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sarcopenia

Diminished muscle mass, muscle atrophy. Etiology: 1) andropause 2) androgen-deprivation therapy [8] 3) bedrest 4) chronic illness a) cancer b) congestive heart failure c) COPD d) chronic renal failure e) chronic infection f) Parkinson's disease g) rheumatoid arthritis 5) protein-calorie malnutrition 6) vitamin D deficiency? [18] 7) old age Epidemiology: 1) 45% of elderly with 20% functionally disabled 2) health cost estimate as $18.5 billion/year in USA 3) begins with 6th decade of life Pathology: 1) see age-associated changes in skeletal muscle 2) neuronal alterations a) decrease in number &/or function of motor neurons b) alterations in axonal function 3) loss of motor endplates - decrease in neurotransmitter release 4) decreased number of motor units - fast fibers affected more than slow fibers 5) increase in cytokines, IL1-beta, IL6, TNF-alpha 6) decreased testosterone, DHEA, growth hormone 7) insulin resistance 8) decreased IGF-1 9) upregulation of FBXO32 (atrogin-1), MuRF1 10) oxidative stress & damage postulated Genetics: - genetically predicted serum 25-OH vitamin D concentration < 20 ng/mL associated with risk of sarcopenia [18] Clinical manifestations: 1) muscle weakness 2) muscle wasting (muscle atrophy) Laboratory: - low serum creatinine is associated with sarcopenia & frailty [17] - serum cystatin C/creatine ratio more accurately assesses renal function (not directly affected by muscle mass) [19] * also see frailty Complications: 1) increased risk of falls 2) increased risk & morbidity of infections 3) diminished glucose tolerance, increase risk of type 2 diabetes [4] 4) muscle dysfunction, not diminished lean muscle mass, associated with late-life cognitive impairment Management: 1) increase exercise, resistance training [1] 2) increase calories, if protein-calorie malnutrition 3) treat intercurrent disease 4) testosterone, DHEA, vitamin D, & leucine of benefit [11] - Vitamin D supplementation is not recommended unless deficient [11] - no improvements in measures of physical function with DHEA [11] 5) vitamin C & vitamin E without proven benefit [11] 6) men: a) testosterone replacement if indicated b) a trial of recombinant growth hormone 7) women - a trial of recombinant growth hormone, with or without DHEA 8) 25-30 g of high-quality protein/meal recommended [10,11,16] - if pressure ulcers, add arginine, zinc & antioxidants or arginine/glutamine/zinc [11] Comparative biology: - p16ink4A silencing by RNA interference restores regenerative capacity of satellite cells in old mice [9]

Related

age-associated changes in skeletal muscle andropause frailty

Useful

testosterone (Delatestryl Testopel, Striant, Intrinsa, Xyosted)

Specific

osteosarcopenia

General

sign/symptom muscular disease; myopathy chronic musculoskeletal disease geriatric disorder; disease of old age; geriatric syndrome

References

  1. Fiatarone MA, O'Neill EF, Ryan ND et al Exercise training and nutritional supplementation for physical frailty in very elderly people. N Engl J Med. 1994 Jun 23;330(25):1769-75. PMID: 8190152 Free article. Clinical Trial.
  2. Geenlund LJ & Nair KS, Sarcopenia--consequences, mechanisms, and potential therapies. Mech Ageing Dev. 2003 Mar;124(3):287-99. Review. PMID: 12663126
  3. Janssen I et al, J AM Ger Soc (JAGS) 52:80, 2004
  4. Fiatarone Singh MA & Rosenberg IH, Nutrition and Aging, In: Principles of Geriatric Medicine, 4th ed,, Hazzard et al (eds), McGraw-Hill, NY, 1999, pg 81-84
  5. Loeser RF & Delbono O, Aging and the Musculoskeletal System, In: Principles of Geriatric Medicine, 4th ed,, Hazzard et al (eds), McGraw-Hill, NY, 1999, pg 81-84
  6. Borst SE Interventions for sarcopenia and muscle weakness in older people. Age Ageing. 2004 Nov;33(6):548-55. Epub 2004 Sep 22. Review. PMID: 15385272
  7. Chin A et al The functional effects of physical exercise training in frail older people : a systematic review. Sports Med. 2008;38(9):781-93. Review. PMID: 18712944
  8. Smith MR et al. Sarcopenia during androgen-deprivation therapy for prostate cancer. J Clin Oncol 2012 Sep 10; 30:3271 PMID: 22649143
  9. Sousa-Victor P et al. Geriatric muscle stem cells switch reversible quiescence into senescence. Nature 2014 Feb 20; 506:316. PMID: 24522534
  10. Paddon-Jones D, Rasmussen BB. Dietary protein recommendations and the prevention of sarcopenia. Curr Opin Clin Nutr Metab Care. 2009 PMID: 19057193
  11. Geriatric Review Syllabus, 8th edition (GRS8) Durso SC and Sullivan GN (eds) American Geriatrics Society, 2013 - Geriatric Review Syllabus, 11th edition (GRS11) Harper GM, Lyons WL, Potter JF (eds) American Geriatrics Society, 2022
  12. Kim JS, Wilson JM, Lee SR. Dietary implications on mechanisms of sarcopenia: roles of protein, amino acids and antioxidants. J Nutr Biochem. 2010 Jan;21(1):1-13. PMID: 19800212
  13. Rolland Y, Onder G, Morley JE et al Current and future pharmacologic treatment of sarcopenia. Clin Geriatr Med. 2011 Aug;27(3):423-47. PMID: 21824556
  14. Volpi E, Ferrando AA, Yeckel CW, Tipton KD, Wolfe RR. Exogenous amino acids stimulate net muscle protein synthesis in the elderly. J Clin Invest. 1998 May 1;101(9):2000-7. PMID: 9576765
  15. Beeri MS, Leugrans SE, Delbono O et al Sarcopenia Is Associated With Incident Alzheimer's Dementia, Mild Cognitive Impairment, and Cognitive Decline. J Am Geriatr Soc. 2021;69(7):1826-1835. PMID: 33954985 PMCID: PMC8286176 (available on 2022-07-01) https://www.medscape.com/viewarticle/954738
  16. Liao CD, Chen HC, Huang SW et al. The role of muscle mass gain following protein supplementation plus exercise therapy in older adults with sarcopenia and frailty risks: a systematic review and meta-regression analysis of randomized trials. Nutrients. 2019 Jul 25;11(8):1713 PMID: 31349606 PMCID: PMC6723070 Free PMC article https://www.mdpi.com/2072-6643/11/8/1713
  17. Loria A et al. Low preoperative serum creatinine is common and associated with poor outcomes after nonemergent inpatient surgery. Ann Surg 2023 Feb; 277:246. PMID: 36448909 https://journals.lww.com/annalsofsurgery/Abstract/2023/02000/Low_Preoperative_Serum_Creatinine_is_Common_and.12.aspx
  18. Sha T, Wang Y, Zhang Y, Lane NE, Li C, Wei J, Zeng C, Lei G. Genetic Variants, Serum 25-Hydroxyvitamin D Levels, and Sarcopenia: A Mendelian Randomization Analysis. JAMA Netw Open. 2023 Aug 1;6(8):e2331558. PMID: 37647062 FPMCID: PMC10469287 Free PMC article. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2808925
  19. An JN, Kim JK, Lee HS, Kim SG, Kim HJ, Song YR. Serum cystatin C to creatinine ratio is associated with sarcopenia in non-dialysis-dependent chronic kidney disease. Kidney Res Clin Pract. 2022 Sep;41(5):580-590. PMID: 35791742 PMCID: PMC9576455 Free PMC article.