Diagnostic reference values for sarcopenia in Tibetans in China

Abstract

Sarcopenia is an age-associated disease characterized by loss of muscle mass and function, but the diagnostic cutoff values remain controversial. To investigate the diagnostic cutoff values and incidence of sarcopenia in a plateau population, the limb skeletal muscle mass, gait speed and grip strength of 2318 Tibetan adults were measured according to the criteria of the Asian Working Group for Sarcopenia. We found that the diagnostic reference values for sarcopenia in the high-altitude population were significantly lower than those in the plain population, and the incidences of sarcopenia in the highaltitude population over 60 years old were 17.2% in men and 36.0% in women, which were significantly higher than those in the plain population. Our study proposes reference values for the diagnosis of sarcopenia in Tibet. We suggest that the cutoff value for sarcopenia in the plateau population should be established based on altitude. Hypoxia may be an important risk factor for sarcopenia.Sarcopenia is a progressive and generalized skeletal muscle disorder involving the accelerated loss of muscle mass and function that is associated with increased adverse outcomes, including falls, functional decline, frailty, and mortality 1 . With the ageing of the population, sarcopenia has become one of the major public health problems in the world 2,3 . Since 2010, the study of sarcopenia in the field of international geriatrics has become increasingly intense, focusing on the diagnostic criteria and pathogenesis of sarcopenia. Both the European and Asian sarcopenia working groups have recommended diagnostic criteria of sarcopenia based on muscle mass, muscle strength and physical function presented by skeletal muscle mass index (SMI), handgrip strength (HS) and gait speed (GS), respectively 4,5 . Currently, the incidence of sarcopenia and the cutoff values for SMI and HS in different populations are very different. The incidence of sarcopenia is related not only to age but also to racial differences. Ethnic factors may be one of the main reasons for the differences in the incidence of sarcopenia among different populations 6-8 . The European Working Group on Sarcopenia in Older People (EWGSOP) has suggested that primary sarcopenia is mainly related to ageing and is a phenotype in the process of biological senescence. Ageing is a sequential process of genetic programming, which inevitably results in a decrease in the amount of ageing muscle, but this process is affected by the environment, lifestyle and ageing-related diseases 9 and shows significant individual differences. Therefore, ethnic and individual differences should be taken into account in determining diagnostic reference values for sarcopenia, and the best reference values should include a wide range of races and ages. Asia is the most dense and fastest ageing region in the world, and sarcopenia will have a very large impact on the Asian population 5 . The Asian Working Group for Sarcopenia (AWGS) has recommended that a large number of investigations should be carried ...

The association between sarcopenia susceptibility and polymorphisms of FTO, ACVR2B, and IRS1 in Tibetans

“…Therefore, it may play a role in the development of sarcopenia in humans. In previous research, the incidences of sarcopenia in Tibetans over 60 were 17.2% in men and 36.0% in women, significantly higher than those in the plain population (Ye et al, 2020). Tibetans are an archaic ethnicity (Lu et al, 2016), have lived at very high altitudes for thousands of years, and have a distinctive suite of genetic traits that enable them to tolerate environmental hypoxia (Simonson et al, 2010; Song et al, 2020), which make them significantly different from the Han and other plain populations genetically (Beall et al, 2010).…”

“…According to the recommended diagnostic AWGS algorithm, GS, HS, and skeletal muscle mass index (SMI) were the primary indicators for sarcopenia diagnosis (Chen et al, 2014). The cutoff values for SMI measurements were 8.07 kg/m 2 for men and 6.62 kg/m 2 for women (Ye et al, 2020). Low physical performance was defined as a GS less than 0.8 m/s (Ye et al, 2020).…”

“…The cutoff values for SMI measurements were 8.07 kg/m 2 for men and 6.62 kg/m 2 for women (Ye et al, 2020). Low physical performance was defined as a GS less than 0.8 m/s (Ye et al, 2020). The cutoff values for HS were <26.7 kg for men and <15.8 kg for women (Ye et al, 2020).…”

“…Low physical performance was defined as a GS less than 0.8 m/s (Ye et al, 2020). The cutoff values for HS were <26.7 kg for men and <15.8 kg for women (Ye et al, 2020).…”

Comparison of Muscle Density in Middle-Aged and Older Chinese Adults Between a High-Altitude Area (Kunming) and a Low-Altitude Area (Beijing)

“…Weight loss has been widely reported in hypoxic chamber experiments and after sojourns at high altitudes (5)(6)(7). Some studies have found that skeletal muscle mass decreased with increasing altitude as the hypoxic environment accelerated the decomposition of skeletal muscle and inhibited protein synthesis (8,9). Muscle weakness is a key factor in the increased risk of falls and might also play a significant role in the increased risk of hip fracture (10,11).…”