Prevalence of muscle dysfunction concomitant with osteoporosis in a home-dwelling Danish population aged 65-93 years-The Copenhagen Sarcopenia Study

Introduction: As life expectancy increases, a growing percentage of older individuals with age-related diseases such as osteoporosis and sarcopenia are expected. Patients with both conditions, i.e. patient with osteosarcopenia, are suggested to have a higher risk of fall and fracture compared to individuals with either condition. Aim: To investigate the potential relationship between low bone mineral density (BMD) and muscle dysfunction in a Danish cohort of older home-dwelling individuals. Furthermore, to examine the prevalence of osteosarcopenia and alterations in prevalence depending on cut-off values chosen. Method: Measures of BMD, relative appendicular lean mass and hand grip strength were assessed in 529 individuals aged 65+ from the population-based cross-sectional Copenhagen Sarcopenia Study (CSS). Osteoporosis was diagnosed according to the World Health Organization guidelines. Sarcopenia was diagnosed in accordance with the guidelines from the European Working Group on Sarcopenia in Older People (EWGSOP2) with application of cut-off values from the EWGSOP2 paper compared to cut-off values derived from a local cohort (CSS). Results: 19.2% had osteoporosis (66 women and 35 men), whereas 2.7% (6 women and 8 men) and 4.2% (7 women and 15 men) had sarcopenia with application of EWGSOP2 and CSS cut-off values, respectively. Using the EWGSOP2 cut-off values, 1.5% (4 women and 4 men) were diagnosed with osteosarcopenia compared to 1.4% (4 women and 3 men) using CSS cut-off values. In the osteoporosis sub-population, 8% (EWGSOP2) and 7% (CSS) had sarcopenia and within the sarcopenia sub-population, 61.5% (EWGSOP2) and 33.3% (CSS) had osteoporosis. At all sites, BMD was lower among individuals with sarcopenia and sarcopenia increased the risk of osteoporosis (odds ratios: EWGSOP2: 7.3 (p < 0.001) and CSS: 2.2 (ns)). Conclusion: Osteosarcopenia was present in 1.5% of a group of healthy home-dwelling older individuals. Notably, individuals with sarcopenia had lower BMD and a higher risk of osteoporosis, whereas the opposite (prevalence of sarcopenia in individuals with osteoporosis) was not as frequent. Our data indicate that screening for sarcopenia and osteoporosis should be performed simultaneously in older individuals at high risk of falls and fractures. However, further studies with outcome-related results are needed to identify optimal measures of osteosarcopenia and cut-off values for sarcopenia.