Muscle Strength and Physical Performance Are Associated With Risk of Postfracture Mortality But Not Subsequent Fracture in Men

Crosstalk between muscle and bone

Clinical studies revealed a relationship between osteoporosis and sarcopenia. Based on this background, crosstalk between muscle and bone has emerged as a novel research field in the past decade. Among the interactions that occur between muscle and bone, humoral factors, such as osteokines and myokines, affect distant muscles and bones, respectively. Recent studies proposed several important myokines that have an impact on bone, such as myostatin and irisin. Signaling by these myokines has potential as a target for drug development and biomarkers for exercise. Mechanical stress, endocrine disorders, and chronic kidney disease partly affect bone through various myokines in crosstalk between muscle and bone. Moreover, the involvement of extracellular vesicles from bone or muscle as communication tools in the interactions between muscle and bone was recently proposed. Further clinical studies are needed to clarify the significance of myokine regulation under physiological and pathophysiological states in humans.

Physical performance and sarcopenia assessment in patients with a recent fracture visiting the Fracture Liaison Service

Impaired physical performance is associated with increased fracture risk. Performance on four physical functioning tests and prevalence of sarcopenia were assessed for 1789 fracture patients and compared to reference data. Performance was low on all tests, especially for patients with a hip, major or ≥ 1 prevalent vertebral fracture.

PURPOSE INTRODUCTION

Impaired physical performance and sarcopenia are associated with increased fracture risk. This study aims to assess physical performance and the prevalence of sarcopenia in patients with a recent clinical fracture attending the Fracture Liaison Service (FLS) compared to population means.

METHODS

In this cross-sectional study, chair stand test (CST), handgrip strength (HGS), timed-up-and-go (TUG), 6-min walking-test (6MWT), and sarcopenia (following EWGSOP2) were assessed. The proportion of patients with impaired/poor performance compared to reference data was calculated (Z-score: ≥  - 2SD to <  - 1 (impaired) and <  - 2 SD (poor)). Associations of fracture type, sex, age, and time since fracture with Z-scores were assessed using linear regression analyses.

RESULTS

A total of 1789 consecutive FLS patients were included (median age (IQR): 66 (59-74), 70.7% females, 3.9 (± 1.6) months after fracture). The prevalence of impaired/poor performance for CST, HGS, TUG, and 6MWT was 39.2%, 30.4%, 21.9%, and 71.5%, respectively (expected proportion of 16%) and 2.8% had sarcopenia. Lower Z-scores (P < 0.001) were found for hip, major, and ≥ 1 prevalent vertebral fracture (VF) in CST (major: regression coefficient (B) (95%CI) =  - 0.25 [- 0.34, - 0.16]; hip: B =  - 0.32 [- 0.47, - 0.17], VF: B =  - 0.22 [- 0.34, - 0.11]), TUG; (major: B =  - 0.54 [- 0.75, - 0.33]; hip: B =  - 1.72 [- 2.08, -1.35], VF: B =  - 0.61 [- 0.88, - 0.57]), 6MWT (major: B =  - 0.34 [- 0.47, - 0.21]; hip: B =  - 0.99 [- 1,22, - 0.77], VF: B =  - 0.36 [- 0.53, - 0.19]).

CONCLUSIONS

Physical performance is significantly lower in FLS patients compared to healthy peers, especially in patients with hip, major or prevalent VF. These findings underline the need to assess and improve the physical performance of FLS patients, despite a low prevalence of sarcopenia.

The "Can Do, Do Do" Framework Applied to Assess the Association between Physical Capacity, Physical Activity and Prospective Falls, Subsequent Fractures, and Mortality in Patients Visiting the Fracture Liaison Service

The "can do, do do" framework combines measures of poor and normal physical capacity (PC, measured by a 6 min walking test, can do/can't do) and physical activity (PA, measured by accelerometer, do do/don't do) into four domains and is able to categorize patient subgroups with distinct clinical characteristics, including fall and fracture risk factors. This study aims to explore the association between domain categorization and prospective fall, fracture, and mortality outcomes. This 6-year prospective study included patients visiting a Fracture Liaison Service with a recent fracture. Outcomes were first fall (at 3 years of follow-up, measured by fall diaries), first subsequent fracture, and mortality (at 6 years). Cumulative incidences of all three outcomes were calculated. The association between domain categorization and time to the three outcomes was assessed by uni- and multivariate Cox proportional hazard analysis with the "can do, do do" group as reference. The physical performance of 400 patients with a recent fracture was assessed (mean age: 64 years; 70.8% female), of whom 61.5%, 20.3%, and 4.9% sustained a first fall, sustained a subsequent fracture, or had died. Domain categorization using the "can do, do do" framework was not associated with time to first fall, subsequent fracture, or mortality in the multivariate Cox regression analysis for all groups. "Can't do, don't do" group: hazard ratio [HR] for first fall: 0.75 (95% confidence interval [CI]: 0.45-1.23), first fracture HR: 0.58 (95% CI: 0.24-1.41), and mortality HR: 1.19 (95% CI: 0.54-6.95). Categorizing patients into a two-dimensional framework seems inadequate to study complex, multifactorial outcomes. A personalized approach based on known fall and fracture risk factors might be preferable.

Handgrip strength is associated with mortality in community-dwelling older adults: the Yilan cohort study, Taiwan

INTRODUCTION

Hand grip strength (HGS) is one of the methods to help early identification of physical frailty and sarcopenia, the major concerns in the aging societies. It is also crucial to evaluate its impact on mortality. However, the available evidence regarding such impact among specific age cohorts (65 to 74 years and above) is limited. This study tried to investigate the relationship between HGS and mortality among specific cohorts of the community-dwelling older individuals in Yilan, Taiwan.

METHODS

A seven-year longitudinal follow-up study was conducted involving 2,468 community-dwelling older individuals in Yilan. The participants were divided into two groups based on their quartiles of hand grip strength: with poor HGS and with good HGS. The association between HGS and mortality was examined using Cox proportional hazards models.

RESULTS

The analysis revealed that age, HGS, gender, medical history of cardiovascular diseases, body mass index, and wrist-hip ratio had significant impacts on seven-year survival. Specifically, individuals with poor HGS exhibited increased mortality, with an adjusted hazard ratio (HR) of 1.87 (95% CI: 1.52-2.30). Furthermore, the adverse effect of poor HGS on mortality was more pronounced in males aged 65-74 years (adjusted HR 4.12, 95% CI: 2.16-7.84), females aged 75 years or older (2.09, 1.43-3.04) and males aged 75 years or older (1.49, 1.07-2.07).

CONCLUSION

Poor hand grip strength is an independent risk factor for mid-term mortality among community-dwelling older individuals in Yilan. The assessment of HGS can serve as a valuable tool in identifying older individuals at higher risk of death.

Sarcopenia, osteoporosis and frailty

Muscles and bones are intricately connected tissues displaying marked co-variation during development, growth, aging, and in many diseases. While the diagnosis and treatment of osteoporosis are well established in clinical practice, sarcopenia has only been classified internationally as a disease in 2016. Both conditions are associated with an increased risk of adverse health outcomes such as fractures, dysmobility and mortality. Rather than focusing on one dimension of bone or muscle mass or weakness, the concept of musculoskeletal frailty captures the overall loss of physiological reserves in the locomotor system with age. The term osteosarcopenia in particular refers to the double jeopardy of osteoporosis and sarcopenia. Muscle-bone interactions at the biomechanical, cellular, paracrine, endocrine, neuronal or nutritional level may contribute to the pathophysiology of osteosarcopenia. The paradigm wherein muscle force controls bone strength is increasingly facing competition from a model centering on the exchange of myokines, osteokines and adipokines. The most promising results have been obtained in preclinical models where common drug targets have been identified to treat these conditions simultaneously. In this narrative review, we critically summarize the current understanding of the definitions, epidemiology, pathophysiology, and treatment of osteosarcopenia as part of an integrative approach to musculoskeletal frailty.