Working Toward Optimal Exercise Prescription: Strength Training Should Not Be Overlooked

Insulin-based or non-insulin-based insulin resistance indicators and risk of long-term cardiovascular and all-cause mortality in the general population: A 25-year cohort study

OBJECTIVE

Although insulin resistance (IR) has been recognized to be a causal component in various diseases, current information on the relationship between IR and long-term mortality in the general population is limited and conclusions varied among different IR indicators and different populations. We aimed to assess associations between different measurements of IR with long-term all-cause mortality and cardiovascular mortality risk for the general population.

RESEARCH DESIGN AND METHODS

We included 13,909 individuals from the Third National Health and Nutrition Examination Survey. Mortality was identified via National Death Index information until December 31, 2019. IR was measured using fasting insulin, homeostasis model assessment of IR (HOMA-IR), homeostasis model assessment of β-cell function, quantitative insulin sensitivity check index (QUICKI), insulin-to-glucose ratio (IGR), triglyceride glucose (TyG) index, TyG-body mass index (TyG-BMI), and hypertriglyceridemic-waist phenotype.

RESULTS

During median 25-year follow-up, 5,306 all-cause mortality events occurred. After multivariate adjustment, variables significantly associated with elevated all-cause mortality risk were (hazard ratio [95 % confidence interval]): higher insulin (1.07 [1.02;1.13]); HOMA-IR (1.08 [1.03;1.13]); IGR (1.05 [1.00;1.11]); TyG (1.07 [1.00;1.14]); TyG-BMI (1.24 [1.02;1.51]); lower QUICKI (0.91 [0.86-0.96]). After stratification by diabetes status, higher insulin, HOMA-IR, TyG-BMI and lower QUICKI were significantly associated with increased risk of all-cause mortality in both diabetes and non-diabetes populations (all P for interaction > 0.05). Higher TyG (adjusted HR 1.17 [1.09;1.26], P for interaction = 0.018) and hypertriglyceridemic-waist phenotype (adjusted HR 1.26 [1.08;1.46], P for interaction = 0.047) were significantly associated with increased risk of all-cause mortality in patients with diabetes, however, these associations could not be seen in people without diabetes. Similar results were observed between the above-mentioned IR indicators and cardiovascular death.

CONCLUSIONS

Fasting insulin, HOMA-IR, TyG-BMI, and QUICKI may indicate mortality risk in diabetes and non-diabetes populations, with TyG and the hypertriglyceridemic-waist phenotype showing particular relevance for individuals with diabetes. Further studies are needed to validate these findings and determine their broader applicability.

Oral health and physical performance in Asian military males: The cardiorespiratory fitness and health in armed forces

Background/purpose

It is unclear about whether the oral health has impact on physical performance. Therefore, this study aimed to examine the association between oral health and physical performance in 300 military adults in Taiwan.

Materials and methods

Oral health was assessed by the presence of periodontitis and dental caries. The status of cardiorespiratory and muscular endurance capacity was respectively assessed by tertiles of time for a 3000-m run and 2-min push-up numbers. Multivariable logistic and linear regression analyses with adjustments for age, smoking, alcohol drinking, blood pressure, anthropometric variables, lipid profile, fasting glucose and physical activity were used to determine the association.

Results

Participants with periodontitis were more likely to have worse 3000-m running performance classified in the lowest tertile [odds ratio (OR) and 95% confidence interval: 1.94 (1.03, 3.66)]. Participants with any dental caries were more likely to have worse push-ups performance classified in the lowest tertile [OR: 2.50 (1.27, 4.92)]. In linear regression analyses, dental caries numbers were inversely correlated with 2-min push-ups numbers [β = -1.04 (-2.07, -0.01)].

Conclusion

This study suggests that oral health is crucial to maintain physical fitness, and dental caries and periodontitis may affect differently on aerobic and muscular endurance capacities.

Prescribing statin therapy in physically (in)active individuals vs prescribing physical activity in statin-treated patients: A four-scenario practical approach

Statins are among the most commonly prescribed medications worldwide. Statin-associated muscle symptoms (SAMS) represent a frequent statin-related adverse effect associated with statin discontinuation and increased cardiovascular disease (CVD) events. Emerging evidence indicate that the majority of SAMS might not be actually caused by statins, and the nocebo/drucebo effect (i.e. adverse effects caused by negative expectations) might also explain SAMS. Physical activity (PA) is a cornerstone in the management of CVD risk. However, evidence of increased creatine-kinase levels in statin-treated athletes exposed to a marathon has been generalized, at least to some extent, to the general population and other types of PA. This generalization is likely inappropriate and might induce fear around PA in statin users. In addition, the guidelines for lipid management focus on aerobic PA while the potential of reducing sedentary behavior and undertaking resistance training have been overlooked. The aim of this report is to provide a novel proposal for the concurrent prescription of statin therapy and PA addressing the most common and clinically relevant scenarios by simultaneously considering the different stages of statin therapy and the history of PA. These scenarios include i) statin therapy initiation in physically inactive patients, ii) PA/exercise initiation in statin-treated patients, iii) statin therapy initiation in physically active patients, and iv) statin therapy in athletes and very active individuals performing SAMS-risky activities.

Effects of a 20-Week High-Intensity Strength Training Program on Muscle Strength Gain and Cardiac Adaptation in Untrained Men: Preliminary Results of a Prospective Longitudinal Study

BACKGROUND

As strength sports gain popularity, there is a growing need to explore the impact of sustained strength training on cardiac biventricular structure and function, an area that has received less attention compared to the well-established physiological cardiac adaptation to endurance training.

OBJECTIVE

This study aims to implement a 20-week high-intensity strength training program to enhance maximal muscle strength and evaluate its impact on cardiac biventricular adaptation in healthy, untrained men.

METHODS

A total of 27 healthy and untrained young men (mean age 22.8, SD 3.2 years) participated in a strength training program designed to increase muscle strength. The training program involved concentric, eccentric, and isometric exercise phases, conducted over a consecutive 20-week time frame with a frequency of 3 weekly training sessions. Participants were evaluated before and after 12 and 20 weeks of training through body composition analysis (bioelectrical impedance), a 12-lead resting electrocardiogram, 3D transthoracic echocardiography, cardiopulmonary exercise testing, and muscle isokinetic dynamometry. The progression of strength training loads was guided by 1-repetition maximum (RM) testing during the training program.

RESULTS

Of the initial cohort, 22 participants completed the study protocol. No injuries were reported. The BMI (mean 69.8, SD 10.8 kg/m² vs mean 72, SD 11 kg/m²; P=.72) and the fat mass (mean 15.3%, SD 7.5% vs mean 16.5%, SD 7%; P=.87) remained unchanged after training. The strength training program led to significant gains in 1-RM exercise testing as early as 4 weeks into training for leg extension (mean 69.6, SD 17.7 kg vs mean 96.5, SD 31 kg; P<.001), leg curl (mean 43.2, SD 9.7 kg vs mean 52.8, SD 13.4 kg; P<.001), inclined press (mean 174.1, SD 41.1 kg vs mean 229.2, SD 50.4 kg; P<.001), butterfly (mean 26.3, SD 6.2 kg vs mean 32.5, SD 6.6 kg; P<.001), and curl biceps on desk (mean 22.9, SD 5.2 kg vs mean 29.6, SD 5.2 kg; P<.001). After 20 weeks, the 1-RM leg curl, bench press, pullover, butterfly, leg extension, curl biceps on desk, and inclined press showed significant mean percentage gains of +40%, +41.1%, +50.3%, +63.5%, +80.1%, +105%, and +106%, respectively (P<.001). Additionally, the isokinetic evaluation confirmed increases in maximal strength for the biceps (+9.2 Nm), triceps (+11.6 Nm), quadriceps (+46.8 Nm), and hamstrings (+25.3 Nm). In this paper, only the training and muscular aspects are presented; the cardiac analysis will be addressed separately.

CONCLUSIONS

This study demonstrated that a short-term high-intensity strength training program was successful in achieving significant gains in muscle strength among previously untrained young men. We intend to use this protocol to gain a better understanding of the impact of high-intensity strength training on cardiac physiological remodeling, thereby providing new insights into the cardiac global response in strength athletes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04187170; https://clinicaltrials.gov/study/NCT04187170.

The effect of home-based resistance exercise training in people with type 2 diabetes: A randomized controlled trial

AIMS

To evaluate the effects of pragmatic home-based resistance exercise training on glycated haemoglobin (HbA1c) as well as muscle strength and body composition in people with type 2 diabetes.

MATERIALS AND METHODS

People with type 2 diabetes were randomized (1:1) to usual care or usual care plus home-based resistance exercise for 32 weeks. The changes in HbA1c, body composition, physical function, quality of life, continuous glucose monitoring and liver fat were compared by randomized group using linear regression.

RESULTS

This study recruited 120 participants (female: n = 46 [38%], age 60.2 (9.4) years, BMI 31.1 (5.4) kg.m-2 ), 64 to intervention and 56 to usual care. Intention to treat analysis revealed no effect on HbA1c (difference in difference: -0.4 mmol/mol, 95% confidence interval [CI]: -3.26, 2.47; p = 0.78) but the intervention increased the number of push-ups (3.6 push-ups, 95% CI: 0.8, 6.4), arm lean mass (116 g, 95% CI: 6, 227) and leg lean mass (438 g, 95% CI 65, 810) and decreased liver fat (-1.27%, 95% CI -2.17, -0.38), with no differences in other outcomes. Per-protocol analysis revealed similar results.

CONCLUSIONS

Home-based resistance exercise is unlikely to lower HbA1c in people with type 2 diabetes but may be of benefit for maintaining muscle mass and function and reducing liver fat.

Resistance Training in Patients With Coronary Artery Disease, Heart Failure, and Valvular Heart Disease: A REVIEW WITH SPECIAL EMPHASIS ON OLD AGE, FRAILTY, AND PHYSICAL LIMITATIONS

PURPOSE

Current guidelines recommend individually adapted resistance training (RT) as a part of the exercise regime in patients with cardiovascular diseases. The aim of this review was to provide insights into current knowledge and understanding of how useful, feasible, safe, and effective RT is in patients with coronary artery disease (CAD), heart failure (HF), and valvular heart disease (VHD), with particular emphasis on the role of RT in elderly and/or frail patients.

REVIEW METHODS

A review based on an intensive literature search: systematic reviews and meta-analyses published in 2010 or later; recent studies not integrated into meta-analyses or systematic reviews; additional manual searches.

SUMMARY

The results highlight the evaluation of effects and safety of RT in patients with CAD and HF with reduced ejection fraction (HFrEF) in numerous meta-analyses. In contrast, few studies have focused on RT in patients with HF with preserved ejection fraction (HFpEF) or VHD. Furthermore, few studies have addressed the feasibility and impact of RT in elderly cardiac patients, and data on the efficacy and safety of RT in frail elderly patients are limited. The review results underscore the high prevalence of age-related sarcopenia, disease-related skeletal muscle deconditioning, physical limitations, and frailty in older patients with cardiovascular diseases (CVD). They underline the need for individually tailored exercise concepts, including RT, aimed at improving functional status, mobility, physical performance and muscle strength in older patients. Furthermore, the importance of the use of assessment tools to diagnose frailty, mobility/functional capacity, and physical performance in the elderly admitted to cardiac rehabilitation is emphasized.