Association between Changes in Muscle Quality with Exercise Training and Changes in Cardiorespiratory Fitness Measures in Individuals with Type 2 Diabetes Mellitus: Results from the HART-D Study

Muscle Quality Index in Morbidly Obesity Patients Related to Metabolic Syndrome Markers and Cardiorespiratory Fitness

BACKGROUND

Muscle quality index (MQI) is an emerging health indicator obtained by dividing handgrip strength by body mass index (BMI) that needs to be studied in morbidly obese patients (defined by BMI ≥ 35 kg/m²).

OBJECTIVE

To determine the association between MQI, metabolic syndrome (MetS) markers, and cardiorespiratory fitness (CRF), and as a second objective to determine the potential mediation role of MQI in the relationship between abdominal obesity and systolic blood pressure (SBP) in this sample.

METHODS

This cross-sectional study included 86 severely/morbidly obese patients (age = 41.1 ± 11.9 y, nine men). MQI, metabolic syndrome markers, CRF, and anthropometric parameters were measured. Two groups were developed according to MQI; High-MQI (n = 41) and Low-MQI (n = 45).

RESULTS

The Low-MQI group reported higher abdominal obesity (High-MQI: 0.7 ± 0.1 vs. Low-MQI: 0.8 ± 0.1 WC/height; p = 0.011), SBP (High-MQI: 133.0 ± 17.5 vs. Low-MQI: 140.1 ± 15.1 mmHg; p = 0.048), and lower CRF (High-MQI; 26.3 ± 5.9 vs. Low-MQI; 22.4 ± 6.1 mL/kg/min, p = 0.003) than the High-MQI group. Waist-to-height ratio (β: -0.07, p = 0.011), SBP (β: -18.47, p = 0.001), and CRF (β: 5.21, p = 0.011) were linked to MQI. In a mediation model, the indirect effect confirms that MQI is a partial mediator of the association between abdominal obesity with SBP.

CONCLUSIONS

MQI in morbidly obesity patients reported an inverse association with MetS markers and a positive association with CRF (VO2_max). It mediates the relationship between abdominal obesity and SBP.

Association between physical activity & sedentary time on frailty status in males and females living with diabetes mellitus: A cross-sectional analysis

BACKGROUND

Physical activity (PA) is a cornerstone for the prevention and the treatment of diabetes mellitus (DM) and frailty. However, no consensus exists on which intensities and types of PA are associated with frailty status among individuals living with DM. To investigate the association between different intensities and types of PA on frailty status in males and females living with DM.

METHODS

A cross-sectional analysis of the 2003-2006 cycles from the National Health and Nutrition Examination Survey (NHANES) was performed in 711 participants living with DM. Frailty status was measured using the 43-item deficit model and DM was self-reported. Weekly PA levels were measured by accelerometer, while resistance training (RT) was measured via questionnaire. Linear and logistic regressions were performed to investigate the associations between different intensities and types of PA and frailty status.

RESULTS

Total time spent performing light PA was associated with a better frailty status in males (ß - 0.041 ± 0.012; p < 0.001) and females (ß - 0.070 ± 0.010; p < 0.0001), while total moderate-to-vigorous PA (MVPA) was associated with a better frailty status in females only (ß-0.235 ± 0.061; p < 0.05). However, once fully adjusted, the different intensities and types of PA were associated more with frailty status for female. When investigating whether different intensities and types of PA were associated with being considered frail, total time spent at MVPA and light PA were associated with higher odds along with total sedentary time for female (all p < 0.01).

CONCLUSION

Each minute engaged in PA was associated with a better frailty status in males and females living with DM, although RT does not appear associated with a better frailty status in adults with DM. Replacing sedentary time with PA is important, especially for females living with DM to have a better frailty status. These results are important as they provide insights into the prevention and the management of frailty in individuals living with DM.

Interindividual variation in cardiometabolic health outcomes following 6 months of endurance training in youth at risk of type 2 diabetes mellitus

This study determined the interindividual variation in the cardiometabolic response to 6 months of moderate or vigorous intensity exercise training (ET) among youth at risk for type 2 diabetes mellitus. Youth were randomized to moderate intensity ET (45-55% heart rate reserve; n = 31), vigorous intensity ET (70-85% heart rate reserve; n = 37), or control (n = 36). Only those attending ≥70% of ET sessions were included. Cardiometabolic measures included insulin sensitivity, hepatic triglyceride content, visceral adipose area, and cardiorespiratory fitness. The contribution of ET to interindividual variation was determined using the standard deviation of individual responses (SD_IR) and considered meaningful if the SD_IR surpassed the smallest worthwhile difference (SWD), calculated as 0.2 × the standard deviation of the control group baseline values. ET meaningfully contributed to the interindividual variation among changes in peak oxygen uptake following moderate (SD_IR: 2.04) and vigorous (SD_IR: 3.43) ET (SWD: 1.17 mL·kg fat free mass^-1·min^-1), body fat percentage and hepatic triglyceride content following moderate-intensity ET (SD_IR: 1.64, SWD: 1.05%; SD_IR: 10.08, SWD: 1.06%, respectively), and visceral fat mass following vigorous ET (SD_IR: 11.06, SWD: 7.13 cm²). Variation in the changes in insulin sensitivity were not influenced by ET. The contribution of ET to interindividual variation appears to be influenced by the desired outcome and prescribed intensity. Trial registration at ClinicalTrials.gov (identifier no.: NCT00755547). Novelty: The contribution of exercise to interindividual variation following training depends on the outcome and exercise intensity. Increasing exercise intensity does not systematically reduce non-response among youth at risk for type 2 diabetes.

Altered accelerator pedal control in a driving simulator in people with diabetic peripheral neuropathy

AIM

To investigate whether the sensory-motor impairment attributable to diabetic peripheral neuropathy would affect control of the accelerator pedal during a driving simulator task.

METHODS

A total of 32 active drivers, 11 with diabetic peripheral neuropathy (mean ± sd age 67±5.0 years), 10 with diabetes but no neuropathy (diabetes group; mean ± sd age 62±10 years), and 11 healthy individuals without diabetes (healthy group; mean ± sd age 60±11 years), undertook a test on a dynamometer to assess ankle plantar flexor muscle strength and ankle joint proprioception function of the right leg, in addition to a driving simulator task. The following variables were measured: maximal ankle plantar flexor muscle strength; speed of strength generation (Nm/s); and ankle joint proprioception (ankle repositioning error, degrees). In the driving simulator task, driving speed (mph), accelerator pedal signal (degrees) and the duration of specific 'loss-of-control events' (s) were measured during two drives (Drive 1, Drive 2).

RESULTS

Participants with diabetic peripheral neuropathy had a lower speed of strength generation (P<0.001), lower maximal ankle plantar flexor muscle strength (P<0.001) and impaired ankle proprioception (P=0.034) compared to healthy participants. The diabetic peripheral neuropathy group drove more slowly compared with the healthy group (Drive 1 P=0.048; Drive 2 P=0.042) and showed marked differences in the use of the accelerator pedal compared to both the diabetes group (P=0.010) and the healthy group (P=0.002). Participants with diabetic peripheral neuropathy had the longest duration of loss-of-control events, but after one drive, this was greatly reduced (P=0.023).

CONCLUSIONS

Muscle function, ankle proprioception and accelerator pedal control are all affected in people with diabetic peripheral neuropathy, adversely influencing driving performance, but potential for improvement with targeted practice remains possible.

Handgrip strength predicts new prediabetes cases among adults: A prospective cohort study

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There was high prediabetes incidence among participants of medical examinations.

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Lower relative handgrip strength (HS) predicted higher prediabetes incidence risk.

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Results significant in individuals < 40 and ≥ 40 years old.

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HS predicted lower prediabetes incidence risk among normal weight individuals.

Conventional risk factors for prediabetes and type 2 diabetes such as obesity do not completely explain the higher prevalence of prediabetes; therefore, research to investigate the role of other independent risk factors is required. A few cross-sectional studies have reported an association between muscle strength and prediabetes among normal-weight adults, but the longitudinal relationship of muscle strength with incident prediabetes among adults has not been reported. This prospective cohort study was conducted to investigate whether relative handgrip strength in adults predicted prediabetes incidence after 2 years of follow-up. The study was conducted in Ibaraki prefecture, Japan and recruited individuals without prediabetes and diabetes attending lifestyle related medical examinations between April 2016 and March 2017 (n = 2054). Individuals who came for the follow-up medical examinations between April 2018 and March 2019 were included in the analysis (n = 1075). One hundred sixty-nine individuals (15.7%) developed prediabetes after a mean follow-up of 24.2 months (SD = 1.9 months). Multivariable adjusted hazard ratios (aHR) of new prediabetes cases were calculated using Cox regression. Higher baseline relative handgrip strength predicted a lower risk (aHR [95% CI] = 0.38 [0.21–0.71] of prediabetes incidence among adults. Importantly, relative handgrip strength predicted new prediabetes cases among normal weight individuals (aHR [95% CI] = 0.39 [0.16–0.96]). The findings suggest that handgrip strength measurement is useful to identify individuals at high risk of newly diagnosed prediabetes, importantly, among normal weight individuals. The identified individuals may benefit from early intervention to reduce the risk of prediabetes.

Exercise training for patients with type 2 diabetes and cardiovascular disease: What to pursue and how to do it. A Position Paper of the European Association of Preventive Cardiology (EAPC)

Patients with type 2 diabetes mellitus suffer from dysregulation of a plethora of cardiovascular and metabolic functions, including dysglycaemia, dyslipidaemia, arterial hypertension, obesity and a reduced cardiorespiratory fitness. Exercise training has the potential to improve many of these functions, such as insulin sensitivity, lipid profile, vascular reactivity and cardiorespiratory fitness, particularly in type 2 diabetes mellitus patients with cardiovascular comorbidities, such as patients that suffered from an acute myocardial infarction, or after a coronary intervention such as percutaneous coronary intervention or coronary artery bypass grafting. The present position paper aims to provide recommendations for prescription of exercise training in patients with both type 2 diabetes mellitus and cardiovascular disease. The first part discusses the relevance and practical applicability of treatment targets that may be pursued, and failure to respond to these targets. The second part provides recommendations on the contents and methods to prescribe exercise training tailored to these treatment targets as well as to an optimal preparation and dealing with barriers and risks specific to type 2 diabetes mellitus and cardiac comorbidity.

The Contributions of Fiber Atrophy, Fiber Loss, In Situ Specific Force, and Voluntary Activation to Weakness in Sarcopenia

The contributions of fiber atrophy, fiber loss, in situ specific force, and voluntary activation to weakness in sarcopenia remain unclear. To investigate, 40 older (20 women; age 72 ± 4 years) and 31 younger adults (15 women, age 22 ± 3 years) completed measurements. The knee extensor maximal voluntary torque (MVC) was measured as well as voluntary activation, patella tendon moment arm length, muscle volume, and fascicle architecture to estimate in situ specific force. Fiber cross-sectional area (FCSA), fiber numbers, and connective tissue contents were also estimated from vastus lateralis biopsies. The MVC, quadriceps volume, and specific force were 39%, 28%, and 17% lower, respectively, in old compared with young, but voluntary activation was not different. The difference in muscle size was due in almost equal proportions to lower type II FCSA and fewer fibers. Five years later (n = 23) the MVC, muscle volume and voluntary activation in old decreased an additional 12%, 6%, and 4%, respectively, but there was no further change in specific force. In situ specific force declines relatively early in older age and reduced voluntary activation occurs later, but the overall weakness in sarcopenia is mainly related to loss of both type I and II fibers and type II fiber atrophy.

A pilot study of short-term toe resistance training in patients with type 2 diabetes mellitus

Objective

The purpose of this pilot study was to investigate the effect of short-term toe resistance training on toe pinch force and toe muscle quality in patients with type 2 diabetes mellitus.

Methods

A total of 12 patients with type 2 diabetes mellitus who were hospitalized to improve glycemic control (8 men and 4 women, duration of diabetes 12.2 ± 9.5 years) were enrolled in this pilot study. Exercise therapy was performed with conventional aerobic exercise and four newly developed toe resistance training exercises for 2 weeks. Changes in anthropometric parameters, blood pressure (BP), heart rate, and muscle parameters, i.e. muscle mass, toe pinch force and toe muscle quality were evaluated after the exercise program.

Results

There were no significant differences of body weight, body mass index, BP, heart rate, and upper/lower muscle mass after exercise performance. However, toe pinch force was significantly increased (pre: 2.92 ± 1.19 kg, post: 3.65 ± 1.58 kg, p = 0.007). Toe muscle quality (toe pinch force/lower leg muscle mass) were also significantly increased (pre: 2.15 ± 0.86 kg/kg, post: 2.72 ± 1.26 kg/kg, p = 0.009).

Conclusions

Two weeks of toe resistance training significantly increased toe pinch force and toe muscle quality in patients with type 2 diabetes mellitus. Toe resistance training is might be essential for treating patients with diabetes mellitus in clinical practice.

Muscle dysfunction in type 2 diabetes: a major threat to patient's mobility and independence

Type 2 diabetes, a common metabolic disease in older people, is a major risk factor for functional limitation, impaired mobility, and loss of independence. In older people, the pathogenesis of functional limitation and disability is complex and multifactorial. A number of potential pathways are involved including cardiovascular disease, peripheral neuropathy, overweight, osteoarthritis, visual deficit, and cognitive impairment, conditions that are all more prevalent among patients with diabetes. Sarcopenia, a geriatric condition characterized by a progressive and generalized loss of skeletal muscle mass and strength, is also involved in the pathogenesis of functional limitations and disability. Recent research has shown that older patients with type 2 diabetes are often affected by skeletal muscle impairment, leading to reduced muscle strength and physical function. Insulin resistance, hyperglycemia, muscle fat infiltration, and peripheral neuropathies are hypothesized as the fundamental biological mechanisms leading to muscle impairment in people with diabetes. This review summarizes the current literature on the biological pathways responsible for skeletal muscle dysfunction in type 2 diabetes and analyzes the role of decline in muscle strength and quality on the association between diabetes and mobility disability.

Muscle grip strength predicts incident type 2 diabetes: Population-based cohort study

OBJECTIVES

To determine the longitudinal relationship of muscle mass and strength with incident type 2 diabetes, and previously unstudied mediating effects of testosterone and inflammation.

METHODS

Community-dwelling male participants (aged ≥35years) of the Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) Study underwent biomedical assessment in 2002-2006 and 2007-2010, including hand grip strength (dynamometer), testosterone and inflammatory markers. Body composition (dual-energy X-ray absorptiometry) was assessed at baseline only. Incident type 2 diabetes was defined as a self-reported doctor diagnosis, diabetes medication use, fasting plasma glucose ≥7.0mmol/L, or glycated haemoglobin ≥6.5% (48mmol/mol) at follow-up, that was not present at baseline.

RESULTS

Of n=1632 men, incident type 2 diabetes occurred in 146 (8.9%). Muscle mass was not associated with incident type 2 diabetes. Grip strength was inversely associated with incident type 2 diabetes [unadjusted odds ratio (OR) per 5kg: 0.87, 95% confidence interval (CI): 0.80-0.95; adjusted OR, 95% CI: 0.87, 0.78-0.97]. Arm muscle quality (grip strength divided by arm lean mass) was similarly associated with incident type 2 diabetes. Testosterone, IL-6 and TNF-α did not significantly mediate the associations. The population attributable fraction of type 2 diabetes from low grip strength was 27% (13-40%), assuming intervention could increase strength by 25%.

CONCLUSIONS

Reduced muscle strength, but not reduced muscle mass, is a risk factor for incident type 2 diabetes in men. This is not mediated by testosterone or inflammation. Intervention could prevent a substantial proportion of disease.