Diagnosis of Osteosarcopenia – Biochemistry and Pathology

Abstract

Sarcopenia and osteopenia/osteoporosis are two frequent conditions that often coexist amongst frail, older adults. Individuals affected from both conditions at the same time harbor a risk for adverse outcome that is substantially higher than the additive risk related to each of the two diseases. This observation lead to the description of a new entity called osteosarcopenia. Affected patients benefit from an appropriate care plan, which is based on a correct diagnosis. Establishment of the diagnosis includes the assessment of clinical risk factors and the determination of bone and muscle mass. The latter two are measured by dual-energy X-ray absorptiometry (DXA). Additional aspects in the workup of patients with osteosarcopenia include the biochemical assessment of bone and muscle metabolism and the exploration of secondary causes, such as hyperparathyroidism, vitamin D deficiency or malnutrition. Considering that these conditions can potentially be treated, patients benefit substantially from early diagnosis and treatment. Guidelines that provide specific recommendations for biochemical tests during the workup of osteosarcopenic patients are currently lacking. Therefore, the following pages provide a rather subjective overview based on the practical experience of the authors and existing separate guidelines for osteoporosis and sarcopenia. Furthermore, histomorphometric analyses and genetic tests will be addressed.