Relationship between sarcopenia classification and thigh muscle mass, fat area, muscle CT value and osteoporosis in middle-aged and older Japanese adults

Moderate resistance training reduces intermuscular adipose tissue and risk factors of atherosclerotic cardiovascular disease for elderly patients with type 2 diabetes

AIM

This study aimed to assess the impact of moderate resistance training on intermuscular adipose tissue (IMAT) in elderly patients with type 2 diabetes and the independent effect of IMAT reduction on metabolic outcomes.

METHODS

In this randomized controlled trial, 85 patients with type 2 diabetes were assigned to either the resistance training group (42 participants) or the control group (43 participants) for a 6-month intervention. The primary outcome was changes in IMAT measured by computed tomography scan and magnetic resonance imaging using the interactive decomposition of water and fat with echo asymmetry and least squares qualification sequence. Secondary outcomes included changes in metabolic parameters.

RESULTS

Thirty-seven participants in each group completed the study. The IMAT area (measured by a computed tomography scan) in the resistance group decreased from 5.176 ± 1.249 cm2 to 4.660 ± 1.147 cm2, which is a change of -0.512 ± 0.115 cm2, representing a 9.89% decrease from the least-squares adjusted mean at baseline, which was significantly different from that of the control group (a change of 0.587 ± 0.115 cm2, a 10.34% increase). The normal attenuation muscle area (representing normal muscle density) in the resistance group increased from 82.113 ± 8.776 cm2 to 83.054 ± 8.761 cm2, a change of 1.049 ± 0.416 cm2, a 1.3% increase, which was significantly different from that of the control group (a change of -1.113 ± 0.416 cm2, a 1.41% decrease). Homeostasis model assessment 2 of beta cell function (HOMA2-β; increased from 52.291 ± 24.765 to 56.368 ± 21.630, a change of 4.135 ± 1.910, a 7.91% increase from baseline) and ratio of insulin increase to blood glucose increase at 30 min after the oral glucose tolerance test (∆I30/∆G30; increased from 4.616 ± 1.653 to 5.302 ± 2.264, a change of 0.715 ± 0.262, a 15.49% increase) in the resistance group were significantly improved compared with those in the control group, which had a change of -3.457 ± 1.910, a 6.05% decrease in HOMA2-β, and a change of -0.195 ± 0.262, a 3.87% decrease in ∆I30/∆G30, respectively. Adjusting for sex, age, diabetes duration, baseline IMAT, and the dependent variable at baseline, linear regression showed that the change in IMAT area was not related to the change in HOMA2 insulin resistance (β = -0.178, p = .402) or the change in HOMA2-β (β = -1.891, p = .197), but was significantly related to the changes in ∆I30/∆G30 (β = -0.439, p = .047), 2-h postprandial glucose (β = 1.321, p = .026), diastolic blood pressure (β = 2.425, p = .018), normal attenuation muscle area (β = -0.907, p = .019) and 10-year risk of atherosclerotic cardiovascular disease (β = 0.976, p = .002).

CONCLUSION

Low-level, moderate resistance training reduces IMAT content. Even a small reduction in IMAT may be related to a decrease in risk factors for atherosclerotic cardiovascular disease, but this small reduction may not be sufficient to reduce insulin resistance.

Preoperative Sarcopenia Severity and Clinical Outcomes after Total Hip Arthroplasty

The outcome of total hip arthroplasty (THA) in patients with end-stage arthritis of the hip is associated with preoperative physical status. This study was performed to examine the relationship between the preoperative severity of sarcopenia and clinical outcomes after THA. This retrospective cohort study was performed among 306 consecutive patients (mean age: 63.7 ± 12.9 years, 222 women) undergoing THA at a university hospital. The severity of sarcopenia was determined based on the skeletal muscle mass index (SMI), handgrip strength, and gait speed according to the criteria of the Asian Working Group for Sarcopenia 2019. The severe sarcopenia prevalence rate was 10.6%. Severe sarcopenia was significantly associated with the risk of delayed functional recovery (adjusted odds ratio, 2.82; 95% confidence interval, 1.03-7.72; p = 0.043) compared with the non-sarcopenia group after adjusting for pre-existing risk factors, including preoperative hip function and physical activity. The addition of SMI, handgrip strength, and gait speed to the model for risk of functional recovery delay significantly increased the area under the receiver operating characteristic curve (p = 0.038). Severe sarcopenia was significantly associated with poorer hip function and patient-reported outcomes at 6 months after surgery compared with the non-sarcopenia group. Severe sarcopenia was adversely associated with postoperative clinical outcomes in patients undergoing THA.

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.

Relationship between quadriceps muscle computed tomography measurement and motor function, muscle mass, and sarcopenia diagnosis

Background

The quadriceps muscle is one of the human body's largest and most clinically important muscles and is evaluated using mid-thigh computed tomography (CT); however, its relationship with motor function and sarcopenia remains unclear. Herein, we investigated the relationship between the cross-sectional area (CSA) of the quadriceps muscle, CT attenuation value (CTV), dual-energy X-ray absorptiometry muscle mass measurements, and muscle strength and motor function to evaluate the relationship between muscle mass loss and motor function decline, determine the diagnostic ability for sarcopenia, and confirm the usefulness of quadriceps muscle CT evaluation.

Methods

A total of 472 middle-aged and older community dwellers (254 men and 218 women) aged ≥40 years (mean age: 62.3 years) were included in this study. The quantity and quality of the quadriceps muscle were assessed using CSA and CTV (CSA×CTV) as a composite index multiplied by quality and quantity. Age-adjusted partial correlations by sex with eight motor functions (knee extension muscle strength, power, normal walking speed, fast walking speed, grip strength, sit-up ability, balance ability, and reaction time) were evaluated, including correction methods for height, weight, and body mass index (BMI). Further, the accuracy of sarcopenia diagnosis was evaluated using appendicular muscle mass with dual-energy X-ray absorptiometry measurements, grip strength, and walking speed as the gold standard, and receiver operating characteristic curves were plotted to evaluate diagnostic performance.

Results

In men, CSA and CSA×CTV were significantly associated with seven of the eight motor functions (p<0.05), excluding only balance ability. BMI-corrected CSA was significantly correlated with all eight motor functions in men and women (p<0.05). In the diagnosis of sarcopenia based on skeletal muscle index, CSA (area under the curve (AUC) 0.935) and CSA×CTV (AUC 0.936) and their correction by height (CSA/height (AUC 0.917) and CSA×CTV/height (AUC 0.920)) were highly accurate and useful for diagnosis in men but moderately accurate in women (CSA (AUC 0.809), CSA×CTV (AUC 0.824), CSA/height (AUC 0.799), CSA×CTV/height (AUC 0.814)).

Conclusion

The present results showed that a single CT image of the quadriceps muscle at the mid-thigh is useful for diagnosing sarcopenic changes, such as loss of muscle mass, muscle weakness, and muscle function.

A potential correlation between adipokines, skeletal muscle function and bone mineral density in middle-aged and elderly individuals

BACKGROUND

Evidence exists of a strong association between inflammation and a decrease in skeletal muscle function and bone mineral density (BMD); however, the specific mechanisms of these associations remain unclear. Adipokines, as key regulators of the inflammatory response, may be implicated in these processes. The objective of this study was to explore the potential correlation between adipokines, skeletal muscle function and BMD in middle-aged and elderly individuals.

METHODS

A comparative cross-sectional study was carried out at the Huadong Hospital Affiliated with Fudan University (Shanghai, China). A total of 460 middle-aged and elderly individuals were recruited, and 125 were enrolled in the analysis. Their biochemical indices, body composition, skeletal muscle function and BMD were measured. Bioinformatic analysis was also employed to identify potential adipokine targets linked to skeletal muscle function and BMD. To validate these targets, plasma and peripheral blood mononuclear cells (PBMCs) were harvested from these individuals and subjected to western blotting (WB) and enzyme-linked immunosorbent assay (ELISA).

RESULTS

Individuals in this cross-sectional study were categorized into 2 groups according to their median skeletal muscle mass (SMM) (28.8 kg for males and 20.6 kg for females). Individuals with lower SMM exhibited poorer grip strength (P = 0.017), longer 5-Times-Sit-to-Stand Test (FTSST) duration (P = 0.029), lower total hip BMD (P = 0.043), lower femoral neck BMD (P = 0.011) and higher levels of inflammatory markers in comparison with individuals with higher SMM. Bioinformatics analysis identified LEP, ADIPOQ, RBP4, and DPP4 as potential adipokine targets associated with skeletal muscle function and BMD. In vitro experiments demonstrated that individuals with decreased skeletal muscle function and BMD expressed higher levels of these adipokines.

CONCLUSIONS

Skeletal muscle function is positively correlated with BMD and negatively correlated with levels of inflammatory markers among middle-aged and elderly individuals. Those with lower skeletal muscle function and BMD tend to have a higher expression of LEP, ADIPOQ, RBP4 and DPP4.

Imaging modalities for measuring body composition in patients with cancer: opportunities and challenges

Body composition assessment (ie, the measurement of muscle and adiposity) impacts several cancer-related outcomes including treatment-related toxicities, treatment responses, complications, and prognosis. Traditional modalities for body composition measurement include body mass index, body circumference, skinfold thickness, and bioelectrical impedance analysis; advanced imaging modalities include dual energy x-ray absorptiometry, computerized tomography, magnetic resonance imaging, and positron emission tomography. Each modality has its advantages and disadvantages, thus requiring an individualized approach in identifying the most appropriate measure for specific clinical or research situations. Advancements in imaging approaches have led to an abundance of available data, however, the lack of standardized thresholds for classification of abnormal muscle mass or adiposity has been a barrier to adopting these measurements widely in research and clinical care. In this review, we discuss the different modalities in detail and provide guidance on their unique opportunities and challenges.