Background & Aims: Osteosarcopenia, the presence of osteopenia/osteoporosis and sarcopenia, is an emerging geriatric giant, which poses a serious global health burden. Methods: The latest studies conducted in recent years in the field of pathophysiology, epidemiology, diagnosis and treatment of osteosarcopenia were reviewed. Results: Getting old and being healthy is contingent on maintaining the integrity of several physiological systems such as the musculoskeletal system which is important for both human movement and storing calcium and glucose. As individuals get to their sixtieth, their muscle mass and bone minerals will decrease and the elderly will become susceptible to sarcopenia and osteoporosis. According to the World Health Organization, the definition of osteopenia and osteoporosis is a T score of less than -1 and -2.5 standard deviations, respectively. Sarcopenia is defined by cut-off amounts for low muscle mass, strength, and/or functional capability and is related to different metabolic conditions. Both diseases have common risk factors and are associated with falls, frailty, fractures, hospitalizations, and mortality as well as causing an increase in healthcare expenses. These disorders put a heavy burden on societies, especially the geriatric population to the extent that in 2010 there were 27.5 million people diagnosed with osteoporosis in the European Union. Osteosarcopenia is defined as low bone density and low muscle mass. As in individual ages, the prevalence of osteosarcopenia increases as well with 59.4 percent and 48.3 percent in men and women above 75 years old. It has been shown in a study of 590 post-menopausal women that the risk for osteoporosis will be 12.9 times higher in the presence of sarcopenia. A recent study of 3334 older individuals reported that individuals with sarcopenia (compared with no sarcopenia) had lower BMD when employing the 2019 European definition of sarcopenia. So there is a bidirectional relationship between osteoporosis and sarcopenia, which results in the development of osteosarcopenia. Major risk factors for this disorder are age and sex, however body mass index and physical activity are reversely related to osteosarcopenia and high fat mass will increase its risk. Glycine-N-acyltransferase (GLYAT) genes polymorphisms, peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), and myocyte enhancer factor-2 (MEF2C) are related to muscle atrophy and bone loss. Furthermore, genetic traits determine peak muscle and bone volume in early life which may be a mechanism for delaying sarcopenia and osteoporosis in old ages. In comparison with non-osteosarcopenic subjects, the risk of falls (ORs: 2.83–3.63; P < 0.05) and fractures (ORs: 3.86– 4.38; P < 0.05) is significantly higher in osteosarcopenic older individuals attending a falls and fractures clinic. The risk of o a minccurance of a minimal-trauma or no trauma fracture when the patient is sarcopenic was also reported to be much greater than in non sarcopenic older persons (relative risk 1.37, 95% CI 1.18–1.58). It has been suggested that clinicians should be alert to the fact that, recognition of one of these conditions makes the investigation for the other one necessary because of their co-occurance. A physical examination must be typical in the comprehensive geriatric investigation. But additional physical assessments are needed to diagnose sarcopenia. Physical assessments are considered to assess muscle strength (grip strength, sit to stand test) or functional capacity (gait speed, short physical performance battery, timed up and go test). The two most used and accurate assessments are gait speed grip power Osteosarcopenia cannot be screened and there is no efficient tool for predicting this condition, but there are tools for osteoporosis and sarcopenia such as SARC-F questionare which is highly specific and most accurate. Bone Marrow Densitometry through DXA is used for osteoporosis in individuals with age more than 50, post-menopausal women, adults with Rheumatoid Arthritis and adults who are on corticosteroid medications. FRAX© is the best tool for risk stratification of osteoporosis. Increased risk for falls and following fractures are identifiable by testing for 25 OH vitamin D, serum calcium, parathyroid hormone and serum testosterone. BMD and muscle mass assessment are the essentials of osteosarcopenia workup. DXA is the greatest tool to assess BMD accurately, and has the benefits of estimating the lean body mass and appendicular lean mass in an accurate manner. Bioelectrical impedance analysis which assesses the fat-free mass, peripheral quantitative computerized tomography, muscle cross-sectional area and intramuscular adipose tissues and magnetic resonance imaging. A new technique named as the D3-creatine dilution method has been found to have strong associations with falls, fractures and risk of mortality in old men. This technique needs further assessment to be considered a typical clinical tool. Resistance training exercises which stimulate muscle protein synthesis and the activity of osteoblasts will improve the activity of older individuals with osteosarcopenia. In addition, this kind of exercise will also improve the cardiometabolic and cognitive health in different populations. This kind of exercise is recommended for preventing osteosarcopenia. As the ability of muscles to absorb dietary amino acids will decline with age, supplementation with dietary proteins in addition to resistance exercises is proposed as an ideal therapy for maintaining the optimal musculoskeletal function in older adults. Whey protein which is rich in Leucine and stimulates mTORC1 in skeletal muscles is the best way to increase muscle protein synthesis on condition that the individual has optimal vitamin D levels. The most prevalent micronutrient in bone structure is calcium and its kinetic is remarkable in muscle contractility force. It has been offered that 1000–1300 mg/day of calcium should be administered in populations with insufficient diets. Creatine is also believed to boost the exercise induced increase in muscle mass and also it causes an increase in bone density. Peripheral DXA, quantitative computerized tomography and radiographic absorptiometry are alternative techniques to DXA that estimate BMD include. Most older adults who experience a low-trauma fracture have BMD in the normal or osteopenic range. BMD assessment techniques are highly sensitive but not so specific for prediction of fracture. Although there is no FDA approved drug for sarcopenia, there are numerous drugs for osteoporosis including antiresorptive (denosumab, bisphosphonates), anabolic (teriparatide, abaloparatide), antisclerostin (romosozumab), and hormonal (hormone replacement therapy, selective oestrogen receptor modulators) agents. Adults with T score of -2.5 or less on DXA, or a FRAX© 10-year fracture risk of ≥3% at the hip or ≥20% for any other osteoporotic fracture will mostly benefit from antiresorptive or anabolic treatment. Denosumab which is a RANK ligand inhibitor has promising effects on bone and muscle and those who consume this drug experience significant increase in lean body mass and handgrip strength; however bisphosphonates have no such effects. Osteosarcopenia requires ongoing monitoring and assessment of falls and fracture risk, quality of life impact, and response to treatment. Conclusion: Osteosarcopenia is a hot topic in geriatric research. Lifestyle, genetic, mechanical factors and endocrine factors are altogether effective in occurrence of osteosarcopenia. Resistance training exercise and nutritional supplementation is a way to hinder osteosarcopenia. There is a definite need for further clinical trials for investigating pharmacologic interventions for this condition and providing new diagnostic methods, screening tools and therapies. |
Rights and permissions | |
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |