The main findings of this study were: (1) the prevalence of OS in the community using the new AWGS 2019 criteria was 19.2%; (2) the prevalence of OS was significantly higher in older women; (3) Hb and albumin levels were lower in subjects with OS; and (4) WHODAS, Kaigo-Yobo, and GDSSF scores were all higher in the OS group after adjusting for general characteristics that were different among the four groups. Therefore, we suggest that osteosarcopenia exacerbates frailty, disability and depression, thereby increasing susceptibility to various chronic diseases.
Huo et al. [21] conducted a cross-sectional study of 680 community-dwelling older individuals and reported that the percentage with OS was almost 40%. A study of community-dwelling Chinese elders (older than age 65) found the prevalence of OS to be 10.4% in men and 15.1% in women. In this study, we observed a prevalence similar to that of community-dwelling Chinese elders. Although the prevalence of OS varies greatly depending on the criteria for diagnosis of osteopenia or sarcopenia, OS is not uncommon in elderly women in the community. In particular, considering the commonality of concomitant osteopenia (including osteoporosis) and sarcopenia in the community, DEXA analyses should measure not only bone density but also muscle mass.
Our results suggest that, in elderly women suspected of being malnourished (low Hb, albumin levels), there may be a risk of impairment due to reduced muscle mass and strength and decreased bone density. There is also a high risk of disability and frailty in these subjects.
WHODAS disability scores were significantly higher in the only osteopenia, only sarcopenia, and OS groups compared to the normal group. Frailty and depression scores were significantly higher in the only sarcopenia and OS groups than in the normal and osteopenia alone groups. Therefore, BMD test performance should be accompanied by the sarcopenia test.
For OS, fall, fracture and mortality rates have been reported to be higher than those with bone loss only or muscle loss only, but other studies have reported different results. [22, 23] However, there are no studies reporting on associations with disability and frailty among these groups. Compared to the osteopenia alone group, the WHODAS score showed a clinically significant difference of 8.8 points when sarcopenia was present suggesting that depression is more likely to impact people with sarcopenia than osteopenia. This is consistent with the results of previous research that identified a correlation between disability, frailty, and depression and sarcopenia. While osteopenia was assessed only by bone density testing, sarcopenia was diagnosed as having a decrease in muscle mass as well as a decrease in muscle strength (function), which may be lower in disability, frailty, and depression. In other words, osteopenia may not have progressed to the point of requiring treatment for assistance in daily life activities. However, sarcopenia may be associated with more activity limitation than osteopenia (not osteoporosis)
This study has several limitations. First, the design was cross-sectional. Therefore, causative relationships could not be ascertained. Second, Because the study subjects are not representative samples, caution should be used when expanding the results of the study.
Nevertheless, our research has strength. The study is meaningful as the first to analyze the relationship between OS and disability, depression, and frailty. Future research should not only focus on OS diagnosis and clinical outcomes such as falls, fractures, and death, but also on the OS patient's quality of life and the occurrence of disability.
In conclusion, OS is a relatively common disease in the community and may cause deterioration of health outcomes. Therefore, concurrent evaluation and management of osteopenia and sarcopenia in the elderly is required.