Poor glycemic control rather than types of diabetes is a risk factor for sarcopenia in diabetes mellitus: The MUSCLES-DM study

Diabetes Mellitus Should Be Considered While Analysing Sarcopenia-Related Biomarkers

Sarcopenia is a chronic, progressive skeletal muscle disease characterised by low muscle strength and quantity or quality, leading to low physical performance. Patients with type 2 diabetes mellitus (T2DM) are more at risk of sarcopenia than euglycemic individuals. Because of several shared pathways between the two diseases, sarcopenia is also a risk factor for developing T2DM in older patients. Various biomarkers are under investigation as potentially valuable for sarcopenia diagnosis and treatment monitoring. Biomarkers related to sarcopenia can be divided into markers evaluating musculoskeletal status (biomarkers specific to muscle mass, markers of the neuromuscular junction, or myokines) and markers assuming causal factors (adipokines, hormones, and inflammatory markers). This paper reviews the current knowledge about how diabetes and T2DM complications affect potential sarcopenia biomarker concentrations. This review includes markers recently proposed by the expert group of the European Society for the Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) as those that may currently be useful in phase II and III clinical trials of sarcopenia: myostatin (MSTN); follistatin (FST); irisin; brain-derived neurotrophic factor (BDNF); procollagen type III N-terminal peptide (PIIINP; P3NP); sarcopenia index (serum creatinine to serum cystatin C ratio); adiponectin; leptin; insulin-like growth factor-1 (IGF-1); dehydroepiandrosterone sulphate (DHEAS); C-reactive protein (CRP); interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α). A better understanding of factors influencing these biomarkers' levels, including diabetes and diabetic complications, may lead to designing future studies and implementing results in clinical practice.

Diabetic Sarcopenia. A proposed muscle screening protocol in people with diabetes : Expert document

OBJECTIVES

To propose the grounds for "diabetic sarcopenia" as a new comorbidity of diabetes, and to establish a muscle screening algorithm proposal to facilitate its diagnosis and staging in clinical practice.

METHOD

A qualitative expert opinion study was carried out using the nominal technique. A literature search was performed with the terms "screening" or "diagnostic criteria" and "muscle loss" or "sarcopenia" and "diabetes" that was sent to a multidisciplinary group of 7 experts who, in a face-to-face meeting, discussed various aspects of the screening algorithm.

RESULTS

The hallmark of diabetic sarcopenia (DS) is muscle mass atrophy characteristic of people with diabetes mellitus (DM) in contrast to the histological and physiological normality of muscle mass. The target population to be screened was defined as patients with DM with a SARC-F questionnaire > 4, glycosylated haemoglobin (HbA1C) ≥ 8.0%, more than 5 years since onset of DM, taking sulfonylureas, glinides and sodium/glucose cotransporter inhibitors (SGLT2), as well as presence of chronic complications of diabetes or clinical suspicion of sarcopenia. Diagnosis was based on the presence of criteria of low muscle strength (probable sarcopenia) and low muscle mass (confirmed sarcopenia) using methods available in any clinical consultation room, such as dynamometry, the chair stand test, and Body Mass Index (BMI)-adjusted calf circumference. DS was classified into 4 stages: Stage I corresponds to sarcopenic patients with no other diabetes complication, and Stage II corresponds to patients with some type of involvement. Within Stage II are three sublevels (a, b and c). Stage IIa refers to individuals with sarcopenic diabetes and some diabetes-specific impairment, IIb to sarcopenia with functional impairment, and IIc to sarcopenia with diabetes complications and changes in function measured using standard tests Conclusion: Diabetic sarcopenia has a significant impact on function and quality of life in people with type 2 diabetes mellitus (T2DM), and it is important to give it the same attention as all other traditionally described complications of T2DM. This document aims to establish the foundation for protocolising the screening and diagnosis of diabetic sarcopenia in a manner that is simple and accessible for all levels of healthcare.

Association between Sarcopenia and Poor Glycemic Control in Older Adults with Type 2 Diabetes Mellitus

BACKGROUND

Aging is associated with a decrease in muscle mass. Insulin resistance and hyperglycemia accelerate muscle loss, leading to a deterioration in strength, muscle mass, and physical capacity in older adults. This study was conducted to determine the association between sarcopenia and poor glycemic control in older adults with type 2 diabetes mellitus (T2D).

METHODS

A cross-sectional study was carried out in older adults with T2D in geriatric outpatient clinics. Sarcopenia was diagnosed as per the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) criteria. According to glycosylated hemoglobin (HbA1c) levels, participants were classified into glycemic control (HbA1c ≤ 7.5%) and poor glycemic control (HbA1c ≥ 7.5%) groups.

RESULTS

Older adults with sarcopenia were found to have poor glycemic control compared to adults without sarcopenia (62.3% vs. 47.9%, p = 0.007). Logistic regression analysis showed an association between poor glycemic control and the presence of sarcopenia (odds ratio (OR): 1.79, 95% confidence interval (CI): 1.17-2.75) and low muscle mass (OR: 1.73, 95% CI: 1.07-2.73).

CONCLUSIONS

Poor glycemic control is associated with the presence of sarcopenia and low muscle mass, which highlights the need to implement better treatment strategies in order to reduce the loss of muscle mass.

Prevalence of Sarcopenia and Dynapenia and Related Clinical Outcomes in Patients with Type 1 Diabetes Mellitus

BACKGROUND

Sarcopenia has recently been recognized as a complication of diabetes. However, there are few results about the prevalence of sarcopenia and dynapenia and the related clinical outcomes in type 1 diabetes mellitus (T1DM). Our objectives were to evaluate the prevalence of sarcopenia and dynapenia and to determine whether there are any associations with disease-related factors in people with T1DM.

METHODS

A cross-sectional study was conducted in people with T1DM. We assessed appendicular skeletal mass index (ASMI) using bioimpedance 50 Hz (Nutrilab Akern). Muscle function was assessed through handgrip strength (HGS) using a Jamar dynamometer. Sarcopenia was defined as a low HGS with low ASMI, whereas dynapenia was defined as low HGS with a normal ASMI. We used HGS data from the Spanish population percentile table and a cut-off point at p5 as dynapenia. The association of clinical, metabolic, and lifestyle variables with sarcopenia and dynapenia was studied.

RESULTS

This study included 62 T1DM patients (66% females, mean age of 38 ± 14 years, body mass index (BMI) of 24.9 ± 4.7 kg/m2). The prevalence of sarcopenia and dynapenia was 8% and 23%, respectively. In our sample, there were more men in the sarcopenic and dynapenic groups. The sarcopenic group showed a significantly higher mean HbA1c value. Lower diabetes duration, PREDIMED score, BMI, and muscle mass measures (fat-free mass index (FFMI), ASMI, and body cell mass index (BCMI)) were significantly associated with sarcopenia. Decreased diabetes duration, PREDIMED score, phase angle (PhA), and HGS values showed a significant association with dynapenia.

CONCLUSIONS

The prevalence of sarcopenia and dynapenia was high in people with T1DM in our study. Specifically, the proportion of dynapenia was quite high. HGS and ASMI are practical tools for the assessment of muscle health status in T1DM, and low values are associated with poor glycemic control, underweight, and low adherence to the Mediterranean diet. Thus, dynapenia may predict accelerated muscle aging in T1DM.

N-acetylcysteine alleviates oxidative stress and apoptosis and prevents skeletal muscle atrophy in type 1 diabetes mellitus through the NRF2/HO-1 pathway

AIMS

Type 1 diabetes mellitus (T1DM) has been linked to the occurrence of skeletal muscle atrophy. Insulin monotherapy may lead to excessive blood glucose fluctuations. N-acetylcysteine (NAC), a clinically employed antioxidant, possesses cytoprotective, anti-inflammatory, and antioxidant properties. The objective of our study was to evaluate the viability of NAC as a supplementary treatment for T1DM, specifically regarding its therapeutic and preventative impacts on skeletal muscle.

MAIN METHODS

Here, we used beagles as T1DM model for 120d to explore the mechanism of NRF2/HO-1-mediated skeletal muscle oxidative stress and apoptosis and the therapeutic effects of NAC. Oxidative stress and apoptosis related factors were analyzed by immunohistochemistry, immunofluorescence, western blotting, and RT-qPCR assay.

KEY FINDINGS

The findings indicated that the co-administration of NAC and insulin led to a reduction in creatine kinase levels, preventing weight loss and skeletal muscle atrophy. Improvement in the reduction of muscle fiber cross-sectional area. The expression of Atrogin-1, MuRF-1 and MyoD1 was downregulated, while Myh2 and MyoG were upregulated. In addition, CAT and GSH-Px levels were increased, MDA levels were decreased, and redox was maintained at a steady state. The decreased of key factors in the NRF2/HO-1 pathway, including NRF2, HO-1, NQO1, and SOD1, while KEAP1 increased. In addition, the apoptosis key factors Caspase-3, Bax, and Bak1 were found to be downregulated, while Bcl-2, Bcl-2/Bax, and CytC were upregulated.

SIGNIFICANCE

Our findings demonstrated that NAC and insulin mitigate oxidative stress and apoptosis in T1DM skeletal muscle and prevent skeletal muscle atrophy by activating the NRF2/HO-1 pathway.

Prevalence and Mechanisms of Skeletal Muscle Atrophy in Metabolic Conditions

Skeletal muscle atrophy is prevalent in a myriad of pathological conditions, such as diabetes, denervation, long-term immobility, malnutrition, sarcopenia, obesity, Alzheimer's disease, and cachexia. This is a critically important topic that has significance in the health of the current society, particularly older adults. The most damaging effect of muscle atrophy is the decreased quality of life from functional disability, increased risk of fractures, decreased basal metabolic rate, and reduced bone mineral density. Most skeletal muscle in humans contains slow oxidative, fast oxidative, and fast glycolytic muscle fiber types. Depending on the pathological condition, either oxidative or glycolytic muscle type may be affected to a greater extent. This review article discusses the prevalence of skeletal muscle atrophy and several mechanisms, with an emphasis on high-fat, high-sugar diet patterns, obesity, and diabetes, but including other conditions such as sarcopenia, Alzheimer's disease, cancer cachexia, and heart failure.