Effects of high-impact training on bone and articular cartilage: 12 months randomized controlled quantitative magnetic resonance imaging study.

  • 07.10.2013 13:53

Juhani Multanen, Miika T Nieminen, Arja Häkkinen, Urho M Kujala, Timo Jämsä, Hannu Kautiainen, Eveliina Lammentausta, Riikka Ahola, Harri Selänne, Risto Ojala, Ilkka Kiviranta, Ari Heinonen

Osteoarthritis and osteoporosis often coexist in postmenopausal women. The simultaneous effect of bone-favorable high-impact training on these diseases is not well understood and is a topic of controversy. We evaluated the effects of high-impact exercise on bone mineral content (BMC) and the estimated biochemical composition of knee cartilage in postmenopausal women with mild knee osteoarthritis. Eighty women aged 50-66 years with mild knee osteoarthritis were randomly assigned to undergo supervised progressive exercise 3 times a week for 12 months (n = 40) or to a non-intervention control group (n = 40). BMC of the femoral neck, trochanter and lumbar spine was measured by dual-energy X-ray absorptiometry (DXA). The biochemical composition of cartilage was estimated using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), sensitive to cartilage glycosaminoglycan content, and T2 mapping that is sensitive to the properties of the collagen network. In addition, clinically important symptoms and as physical performance related risk factors of falling; dynamic balance, maximal isometric knee extension and flexion forces, leg power and cardiorespiratory fitness were evaluated. Thirty-six trainees and 40 controls completed the study. The mean gain in femoral neck BMC in the exercise group was 0.6% (95% CI: -0.2 to 1.4) and the mean loss in the control group was -1.2% (95% CI: -2.1 to -0.4). The baseline, body mass and body mass change adjusted BMC change between the groups was significant (P = 0.005), while no changes occurred in the biochemical composition of the cartilage, as investigated by MRI. Balance, muscle force and cardiorespiratory fitness improved significantly more (3-11%) in the exercise group than in the control group. Progressively implemented high-impact training, which increased bone mass, did not affect the biochemical composition of cartilage and may be feasible in the prevention of osteoporosis and physical performance related risk factors of falling in postmenopausal women.

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