The relationship between sarcopenia-related measurements and osteoporosis: The SARCOP study

As muscle and bone are closely-related, we have explored the association between sarcopenia-related measurements and bone mineral density (BMD) (and osteoporosis) in postmenopausal women. Grip strength, anterior thigh muscle thickness and chair stand test were found to be related with BMD. Additionally, grip strength < 22 kg increased the odds ratio of osteoporosis 1.6 times.

As muscle and bone are two closely related tissues, we aimed to investigate the association between sarcopenia-related measurements (i.e., sonographic anterior thigh muscle thickness, grip strength, chair stand test (CST), gait speed) and clinical factors, lumbar/femoral BMD, and the presence of osteoporosis (OP) in postmenopausal women.

Community dwelling postmenopausal women from two physical and rehabilitation medicine outpatient clinics were consecutively included in this cross-sectional study. Demographic data, age, weight, height, education/exercise status, smoking, and comorbidities were registered. BMD measurements were performed from lumbar vertebrae (L1-4) and femoral neck using dual energy X-ray absorptiometry (DXA). A T-score of ≤ -2.5 SD in the lumbar vertebrae (L1-L4) and/or femoral neck was accepted as OP. Anterior thigh muscle thickness (MT) at the midthigh level was measured sonographically using a linear probe. Grip strength was measured from the dominant side. Physical performance was assessed by CST and gait speed.

Among 546 postmenopausal women, 222 (40.7%) had OP. Among sarcopenia-related parameters, grip strength and anterior thigh MT were positively associated with lumbar vertebral BMD. CST performance was positively associated with femoral neck BMD. After adjusting for confounding factors, low grip strength (< 22 kg) increased 1.6 times the risk of OP.

Loss of muscle mass/function (i.e., sarcopenia) can coexist with loss of trabecular and cortical bone. To this end, grip strength and anterior thigh MT seem to be associated with the lumbar vertebral BMD, while CST is associated with the femoral neck BMD. Lastly, low grip strength might have an association with postmenopausal OP.