7.3 ± 3.7 years) from the Finnish Twin Cohort to investigate the association of long-term, estrogen-based HRT with skeletal muscle transcriptome. Pathway analysis of muscle transcript profiles revealed …
Sports-related injuries in elderly men still active in sports.
By means of a questionnaire with a complementary interview and physical examination, the site and nature of sports injuries were investigated over a 10-year period (1977-1987) in 97 elderly athletes (age range 70-81 years). The athletes were still active in training and competition with a mean competition background of 15 years. Of the subjects studied 30 were strength/power athletes and the remaining 67 endurance athletes. Altogether we found 273 sports-related injuries (169 acute and 104 overuse injuries). Of the injuries 75% had occurred in the lower extremities. The most commonly injured part of the body was the knee (20% of all cases). Sprains of the thigh and knee were the most freque…
Influence of long-term postmenopausal hormone replacement therapy on estimated structural bone strength: A study in discordant monozygotic twins.
Although postmenopausal hormone-replacement therapy (HRT) is known to prevent fractures, knowledge on the influence of long-term HRT on bone strength and its determinants other than areal bone mineral density is scarce. This study used a genetically controlled design with 24 monozygotic female twin pairs aged 54 to 72 years in which one cotwin was using HRT (mean duration 8 years) and the other had never used HRT. Estimated bone strength, cross-sectional area, volumetric bone mineral density, bone mineral mass, and cross-sectional density and mass distributions were assessed in the tibial shaft, distal tibia, and distal radius with peripheral computed tomography (pQCT). In the tibial shaft,…