Effect of Aerobic or Resistance Exercise, or Both, on Bone Mineral Density and Bone Metabolism in Obese Older Adults While Dieting: A Randomized Controlled Trial

SIRT1 signaling pathways in sarcopenia: Novel mechanisms and potential therapeutic targets

Sarcopenia is an aging-related skeletal disease characterized by decreased muscle mass, strength, and physical function, severely affecting the quality of life (QoL) of the elderly population. Sirtuin 1 (SIRT1), as a nicotinamide adenine dinucleotide (NAD+)-dependent histone deacetylases, has been reported to participate in various aging-related signaling pathways and exert protective effect on many human diseases. SIRT1 functioned as an important role in the occurrence and progression of sarcopenia through regulating key pathways related to protein homeostasis, apoptosis, mitochondrial dysfunction, insulin resistance and autophagy in skeletal muscle, including SIRT1/Forkhead Box O (FoxO), AMP-activated protein kinase (AMPK)/SIRT1/nuclear factor κB (NF-κB), SIRT1/p53, AMPK/SIRT1/peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), and SIRT1/live kinase B1 (LKB1)/AMPK pathways. However, the specific mechanisms of these processes have not been fully illuminated. Currently, several SIRT1-mediated interventions on sarcopenia have been preliminarily developed, such as SIRT1 activator polyphenolic compounds, exercising and calorie restriction. In this review, we summarized the predominant mechanisms of SIRT1 involved in sarcopenia and therapeutic modalities targeting the SIRT1 signaling pathways for the prevention and prognosis of sarcopenia.

Age- and Sex-Dependent Effects of Moderate Exercise on Endogenous Pain Inhibition in Rats

Diffuse noxious inhibitory controls (DNICs), or the pain inhibits pain phenomenon, refer to reduced pain-like behaviors that are displayed following a noxious conditioning stimulus located far from the test stimulus and have also been referred to as "descending control of nociception" when measured in awake-behaving animals. In this study, we sought to determine the impact of moderate long-term exercise on the DCN response and determine if this effect differed across age and sex. After a six-week exercise program consisting of 30 min of moderate treadmill running 5 days a week, the animals' forepaws were injected with capsaicin, and DCN responses were assessed using thermal withdrawal latencies of the hind paw. Young, exercised male and female rats displayed prolonged DCN responses relative to their sedentary counterparts, with the young exercised male group displaying longer-lasting DCN facilitation than the young exercised females. Exercise did not impact DCN responses in either male or female aged rats. Additionally, the serum testosterone levels did not change following exercise in any group. Importantly, the levels of corticosterone did not change following the exercise program, indicating that changes in the DCN response are not due to stress-induced analgesia. Our findings suggest that moderate exercise can facilitate the DCN response in young animals, even when this exercise does not change the levels of serum testosterone.

The microarchitecture and chemical composition of the femur neck of senescent female rats after different physical training protocols

A sedentary lifestyle, coupled with a decrease in estrogen, impairs bone homeostasis, favoring to the development of osteopenia and osteoporosis, both recognized as risk factors for fractures. Here, we investigated the quality of the femur, particularly the femur neck region, and the ambulation performance of senescent rats subjected to three different physical training protocols during the periestropause period. Forty-eight female rats, 18 months of age, were subjected to a 120-day training period, three times a week. The rats were distributed into four groups: aerobic training (AT), strength training (ST), concurrent training (CT), or no training (NT). After the experimental period, at 21 months of age, ambulation performance and femur were analyzed using microtomography, Raman stereology, densitometry, and mechanical strength tests. The results demonstrated greater remodeling activity and improvement in resistance and bone microarchitecture in the femur neck of senescent female rats after undergoing physical training. Our verified higher intensities of bands related to collagen, phosphate, amide III, and amide I. Furthermore, the analysis of the secondary collagen structures indicated alterations in the collagen network due to the exercise, resulting in increased bone strength. Both AT and strength-based training proved beneficial, with AT showing greater adaptations in bone density and stiffness in the femur, while strength-based training greater adaptations in trabecular and cortical structure. These insights contribute to the understanding of the potential interventions for preventing osteopenia and osteoporosis, which are critical risk factors for fractures.

Effects of exercise training on bone health in adults living with HIV: a systematic review with meta-analysis

We investigated the effects of exercise training on bone mineral density (BMD) in people living with Human Immunodeficiency Virus (PLHIV). Pubmed, Scopus, Cochrane Library, and ScienceDirect databases were searched for trials investigating exercise training-induced changes in BMD of PLHIV at baseline vs. post-intervention assessed by dual-energy X-ray absorptiometry (DXA). Hedge effect sizes (ES) were calculated incorporating fixed effects for BMD variation assumptions. Disaggregated comparisons were performed for trials with more than one intervention or BMD site assessment. Seven trials included 210 PLHIV and 35 non-HIV-infected controls. Methodological quality evaluated using the Physiotherapy Evidence Database (PEDro) scale ranged from poor to moderate. Interventions applied isolated resistance, combined aerobic and resistance, and multimodal exercise protocols performed 3 d/wk for 12-to 104 week. One controlled and another uncontrolled trial presented significant effects, reporting improvements at the femoral neck and total (ES 2.14 and 0.49, respectively). Magnitude of those specific ES influenced the overall effect (controlled and uncontrolled trials), which was small but significant (k = 12, ES 0.277, 95% confidence interval 0.120-0.434). Resistance training may promote favorable adaptations in BMD of PLHIV, particularly in femur. Future research should elucidate the optimal dose-response relationship and physiological mechanisms underlying exercise-induced adaptations on the BMD of PLHIV.

The effect of the whole-process care model of the medical union on the improvement of kinesiophobia and bone mineral density in patients with osteoporosis

OBJECTIVE

To observe the effect of the whole-process care model of the medical union on the improvement of kinesiophobia and bone mineral density in patients with osteoporosis.

METHODS

In this descriptive study, a convenient sampling method was used to select 148 patients with osteoporosis who visited the hospital from January 2020 to December 2021. Patients aged ≥ 18 years and diagnosed with osteoporosis through quantitative computed tomography (QCT) were included in the study. They were able to cooperate during follow-up and had normal cognitive function. Patients with combined spinal curvature, thoracic deformity, and pulmonary dysfunction, accompanied by severe cardiovascular or limb dysfunction, and those who withdrew midway or participated in other clinical studies were excluded. According to whether to use the whole-process care model of the medical union, they were divided into intervention group and control group, with 74 cases each. The control group used conventional care, and the intervention group used the whole-process care model of the medical association. The occurrence of kinesiophobia between the two groups were compared. The dual-energy X-ray absorption detector is used to measure differences in bone density changes.

RESULTS

There was no significant difference between the two groups in the TSK scale score and the incidence of kinesiophobia before intervention (P > 0.05). The TSK scale scores of patients in the intervention group were higher than those in the control group at 3 months and 6 months after operation (P < 0.05). The incidence of kinesiophobia in the intervention group for 3 months and 6 months was significantly lower than that in the control group (P < 0.05). There was no significant difference in bone mineral density between the two groups before and 3 months after intervention (P > 0.05). The bone mineral density of lumbar spine, femoral neck and total hip in the intervention group was significantly higher than that in the control group after 6 months of intervention (P < 0.05).

CONCLUSION

The whole-process care model of the medical association is used for osteoporosis patients, which might reduce the risk of kinesiophobia and improve the bone density of the lumbar spine and total hip in patients. But further promotion and improvement of relevant support systems are needed to achieve comprehensive promotion and maximize clinical benefits in this field.

Narrative Review of Effects of Glucagon-Like Peptide-1 Receptor Agonists on Bone Health in People Living with Obesity

Glucagon-like peptide-1 Receptor agonists (GLP-1Ras) such as liraglutide and semaglutide have been recently approved as medications for chronic weight management in people living with obesity (PwO); GLP-1 may enhance bone metabolism and improve bone quality. However, the effects of GLP-1Ras on skeletal health remain to be determined and that's the purpose of this narrative review. Nevertheless, bone consequences of intentional weight loss interventions in PwO are well known: (i) significant weight loss induced by caloric restriction and bariatric surgery results in accelerated bone turnover and bone loss, and (ii) unlike caloric restriction interventions, PwO experience a substantial deterioration in bone microarchitecture and strength associated with an increased risk of fracture after bariatric surgery especially malabsorptive procedures. Liraglutide seems to have a positive effect on bone material properties despite significant weight loss in several rodent models. However, most of positive effects on bone mineral density and microarchitecture were observed at concentration much higher than approved for obesity care in humans. No data have been reported in preclinical models with semaglutide. The current evidence of the effects of GLP-1Ra on bone health in PwO is limited. Indeed, studies on the use of GLP-1Ra mostly included patients with diabetes who were administered a dose used in this condition, did not have adequate bone parameters as primary endpoints, and had short follow-up periods. Further studies are needed to investigate the bone impact of GLP-1Ra, dual- and triple-receptor agonists for GLP-1, glucose-dependent insulin releasing polypeptide (GIP), and glucagon in PwO.

Obesity and Skeletal Fragility

Skeletal fracture has recently emerged as a complication of obesity. Given the normal or better than normal bone mineral density (BMD), the skeletal fragility of these patients appears to be a problem of bone quality rather than quantity. Type 2 diabetes mellitus (T2DM), the incidence of which increases with increasing body mass index, is also associated with an increased risk for fractures despite a normal or high BMD. With the additional bone pathology from diabetes itself, patients with both obesity and T2DM could have a worse skeletal profile. Clinically, however, there are no available methods for identifying those who are at higher risk for fractures or preventing fractures in this subgroup of patients. Weight loss, which is the cornerstone in the management of obesity (with or without T2DM), is also associated with an increased risk of bone loss. This review of the literature will focus on the skeletal manifestations associated with obesity, its interrelationship with the bone defects associated with T2DM, and the available approach to the bone health of patients suffering from obesity.

Effect of six weeks of resistance training on bone preservation in older adults: a randomized control trial

BACKGROUND

It has been established that chronic resistance exercise contributes to positive changes to bone in older adults.

AIMS

This study evaluated the effect of 6 weeks of resistance exercise with either elastic bands or dumbbells vs. a control period on bone morphology of older adults.

METHODS

Fifty-seven adults (mean ± SD; age = 66.5 ± 7.09 yrs; height = 165.2 ± 10.6 cm; body mass = 74.5 ± 14.6 kg) were randomized into three groups (dumbbell, elastic, or control). Participants underwent a total body dual-energy X-ray absorptiometry (DXA) scan for total body and segmental bone mineral content (BMC) and bone mineral density (BMD) before and following 6-week intervention. Age-matched Z-scores for BMD and BMC were recorded. Data were analyzed using two-way repeated measures ANOVAs and 0.05 significance level.

RESULTS

BMCarm improved for the dumbbell group (p = 0.016) after the training, with no change in BMD for any group (p > 0.05). Additionally, significant (time x treatment group) interaction (p = 0.024) of age-matched Z-scores indicated an improvement in only the dumbbell group after 6 weeks (p = 0.015), with no change in the elastic group despite them having greater Z-scores than the control group.

DISCUSSION

This study is the first to demonstrate acute normative adaptations as dumbbell-based programs may promote positive maintenance of bone metrics over 6 weeks, despite the lack of significant change in absolute BMC or BMD.

CONCLUSION

Adults did not lose relative bone mass with acute exercise using dumbbells as the external load applied and this may lead to positive changes following chronic training. There was no bone-related impact from elastic bands, suggesting a weighted load or force produced relative to gravity is beneficial.

Resistance training decreased abdominal adiposity in postmenopausal women

OBJECTIVE

To investigate if abdominal adipose tissue volumes and ratios change after a 15-week structured resistance training intervention in postmenopausal women with vasomotor symptoms (VMS).

STUDY DESIGN

Sixty-five postmenopausal women with VMS and low physical activity were randomized to either three days/week supervised resistance training or unchanged physical activity for 15 weeks. Women underwent clinical anthropometric measurements and magnetic resonance imaging (MRI) at baseline and after 15 weeks. MRI was done using a Philips Ingenia 3.0 T MR scanner (Philips, Best, The Netherlands). The per protocol principle was used in the analysis of data.

MAIN OUTCOME MEASUREMENTS

The absolute change from baseline to week 15 in visceral adipose tissue (VAT) volume and the relative ratio (VAT ratio) between VAT and total abdominal adipose tissue (TAAT), i.e. the sum of abdominal subcutaneous adipose tissue (ASAT) and VAT.

RESULTS

There were no significant differences between the groups in characteristics, anthropometry or MRI measures at baseline. Women who were compliant with the intervention (i.e. participated in at least two of the three scheduled training sessions per week) had significantly different reduction over time in ASAT (p = 0.006), VAT (p = 0.002), TAAT (p = 0.003) and fat ratio (p < 0.001) compared with women in the control group.

CONCLUSIONS

Implementation of a 15-week resistance training regimen in midlife may help women to counteract the abdominal fat redistribution associated with the menopausal transition.

CLINICAL TRIALS

gov registered ID: NCT01987778.

Targeting Energy Intake and Circadian Biology to Engage Mechanisms of Aging in Older Adults With Obesity: Calorie Restriction and Time-Restricted Eating

With the rise in obesity across age groups, it has been a hindrance to engaging in physical activity and mobility in older adults. Daily calorie restriction (CR) up to 25% has been the cornerstone of obesity management even though the safety in older adults remains incompletely understood. Although some adults can follow CR with clinically significant weight loss and improved health metrics, CR faces 2 obstacles-many fail to adopt CR and even among those who can adopt it short term, long-term compliance can be difficult. Furthermore, there is a continuing debate about the net benefits of CR-induced weight loss in older adults because of the concern that CR may worsen sarcopenia, osteopenia, and frailty. The science of circadian rhythm and its plasticity toward the timing of nutrition offer promise to alleviate some challenges of CR. The new concept of Time-Restricted Feeding/Eating (TRF for animal studies and TRE for human studies) can be an actionable approach to sustaining the circadian regulation of physiology, metabolism, and behavior. TRE can often (not always) lead to CR. Hence, the combined effect of TRE through circadian optimization and CR can potentially reduce weight and improve cardiometabolic and functional health while lessening the detrimental effects of CR. However, the science and efficacy of TRE as a sustainable lifestyle in humans are in its infancy, whereas animal studies have offered many desirable outcomes and underlying mechanisms. In this article, we will discuss the scope and opportunities to combine CR, exercise, and TRE to improve functional capacity among older adults with obesity.

Chronic Stress and Steatosis of Muscles, Bones, Liver, and Pancreas: A Review

BACKGROUND

Chronic stress is a recognized risk factor for poor health, body composition disequilibrium, impaired mental health, and deterioration of quality of life. Chronic stress-related cortisol oversecretion and circadian dysregulation and associated systemic low grade, injurious inflammation ("para-inflammation") contribute to steatosis in various metabolically active solid organs, affecting both their structure and function. The aim of this review was to summarize current knowledge on the impact of chronic stress and associated para-inflammation on skeletal muscle, bone, liver, and pancreas, leading to their steatosis. Current management of these maladaptive conditions is also included and underscored in this review.

SUMMARY

Steatosis of metabolically active solid organs is involved in various metabolic processes and considered a risk factor for chronic noncommunicable diseases, yet its role in chronic stress physiology and pathophysiology has been overlooked.

KEY MESSAGES

Chronic stress-associated steatosis of several solid organs is generally disregarded in current clinical practice. Physicians should be alert for these steatoses and should address them adequately so as to provide appropriate medical care. New guidelines generated by learned societies are needed, along with large observational studies, to offer novel solutions to this old problem.

Reduced muscle strength (dynapenia) in women with obesity confers a greater risk of falls and fractures in the UK Biobank

OBJECTIVE

This study aimed to determine the independent effects of obesity and dynapenia on falls risk, areal bone mineral density, and fracture risk (lower extremity or all other fractures).

METHODS

A total of 16,147 women (aged 60-82 years) from the UK Biobank were categorized by handgrip strength (HGS; dynapenia status: HGS ≤ 21 kg) and body weight (BMI: normal weight, overweight, or obesity). Multiple logistic regression models examined the association among dynapenia and obesity and self-reported falls (previous 12 months), lower extremity fractures, and all other fractures (previous 5 years).

RESULTS

A total of 3793/16,147 women fell, and 1413/15,570 (9.1%) eligible women experienced fall-related fractures. Obesity (odds ratio [OR] 1.25; 95% CI: 1.12-1.38) and dynapenia (OR 0.87; 95% CI: 0.77-0.98) were both independently associated with greater lower extremity fracture risk, independently of areal bone mineral density. However, considering all other fracture sites, obesity conferred protection (OR 0.77; 95% CI: 0.61-0.96), except in those with low HGS, who had an equivalent fracture risk to those with normal weight (OR 1.06; 95% CI: 0.82-1.38).

CONCLUSIONS

Dynapenia further increases the increased risk of leg and ankle fractures in obesity and counteracts the protective effects of obesity on fracture risk at all other sites (wrist, arm, hip, spine, other bones).

Effects of exercise training on inflammatory and cardiometabolic health markers in overweight and obese adults: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

The improvements in inflammation and cardiometabolic health play an important role in the prevention and treatment of obesity. However, the interactions between different exercise training (ET) modalities with inflammatory and cardiometabolic biomarkers are not completely understood. This systematic review and meta-analysis investigated the effects of ET on inflammatory and cardiometabolic health markers in overweight and obese adults.

EVIDENCE ACQUISITION

A systematic search was conducted in PubMed, CINAHL, MEDLINE, Cochrane, Google Scholar, Scopus and Web of Science up to December 15, 2021. Thirty-five studies including 2752 participants were included and analyzed using a random-effects model to estimate weighted mean differences (MD) with 95% confidence intervals (CI).

EVIDENCE SYNTHESIS

The meta-analysis found that ET significantly (P<0.05) increased adiponectin (WMD: 0.72 µg/mL; 95% CI: 0.60 to 0.84; SMD=0.65) and maximal oxygen consumption levels (WMD: 5.26 mL.kg.min; 95% CI: 3.84, 6.69; SMD=1.21). Moreover, ET significantly (P<0.05) reduced fasting insulin (WMD: -2.40 μIU/mL; 95% CI: -3.43 to -1.37; SMD=-0.87), fasting blood glucose (WMD: -5.41 mg/dL; 95% CI: -7.91, -2.91; SMD=-0.66), insulin resistance (WMD: -0.66; 95% CI: -1.08, -0.24; SMD=-0.66) and triglyceride levels (WMD: -10.88 mg/dL; 95% CI: -17.61, -4.15; SMD=-0.91). No significant changes were observed in interleukin-6, tumor necrosis factor-α, leptin, C-reactive protein and cholesterol concentrations. Subgroup analysis by type of training indicated that aerobic and resistance exercise had the most consistent beneficial effects as compared to other modalities.

CONCLUSIONS

Our findings suggest that ET may improve inflammation and cardiometabolic health in overweight and obese adults. Aerobic and resistance training appear to be more beneficial for improving adiponectin, fasting insulin, fasting blood glucose, insulin resistance index and triglyceride levels as compared to other exercise modalities. Further long-term studies are required to confirm and expand on these findings.

Weight strategy in older adults with obesity: calorie restriction or not?

PURPOSE OF REVIEW

Along with the marked increase in the population of older adults with obesity is the need for effective strategies to treat aging- and obesity-related complications. This review highlights recent progress in obesity management in older adults.

RECENT FINDINGS

Although calorie restriction is needed to significantly reduce fat mass, an exercise protocol is crucial to ameliorate functional outcomes. The addition of a resistance exercise protocol improves the response of muscle protein synthesis to anabolic stimuli, preventing the calorie restriction-induced reduction in muscle and bone mass. The addition of an aerobic exercise protocol improves cardiorespiratory fitness and cognitive function. However, the addition of both aerobic and resistance exercise protocols to calorie restriction provides the greatest improvements in myocellular quality, frailty, and cardiometabolic and cognitive outcomes, translating into the greatest improvement in quality of life. Such comprehensive lifestyle intervention effectively improves glucometabolic control and age-relevant outcomes in older adults with diabetes. When combined with testosterone therapy, such lifestyle intervention also preserves muscle and bone mass in older, men with obesity and hypogonadism.

SUMMARY

We conclude that calorie restriction among older adults with obesity should be prescribed in combination with both aerobic and resistance exercise to maximize benefits on overall health.

Association of Knee Extensor Muscle Strength and Cardiorespiratory Fitness With Bone Stiffness in Japanese Adults: A Cross-sectional Study

BACKGROUND

Knee extensor muscle strength and cardiorespiratory fitness (CRF) are major components of physical fitness. Because the interactive association of knee extensor muscle strength and CRF with bone health remains unclear, we aimed to investigate such association in Japanese adults.

METHODS

Altogether, 8,829 Japanese adults (3,731 men and 5,098 women) aged ≥45 years completed the maximum voluntary knee extension test, submaximal exercise test, medical examination, and a questionnaire on lifestyle habits. Using an osteo-sono assessment index, low bone stiffness tendency was defined as 80% under the young-adults mean. Multivariable odds ratios (ORs) and 95% confidence intervals (CIs) were calculated after confounder adjustment.

RESULTS

Overall, 542 men (14.5%) and 978 women (19.2%) had low bone stiffness tendency. We observed an inverse association between muscle strength and low bone stiffness tendency after adjustment for CRF in both sexes (P for linear trend <0.001). Compared with the lowest CRF, the multivariable ORs for low bone stiffness tendency in the highest CRF were 0.47 (95% CI, 0.36-0.62) for men and 1.05 (95% CI, 0.82-1.35) for post-menopausal women (P < 0.001 and P = 0.704, respectively). No interactive association between muscle strength and CRF for low bone stiffness tendency existed in both sexes and irrespective of menopausal status.

CONCLUSION

Knee extensor muscle strength and CRF were associated additively, not synergistically, with bone health. Maintaining high levels of both physical fitness components may improve musculoskeletal health in the cohort. The relationship between physical fitness and bone status should be longitudinally investigated in the future.

Osteosarcopenia in Patients with Chronic Obstructive Pulmonary Diseases: Which Pathophysiologic Implications for Rehabilitation?

Chronic obstructive pulmonary disease (COPD) is a burdensome condition affecting a growing number of people worldwide, frequently related to major comorbidities and functional impairment. In these patients, several factors might have a role in promoting both bone and muscle loss, including systemic inflammation, corticosteroid therapies, sedentary behaviours, deconditioning, malnutrition, smoking habits, and alcohol consumption. On the other hand, bone and muscle tissues share several linkages from functional, embryological, and biochemical points of view. Osteosarcopenia has been recently defined by the coexistence of osteoporosis and sarcopenia, but the precise mechanisms underpinning osteosarcopenia in patients with COPD are still unknown. In this scenario, a deeper understanding of the molecular basis of osteosarcopenia might guide clinicians in a personalized approach integrating skeletal muscle health with the pulmonary rehabilitation framework in COPD. Taken together, our results summarized the currently available evidence about the multilevel interactions between osteosarcopenia and COPD to pave the way for a comprehensive approach targeting the most common risk factors of these pathological conditions. Further studies are needed to clarify the role of modern clinical strategies and telemedicine solutions to optimize healthcare delivery in patients with COPD, including osteopenia, osteoporosis, and sarcopenia screening in these subjects.

Weight Loss Interventions and Skeletal Health in Persons with Diabetes

PURPOSE OF REVIEW

Weight loss is recommended for improving glycemic control and reducing cardiovascular risk factors in persons with diabetes. However, both diabetes and weight loss have been associated with detrimental skeletal health. This review aims to summarize recent study findings on the effects of lifestyle interventions for weight loss on skeletal health among persons with type 2 diabetes (T2D).

RECENT FINDINGS

A few large-scale observational studies have demonstrated an increased fragility fracture risk associated with weight loss among persons with T2D. Randomized control trials in persons with T2D also have shown that intentional lifestyle interventions for weight loss are associated with a greater decrease in bone mineral density (BMD) and an increase in the risk of fracture. The biological mechanisms underlying the compromised bone health during lifestyle interventions for weight loss are complex and not yet conclusive. However, there is evidence to suggest that bone loss and increased fracture risk during intentional weight loss may be mitigated by some intervention approaches, such as high protein intake, calcium supplementation, and resistance and balance training. There is still a lack of studies investigating the effects of different interventions for weight loss on skeletal health among persons with T2D. However, certain types of diet and physical activity intervention combined with bone monitoring and fracture risk prediction may help achieve weight loss goals and maintain skeletal health among persons with T2D during intentional weight loss.

Effects of Tai Chi and brisk walking on the bone mineral density of perimenopausal women: A randomized controlled trial

Background

There is a lack of information on whether the positive effect of Tai Chi (TC) and brisk walking (BW) exercise on bone mineral density (BMD) in perimenopausal women remains after exercise cessation. To compare the effects of regular TC and BW exercise on BMD in perimenopausal women and to analyze the maintenance effects after exercise cessation.

Methods

The TC and BW groups performed 48 weeks of exercise. The BMD of the lumbar spine and dominant-side proximal femur was measured in all subjects at weeks 0, 48, 52, and 56.

Results

Compared with baseline, the BMD of the lumbar spine (L_2-4) at week 48 increased by 5.05% (P = 0.031) in the TC group, and the BMD of the femoral neck at week 48 increased by 8.23% (P = 0.031) in the BW group. At 4 and 8 weeks after exercise cessation, the BMD of L_2-4 in the TC group was still increased by 5.05% (P = 0.041) and 5.05% (P = 0.023), respectively, and the BMD of the femoral neck was still increased by 8.23% (P = 0.018) and 9.41% (P = 0.007), respectively, in the BW group.

Conclusion

Forty-eight weeks of TC exercise significantly increases the BMD of L_2-4 in perimenopausal women, and BW exercise significantly increases the BMD of the femoral neck; these effects are maintained at 4 and 8 weeks after exercise cessation. These results suggest that these two exercises reduce the BMD decrease caused by aging.

Age- and sex-specific effects of a long-term lifestyle intervention on body weight and cardiometabolic health markers in adults with prediabetes: results from the diabetes prevention study PREVIEW

AIMS/HYPOTHESIS

Lifestyle interventions are the first-line treatment option for body weight and cardiometabolic health management. However, whether age groups or women and men respond differently to lifestyle interventions is under debate. We aimed to examine age- and sex-specific effects of a low-energy diet (LED) followed by a long-term lifestyle intervention on body weight, body composition and cardiometabolic health markers in adults with prediabetes (i.e. impaired fasting glucose and/or impaired glucose tolerance).

METHODS

This observational study used longitudinal data from 2223 overweight participants with prediabetes in the multicentre diabetes prevention study PREVIEW. The participants underwent a LED-induced rapid weight loss (WL) period followed by a 3 year lifestyle-based weight maintenance (WM) intervention. Changes in outcomes of interest in prespecified age (younger: 25-45 years; middle-aged: 46-54 years; older: 55-70 years) or sex (women and men) groups were compared.

RESULTS

In total, 783 younger, 319 middle-aged and 1121 older adults and 1503 women and 720 men were included in the analysis. In the available case and complete case analyses, multivariable-adjusted linear mixed models showed that younger and older adults had similar weight loss after the LED, whereas older adults had greater sustained weight loss after the WM intervention (adjusted difference for older vs younger adults -1.25% [95% CI -1.92, -0.58], p<0.001). After the WM intervention, older adults lost more fat-free mass and bone mass and had smaller improvements in 2 h plasma glucose (adjusted difference for older vs younger adults 0.65 mmol/l [95% CI 0.50, 0.80], p<0.001) and systolic blood pressure (adjusted difference for older vs younger adults 2.57 mmHg [95% CI 1.37, 3.77], p<0.001) than younger adults. Older adults had smaller decreases in fasting and 2 h glucose, HbA1c and systolic blood pressure after the WM intervention than middle-aged adults. In the complete case analysis, the above-mentioned differences between middle-aged and older adults disappeared, but the direction of the effect size did not change. After the WL period, compared with men, women had less weight loss (adjusted difference for women vs men 1.78% [95% CI 1.12, 2.43], p<0.001) with greater fat-free mass and bone mass loss and smaller improvements in HbA1c, LDL-cholesterol and diastolic blood pressure. After the WM intervention, women had greater fat-free mass and bone mass loss and smaller improvements in HbA1c and LDL-cholesterol, while they had greater improvements in fasting glucose, triacylglycerol (adjusted difference for women vs men -0.08 mmol/l [-0.11, -0.04], p<0.001) and HDL-cholesterol.

CONCLUSIONS/INTERPRETATION

Older adults benefited less from a lifestyle intervention in relation to body composition and cardiometabolic health markers than younger adults, despite greater sustained weight loss. Women benefited less from a LED followed by a lifestyle intervention in relation to body weight and body composition than men. Future interventions targeting older adults or women should take prevention of fat-free mass and bone mass loss into consideration.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrials.gov NCT01777893.

Older Women who are Overweight or Obese Have Vertebral Abnormalities, Partially Degraded TBS, and BMD that Worsen with Weight Loss

Obesity is a risk factor for chronic diseases and moderate weight loss is generally recommended. Energy restriction results in the loss of hip bone mineral density (BMD) in older adults, but there is no consistent decline at the lumbar spine (LS), possibly due to vertebral abnormalities although this may also be dependent on the amount of weight loss. In this secondary analysis of weight loss trials investigating BMD and trabecular bone score (TBS) changes over 12-18 months, 92 postmenopausal women (60.8 ± 5.8 years; body mass index 32.7 ± 4.4 kg/m²) without osteoporosis, were divided into two groups: those who lost < 5% body weight (minimal) or ≥ 5% (moderate). Hip and LS-BMD and TBS were measured at baseline, 6 and 12-18 months. Exclusion of vertebral abnormalities (VE) was used to calculate BMD at the spine (LS-BMD-VE) using standard guidelines. Women lost 2.3 ± 2.4% and 8.5 ± 4.7% weight in the minimal and moderate weight loss groups, respectively. Over one third of the women had at least one vertebral abnormality or partially degraded TBS at baseline that worsened after weight loss, increasing to over 50% in this population (p < 0.05). TBS and hip BMD decreased with weight loss (p < 0.05), but LS-BMD did not decrease significantly. However, after excluding vertebral abnormalities, the LS-BMD-VE decreased in the entire population (p < 0.01), and by 1.7 ± 4.3% in the moderate weight loss group. This study suggests that older women without osteoporosis have vertebral abnormalities that obfuscated declines in BMD with weight loss, indicating that bone at the spine is further compromised.

Effects of physical exercise on bone mineral density in older postmenopausal women: a systematic review and meta-analysis of randomized controlled trials

Osteoporosis or decreased bone mineral density (BMD) is the most important risk factor for fractures, especially in older postmenopausal women (PMW). However, the interactions between exercise training and bone mineral density are not completely understood. We evaluated the effects of physical exercise on BMD in women aged ≥ 60 years postmenopausal.

PURPOSE

This systematic review and meta-analysis sets out to determine the effects of physical exercise on BMD in older postmenopausal women.

METHODS

A systematic search was conducted in Medline, Science Direct, Cochrane, PubMed, CINAHL, Google Scholar, Scopus, and ProQuest up to December 25, 2021. Fifty-three studies, which assessed a total of 2896 participants (mean age: between 60 and 82 years), were included and analyzed using a random-effects model to estimate weighted mean differences (WMD) with 95% confidence intervals (CI).

RESULTS

The meta-analysis found that exercise training significantly (p < 0.05) increased femoral neck (WMD: 0.01 g/cm²; 95% CI, 0.00 to 0.01], p = 0.0005; I² = 57%; p < 0.0001), lumbar spine (WMD: 0.01 g/cm², 95% CI, 0.01 to 0.02], I² = 81%; p = 0.0001), and trochanter (WMD: 0.01 g/cm², 95% CI 0.00, 0.02]; p = 0.009; I² = 17%; p = 0.23). There were no significant differences between the intervention and control groups for total body and total hip BMD.

CONCLUSION

Our findings suggest that exercise training may improve bone mineral density in older PMW. This improvement is mediated by increases in the femoral neck, lumbar spine, and trochanter BMD. Further long-term studies are required to confirm these findings.

Geriatric Vulnerabilities Among Obese Older Adults With and Without Sarcopenia: Findings From a Nationally Representative Cohort Study

BACKGROUND AND PURPOSE

Sarcopenic obesity is associated with loss of independence among older adults, but the epidemiology of sarcopenic obesity and associated geriatric vulnerabilities are poorly understood. Thus, our objectives were to: (1) estimate the prevalence of older adults with sarcopenic obesity and (2) examine rates of geriatric vulnerabilities among obese older adults, with and without sarcopenia.

METHODS

A nationally representative sample of 1600 community-dwelling older adults 65 years and older with obesity and documented measures of muscle function from the National Health and Aging Trends Study (NHATS) was identified as sarcopenic using sex-adjusted grip strength and Short Physical Performance Battery scores. Differences in the prevalence of geriatric vulnerabilities (including pain, depression, disability, and social isolation) were compared between obese older adults with and without sarcopenia.

RESULTS AND DISCUSSION

Among obese older adults, 18% (n = 318/1600) were sarcopenic. After adjusting for age and sex, sarcopenic obese older adults had 3.7 times the odds of having 2 or more comorbid conditions (odds ratio [OR] = 3.7; 95% CI 2.2-5.0) and 6.4 times the odds of being frail (OR = 6.4; 95% CI 4.4-9.5) as compared with nonsarcopenic obese older adults. Sarcopenic obese older adults were also more likely to have 1 or more activities of daily living disabilities (OR = 3.7; 95% CI 2.5-5.4), be socially isolated (OR = 2.1; 95% CI 1.3-3.2), and report activity-limiting pain (OR = 2.0; 95% CI 1.5-2.7) as compared with nonsarcopenic obese older adults. These findings, in a nationally representative cohort, suggest obese older adults who are sarcopenic have higher rates of geriatric vulnerabilities that could impact delivery and outcomes of exercise and nutrition interventions.

CONCLUSIONS

Concomitant obesity and sarcopenia are associated with higher rates of geriatric vulnerabilities among a nationally representative sample of older adults. More comprehensive interventions, beyond exercise and diet modifications, may be necessary to additionally address these newly identified social and physiological risks.

Effects of Endurance Cycling on Mechanomyographic Median Power Frequency of the Vastus Lateralis

This study examined the effects of cycling training on mechanomyographic median power frequency (MMGMDF)–torque relationships of the vastus lateralis (VL). Ten males (Age ± SD; 20.20 ± 1.87 years) and 14 females (21.93 ± 5.33 years) performed isometric trapezoidal muscle actions with the knee extensors at 40% maximal voluntary contraction (MVC) before (PRE) and following 10 weeks of cycling training at the same absolute submaximal torque as pre-training (POSTABS). MMGMDF–torque relationships (increasing and decreasing segment) were log-transformed and b terms (slopes) were calculated. MMGMDF was averaged during steady torque. For POSTABS, the b terms for the females (0.133 ± 0.190) were greater than for the males (−0.083 ± 0.200; p = 0.013) and compared to PRE (0.008 ± 0.161; p = 0.036). At PRE, the b terms for the linearly increasing-muscle action (0.123 ± 0.192) were greater compared to the linearly decreasing-muscle action (−0.061 ± 0.188; p < 0.001), whereas no differences existed between muscle actions for POSTABS (p > 0.05). In conclusion, 10 weeks of cycling training resulted in different motor unit (MU) control strategies between sexes and altered MU control strategies between muscle actions for the VL during a moderate-intensity contraction.

The relationship between central obesity and bone mineral density: a Mendelian randomization study

BACKGROUND

The relationship between obesity and osteoporosis is an important public health issue. The goal of this study was to investigate whether and to what extent central obesity traits affect bone mineral density (BMD).

METHODS

We conducted a two-sample Mendelian randomization analysis. Genomewide significant single nucleotide polymorphisms associated with waist circumference, hip circumference, waist-to-hip ratio, waist circumference adjusted by body mass index (WCadjBMI), hip circumference adjusted by BMI (HCadjBMI) and waist-to-hip ratio adjusted by BMI (WHRadjBMI) were obtained from a large-scale database containing 224,459 samples. The BMD summary dataset was obtained from a UK Biobank database including 265,627 participants.

RESULTS

The results provided strong evidence that the HCadjBMI trait was causally and negatively associated with BMD (β: - 0.135, 95% CI - 0.216 to - 0.054; P = 0.001), while the WHR trait was causally and positively associated with BMD (β: 0.194, 95% CI 0.062 to 0.325, P = 0.004). No significant effects were observed for other traits on BMD.

CONCLUSIONS

This study indicates variations in the abilities of different central obesity traits to influence BMD. These results should be considered in further studies and public health measures on obesity and osteoporosis prevention strategies.

Acute effects of the resistance exercise associated with different blood flow restriction pressures on bone remodeling biomarkers

Background

The present study analyzed the acute responses of parathyroid hormone (PTH) and bone-specific alkaline phosphatase (BSAP) to the low-intensity resistance exercise with blood flow restriction using different occlusion pressures.

Methods

Twelve women completed the three protocols of this crossover study: resistance exercise without blood flow restriction (RE), resistance exercise with blood flow restriction and occlusion pressure corresponding to 70% of systolic blood pressure (RE + BFR70), and resistance exercise with blood flow restriction and occlusion pressure corresponding 130% of systolic blood pressure (RE + BFR130). All exercises were performed in a guided squat apparatus with load corresponded to 30% of one-repetition maximum test.

Results

Relative to resting levels, PTH concentrations decreased significantly (p = .000) post-exercise in all groups and increased significantly (p = .000) 15 min post-exercise in RE + BFR70 and RE + BFR130 groups; PTH concentrations returned to resting levels after the 30-min recovery period in all groups. There was no significant difference (p >.05) between BSAP values at rest and 30 min post-exercise.

Conclusion

In conclusion, our results showed that protocols with blood flow restriction using occlusion pressures equivalent to 70% and 130% of systolic blood pressure were more effective than RE alone to induce PTH peaks, and to promote a metabolic condition favorable to bone anabolism.

Bone fragility in diabetes: novel concepts and clinical implications

Increased fracture risk represents an emerging and severe complication of diabetes. The resulting prolonged immobility and hospitalisations can lead to substantial morbidity and mortality. In type 1 diabetes, bone mass and bone strength are reduced, resulting in up to a five-times greater risk of fractures throughout life. In type 2 diabetes, fracture risk is increased despite a normal bone mass. Conventional dual-energy x-ray absorptiometry might underestimate fracture risk, but can be improved by applying specific adjustments. Bone fragility in diabetes can result from cellular abnormalities, matrix interactions, immune and vascular changes, and musculoskeletal maladaptation to chronic hyperglycaemia. This Review summarises how the bone microenvironment responds to type 1 and type 2 diabetes, and the mechanisms underlying fragility fractures. We describe the value of novel imaging technologies and the clinical utility of biomarkers, and discuss current and future therapeutic approaches that protect bone health in people with diabetes.

Investigation of the Relationship between the Mid_Thigh Adipose Tissue Distribution Measured by MRI and Serum Osteocalcin—A Sex-Based Approach

Osteocalcin, in its non-carboxylated form, has a positive effect on glucose metabolism. Additionally, osteocalcin levels are related to body composition, especially muscle mass. The relation to the distribution of different adipose tissue types, such as subcutaneous, intermuscular, and visceral adipose tissue, is unclear. This study aimed to investigate associations between serum osteocalcin and the distribution of subcutaneous and intermuscular adipose tissue of the mid-thigh. Furthermore, the influence of different training methods on osteocalcin levels was investigated. We performed adipose tissue quantification of subcutaneous adipose tissue (SAT) and intramuscular adipose tissue (IMAT) using MRI measurements of the mid-thigh in 128 volunteers (63 male/65 female). Laboratory analysis included blood lipid panel, serum insulin, adiponectin, and osteocalcin measurements. The main observation was a significant correlation of total serum osteocalcin (TOC) and the distribution of adipose tissue of the mid-thigh (SAT/(SAT + IMAT)) (cc = −0.29/p-value = 0.002), as well as the cross-sectional muscle area (MA), increasing with the weekly resistance training duration in males. Additionally, TOC (p-value = 0.01) and MA (p-value = 0.03) were negatively related to serum insulin. The significant relationship between TOC and SAT/(SAT + IMAT) is a new finding and confirms the negative influence of IMAT on glucose metabolism in a sex-specific approach. We could substantiate this by the negative relation of TOC with serum insulin.

DXA parameters, Trabecular Bone Score (TBS) and Bone Mineral Density (BMD), in fracture risk prediction in endocrine-mediated secondary osteoporosis

Osteoporosis, a disease characterized by low bone mass and alterations of bone microarchitecture, leading to an increased risk for fragility fractures and, eventually, to fracture; is associated with an excess of mortality, a decrease in quality of life, and co-morbidities. Bone mineral density (BMD), measured by dual X-ray absorptiometry (DXA), has been the gold standard for the diagnosis of osteoporosis. Trabecular bone score (TBS), a textural analysis of the lumbar spine DXA images, is an index of bone microarchitecture. TBS has been robustly shown to predict fractures independently of BMD. In this review, while reporting also results on BMD, we mainly focus on the TBS role in the assessment of bone health in endocrine disorders known to be reflected in bone.

Aging, obesity, sarcopenia and the effect of diet and exercise intervention

The number of adults 65 years and older is increasing worldwide and will represent the 20% of the population by 2030. Half of them will suffer from obesity. The decline in muscle mass and strength, known as sarcopenia, is very common among older adults with obesity (sarcopenic obesity). Sarcopenic obesity is strongly associated with frailty, cardiometabolic dysfunction, physical disability, and mortality. Increasing efforts have been hence made to identify effective strategies able to promote healthy aging and curb the obesity pandemic. Among these, lifestyle interventions consisting of diet and exercise protocols have been extensively explored. Importantly, diet-induced weight loss is associated with fat, muscle, and bone mass losses, and may further exacerbate age-related sarcopenia and frailty outcomes in older adults. Successful approaches to induce fat mass loss while preserving lean and bone mass are critical to reduce the aging- and obesity-related physical and metabolic complications and at the same time ameliorate frailty. In this review article, we discuss the most recent evidence on the age-related alterations in adipose tissue and muscle health and on the effect of calorie restriction and exercise approaches for older adults with obesity and sarcopenia, emphasizing the existing gaps in the literature that need further investigation.

Exercise vs Conventional Treatment for Treatment of Primary Osteoporosis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

Physical exercise has obvious effects on bone loss, pain relief, and improvement of bone metabolism indexes in patients with osteoporosis, but currently lacks sufficient evidence. The aim of this systematic review and meta‐analysis was to synthesize and present the best available evidence on the effectiveness and safety of exercises in the treatment of primary osteoporosis.

Methods

Publications pertaining to the effectiveness of exercise on bone mineral density (BMD), visual analog scores (VAS), and biochemical markers of bone metabolism in primary osteoporosis (POP) from PubMed, Cochrane Library, Embase, VIP, CNKI, and Wanfang Database were retrieved from their inception to April 2020.

Results

A total of 20 studies with 1824 participants were included. The results of the meta‐analysis revealed that exercise therapy for lumbar spine and femoral neck BMD is statistically different from conventional therapy (lumbar spine BMD: SMD = 0.78, 95%CI: 0.46, 1.10, P < 0.00001, I² = 85%; femoral neck BMD (SMD = 0.80, 95%CI: 0.34, 1.27, P = 0.0007, I² = 88%), exercise therapy can significantly increase the lumbar spine BMD of patients with OP, especially in lumbar spine2‐4 BMD (SMD = 0.47; 95%CI: 0.20, 0.75; P = 0.0008; I² = 69%). Compared with conventional treatment, kinesitherapy also has significant differences in alleviating the pain of POP patients (SMD = −1.39, 95%CI: −2.47,−0.31, P = 0.01, I² = 97%). Compared with conventional therapy, kinesitherapy has no significant difference in improving biochemical markers of bone metabolism such as bone glaprotein (BGP) (SMD = 2.59, 95%CI:0.90, 4.28, P = 0.003, I² = 98%), N‐terminal pro peptide of type I procollagen (PINP) (SMD = 0.77, 95%CI: −0.44 to 1.98, P = 0.21, I² = 95%), serum phosphorus (SMD = 0.04, 95%CI: −0.13, 0.22, P = 0.61, I² = 30%), alkaline phosphatase (ALP) (SMD = −0.08, 95%CI: −0.44, 0.27, P = 0.64, I² = 76%), and serum calcium (SMD = 0.12, 95%CI: −0.18, 0.43, P = 0.42, I² = 63%) in POP patients.

Conclusions

Kinesitherapy significantly improved lumbar spine and femoral neck BMD, and relieve the pain of patients in the current low‐quality evidence. Additional high‐quality evidence is required to confirm the effect of exercise therapy on the biochemical markers of bone metabolism in POP patients.

The effects of biophysical stimulation on osteogenic differentiation and the mechanisms from ncRNAs

Ample proof showed that non-coding RNAs (ncRNAs) play a crucial role in proliferation and differentiation of osteoblasts and bone marrow stromal cells (BMSCs). Varied forms of biophysical stimuli like mechanical strain, fluid shear stress (FSS), microgravity and vibration are verified to regulate ncRNAs expression in osteogenic differentiation and influence the expression of target genes associated with osteogenic differentiation and ultimately regulate bone formation. The consequences of biophysical stimulation on osteogenic differentiation validate the prospect of exercise for the prevention and treatment of osteoporosis. In this review, we tend to summarize the studies on regulation of osteogenic differentiation by ncRNAs beneath biophysical stimulation and facilitate to reveal the regulatory mechanism of biophysical stimulation on ncRNAs, and provide an update for the prevention of bone metabolism diseases by exercise.

The Ability of Exercise to Mitigate Caloric Restriction-Induced Bone Loss in Older Adults: A Structured Review of RCTs and Narrative Review of Exercise-Induced Changes in Bone Biomarkers

Despite the adverse metabolic and functional consequences of obesity, caloric restriction- (CR) induced weight loss is often contra-indicated in older adults with obesity due to the accompanying loss of areal bone mineral density (aBMD) and subsequent increased risk of fracture. Several studies show a positive effect of exercise on aBMD among weight-stable older adults; however, data on the ability of exercise to mitigate bone loss secondary to CR are surprisingly equivocal. The purpose of this review is to provide a focused update of the randomized controlled trial literature assessing the efficacy of exercise as a countermeasure to CR-induced bone loss among older adults. Secondarily, we present data demonstrating the occurrence of exercise-induced changes in bone biomarkers, offering insight into why exercise is not more effective than observed in mitigating CR-induced bone loss.

Testosterone Replacement Therapy Added to Intensive Lifestyle Intervention in Older Men With Obesity and Hypogonadism

BACKGROUND

Obesity and hypogonadism additively contribute to frailty in older men; however, appropriate treatment remains controversial.

OBJECTIVE

Determine whether testosterone replacement augments the effect of lifestyle therapy on physical function in older men with obesity and hypogonadism.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

VA Medical Center.

PARTICIPANTS

83 older (age ≥65 years) men with obesity (body mass index ≥30 kg/m2) and persistently low am testosterone (<10.4 nmol/L) associated with frailty.

INTERVENTIONS

Participants were randomized to lifestyle therapy (weight management and exercise training) plus either testosterone (LT+Test) or placebo (LT+Pbo) for 6 months.

OUTCOME MEASURES

Primary outcome was change in Physical Performance Test (PPT) score. Secondary outcomes included other frailty measures, body composition, hip bone mineral density (BMD), physical functions, hematocrit, prostate specific antigen (PSA), and sex hormones.

RESULTS

PPT score increased similarly in LT+Test and LT+Pbo group (17% vs. 16%; P = 0.58). VO2peak increased more in LT+Test than LT+Pbo (23% vs. 16%; P = 0.03). Despite similar -9% weight loss, lean body mass and thigh muscle volume decreased less in LT+Test than LT+Pbo (-2% vs. -3%; P = 0.01 and -2% vs -4%; P = 0.04). Hip BMD was preserved in LT+Test compared with LT+Pbo (0.5% vs -1.1%; P = 0.003). Strength increased similarly in LT+Test and LT+Pbo (23% vs 22%; P = 0.94). Hematocrit but not PSA increased more in LT+Test than LT+Pbo (5% vs 1%; P < 0.001). Testosterone levels increased more in LT+Test than LT+Pbo (167% vs 27%; P < 0.001).

CONCLUSION

In older, obese hypogonadal men, adding testosterone for 6 months to lifestyle therapy does not further improve overall physical function. However, our findings suggest that testosterone may attenuate the weight loss-induced reduction in muscle mass and hip BMD and may further improve aerobic capacity.

The effect of exercise training on osteocalcin, adipocytokines, and insulin resistance: a systematic review and meta-analysis of randomized controlled trials

Recently, it has been reported that osteocalcin (OC), in particular its undercarboxylated (ucOC) form, is not only a bone remodeling marker but also an active hormone that intercedes glucose metabolism in humans. This study aimed to determine the impact of an exercise intervention on ucOC, adiponectin, leptin, and insulin resistance (measured by HOMA-IR). PubMed, CINAHL, Medline, Google Scholar, and Scopus databases and reference lists of included studies were searched. Twenty-two randomized controlled trials (RCTs) of exercise training impact in adults were included in the analysis. Results showed an overall significant increase in serum ucOC (MD: 0.15 ng/ml; 95% CI: 0.05 to 0.25) and adiponectin (MD: 2.83 mg/ml; 95% CI: 1.67 to 3.98), a significant decline in leptin (MD: - 4.89 pg/ml; 95% CI: - 6.94 to - 2.84), fasting glucose (MD: - 2.29 mg/dl; 95% CI: - 4.04 to - 0.54), fasting insulin (MD, - 8.90 μIU/ml; 95% CI: - 13.81 to - 3.98), and HOMA-IR (MD: - 1.96; 95% CI: - 3.11 to - 0.80). However, after removal of studies that had prescribed a balanced diet along with exercise intervention, total OC (TOC) levels also increased in the exercise group compared with the control group (MD: 0.36 ng/ml; 95% CI: 0.07 to 0.65). Our findings demonstrate that exercise-induced increases in ucOC are the probable cause of increased adiponectin. Additionally, increases in ucOC itself are probably due to changes in leptin levels and other factors, rather than its direct impact on bone and its osteoblastic activity. Further studies are required to clarify the mechanisms underlying the impact of exercise training on ucOC, adipocytokines, and insulin resistance.

Evidence on physical activity and osteoporosis prevention for people aged 65+ years: a systematic review to inform the WHO guidelines on physical activity and sedentary behaviour

BACKGROUND

Various physical activity interventions for prevention and treatment of osteoporosis have been designed and evaluated, but the effect of such interventions on the prevention of osteoporosis in older people is unclear. The aim of this review was to investigate the association between physical activity and osteoporosis prevention in people aged 65 years and above.

METHODS

A systematic review was conducted and searches for individual studies were conducted in PubMed (January 2010 to March 2020) and for systematic reviews were conducted in PubMed, Embase, CINAHL and SPORTDiscus (January 2008 to July 2020). Records were screened according to the following eligibility criteria: i) population: adults aged 65 years and older; ii) exposure: greater volume, duration, frequency, or intensity of physical activity; iii) comparison: no physical activity or lesser volume, duration, frequency, or intensity of physical activity; iv) outcome: osteoporosis related measures (e.g., bone mineral density). The methodological quality of included studies was assessed and meta-analysis summarised study effects. The GRADE approach was used to rate certainty of evidence.

RESULTS

We included a total of 59 studies, including 12 observational studies and 47 trials. Within the included trials, 40 compared physical activity with no intervention controls, 11 compared two physical activity programs, and six investigated different doses of physical activity. Included studies suggest that physical activity interventions probably improve bone health among older adults and thus prevent osteoporosis (standardised effect size 0.15, 95% CI 0.05 to 0.25, 20 trials, moderate-certainty evidence, main or most relevant outcome selected for each of the included studies). Physical activity interventions probably improve lumbar spine bone mineral density (standardised effect size 0.17, 95% CI 0.04 to 0.30, 11 trials, moderate-certainty evidence) and may improve hip (femoral neck) bone mineral density (standardised effect size 0.09, 95% CI - 0.03 to 0.21, 14 trials, low-certainty evidence). Higher doses of physical activity and programs involving multiple exercise types or resistance exercise appear to be most effective. Typical programs for which significant intervention impacts were detected in trials were undertaken for 60+ mins, 2-3 times/week for 7+ months. Observational studies suggested a positive association between long-term total and planned physical activity on bone health.

CONCLUSIONS

Physical activity probably plays a role in the prevention of osteoporosis. The level of evidence is higher for effects of physical activity on lumbar spine bone mineral density than for hip. Higher dose programs and those involving multiple exercises and resistance exercises appear to be more effective.

Nutritional Therapy for Athletes with Diabetes

Diabetes is a worldwide disease also affecting the sports field. The two main forms of diabetes, namely type 1 diabetes (T1D) and type 2 diabetes (T2D), differ in both their pathological and pharmacological characteristics and thus require a distinct nutritional treatment. Diet plays an important role in the management of athletes with diabetes and is crucial to achieving their best performance. This review aims to investigate the objectives of nutritional therapy before, during and after training, in order to improve the best composition of macronutrients during meals. In this review, we provide a brief overview of recent studies about nutritional approaches to people with diabetes for performance optimization and for the control of diabetes-related complications. Thereafter, we discuss the differences between macronutrients and dietary intake before, during and after training. It can be concluded that each sport has particular characteristics in terms of endurance and power, hence demanding a specific energy expenditure and consequent nutritional adjustments. Therefore, the management of athletes with diabetes must be personalized and supported by medical professionals, including a diabetologist, physiologist and a nutritionist.

MANAGEMENT OF ENDOCRINE DISEASE: Bone complications of bariatric surgery: updates on sleeve gastrectomy, fractures, and interventions

Despite well recognized improvements in obesity-related comorbidities, increasing evidence implicates bariatric surgery in the onset of adverse skeletal health outcomes. The purpose of this review is to provide a focused update in three critical areas: (i) emergent data on sleeve gastrectomy and bone loss, (ii) evidence linking bariatric surgery to incident fracture, and (iii) intervention strategies designed to mitigate surgical bone loss. Better understanding of these issues will inform our treatment of skeletal health for patients planning bariatric surgery.

The Effect of Kinesitherapy on Bone Mineral Density in Primary Osteoporosis: A Systematic Review and Meta-Analysis of Randomized Controlled Trial

Objective

Osteoporosis (OP) is a well-established age-related disease, pathologically characterized by bone microarchitectural deterioration, increased fragility, and low BMD. Primary osteoporosis (POP) is the most common type of OP.

Methods

Publications pertaining to the effectiveness of kinesitherapy on BMD in POP from PubMed, SCI, Cochrane Library, Embase, VIP, CNKI, and Wanfang Database were retrieved from their inception to October 2019.

Results

A total of 21 studies with 1840 participants were included. The results of the meta-analysis revealed that kinesitherapy plus antiosteoporosis medications had a positive effect on lumbar spine BMD when the duration of intervention was 6 months (MD = 0.11 g/cm²; 95% CI: 0.06–0.15; P < 0.0001) or >6 months (MD = 0.04 g/cm²; 95% CI: 0.02–0.06; P < 0.0001) compared with antiosteoporosis medications alone. Additional kinesitherapy plus antiosteoporosis medications were associated with improved femoral neck BMD compared with antiosteoporosis medications alone (MD = 0.09 g/cm²; 95% CI: 0.03–0.16; P=0.004).

Conclusions

Kinesitherapy plus antiosteoporosis medications significantly improved lumbar spine and femoral neck BMD in the current low-quality evidence. Additional high-quality evidence is required to confirm the effect of kinesitherapy on BMD in patients with POP.

Effects of Impact Versus Non-impact Cardiovascular Machines in Individuals between Age 50 and 80 Years

Older adults are at increased risk of injury when initiating exercise due to inactivity, functional limitation, illness, or fall risk. We studied a novel non-impact cardio unit in an effort to determine whether there were differences in physiologic, functional, and strength benefits compared to a treadmill (TM), while producing less stress on the knee and lessening the risk of fall and injury. Utilizing a prospective, randomized, non-blinded, cohort design, individuals aged 50–80 years were recruited and enrolled in a 16-week exercise program. Subjects were randomly allocated to either exercise on the Cybex arc trainer or on a TM. Participants exercised for 120 min per week. Resistance was adjusted to achieve a target RPE in each group. Functional, strength, and physiologic markers were analyzed through balance testing, ten – repetition max leg press, body composition analysis, and lipid panel results. Overall health-related quality of life was also measured. There was a significant improvement in triglyceride and very low density lipoprotein levels from baseline to exit within the arc trainer group. An equal and significant increase in strength capacity was observed in both the arc trainer and TM groups, as were feelings of increased energy, improved emotional well-being, and decreased fatigue. Leg strength increased, percentage of body fat decreased, and balance improved following use of either an arc trainer or a TM in a study population of 58 participants over a 16-week period. This study demonstrated that positive change occurs, physiologically and psychologically when an arc trainer or TM is utilized. Given the similar benefits seen in this study, use of a non-impact modality such as the arc trainer may be a better alternative in the older population.

Caloric restriction induces anabolic resistance to resistance exercise

Purpose

Weight loss can result in the loss of muscle mass and bone mineral density. Resistance exercise is commonly prescribed to attenuate these effects. However, the anabolic endocrine response to resistance exercise during caloric restriction has not been characterized.

Methods

Participants underwent 3-day conditions of caloric restriction (15 kcal kg FFM⁻¹) with post-exercise carbohydrate (CRC) and with post-exercise protein (CRP), and an energy balance control (40 kcal kg FFM⁻¹) with post-exercise carbohydrate (CON). Serial blood draws were taken following five sets of five repetitions of the barbell back squat exercise on day 3 of each condition.

Results

In CRC and CRP, respectively, growth hormone peaked at 2.6 ± 0.4 and 2.5 ± 0.9 times the peak concentrations observed during CON. Despite this, insulin-like growth factor-1 concentrations declined 18.3 ± 3.4% in CRC and 27.2 ± 3.8% in CRP, which was greater than the 7.6 ± 3.6% decline in CON, over the subsequent 24 h. Sclerostin increased over the first 2 days of each intervention by 19.2 ± 5.6% in CRC, 21.8 ± 6.2% in CRP and 13.4 ± 5.9% in CON, but following the resistance exercise bout, these increases were attenuated and no longer significant.

Conclusion

During caloric restriction, there is considerable endocrine anabolic resistance to a single bout of resistance exercise which persists in the presence of post-exercise whey protein supplementation. Alternative strategies to restore the sensitivity of insulin-like growth factor-1 to growth hormone need to be explored.

Electronic supplementary material

The online version of this article (10.1007/s00421-020-04354-0) contains supplementary material, which is available to authorized users.

Optimal Human Functioning Requires Exercise Across the Lifespan: Mobility in a 1g Environment Is Intrinsic to the Integrity of Multiple Biological Systems

It is widely acknowledged that achieving and maintaining a healthier lifestyle can be enhanced through regular participation in sport and physical activity. Coevally, a growing number of health professionals regard exercise as a legitimate intervention strategy for those who have lost their health. Exercise has been shown to be effective for overweight or obese individuals, who are at risk to lose their health due to development of type II diabetes, cardiovascular disease, as well as, infiltration of muscles, bone and other organs with fat, so it can be considered medicine. However, exercise and associated mobility likely also have a strong prevention component that can effectively contribute to the maintenance of the integrity of multiple biological systems for those who do not have overt risk factors or ongoing disease. While prevention is preferred over intervention in the context of disease, it is clear that exercise and associated mobility, generally, can be an effective influence, although overtraining and excessive loading can be deleterious to health. The basis for the generally positive influence of exercise likely lies in the fact that many of our physiological systems are designed to function in the mechanically dynamic and active 1g environment of Earth (e.g., muscles, cartilage, ligaments, tendons, bones, and cardiovascular system, and neuro-cognitive function), and nearly all these systems subscribe to the “use it or lose it” paradigm. This conclusion is supported by the changes observed over the more than 50 years of space flight and exposure to microgravity conditions. Therefore, the premise advanced is: “exercise is preventative for loss of health due to age-related decline in the integrity of several physiological systems via constant reinforcement of those systems, and thus, optimal levels of exercise and physical activity are endemic to, essential for, and intrinsic to optimal health and wellbeing.”