Mehr Muskulatur – gesündere Knochen?

Zusammenfassung

Aufgrund einer steigenden Anzahl von Osteo porose-Erkrankungen gilt es, präventive Ansätze zu finden, um das Risiko spontaner Frakturen im höheren Lebensalter zu reduzieren. Lange wurde postuliert, dass Frakturen aufgrund einer reduzierten Knochenmasse entstehen. Das Konzept der “Peak Bone Mass” beruht auf der Hypothese, dass eine Anhäufung von Knochenmasse in der Adoleszenz die Frakturrate im Alter senken könne. Die Knochenmasse beschreibt jedoch nur, wie viel Knochenmasse absolut ein Individuum besitzt, nicht jedoch, ob die Knochen die erforderliche Festigkeit aufweisen. Die Knochenmasse ist vielmehr eine Funktion aus Körperlänge und muskulärer Beanspruchung, weniger jedoch des Alters. Die Knochenfestigkeit wird dabei durch verschiedene Einflussfaktoren geregelt, wie das Osteozytennetzwerk “Mechanostat”, das die aktuelle Beanspruchung misst und Adaptationsvorgänge einleitet, aber auch durch Hormone, Ernährung und Medikamente. Von der Beschreibung der reinen Knochenmasse aus ist, basierend auf diesen regulierenden Faktoren und Erkenntnissen über die Interaktion der aufgeführten Faktoren, das Konzept der funktionellen Muskel-Knochen-Einheit entstanden, welches beschreibt, dass die Entwicklung und der Erhalt der knöchernen Stabilität mit ihrer Festigkeit von der Muskulatur abhängig ist. In der Schlussfolgerung muss bei auftretenden Frakturen sowohl in der adulten Medizin als auch in der Pädiatrie zur Beurteilung des Skelettsystems die Muskulatur mit einbezogen werden, um eine Aussage darüber treffen zu können, ob es sich um eine primäre oder sekundäre Knochenerkrankung handelt.

Summary

To prevent osteoporosis and atraumatic fractures in the elderly different concepts for bone mass accumulation have been described. It was postulated that fractures are based on reduced bone mass. The peak bone mass concept implies that optimal skeletal development during childhood and adolescence will prevent fractures in late adulthood. Measuring bone mass is only a surrogate for bone strength but can not be regarded as a measure of individual's fracture risk. Bone mass is a function of height and mechanical loads. Bone strength is regulated and adapted by osteoblasts and osteoclasts depending on mechanical loads which are detected by the mechanostat (osteocytes). Additionally, non-mechanical factors as hormones and nutrition can influence bone strength and adaption. Thus, bone mass follows the development of body mass and muscle strength. Preservation of bone strength needs continuously mechanical loads. Measuring the ratio of muscle force to bone strength and analyzing the results of this functional muscle bone unit is a new approach to distinguish between a primary and secondary bone disease.

Schlüsselwörter

Muskel-Knochen-Einheit - Osteoporose - Mineralisierungsstörung - Knochendichte - Knochenmasse

Keywords

Muscle-bone unit - osteoporosis - mineralization defect - bone density - bone mass

• Literatur

• 1 Kanis JA, Melton 3rd LJ, Christiansen C. et al. The diagnosis of osteoporosis. J Bone Miner Res 1994; 9 (8) 1137-1141.
• 2 Bonjour JP, Theintz G, Buchs B. et al. Critical years and stages of puberty for spinal and femoral bone mass accumulation during adolescence. J Clin Endocrinol Metab 1991; 73 (3) 555-563.
• 3 Gilsanz V, Gibbens DT, Carlson M. et al. Peak trabecular vertebral density: a comparison of adolescent and adult females. Calcif Tissue Int 1988; 43 (4) 260-262.
• 4 Gilsanz V, Gibbens DT, Roe TF. et al. Vertebral bone density in children: effect of puberty. Radiology 1988; 166 (3) 847-850.
• 5 Glastre C, Braillon P, David L. et al. Measurement of bone mineral content of the lumbar spine by dual energy x-ray absorptiometry in normal children: correlations with growth parameters. J Clin Endocrinol Metab 1990; 70 (5) 1330-1333.
• 6 Mazess RB, Cameron JR. Growth of bone in school children: comparison of radiographic morphometry and photon absorptiometry. Growth 1972; 36 (1) 77-92.
• 7 Mazess RB. On aging bone loss. Clin Orthop Relat Res 1982; 165: 239-252.
• 8 Riggs BL, Melton 3rd LJ. Involutional osteoporosis. N Engl J Med 1986; 314 (26) 1676-1686.
• 9 Hansen MA, Overgaard K, Riis BJ, Christiansen C. Role of peak bone mass and bone loss in postmenopausal osteoporosis: 12 year study. BMJ 1991; 303 (6808) 961-964.
• 10 Riggs BL, Melton 3rd LJ. Evidence for two distinct syndromes of involutional osteoporosis. Am J Med 1983; 75 (6) 899-901.
• 11 Seeman E, Tsalamandris C, Formica C. Peak bone mass, a growing problem?. Int J Fertil Menopausal Stud 1993; 38 (Suppl 2) 77-82.
• 12 Seeman E, Hopper JL, Bach LA. et al. Reduced bone mass in daughters of women with osteoporosis. N Engl J Med 1989; 320 (9) 554-558.
• 13 Genant HK, Cooper C, Poor G. et al. Interim report and recommendations of the World Health Organization Task-Force for Osteoporosis. Osteoporos Int 1999; 10 (4) 259-264.
• 14 Pinilla TP, Boardman KC, Bouxsein ML. et al. Impact direction from a fall influences the failure load of the proximal femur as much as agerelated bone loss. Calcif Tissue Int 1996; 58 (4) 231-235.
• 15 Sandor T, Felsenberg D, Brown E. Comments on the hypotheses underlying fracture risk assessment in osteoporosis as proposed by the World Health Organization. Calcif Tissue Int 1999; 64 (3) 267-270.
• 16 Schonau E. The peak bone mass concept: is it still relevant?. Pediatr Nephrol 2004; 19 (8) 825-831.
• 17 Bianchi ML, Baim S, Bishop NJ. et al. Official positions of the International Society for Clinical Densitometry (ISCD) on DXA evaluation in children and adolescents. Pediatr Nephrol. 2009 Jul 15.
• 18 Rauch F, Schoenau E. Changes in bone density during childhood and adolescence: an approach based on bone's biological organization. J Bone Miner Res 2001; 16 (4) 597-604.
• 19 Schoenau E, Neu CM, Beck B. et al. Bone mineral content per muscle cross-sectional area as an index of the functional muscle-bone unit. J Bone Miner Res 2002; 17 (6) 1095-1101.
• 20 Frost HM, Schonau E. The “muscle-bone unit” in children and adolescents: a 2000 overview. J Pediatr Endocrinol Metab 2000; 13 (6) 571-590.
• 21 Ward LM, Glorieux FH. The spectrum of pediatric osteoporosis. In: Glorieux FH, Pettifor J, Jueppner H. eds. Pediatric Bone Biology and diseases. New York: Academic press; 2003: 401-442.
• 22 Wolff J. Das Gesetz der Transformation der Knochen. Charité Berlin Julius Wolff Institut. Berlin: Hirschwald; 1892
• 23 Schoenau E, Frost HM. The “muscle-bone unit” in children and adolescents. Calcif Tissue Int 2002; 70 (5) 405-407.
• 24 Frost HM. Changing concepts in skeletal physiology: Wolff's Law, the Mechanostat, and the “Utah Paradigm”. J Hum Biol 1998; 10 (5) 599-605.
• 25 Marotti G. The osteocyte as a wiring transmission system. J Musculoskelet Neuronal Interact 2000; 1 (2) 133-136.
• 26 Johnston Jr. CC, Miller JZ, Slemenda CW. et al. Calcium supplementation and increases in bone mineral density in children. N Engl J Med 1992; 327 (2) 82-87.
• 27 Lee WT, Leung SS, Leung DM, Cheng JC. A follow-up study on the effects of calcium-supplement withdrawal and puberty on bone acquisition of children. Am J Clin Nutr 1996; 64 (1) 71-77.
• 28 Slemenda CW, Peacock M, Hui S. et al. Reduced rates of skeletal remodeling are associated with increased bone mineral density during the development of peak skeletal mass. J Bone Miner Res 1997; 12 (4) 676-682.
• 29 Karlsson MK, Linden C, Karlsson C. et al. Exercise during growth and bone mineral density and fractures in old age. Lancet 2000; 355 (9202) 469-470.
• 30 Pajamaki I, Kannus P, Vuohelainen T. et al. The bone gain induced by exercise in puberty is not preserved through a virtually life-long deconditioning: a randomized controlled experimental study in male rats. J Bone Miner Res 2003; 18 (3) 544-552.
• 31 Schoenau E, Werhahn E, Schiedermaier U. et al. Influence of muscle strength on bone strength during childhood and adolescence. Horm Res 1996; 45 (Suppl 1) 63-66.
• 32 Schoenau E. The “functional muscle-bone unit”: a two-step diagnostic algorithm in pediatric bone disease. Pediatr Nephrol 2005; 20 (3) 356-359.
• 33 Fricke O, Weidler J, Tutlewski B, Schoenau E. Mechanography – a new device for the assessment of muscle function in pediatrics. Pediatr Res 2006; 59 (1) 46-49.
• 34 Witt F, Schell H, Heller M, Duda GN. Die Bedeutung der Biomechanik bei der physiologischen Frakturheilung. Osteologie 2011; 20: 17-22.
• 35 Tsampalieros A, Kalkwarf HJ, Wetzsteon RJ. et al. Changes in bone structure and the muscle-bone unit in children with chronic kidney disease. Kidney Int 2013; 83 (3) 495-502.
• 36 Roth J, Linge M, Tzaribachev N. et al. Musculoskeletal abnormalities in juvenile idiopathic arthritis – a 4-year longitudinal study. Rheumatology (Oxford) 2007; 46 (7) 1180-1184.
• 37 Ruth EM, Weber LT, Schoenau E. et al. Analysis of the functional muscle-bone unit of the forearm in pediatric renal transplant recipients. Kidney Int 2004; 66 (4) 1694-1706.
• 38 Runge M, Rehfeld G, Resnicek E. Balance training and exercise in geriatric patients. J Musculoskelet Neuronal Interact 2000; 1 (1) 61-65.
• 39 Bruyere O, Wuidart MA, Di Palma E. et al. Controlled whole body vibration to decrease fall risk and improve health-related quality of life of nursing home residents. Arch Phys Med Rehabil 2005; 86 (2) 303-307.
• 40 Nowak A, Straburzynska-Lupa A, Kusy K. et al. Bone mineral density and bone turnover in male masters athletes aged 40-64. Aging Male 2010; 13 (2) 133-141.
• 41 Nikander R, Sievanen H, Heinonen A. et al. Targeted exercise against osteoporosis: A systematic review and meta-analysis for optimising bone strength throughout life. BMC Med 2010; 8: 47.