Poor bone microarchitecture in older men with impaired physical performance--the STRAMBO study

Effects of 12-week power training on bone in mobility-limited older adults: randomised controlled trial

This study examines how power training affects estimated bone strength, revealing that females benefit more than males, especially in the upper limbs (radius). These findings highlight the importance of designing sex-specific exercise programs to enhance bone health. Further research is needed to optimize training duration and address site-specific differences.

PURPOSE

This study aimed to compare the effects of 12-week of power training (PWT), an explosive form of strength training, on bone microarchitecture, estimated bone strength, and markers in mobility-limited (gait speed < 0.9 m/s) older adults.

METHODS

Fifty-seven older adults (83 ± 5 years) were randomly assigned to either a training group (TRAIN, n = 28, 15 females, 13 males) performing high-intensity PWT or a control group (CTRL, n = 29, 22 females, 7 males) maintaining their usual lifestyle. High-resolution peripheral quantitative computed tomography (HR-pQCT) assessed bone geometry, densities, microarchitecture (e.g. trabecular number (Tb.N) and thickness (Tb.Th)), and estimated bone strength (stiffness and failure load) at the tibia and radius. Blood markers for bone metabolism (PINP and CTX-1) and muscle strength (handgrip and leg press) were also measured.

RESULTS

Baseline sex differences showed females having lower stiffness (- 37.5%) and failure load (- 38%) at the radius compared with males. After PWT, females in the TRAIN group exhibited declines in Tb.N (- 4.4%) and improvements in Tb.Th (+ 6.0%), stiffness (+ 2.7%), and failure load (+ 2.4%) at the radius (p < 0.05). A time x group interaction indicated increases in leg press strength for the whole TRAIN group (+ 23%), and within females (+ 29%) and males (+ 19%) (p < 0.001). Baseline handgrip strength correlated with stiffness (r = 0.577) and failure load (r = 0.612) at the radius (p < 0.001). Females in the TRAIN group showed a reduction in PINP (- 25%), while males showed an increase in CTX-1 (+ 18%).

CONCLUSION

A 12-week PWT may enhance estimated bone strength in mobility-limited older adults, especially at sites less accustomed to daily loading (i.e. radius).

CLINICAL TRIAL REGISTRATION

NCT02051725.

Decline in muscle strength and physical function after fracture in men - the prospective STRAMBO study

Studies on muscle strength and physical function after fracture are focused on short follow-ups and adjacent anatomical region. We compared loss of muscle strength and physical function in men after fracture with normal ageing-related decline. In 823 men aged 60-87, measurements of grip strength and clinical tests (chair stands, balance) were performed every 4 years for 12 years. In 155 men with incident fracture, we compared the status after vs. before the fracture. In men without fracture (controls), we compared the status on the first follow-up (4 years) vs. baseline. In men with fracture, grip strength decreased more than in the controls (41%, 0.28SD, P < .01). Men with fracture had higher risk of incident deterioration on the five chair-stand test vs. the controls (OR = 2.45, P < .001). They had higher risk of incident inability to stand for 10s with closed eyes vs. the controls (OR = 4.80, P < .01). They also had higher risk of deterioration on the tandem walk than the controls: forwards (OR = 2.04, P < .01), backwards (OR = 2.25, P < .005). The rapid physical decline was not limited to the region of the fracture site. In men who had incident non-upper limb fractures, grip strength decreased more (32%, P < .05) vs. the controls. In men who had incident non-lower limb fractures, the risk of decline in the tests of the lower limbs was higher vs. controls (chair stands, OR = 2.73, P < .001). The risk of decline was higher in men with clinical fractures which occurred >1 year before the next visit vs. controls (tandem walk forwards, OR = 2.98, P < .005). Overall, in older men, fractures were associated with greater loss of muscle strength and physical function vs. normal ageing. This accelerated decline was also found in the anatomical regions remote from the fracture site. Thus, programs to decrease or reverse the post-fracture decline could have beneficial effects on subsequent fracture risk.

Bone Microarchitecture Decline and Risk of Fall and Fracture in Men With Poor Physical Performance-The STRAMBO Study

CONTEXT

High fracture risk in individuals with low muscle strength is attributed to high risk of falls.

OBJECTIVE

This work aims to study the association of muscle mass and physical performance with bone microarchitecture decline and risk of fall and nonvertebral fracture in men.

METHODS

A prospective, 8-year follow-up of a cohort was conducted among the general population. A total of 821 volunteer men aged 60 and older participated. Hip areal bone mineral density (aBMD) and appendicular lean mass (ALM) were assessed at baseline by dual x-ray absorptiometry. Lower-limb relative ALM (RALM-LL) is ALM-LL/(leg length)2. The physical performance score reflects the ability to perform chair stands and static and dynamic balance. Bone microarchitecture was assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline and after 4 and 8 years. Statistical analyses were adjusted for shared risk factors. Outcome measurements included the rate of change in the HR-pQCT indices, incident falls, and fractures.

RESULTS

Cortical bone loss and estimated bone strength decline were faster in men with low vs normal RALM-LL (failure load: -0.74 ± 0.09 vs -0.43 ± 0.10%/year; P < .005). Differences were similar between men with poor and those with normal physical performance (failure load: -1.12 ± 0.09 vs -0.40 ± 0.05%/year; P < .001). Differences were similar between men having poor performance and low RALM-LL and men having normal RALM-LL and performance (failure load: -1.40 ± 0.17 vs -0.47 ± 0.03%/year; P < .001). Men with poor physical performance had a higher risk of fall (hazard ratio [HR] = 3.52; 95% CI, 1.57-7.90, P < .05) and fracture (HR = 2.68; 95% CI, 1.08-6.66, P < .05).

CONCLUSION

Rapid decline of bone microarchitecture and estimated strength in men with poor physical performance and low RALM-LL may contribute to higher fracture risk.

Impact of Bone Fracture on Muscle Strength and Physical Performance-Narrative Review

PURPOSE OF REVIEW

Low muscle strength and poor physical performance are associated with high risk of fracture. Many studies assessed clinical and functional outcomes of fractures. Fewer studies analyzed the impact of fractures on muscle strength and physical performance.

RECENT FINDINGS

Vertebral fractures (especially multiple and severe ones) are associated with back pain, back-related disability, lower grip strength, lower strength of lower limbs, lower gait speed, and poor balance. Patients with hip fracture have slower gait and lower quadriceps strength. Non-vertebral fractures were associated with lower strength of the muscles adjacent to the fracture site (e.g., grip strength in the case of distal radius fracture, knee extensors in the case of patellar fracture) and poor physical function dependent on the muscles adjacent to the fracture site (e.g., limited range of motion of the shoulder in the case of humerus fracture, gait disturbances in the case of the ankle fracture). Individuals with a fracture experience a substantial deterioration of muscle strength and physical performance which exceeds that related to aging and is focused on the period close to the fracture occurrence. After fracture, muscle strength increased and physical performance improved. The rate of normalization depended partly on the therapeutic approach and on the rehabilitation program. A subgroup of patients, mainly the elderly, never returns to the pre-fracture level of physical performance. The permanent decline of physical function after fracture may be related to the limitation of movements due to pain, low physical activity, poor health before the fracture, and reduced efficacy of retraining after immobilization.

Bone mineral density and trabecular bone score in Chinese subjects with sarcopenia

Background

As the general population is aging worldwide, the incidence of sarcopenia and osteoporosis is also rapidly increasing. Studies have found the link between sarcopenia and osteoporosis, but the relationship between sarcopenia and osteoporosis, especially bone microarchitecture, remains unclear.

Aims

To investigate the relationship between components of sarcopenia (muscle mass, handgrip strength, and gait speed) and components of osteoporosis [bone mass measured by bone mineral density (BMD) and bone microarchitecture measured by trabecular bone score (TBS)] in Chinese subjects.

Methods

318 Chinese men and 203 Chinese women were included in our study. Muscle mass and BMD were measured by dual-energy X-ray absorptiometry (DXA). TBS iNsight^® software was used for TBS. Jamar hydraulic hand dynamometer was used to assess muscle strength, and gait speed was used to assess physical performance.

Results

We found that the relative appendicular skeletal muscle mass (RASM) in both genders and handgrip strength in women correlated positively with TBS, RASM in men and handgrip strength in women correlated positively with BMDs. In the multiple linear regression model, RASM was positively associated with TBS in both genders, but no significant association was observed between RASM and BMDs. Interestingly, handgrip strength showed positive association with all evaluated BMDs and TBS in women, but not in men. Women with sarcopenia had lower TBS and BMDs at all evaluated sites. Men with sarcopenia had lower BMDs only at femur neck and total hip.

Conclusions

The reduction of muscle mass and strength was significantly associated with decreased bone mass and deteriorated bone microarchitecture. More importantly, low muscle mass is an independent risk factor for bone microarchitecture in Chinese subjects.

Longitudinal Change in Peripheral Quantitative Computed Tomography Assessment in Older Adults: The Hertfordshire Cohort Study

There are few longitudinal data on change in bone structure and muscle mass, strength and function in later life. We report these, and consider bone-muscle interrelationships in older men and women. We studied 188 men and 166 women from the Hertfordshire Cohort Study, who underwent peripheral quantitative computed tomography (pQCT) of the radius and tibia in 2004-2005 and then again in 2011-2012. Grip strength and gait speed were also assessed at both timepoints. Percentage change per year was calculated for grip strength, gait speed, muscle cross-sectional area (mCSA), fat cross-sectional area (fCSA) and diaphyseal bone parameters [total area (Tt.Ar), cortical area (Ct.Ar), cortical density (cBMD) and trabecular density (tBMD)]. The mean (SD) age of men and women at baseline was 68.9 (2.5) and 69.2 (2.6) years, respectively. Rates of muscle area and strength loss did not differ by sex. Tt.Ar increased with age and faster in men [mean (SD) 1.78 (1.64) %/year] than women [mean (SD) 1.03 (1.69) %/year] in the radius (p < 0.001). In both the radius (p = 0.006) and tibia (p < 0.001), Ct.Ar reduced more rapidly in women than men. Change in Ct.Ar was associated with change in muscle area in the corresponding limb (radius; men: regression coefficient 0.36, 95% CI 0.20-0.52, p < 0.001; tibia; men: regression coefficient 0.14, 95% CI 0.00-0.27, p = 0.043, women: regression coefficient 0.16, 95% CI 0.01-0.30, p = 0.032). We have demonstrated that muscle strength and function decrease faster than muscle mass and have provided further evidence that changes in bone structure with age differ by sex.

Bone health assessment in older people with or without muscle health impairment

This study investigated the relationship between muscle and bone status in elderly individuals. Our results suggested links between sarcopenia and osteoporosis; impairment in muscle status (i.e., muscle mass, muscle strength, and physical performance) is associated with deterioration in bone mass and texture subsequently leading to an increased risk of fracture.

INTRODUCTION

Accumulating evidence has shown associations between sarcopenia and osteoporosis, but existing studies face inconsistencies in the clinical definition of both conditions. Thus, we sought to investigate bone health among older individuals with or without muscle health impairment.

METHODS

We conducted an analysis of cross-sectional data available from the Sarcopenia and Physical Impairment with Advancing Age (SarcoPhAge) study. Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People (EWGSOP) (i.e., a low muscle mass plus either low muscle strength or low physical performance). Muscle mass and areal bone mineral density (aBMD) were determined using dual-energy X-ray absorptiometry (DEXA). Muscle strength was assessed using a hand dynamometer, and physical performance was assessed with the Short Physical Performance Battery test. Using the cutoff limits proposed by the EWGSOP, we have classified women in the "low SMI group" when its value was < 5.50 kg/m², in the "low muscle strength group" when strength was < 20 kg, and in the "low physical performance group" when SPPB < 8 points. The thresholds of < 7.26 kg/m² (for SMI), < 30 kg (for muscle strength), and SPPB < 8 points were used for men. The 10-year fracture risk was obtained using the FRAX® tool. Moreover, bone texture was determined using the trabecular bone score (TBS) method.

RESULTS

The study sample consisted of 288 older subjects aged 74.7 ± 5.7 years, and 59.0% of the subjects were women. Sarcopenia was diagnosed in 43 individuals (14.9%), and osteoporosis was diagnosed in 36 subjects (12.5%). Moreover, aBMD values were, most of the time, lower in older men and women with muscle impairment (i.e., low muscle mass, low muscle strength, and low physical performance). For these subjects, we also noted a higher probability of fracture. When comparing bone quality, there were no significant differences in the TBS values between sarcopenic and non-sarcopenic older men and women or between those with low and high muscle mass. However, when controlling for confounders (i.e., age, BMI, number of co-morbidities, smoking status, and nutritional status), TBS values were lower in older women with low muscle strength (p = 0.04) and in older men with low physical performance (p = 0.01).

CONCLUSIONS

Our study showed interrelationships between components of sarcopenia and osteoporosis, with older subjects with muscle impairment having poorer bone health.

Muscle size, strength, and physical performance and their associations with bone structure in the Hertfordshire Cohort Study

Sarcopenia is associated with a greater fracture risk. This relationship was originally thought to be explained by an increased risk of falls in sarcopenic individuals. However, in addition, there is growing evidence of a functional muscle-bone unit in which bone health may be directly influenced by muscle function. Because a definition of sarcopenia encompasses muscle size, strength, and physical performance, we investigated relationships for each of these with bone size, bone density, and bone strength to interrogate these hypotheses further in participants from the Hertfordshire Cohort Study. A total of 313 men and 318 women underwent baseline assessment of health and detailed anthropometric measurements. Muscle strength was measured by grip strength, and physical performance was determined by gait speed. Peripheral quantitative computed tomography (pQCT) examination of the calf and forearm was performed to assess muscle cross-sectional area (mCSA) at the 66% level and bone structure (radius 4% and 66% levels; tibia 4% and 38% levels). Muscle size was positively associated with bone size (distal radius total bone area β = 17.5 mm2 /SD [12.0, 22.9]) and strength (strength strain index (β = 23.3 mm3 /SD [18.2, 28.4]) amongst women (p < 0.001). These associations were also seen in men and were maintained after adjustment for age, height, weight-adjusted-for-height, limb-length-adjusted-for-height, social class, smoking status, alcohol consumption, calcium intake, physical activity, diabetes mellitus, and in women, years since menopause and estrogen replacement therapy. Although grip strength showed similar associations with bone size and strength in both sexes, these were substantially attenuated after similar adjustment. Consistent relationships between gait speed and bone structure were not seen. We conclude that although muscle size and grip strength are associated with bone size and strength, relationships between gait speed and bone structure and strength were not apparent in this cohort, supporting a role for the muscle-bone unit.

Correlates of bone microarchitectural parameters and serum sclerostin levels in men: the STRAMBO study

Sclerostin is predominantly expressed by osteocytes. Serum sclerostin levels are positively correlated with areal bone mineral density (aBMD) measured by dual-energy X-ray absorptiometry (DXA) and bone microarchitecture assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) in small studies. We assessed the relation of serum sclerostin levels with aBMD and microarchitectural parameters based on HR-pQCT in 1134 men aged 20 to 87 years using multivariable models adjusted for confounders (age, body size, lifestyle, comorbidities, hormones regulating bone metabolism, muscle mass and strength). The apparent age-related increase in serum sclerostin levels was faster before the age of 63 years than afterward (0.43 SD versus 0.20 SD per decade). In 446 men aged ≤63 years, aBMD (spine, hip, whole body), trabecular volumetric BMD (Tb.vBMD), and trabecular number (Tb.N) at the distal radius and tibia were higher in the highest sclerostin quartile versus the three lower quartiles combined. After adjustment for aBMD, men in the highest sclerostin quartile had higher Tb.vBMD (mainly in the central compartment) and Tb.N at both skeletal sites (p < 0.05 to 0.001). In 688 men aged >63 years, aBMD was positively associated with serum sclerostin levels at all skeletal sites. Cortical vBMD (Ct.vBMD) and cortical thickness (Ct.Th) were lower in the first sclerostin quartile versus the three higher quartiles combined. Tb.vBMD increased across the sclerostin quartiles, and was associated with lower Tb.N and more heterogeneous trabecular distribution (higher Tb.Sp.SD) in men in the lowest sclerostin quartile. After adjustment for aBMD, men in the lowest sclerostin quartile had lower Tb.vBMD and Tb.N, but higher Tb.Sp.SD (p < 0.05 to 0.001) at both the skeletal sites. In conclusion, serum sclerostin levels in men are strongly positively associated with better bone microarchitectural parameters, mainly trabecular architecture, regardless of the potential confounders.

Osteoporosis in older men: recent advances in pathophysiology and treatment

Osteoporosis remains underrecognized and undertreated but more so in men, adding considerably to fracture burden and costs. Fracture-related morbidity and mortality is higher in men, partly due to greater frailty. Improved peak bone mass, geometry and turn-over contribute to lower fracture incidence in men. Bioavailable androgens and oestrogens regulate these aspects of musculoskeletal sexual dimorphism, yet the direct cellular and molecular targets of sex steroids in bone remain incompletely understood. Screening with clinical risk factors and dual energy X-ray absorptiometry are advised in men from age 70 (or 50 with additional risk factors). We now have compelling evidence that osteoporosis drugs are equally effective in men and women, not only to increase bone density but also to prevent osteoporotic fractures. The use of testosterone or selective androgen receptor modulators for osteoporosis, sarcopenia, frailty and falls in men with late-onset hypogonadism requires further investigation.

Endocrine and clinical correlates of myostatin serum concentration in men--the STRAMBO study

CONTEXT

Myostatin is expressed mainly in skeletal muscle cells and acts as an inhibitor of muscle growth and differentiation. However, data on the determinants of serum myostatin concentrations in humans are limited.

OBJECTIVE

The aim of the study was to assess the correlates of serum myostatin concentrations in men.

DESIGN

We conducted a cross-sectional analysis of the STRAMBO cohort.

SETTING

Men holding private health insurance coverage with Mutuelle de Travailleurs de la Région Lyonnaise were included in the study.

PARTICIPANTS

A total of 1121 male volunteers aged 20-87 yr participated in the study.

INTERVENTIONS

Nonfasting blood samples were collected.

MAIN OUTCOME MEASURES

We measured the association of the investigated variables with circulating myostatin levels.

RESULTS

Serum myostatin levels increased slightly with age until 57 yr and then decreased. Circulating myostatin levels showed circannual variation, with the highest concentration in spring. In men older than 57 yr, serum myostatin levels decreased across increasing quartiles of body mass index and of total central and peripheral fat mass (P<0.05 to <0.001). Serum myostatin levels were positively correlated with serum levels of 25-hydroxycholecalciferol (25OHD), even after adjustment for season. Average myostatin levels were 0.47 sd higher in men with 25OHD above 40 ng/ml, compared with those with 25OHD below 20 ng/ml (P<0.05). Current smokers had lower myostatin concentration. Neither current physical activity nor serum levels of PTH, testosterone, and 17β-estradiol were associated with myostatin concentrations.

CONCLUSIONS

In men, circulating myostatin levels show seasonal changes and are associated with age, body mass index, fat mass, smoking, and 25OHD levels.

Poor trabecular microarchitecture at the distal radius in older men with increased concentration of high-sensitivity C-reactive protein--the STRAMBO study

Low-grade inflammation, assessed by serum high-sensitivity C-reactive protein (hsCRP) concentration, is associated with higher fracture risk irrespective of areal bone mineral density (aBMD). We assessed the association of hsCRP with bone microarchitecture (measured by high-resolution pQCT) at the distal radius and tibia in 1,149 men, aged 19-87 years. hsCRP concentration increased with age until the age of 72, then remained stable. aBMD was not correlated with hsCRP level. After adjustment for confounders, bone microarchitecture was not associated with hsCRP level in men aged <72. After the age of 72, hsCRP >5 mg/L was associated with lower trabecular density, lower trabecular number, higher trabecular spacing, and more heterogeneous trabecular distribution (p < 0.05-0.005) at the distal radius versus hsCRP ≤ 5 mg/L. Similar differences were found for the fourth hsCRP quartile (>3.69 mg/L) versus the three lower quartiles combined. Cortical parameters of distal radius and microarchitectural parameters of distal tibia did not vary according to hsCRP concentration in men aged ≥ 72. Fracture prevalence increased with increasing hsCRP level. After adjustment for confounders (including aBMD), odds for fracture were higher in men with hsCRP >5 mg/L compared to hsCRP <1 mg/L (OR = 2.22, 95 % CI 1.29-3.82) and did not change after additional adjustment for microarchitectural parameters. The association between hsCRP level and bone microarchitecture was observed only for trabecular parameters at the radius in men aged ≥72. Impaired bone microarchitecture does not seem to explain the association between elevated CRP level and higher risk of fracture.