Associations of Health-Related Quality of Life, Fear of Falling and Objective Measures of Physical Function with Bone Health in Postmenopausal Women with Low Bone Mass.

Health-related quality of life (HRQoL) and physical function deteriorate with age and may adversely impact bone health in older adults. We determined associations of objective measures of physical function and HRQoL with bone health in postmenopausal women with low areal bone mineral density (aBMD). Fifty postmenopausal women (64.4 7.7 years old, mean standard deviation) with low spine, hip or femoral neck aBMD (T- or Z-score < -1.0) on dual-energy X-ray absorptiometry (DXA) participated. Femoral surface BMD, trabecular, integral and cortical volumetric BMD (vBMD) measurements were obtained using 3D-SHAPER software on DXA. Distal tibial vBMD and microarchitecture were assessed using high-resolution peripheral quantitative computed tomography (HRpQCT). Participants completed self-administered EuroQol-5D (EQ-5D) and modified falls efficacy scale (MFES) questionnaires, and physical function assessments. Stair climb power was positively associated with bone parameters at the hip, femoral neck, and distal tibia (all p < 0.05) in multivariable linear regression. EQ-5D demonstrated no significant associations with bone parameters and MFES was positively associated only with distal tibial cortical vBMD and cortical von Mises stress (both p < 0.05). Objective measures of physical function, particularly muscle power, are more consistently associated with bone parameters compared with self-administered HRQoL questionnaires.

Associations of Sarcopenia and Its Components with Bone Structure and Incident Falls in Swedish Older Adults.

The aim of this study was to compare bone structure parameters and likelihood of falls across European Working Group on Sarcopenia in Older People (EWGSOP2) sarcopenia categories. 3334 Swedish 70-year olds had appendicular lean mass (normalized to height; ALMHt), lumbar spine and total hip areal BMD (aBMD) estimated by dual-energy X-ray absorptiometry. Volumetric BMD (vBMD) and structure at the distal and proximal tibia and radius were estimated by peripheral quantitative computed tomography. Hand grip strength and timed up-and-go were assessed, and sarcopenia was defined according to EWGSOP2 criteria. Incident falls were self-reported 6 and 12 months after baseline. Only 0.8% and 1.0% of participants had probable and confirmed sarcopenia, respectively. Almost one-third of participants with confirmed sarcopenia reported incident falls, compared with 20% for probable sarcopenia and 14% without sarcopenia (P = 0.025). Participants with confirmed sarcopenia had poorer bone parameters (all P < 0.05) except endosteal circumference at the proximal radius and tibia, while those with probable sarcopenia had lower cortical area at the proximal radius (B = - 5.9; 95% CI - 11.7, - 0.1 mm2) and periosteal and endosteal circumferences at the proximal tibia (- 3.3; - 6.4, - 0.3 and - 3.8; - 7.5, - 0.1 mm2, respectively), compared with those without sarcopenia. Compared with probable sarcopenia, confirmed sarcopenic participants had significantly lower lumbar spine and total hip aBMD, distal radius and tibia total vBMD, and proximal radius and tibia cortical vBMD, area and thickness (all P < 0.05). Swedish 70-year olds with confirmed sarcopenia demonstrate poorer BMD and bone architecture than those with probable and no sarcopenia, and have increased likelihood of incident falls.

Associations of Serum 25-Hydroxyvitamin D with Physical Performance and Bone Health in Overweight and Obese Older Adults.

Low vitamin D status commonly accompanies obesity, and both vitamin D deficiency and obesity have been associated with falls and fracture risk in older adults. We aimed to determine the associations of serum 25-hydroxyvitamin D (25(OH)D) concentrations with physical performance and bone health in community-dwelling, overweight and obese older men and women. Serum 25(OH)D concentrations were measured in 84 participants with body mass index ≥25 kg/m² (mean ± SD age 62.4 ± 7.9 years; 55% women). Physical function was determined by short physical performance battery, hand grip and quadriceps strength, and stair climb power tests. Body composition and bone structure were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography, respectively. Mean ± SD 25(OH)D was 49.6 ± 17.7 nmol/L, and 50% of participants had low 25(OH)D (<50 nmol/L) levels. 25(OH)D concentrations were positively associated with quadricep strength and stair climb power in women (B = 0.15; 95% CI 0.02⁻0.27 kg and B = 1.07; 95% CI 0.12⁻2.03 W, respectively) but not in men. There were no associations between 25(OH)D and bone parameters in either sex after multivariable adjustment (all p > 0.05). Lower 25(OH)D concentrations are associated with poorer quadricep strength and muscle power in overweight and obese older women but not men.

Sex-specific associations between insulin resistance and bone parameters in overweight and obese older adults.

OBJECTIVES: To determine sex-specific associations between insulin resistance and bone parameters measured by peripheral quantitative computed tomography in overweight and obese community-dwelling older adults. STUDY DESIGN: Cross-sectional study of 79 community-dwelling overweight and obese adults (mean ± SD age 62.8 ± 7.9 years; body mass index 32.3 ± 6.1 kg/m2 ; 58% women). MAIN OUTCOME MEASURES: Peripheral quantitative computed tomography assessed distal radius and tibia trabecular volumetric bone mineral density (vBMD) and proximal radius and tibia cortical vBMD, periosteal circumference, endosteal circumference and stress-strain index. The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) score was calculated from fasting glucose and insulin values. Lean mass was assessed using dual-energy X-ray absorptiometry. Total minutes of moderate and vigorous physical activity (MVPA) were calculated using the Active Australia Survey. RESULTS: Men and women in this cohort had no significant differences in fasting glucose and insulin concentrations, HOMA-IR values and diabetes prevalence (all P > 0.05). In women, HOMA-IR was positively correlated with proximal radius periosteal and endosteal circumference (r = 0.331; P = 0.034 and r = 0.325; P = 0.038, respectively). These associations became nonsignificant in multivariable regression analyses; however, HOMA-IR was negatively associated with proximal radius cortical vBMD (B = -4.79; 95% CI -8.66, -0.92) after adjusting for age, lean mass and MVPA. All associations between HOMA-IR and bone parameters became nonsignificant in a sensitivity analysis excluding individuals with diabetes, or self-reported use of glucose-lowering medications. There were no associations between HOMA-IR and bone parameters in men. CONCLUSIONS: Homeostatic Model Assessment of Insulin Resistance was negatively associated with radial cortical vBMD in overweight and obese older women, but not in men. Further studies are needed to clarify sex-specific associations between insulin resistance and bone health in overweight and obese older adults.

Metabolic Syndrome and Its Associations with Components of Sarcopenia in Overweight and Obese Older Adults.

Ageing, obesity and the metabolic syndrome (MetS) may all contribute to poor muscle health (sarcopenia). This study aimed to determine the cross-sectional associations between MetS (International Diabetes Federation classification) and sarcopenia (revised European Working Group on Sarcopenia in Older People definition) in 84 overweight and obese older adults. Components of sarcopenia included muscle strength (hand grip and leg extension), physical performance (stair climb test and short physical performance battery (SPPB), including gait speed and repeated chair stands time), muscle mass (appendicular lean mass (ALM), dual-energy X-ray absorptiometry), muscle size (peripheral quantitative computed tomography-determined calf and forearm cross-sectional area (CSA)) and muscle quality (muscle density and strength normalised to lean mass). Waist circumference was associated with greater muscle size, but poorer leg extension strength, chair stands and stair climb time, gait speed, SPPB scores and muscle quality measures (all p < 0.05). MetS was positively associated with ALM and forearm muscle CSA, and negatively associated with muscle quality measures and chair stands time (all p < 0.05). MetS is associated with larger muscle size, yet poorer muscle quality in overweight and obese older adults. Assessments of muscle function and quality should be considered for obese older adults and those with MetS.

Mid-calf skeletal muscle density and its associations with physical activity, bone health and incident 12-month falls in older adults: The Healthy Ageing Initiative.

BACKGROUND: Lower skeletal muscle density, indicating greater infiltration of adipose tissue into muscles, is associated with higher fracture risk in older adults. We aimed to determine whether mid-calf muscle density is associated with falls risk and bone health in community-dwelling older adults. METHODS: 2214 community-dwelling men and women who participated in the Healthy Ageing Initiative (Sweden) study at age 70 were included in this analysis. Mid-calf muscle density (mg/cm3) at the proximal tibia, and volumetric bone mineral density (vBMD) and architecture at the distal and proximal tibia and radius, were assessed by peripheral quantitative computed tomography. Whole-body lean and fat mass, lumbar spine and total hip areal bone mineral density (aBMD) were assessed by dual-energy X-ray absorptiometry. Participants completed seven-day accelerometer measurements of physical activity intensity, and self-reported falls data were collected 6 and 12 months later. RESULTS: 302 (13.5%) participants reported a fall at the 6- or 12-month interview, and 29 (1.3%) reported a fall at both interviews. After adjustment for confounders, each standard deviation decrease in mid-calf muscle density was associated with a trend towards greater likelihood of experiencing a fall (OR 1.13; 95% CI 1.00, 1.29 per SD lower) and significantly greater likelihood of multiple falls (1.61; 1.16, 2.23). Higher muscle density was not associated with total hip aBMD, and was associated with lower lumbar spine aBMD (B = -0.003; 95% CI -0.005, -0.001 per mg/cm3) and higher proximal cortical vBMD (0.74; 0.20, 1.28) at the radius. At the tibia, muscle density was positively associated with distal total and trabecular vBMD, and proximal total and cortical vBMD, cortical thickness, cortical area and stress-strain index (all P < 0.05). Only moderate/vigorous (%) intensity physical activity, not sedentary time or light activity, was associated with higher mid-calf muscle density (0.086; 0.034, 0.138). CONCLUSIONS: Lower mid-calf muscle density is independently associated with higher likelihood for multiple incident falls and appears to have localised negative effects on bone structure in older adults.

Calf muscle density is independently associated with physical function in overweight and obese older adults.

OBJECTIVES: To determine whether associations of calf muscle density with physical function are independent of other determinants of functional decline in overweight and obese older adults. METHODS: This was a secondary analysis of a cross-sectional study of 85 community-dwelling overweight and obese adults (mean±SD age 62.8±7.9 years; BMI 32.3±6.1 kg/m2; 58% women). Peripheral quantitative computed tomography assessed mid-calf muscle density (66% tibial length) and dual-energy X-ray absorptiometry determined visceral fat area. Fasting glucose, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and C-reactive protein (CRP) were analysed. Physical function assessments included hand grip and knee extension strength, balance path length (computerised posturography), stair climb test, Short Physical Performance Battery (SPPB) and self-reported falls efficacy (Modified Falls Efficacy Scale; M-FES). RESULTS: Visceral fat area, not muscle density, was independently associated with CRP and fasting glucose (B=0.025; 95% CI 0.009-0.042 and B=0.009; 0.001-0.017, respectively). Nevertheless, higher muscle density was independently associated with lower path length and stair climb time, and higher SPPB and M-FES scores (all P⟨0.05). Visceral fat area, fasting glucose and CRP did not mediate these associations. CONCLUSIONS: Higher calf muscle density predicts better physical function in overweight and obese older adults independent of insulin resistance, visceral adiposity or inflammation.

Prescribing Physical Activity for the Prevention and Treatment of Osteoporosis in Older Adults.

Osteoporosis is an age-related disease, characterised by low bone mineral density (BMD) and compromised bone geometry and microarchitecture, leading to reduced bone strength. Physical activity (PA) has potential as a therapy for osteoporosis, yet different modalities of PA have varying influences on bone health. This review explores current evidence for the benefits of PA, and targeted exercise regimes for the prevention and treatment of osteoporosis in older adults. In particular, the outcomes of interventions involving resistance training, low- and high-impact weight bearing activities, and whole-body vibration therapy are discussed. Finally, we present recommendations for future research that may maximise the potential of exercise in primary and secondary prevention of osteoporosis in the ageing population.