Body composition changes at 12 months following different surgical weight loss interventions in adults with obesity: A systematic review and meta-analysis of randomized control trials

To determine relative lean mass and fat mass changes in adults with obesity following surgical weight loss interventions, a systematic review and meta-analysis was conducted. The Cochrane Central Register of Controlled Trials, PubMed, Web of Science, EMBASE, and Scopus were screened for eligible studies. Inclusion criteria included randomized controlled trials (RCTs) performed in populations with obesity (body mass index ≥30 kg/m² ) aged over 18 years, who underwent any type of bariatric surgery and reported body composition measures via dual-energy X-ray absorptiometry or bio-electrical impedance analysis. Authors conducted full text screening and determined that there were six RCTs eligible for inclusion, with data extracted at 12 months post-surgery. Meta-analysis revealed that, relative to gastric banding, Roux-en-Y gastric bypass (RYGB) led to greater total body mass loss (mean difference [MD]: -9.33 kg [95% CI: -12.10, -6.56]) and greater fat mass loss (MD: -8.86 kg [95% CI: -11.80, -5.93], but similar lean mass loss (MD: -0.55 kg [95% CI: -3.82, 2.71]. RYGB also led to similar changes in total body mass, fat mass, and lean mass compared with sleeve gastrectomy. RYGB results in greater 12-month weight and fat loss, but similar changes in lean mass, compared with gastric banding. Further RCTs comparing body composition changes following different bariatric surgery procedures are required.

The Inverse Association of Leg Fat Mass and Osteoporosis in Individuals with Type 2 Diabetes Independent of Lean Mass

PURPOSE

Recent studies revealed that high levels of thigh fat were independently associated with better glucose and lipid metabolism, as well as lower risk of hypertension and cardiometabolic disease. Therefore, the purpose of this study was to evaluate the association between leg fat mass (FM) and osteoporosis (OP) in individuals with type 2 diabetes (T2DM).

PATIENTS AND METHODS

In this cross-sectional study, a total of 1,259 individuals aged 50 years or older with T2DM (female 536, male 723) were included. A bioelectrical impedance analyser was used to assess the segment body composition containing FM and lean mass (LM) of arms, legs, and trunk. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry.

RESULTS

Leg FM was positively correlated with BMD of all sites in females and BMD of femoral neck and total hip in males after adjusting age, diabetes duration, glucose and lipid metabolism indexes, and lifestyle (all P<0.05). LM was positively associated with BMD at almost sites (P<0.001), while leg FM/LM ratio had no relationship with BMD at any skeleton sites (P>0.05). Compared with the bottom tertile group of leg FM, the risk of OP was significantly lower in the top tertile group both in females (T3 vs T1: OR=0.206, 95% CI=0.098-0.433, P<0.001) and males (T3 vs T1: OR=0.385, 95% CI=0.182-0.815, P<0.05), even after adjusting for LM.

CONCLUSION

In the present study, higher leg FM was correlated with the lower risk of OP in both men and postmenopausal women with T2DM independently of total LM.

Exercise attenuates bone mineral density loss during diet-induced weight loss in adults with overweight and obesity: A systematic review and meta-analysis

BACKGROUND

Weight-loss-induced fat loss improves cardiometabolic health in individuals with overweight and obesity; however, weight loss can also result in bone loss and increased fracture risk. Weight-loss-induced bone loss may be attenuated with exercise. Our aim was to compare changes in bone mineral density (BMD) in adults with overweight and obesity who undertook diet-induced weight loss alone or in combination with exercise.

METHODS

We included randomized controlled trials (RCTs) in adults with overweight or obesity (aged ≥18 years; body mass index ≥25 kg/m2) that prescribed diet-induced weight loss alone or in combination with supervised exercise, and measured any bone structural parameters. Risk of bias was assessed using the Cochrane Risk of Bias tool. Random-effects meta-analyses determined mean changes and net mean differences (95% confidence intervals (95%CIs)) in the percentage of areal BMD (aBMD) change between groups.

RESULTS

We included 9 RCTs. Diet-induced weight loss led to significant losses in femoral neck aBMD (mean change: -1.73% (95%CI: -2.39% to -1.07%), p < 0.001) and total hip aBMD (-2.19% (95%CI: -3.84% to -0.54%), p = 0.009). Femoral neck aBMD losses were significantly greater in the diet-induced weight loss group compared to the exercise plus diet-induced weight loss group (net difference: -0.88% (95%CI: -1.73% to -0.03%)); however, there were no differences in aBMD changes at any other skeletal site: total hip (-1.96% (95%CI: -4.59% to 0.68%)) and lumbar spine (-0.48% (95%CI: -1.81% to 0.86%)). aBMD changes did not differ significantly according to exercise modality (resistance exercise, aerobic exercise, or a combination of the two) during diet-induced weight loss.

CONCLUSION

Diet-induced weight loss led to greater femoral neck bone loss compared to diet-induced weight loss plus exercise. Bone loss at the total hip and lumbar spine was not attenuated by exercise during diet-induced weight loss. The lack of consistent skeletal benefits may be due to the insufficient duration and/or training intensities of most exercise interventions. Additional RCTs with appropriate, targeted exercise interventions should be conducted.

Risk Factors for Incident Falls and Fractures in Older Men With and Without Type 2 Diabetes Mellitus: The Concord Health and Ageing in Men Project

BACKGROUND

Type 2 diabetes mellitus (T2DM) increases falls and fracture risk. Our objective was to compare incidence and risk factors for falls and fractures in community-dwelling older men with and without T2DM.

METHODS

A total of 1705 men (471 with T2DM; 1234 without T2DM) aged ≥70 years were assessed at baseline. Men were contacted every 4 months for 6.0 ± 2.2 years to ascertain incident falls and fractures, with the latter being confirmed by radiographic reports. Hip fractures were ascertained via data linkage (follow-up: 8.8 ± 3.6 years). Risk factors for falls and fractures included physical activity and function, body composition, medications, and vision measures.

RESULTS

Men with T2DM had similar fall (incident rate ratio [IRR]: 0.92 [95% confidence interval {CI}: 0.70, 1.12], n = 1246) and fracture rates (hazard ratio [HR]: 0.86 [95% CI: 0.56, 1.32], n = 1326) compared to men without T2DM after adjustment for significant risk factors. In men with T2DM, depression (IRR: 1.87 [95% CI: 1.05, 3.34], n = 333), sulphonylurea usage (IRR: 2.07 [95% CI: 1.30, 3.27]) and a greater number of prescription medications (IRR: 1.13 [95% CI: 1.03, 1.24]) were independently associated with increased fall rates, and higher total hip bone mineral density was independently associated with lower fracture rates (HR: 0.63 [95% CI: 0.47, 0.86], n = 351). Interaction terms demonstrated that better contrast sensitivity was independently associated with lower fracture rates (HR: 0.14 [95% CI: 0.02, 0.87]) in men with T2DM compared to men without T2DM.

CONCLUSION

Fall and fracture rates were similar in men with and without T2DM after adjusting for significant risk factors. Vision assessments including contrast sensitivity measures may improve fracture prediction in older men with T2DM.

Fracture incidence in adults in relation to age and gender: A study of 27,169 fractures in the Swedish Fracture Register in a well-defined catchment area

Studies on fracture incidence have mostly been based on retrospectively registered data from local hospital databases. The Swedish Fracture Register (SFR) is a national quality register collecting data prospectively on fractures, at the time of care-seeking. In the present study the incidence of all different fractures, regardless of location, in adults’ ≥ 16 years treated at the only care provider for patients with fractures within a catchment area of approximately 550,000 inhabitants, during 2015‒2018 are described. Age, gender, and fracture location (according to AO/OTA classification) was used for the analyses and presentation of fracture incidences. During the 4-year study period, 23,917 individuals sustained 27,169 fractures. The mean age at fracture was 57.9 years (range 16‒105 years) and 64.5% of the fractures occurred in women. The five most common fractures accounted for more than 50% of all fractures: distal radius, proximal femur, ankle, proximal humerus, and metacarpal fractures. Seven fracture incidence distribution groups were created based on age- and gender-specific incidence curves, providing visual and easily accessible information on fracture distribution. This paper reports on incidence of all fracture locations based on prospectively collected data in a quality register. The knowledge on fracture incidence related to age and gender may be of importance for the planning of orthopaedic care, involving both in- and out-patients as well as allocating surgical resources. Further, this might be useful for organizing preventive measures, especially in countries with similar socioeconomic structure and fracture burden.

Exploring the Impact of Obesity on Skeletal Muscle Function in Older Age

Sarcopenia is of important clinical relevance for loss of independence in older adults. The prevalence of obesity in combination with sarcopenia ("sarcopenic-obesity") is increasing at a rapid rate. However, whilst the development of sarcopenia is understood to be multi-factorial and harmful to health, the role of obesity from a protective and damaging perspective on skeletal muscle in aging, is poorly understood. Specifically, the presence of obesity in older age may be accompanied by a greater volume of skeletal muscle mass in weight-bearing muscles compared with lean older individuals, despite impaired physical function and resistance to anabolic stimuli. Collectively, these findings support a potential paradox in which obesity may protect skeletal muscle mass in older age. One explanation for these paradoxical findings may be that the anabolic response to weight-bearing activity could be greater in obese vs. lean older individuals due to a larger mechanical stimulus, compensating for the heightened muscle anabolic resistance. However, it is likely that there is a complex interplay between muscle, adipose, and external influences in the aging process that are ultimately harmful to health in the long-term. This narrative briefly explores some of the potential mechanisms regulating changes in skeletal muscle mass and function in aging combined with obesity and the interplay with sarcopenia, with a particular focus on muscle morphology and the regulation of muscle proteostasis. In addition, whilst highly complex, we attempt to provide an updated summary for the role of obesity from a protective and damaging perspective on muscle mass and function in older age. We conclude with a brief discussion on treatment of sarcopenia and obesity and a summary of future directions for this research field.

Incidence and predictors of fractures in older adults with and without obesity defined by body mass index versus body fat percentage

PURPOSE

The aim of this study was to determine and compare risk factors associated with incident fractures in older adults with and without obesity, defined by both body mass index (BMI) and body fat percentage.

METHODS

1,099 older adults (mean ± standard deviation age = 63.0 ± 7.5) years, participated in this prospective cohort study. Obesity status at baseline was defined by BMI (≥30 kg/m²) obtained by anthropometry and body fat percentage (≥30% for men and ≥40% for women) assessed by dual-energy X-ray absorptiometry (DXA). Total hip and lumbar spine areal bone mineral density (aBMD) were assessed by DXA up to five years. Incident fractures were self-reported up to 10 years.

RESULTS

Prevalence of obesity was 28% according to BMI and 43% according to body fat percentage. Obese older adults by BMI, but not body fat percentage, had significantly higher aBMD at the total hip and spine compared with non-obese (both p-value<0.05). Obese older adults by body fat percentage had significantly higher likelihood of all incident fractures (OR: 1.71; CI:1.08, 2.71) and non-vertebral fractures (OR: 1.88; CI:1.16, 3.04) compared with non-obese after adjusting for confounders. Conversely, obese older adults by BMI had a significantly lower likelihood (OR: 0.54; CI:0.31, 0.94) of non-vertebral fractures although this was no longer significant after adjustment for total hip aBMD (all p-value > 0.05). Mediation analysis confirmed that aBMD meditated the effects of BMI, but not body fat percentage, on all incident fractures. Higher baseline falls risk score was the only consistent predictor of increased likelihood of incident fracture in obese individuals only, according to both BMI and body fat percentage (both p-value<0.05).

CONCLUSIONS

Obesity defined by body fat percentage is associated with increased likelihood of incident fractures in community-dwelling older adults, whereas those who are obese according to BMI have reduced likelihood of incident fracture which appears to be explained by higher aBMD. Falls risk assessment may improve identification of obese older adults at increased risk of incident fractures.

A Comparison of Bone-Targeted Exercise Strategies to Reduce Fracture Risk in Middle-Aged and Older Men with Osteopenia and Osteoporosis: LIFTMOR-M Semi-Randomized Controlled Trial

The Lifting Intervention For Training Muscle and Osteoporosis Rehabilitation for Men (LIFTMOR-M) trial examined efficacy and safety of two novel exercise programs in older men with low BMD. Men with low hip and/or LS BMD were randomized to high-intensity progressive resistance and impact training (HiRIT) or machine-based isometric axial compression (IAC) and compared to a nonrandomized matched control (CON). Outcomes included: hip and LS BMD; calcaneal ultrasound parameters; anthropometry; body composition; function (timed up-and-go [TUG], five-times sit-to-stand [FTSTS]); back extensor strength (BES); leg extensor strength (LES); compliance and adverse events. Ninety-three men (67.1 ± 7.5 years; 82.1 ± 11.6 kg; 175.2 ± 6.7 cm; FN T-score -1.6 ± 0.6) were randomized to HiRIT (n = 34) or IAC (n = 33), or allocated to CON (n = 26). HiRIT improved trochanteric BMD (2.8 ± 0.8%; -0.1 ± 0.9%, p = .024), LS BMD (4.1 ± 0.7%; 0.9 ± 0.8%, p = .003), BUA (2.2 ± 0.7%; -0.8 ± 0.9%, p = .009), stiffness index (1.6 ± 0.9%; -2.0 ± 1.1%, p = .011), lean mass (1.5 ± 0.8%; -2.4 ± 0.9%, p = .002), TUG, FTSTS, BES, and LES (p < .05) compared with CON. IAC improved lean mass (0.8 ± 0.8%; -2.4 ± 0.9%, p = .013) and FTSTS (-4.5 ± 1.6%; 7.5 ± 2.0%, p < .001) compared with CON. HiRIT improved LS BMD (4.1 ± 0.7%; 2.0 ± 0.7%, p = .039), stiffness index (1.6 ± 0.9%; -1.3 ± 0.9%, p = .025), and FTSTS (-10.7 ± 1.6%; -4.5 ± 1.7%, p = .010) compared with IAC. Exercise compliance was high (HiRIT 77.8 ± 16.6%; IAC 78.5 ± 14.8%, p = .872). There were five minor adverse events (HiRIT, 2; IAC, 3). HiRIT was well-tolerated and improved bone, function and fracture risk more than CON or IAC. © 2020 American Society for Bone and Mineral Research.

Primary osteoporosis in men: an unmet medical need

Osteoporosis is a skeletal disease characterized by loss of bone strength and increased risk of fractures. Even though fracture prevalence is higher in women, fractures also constitute a significant public health issue in older men. Men are screened less and more frequently undertreated than female patients. It is the goal of this review, to summarize updated information about the current understanding of pathophysiology and clinical aspects of diagnosis and treatment of osteoporosis in men.