Understanding the variation in exercise responses to guide personalized physical activity prescriptions

Understanding the factors that contribute to exercise response variation is the first step in achieving the goal of developing personalized exercise prescriptions. This review discusses the key molecular and other mechanistic factors, both extrinsic and intrinsic, that influence exercise responses and health outcomes. Extrinsic characteristics include the timing and dose of exercise, circadian rhythms, sleep habits, dietary interactions, and medication use, whereas intrinsic factors such as sex, age, hormonal status, race/ethnicity, and genetics are also integral. The molecular transducers of exercise (i.e., genomic/epigenomic, proteomic/post-translational, transcriptomic, metabolic/metabolomic, and lipidomic elements) are considered with respect to variability in physiological and health outcomes. Finally, this review highlights the current challenges that impede our ability to develop effective personalized exercise prescriptions. The Molecular Transducers of Physical Activity Consortium (MoTrPAC) aims to fill significant gaps in the understanding of exercise response variability, yet further investigations are needed to address additional health outcomes across all populations.

The Effect of Choline and Resistance Training on Strength and Lean Mass in Older Adults

Choline plays many important roles, including the synthesis of acetylcholine, and may affect muscle responses to exercise. We previously observed correlations between low choline intake and reduced gains in strength and lean mass following a 12-week resistance exercise training (RET) program for older adults. To further explore these findings, we conducted a randomized controlled trial. Three groups of 50-to-69-year-old healthy adults underwent a 12-week RET program (3x/week, 3 sets, 8-12 reps, 70% of maximum strength (1RM)) and submitted >48 diet logs (>4x/week for 12 weeks). Participants' diets were supplemented with 0.7 mg/kg lean/d (low, n = 13), 2.8 mg/kg lean/d (med, n = 11), or 7.5 mg/kg lean/d (high, n = 13) of choline from egg yolk and protein powder. The ANCOVA tests showed that low choline intake, compared with med or high choline intakes, resulted in significantly diminished gains in composite strength (leg press + chest press 1RM; low, 19.4 ± 8.2%; med, 46.8 ± 8.9%; high, 47.4 ± 8.1%; p = 0.034) and thigh-muscle quality (leg press 1RM/thigh lean mass; low, 12.3 ± 9.6%; med/high, 46.4 ± 7.0%; p = 0.010) after controlling for lean mass, protein, betaine, and vitamin B12. These data suggest that low choline intake may negatively affect strength gains with RET in older adults.

Association of the Mediterranean Dietary Quality Index with handgrip strength and muscle endurance: A cross‐sectional study

Mediterranean diet is a healthy eating pattern associated with various health advantages. Different scoring methods of adherence to this diet have been used to investigate the association between the Mediterranean diet and muscle outcomes. The present study aimed to investigate the association of the Mediterranean Dietary Quality Index (Med‐DQI) with handgrip strength (HS) and muscle endurance (ME). The current cross‐sectional study involved 268 Iranian adults aged 18–70 years. Anthropometric measures were evaluated. We used the 168‐item food frequency questionnaire (FFQ) to develop the Med‐DQI score. The Med‐DQI score ranges from 0 to 14 (lower score suggests higher adherence to Mediterranean diet). HS was measured by a digital handgrip dynamometer, and ME was the amount of time to reach a maximum of 50% of grip strength. Multiple regression analysis was used to determine the association of Med‐DQI and its components with HS and ME. Med‐DQI score was not associated with mean handgrip strength (MHS) (p = .34) and mean muscle endurance (MME) (p = .69) in the crude model. The associations remained insignificant after the adjustment of covariates (p = .16, .31, respectively). Among the components of Med‐DQI, cholesterol, meats, fish, and cereals were positively correlated with MHS (p < .001 for all). Meats (p = .02), olive oil (p < .001), cereals (p = .04), fruits and vegetables (p < .001 for all) were also positively correlated with MME. According to our findings, Med‐DQI score is not associated with MHS and MME in a population of Iranian adults. Further longitudinal studies are required to confirm these findings.

Potential Benefits of Combined Statin and Metformin Therapy on Resistance Training Response in Older Individuals

Metformin and statins are currently the focus of large clinical trials testing their ability to counter age-associated declines in health, but recent reports suggest that both may negatively affect skeletal muscle response to exercise. However, it has also been suggested that metformin may act as a possible protectant of statin-related muscle symptoms. The potential impact of combined drug use on the hypertrophic response to resistance exercise in healthy older adults has not been described. We present secondary statin analyses of data from the MASTERS trial where metformin blunted the hypertrophy response in healthy participants (&gt;65 years) following 14 weeks of progressive resistance training (PRT) when compared to identical placebo treatment (n = 94). Approximately one-third of MASTERS participants were taking prescribed statins. Combined metformin and statin resulted in rescue of the metformin-mediated impaired growth response to PRT but did not significantly affect strength. Improved muscle fiber growth may be associated with medication-induced increased abundance of CD11b+/CD206+ M2-like macrophages. Sarcopenia is a significant problem with aging and this study identifies a potential interaction between these commonly used drugs which may help prevent metformin-related blunting of the beneficial effects of PRT.

Trial Registration: ClinicalTrials.gov, NCT02308228, Registered on 25 November 2014.

Angiotensin II receptor blocker and statin combination therapy associated with higher skeletal muscle index in patients with cardiovascular disease: A retrospective study

WHAT IS KNOWN AND OBJECTIVE

Reduction in skeletal muscle mass is the most important component in diagnosing sarcopenia. Ageing and chronic heart failure due to cardiovascular diseases (CVDs) accelerate the reduction of skeletal muscles. However, there are no currently available drugs that are effective for sarcopenia. The purpose of this study was to explore the association between prescribed medications and skeletal muscle mass in patients with CVD.

METHODS

This was a single-centre, retrospective, cross-sectional study. The subjects were 636 inpatients with CVD who took prescribed medicines for at least 4 weeks at the time of admission. Skeletal muscle volume was assessed using a bioelectrical impedance assay.

RESULTS AND DISCUSSION

Single regression analysis showed that 10 and 3 medications were positively and negatively associated with skeletal muscle index (SMI), respectively. Stepwise multivariate regression analysis revealed that angiotensin II receptor blocker (ARB)/statin combination, dipeptidyl peptidase-4 inhibitor, and antihyperuricemic agents were positively associated with SMI while diuretics and antiarrhythmic agents were negatively associated with SMI. After adjustment using propensity score matching, the SMI was found to be significantly higher in ARB/statin combination users than in non-users.

WHAT IS NEW AND CONCLUSION

Combination use of ARB/statin was associated with a higher SMI in patients with CVD. A future randomised, controlled trial is warranted to determine whether the ARB/statin combination will increase the SMI and prevent sarcopenia in patients with CVD.

Short-term high-fat diet induces muscle fiber type-selective anabolic resistance to resistance exercise

Chronic obesity and insulin resistance are considered to inhibit contraction-induced muscle hypertrophy, through impairment of mammalian target of rapamycin complex 1 (mTORC1) and muscle protein synthesis (MPS). A high-fat diet is known to rapidly induce obesity and insulin resistance within a month. However, the influence of a short-term high-fat diet on the response of mTORC1 activation and MPS to acute resistance exercise (RE) is unclear. Thus the purpose of this study was to investigate the effect of a short-term high-fat diet on the response of mTORC1 activation and MPS to acute RE. Male Sprague-Dawley rats were randomly assigned to groups and fed a normal diet, high-fat diet, or pair feed for 4 wk. After dietary habituation, acute RE was performed on the gastrocnemius muscle via percutaneous electrical stimulation. The results showed that 4 wk of a high fat-diet induced intramuscular lipid accumulation and insulin resistance, without affecting basal mTORC1 activity or MPS. The response of RE-induced mTORC1 activation and MPS was not altered by a high-fat diet. On the other hand, analysis of each fiber type demonstrated that response of MPS to an acute RE was disappeared specifically in type I and IIa fiber. These results indicate that a short-term high-fat diet causes anabolic resistance to acute RE, depending on the fiber type.NEW & NOTEWORTHY A high-fat diet is known to rapidly induce obesity, insulin resistance, and anabolic resistance to nutrition within a month. However, the influence of a short-term high-fat diet on the response of muscle protein synthesis to acute resistance exercise is unclear. We observed that a short-term high-fat diet causes obesity, insulin resistance, intramuscular lipid droplet accumulation, and anabolic resistance to resistance exercise specifically in type I and IIa fibers.

How to Overcome Anabolic Resistance in Dialysis-Treated Patients?

A current hypothesis is that dialysis-treated patients are "anabolic resistant" i. e., their muscle protein synthesis (MPS) response to anabolic stimuli is blunted, an effect which leads to muscle wasting and poor physical performance in aging and in several chronic diseases. The importance of maintaining muscle mass and MPS is often neglected in dialysis-treated patients; better than to describe mechanisms leading to energy-protein wasting, the aim of this narrative review is to suggest possible strategies to overcome anabolic resistance in this patient's category. Food intake, in particular dietary protein, and physical activity, are the two major anabolic stimuli. Unfortunately, dialysis patients are often aged and have a sedentary behavior, all conditions which per se may induce a state of "anabolic resistance." In addition, patients on dialysis are exposed to amino acid or protein deprivation during the dialysis sessions. Unfortunately, the optimal amount and formula of protein/amino acid composition in supplements to maximixe MPS is still unknown in dialysis patients. In young healthy subjects, 20 g whey protein maximally stimulate MPS. However, recent observations suggest that dialysis patients need greater amounts of proteins than healthy subjects to maximally stimulate MPS. Since unneccesary amounts of amino acids could stimulate ureagenesis, toxins and acid production, it is urgent to obtain information on the optimal dose of proteins or amino acids/ketoacids to maximize MPS in this patients' population. In the meantime, the issue of maintaining muscle mass and function in dialysis-treated CKD patients needs not to be overlooked by the kidney community.

High-Intensity Interval Aerobic Resistance Training to Counteract Low Relative Appendicular Lean Soft Tissue Mass in Middle Age: Study Protocol for a Randomized Controlled Trial

BACKGROUND

Sarcopenia is the age-related loss of skeletal muscle mass and function and may exist in early middle age. Previous research in this area has focused on resistance training in older individuals; however, there is a lack of intervention trials in middle-aged adults with low relative appendicular lean soft tissue mass who may be at risk for sarcopenia in older age.

OBJECTIVE

This randomized controlled trial aims to determine the effects of a high-intensity interval aerobic resistance training intervention on appendicular lean soft tissue mass in middle-aged adults with low relative appendicular lean soft tissue mass.

METHODS

We will conduct a 40-week, single-blinded randomized controlled trial in 84 middle-aged adults with low appendicular lean soft tissue mass in the wider Dunedin area, New Zealand. We will randomly allocate participants to receive either a group-based, 20-week high-intensity interval aerobic resistance training intervention program or a single, 60-minute education session on current exercise recommendations. After the first 20 weeks, both groups will be given a 20-week home program. The study will assess primary and secondary outcome measures, including body composition (regional and whole-body lean soft tissue mass, fat mass, percentage body fat, measured by dual x-ray absorptiometry), blood biomarkers (cortisol, creatinine, C-reactive protein, lipid profile, hemoglobin), physical fitness (maximum oxygen consumption, blood pressure), physical activity (accelerometry), physical function (handgrip strength, sit-to-stand, gait speed, quadriceps strength), and self-reported questionnaires (health outcomes, self-efficacy, perceived enjoyment of physical activity, and multifactorial lifestyle), at baseline, 20 weeks, and 40 weeks. Physical function and self-reported questionnaires will also be measured at 10 weeks. We will assess the primary outcome measure, total body lean soft tissue mass, at baseline, 20 weeks, and 40 weeks. Analyses will be performed using intention-to-treat principles, comparing the outcomes resulting from the intervention, using linear mixed models.

RESULTS

We obtained ethical approval for this study from The University of Otago Human Ethics Committee on December 10, 2018. Participant recruitment started on February 11, 2019 and was completed on May 14, 2019. Data collection started on February 25, 2019 and was completed on February 28, 2020. We expect to publish the results in January 2021.

CONCLUSIONS

High-intensity interval aerobic resistance training is a time-efficient form of exercise, enabling busy middle-aged adults to meet physical activity recommendations while maximizing training results. The findings can inform the development of future prevention-focused interventions aimed at counteracting the high prevalence of sarcopenia in the aging population.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ACTRN12618001778279); https://tinyurl.com/y555z6fz.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/22989.

Functional training added to intradialytic cycling lowers low-density lipoprotein cholesterol and improves dialysis adequacy: a randomized controlled trial

Background

Exercise has various positive effects on hemodialysis patients. However, there is no clear evidence which type of exercise yields better results. This study aimed to determine the effects of guided functional training added to the intradialytic cycling on dialysis adequacy and biochemical parameters in hemodialysis patients. Additionally, we aimed to investigate if patients could transfer functional exercise to an unsupervised home environment and retain gained improvements.

Methods

Randomization was done to a functional training intervention group (INT) (n = 20) or intradialytic cycling control group (CON) (n = 20). The INT attended a pre-dialysis functional training in the first 8 weeks. In the second 8 weeks, they performed functional exercises at unsupervised home environment on non-dialysis days. During the whole study, both groups participated in the intradialytic cycling program.

Results

Both groups demonstrated a significant increase in dialysis adequacy (Kt/V) in the eight (0.15, 95% CI 0.06 to 0.24; p = 0.003 for INT and 0.21, 95% CI 0.11 to 0.3; p < 0.001 for CON) and the 16th study week (0.13, 95% CI 0.03 to 0.24; p = 0.017 for INT and 0.13, 95% CI 0.03 to 0.22; p = 0.013 for CON) compared to their baseline values with no significant between-group differences. At week eight, the total cholesterol was significantly lowered in the INT (− 0.34 mmol/L, 95% CI − 0.6 to − 0.07; p = 0.016) and remained lower at week 16 (− 0.32 mmol/L, 95% CI − 0.64 to − 0.01; p = 0.049) with no significant changes in the CON. Low-density lipoprotein levels in the INT were significantly reduced after 8 weeks (− 0.35 mmol/L, 95% CI − 0.64 to − 0.06; p = 0.022) and remained reduced after 16 weeks (− 0.28 mmol/L, 95% CI − 0.52 to − 0.03; p = 0.030). There were no significant differences found for albumin, high-density lipoprotein cholesterol, triglycerides, C-reactive protein, and hemoglobin in both groups.

Conclusions

We demonstrated that functional training added to intradialytic cycling improved lipid profile and dialysis adequacy. Additionally, the effects of the unsupervised, home-based program were preserved during the second study phase. This study supports the assumption that combined training is more effective compared to solely intradialytic exercise.

Trial registration

ClinicalTrials.Gov, NCT03334123. Registered 07 November 2017.

Inflammation Strikes Again: Frailty and HIV

PURPOSE OF REVIEW

As a consequence of antiretroviral therapy, the proportion of older HIV-infected adults is increasing, with a concomitant shift in burden of illness to age-related syndromes and disease. Frailty is an age-related syndrome of increased vulnerability to stress, predictive of major adverse clinical outcomes among HIV-infected and uninfected persons alike. Understanding frailty pathogenesis is critical to developing interventions to improve health outcomes in HIV. Here, we review the current evidence for the relationship between inflammation and frailty in HIV, and the potential for novel, inflammation-targeted interventions.

RECENT FINDINGS

Dysregulated inflammation has been consistently associated with frailty in elderly HIV-uninfected persons. Dysregulated inflammation is also central to HIV pathophysiology and several recent studies have demonstrated the important association of inflammation with frailty in HIV. Some evidence suggests that anti-inflammatory therapies may be effective in ameliorating the adverse impact of frailty among aging HIV-infected adults, though further investigation is necessary. Inflammation has been implicated in frailty in HIV infection, and improved understanding of the role that inflammation plays in frailty pathogenesis is key to the development of effective therapies to slow or prevent frailty in the vulnerable HIV-infected population.

The effects of hindlimb unloading versus dietary cholesterol and resistance training on rat skeletal muscle responses

Background

The loss of muscle mass and concomitantly strength, poses a serious risk to the elderly and to astronauts. Dietary cholesterol (CL), in conjunction with resistance training (RT), has been strongly associated with improvements in lean mass. The purpose of this study was to examine the effects of two opposing environments on rat skeletal muscle: (1) hindlimb unloading and (2) CL and RT.

Methods

In protocol 1, 13 male Sprague-Dawley rats were unloaded for 28 days (HU; n = 6) or served as cage controls (CC; n = 7). In protocol 2, 42 rats were assigned to 1 of 6 groups: CC (n = 7), CC + CL (n = 4), RT controls (RTC; n = 7), RTC + CL (n = 8), RT (n = 8) and RT + CL (n = 8). RT/RTC consisted of squat-like exercise. RT had weights added progressively from 80 to 410 g over 5 weeks. CL was supplemented in the chow with either 180 ppm (controls) or 1800 ppm (CL). Lower limb muscles were harvested at the end of both protocols and analyzed by Western Blotting for sterol regulatory element-binding protein-2 (SREBP-2) and low-density lipoprotein-receptor (LDL-R) and protein synthesis.

Results

Gastrocnemius and plantaris masses and their body mass ratios were significantly lower in the HU rats than control rats. The RT rats gained significantly less body and lean mass than the RTC groups, but the plantar flexor muscles did not show any significant differences among groups. Moreover, RT groups had significantly higher plantaris mixed muscle fractional synthesis rate (FSR) than the RTC and CC animals, with the CL groups showing greater FSR than control rats. No significant differences among groups in SREBP-2 or LDL-R were observed in either protocol.

Conclusions

These studies provide evidence for a relationship between skeletal muscle and cholesterol metabolism, but the exact nature of that association remains unclear.

Selective prescribing of statins and the risk of mortality, hospitalizations, and falls in aged care services

BACKGROUND

Compared to randomized controlled trials, nonexperimental studies often report larger survival benefits but higher rates of adverse events for statin use vs nonuse.

OBJECTIVE

We compared characteristics of statin users and nonusers living in aged care services and evaluated the relationships between statin use and all-cause mortality, all-cause and fall-related hospitalizations, and number of falls during a 12-month follow-up.

METHODS

A prospective cohort study of 383 residents aged ≥65 years was conducted in six Australian aged care services. Data were obtained from electronic medical records and medication charts and through a series of validated assessments.

RESULTS

The greatest differences between statin users and nonusers were observed in activities of daily living, frailty, and medication use (absolute standardized difference >0.40), with users being less dependent and less frail but using a higher number of medications. Statin use was associated with a decreased risk of all-cause mortality (adjusted hazard ratio [HR] 0.58, 95% confidence interval [CI] 0.37-0.93) and hospitalizations (HR 0.67, 95% CI 0.46-0.98). After exclusion of residents unable to sit or stand, statin use was associated with a nonsignificant increase in the risk of fall-related hospitalizations (HR 1.47, 95% CI 0.80-2.68) but with a lower incidence of falls (incidence rate ratio 0.67, 95% CI 0.47-0.96).

CONCLUSIONS

The observed associations between statin use and the outcomes may be largely explained by selective prescribing and deprescribing of statins and variation in likelihood of hospitalization based on consideration of each resident's clinical and frailty status. Randomized deprescribing trials are needed to guide statin prescribing in this setting.

Single-Arm Resistance Training Study to Determine the Relationship between Training Outcomes and Muscle Growth Factor mRNAs in Older Adults Consuming Numerous Medications and Supplements

OBJECTIVES

Determine if the muscle mRNA levels of three growth factors (insulin-like growth factor-1 [IGF1], ciliary neurotropic factor [CNTF], and vascular endothelial growth factor-D [VEGFD]) are correlated with muscle size and strength gains from resistance exercise while piloting a training program in older adults taking medications and supplements for age-associated problems.

DESIGN

Single-arm prospective study.

SETTING

US Veterans Affairs hospital.

PARTICIPANTS

Older (70±6 yrs) male Veterans (N=14) of US military service.

INTERVENTION

Thirty-five sessions of high-intensity (80% one-rep max) resistance training including leg press, knee curl, and knee extension to target the thigh muscles.

MEASUREMENTS

Vastus lateralis biopsies were collected and body composition (DEXA) was determined pre- and post-training. Simple Pearson correlations were used to compare training outcomes to growth factor mRNA levels and other independent variables such as medication and supplement use.

RESULTS

Average strength increase for the group was ≥ 25% for each exercise. Subjects averaged taking numerous medications (N=5±3) and supplements (N=2±2). Of the growth factors, a significant correlation (R>0.7, P≤0.003) was only found between pre-training VEGFD and gains in lean thigh mass and extension strength. Mass and strength gains were also correlated with use of α-1 antagonists (R=0.55, P=0.04) and pre-training lean mass (R=0.56, P=0.04), respectively.

CONCLUSIONS

Muscle VEGFD, muscle mass, and use of α-1 antagonists may be predisposing factors that influence the response to training in this population of older adults but additional investigation is required to determine if these relationships are due to muscle angiogenesis and blood supply.

Safety and Effectiveness of Statins for Prevention of Recurrent Myocardial Infarction in 12 156 Typical Older Patients: A Quasi-Experimental Study

BACKGROUND

There is limited evidence on statin risk and effectiveness for patients aged 80+. We estimated risk of recurrent myocardial infarction, muscle-related and other adverse events, and statin-related incremental costs in "real-world" older patients treated with statins versus no statins.

METHODS

We used primary care electronic medical records from the UK Clinical Practice Research Datalink. Subhazard ratios (competing risk of death) for myocardial infarction recurrence (primary end point), falls, fractures, ischemic stroke, and dementia, and hazard ratios (Cox) for all-cause mortality were used to compare older (60+) statin users and 1:1 propensity-score-matched controls (n = 12,156). Participants were followed-up for 10 years.

RESULTS

Mean age was 76.5±9.2 years; 45.5% were women. Statins were associated with near significant reduction in myocardial infarction recurrence (subhazard ratio = 0.84, 0.69-1.02, p = .073), with protective effect in the 60-79 age group (0.73, 0.57-0.94) but a nonsignificant result in the 80+ group (1.06, 0.78-1.44; age interaction p = .094). No significant associations were found for stroke or dementia. Data suggest an increased risk of falls (1.36, 1.17-1.60) and fractures (1.33, 1.04-1.69) in the first 2 years of treatment, particularly in the 80+ group. Treatment was associated with lower all-cause mortality. Statin use was associated with health care cost savings in the 60-79 group but higher costs in the 80+ group.

CONCLUSIONS

Estimates of statin effectiveness for the prevention of recurrent myocardial infarction in patients aged 60-79 years were similar to trial results, but more evidence is needed in the older group. There may be an excess of falls and fractures in very old patients, which deserves further investigation.

Cardiac cachexia: hic et nunc

Cardiac cachexia (CC) is the clinical entity at the end of the chronic natural course of heart failure (HF). Despite the efforts, even the most recent definition of cardiac cachexia has been challenged, more precisely, the addition of new criteria on top of obligatory weight loss. The pathophysiology of CC is complex and multifactorial. A better understanding of pathophysiological pathways in body wasting will contribute to establish potentially novel treatment strategies. The complex biochemical network related with CC and HF pathophysiology underlines that a single biomarker cannot reflect all of the features of the disease. Biomarkers that could pick up the changes in body composition before they convey into clinical manifestations of CC would be of great importance. The development of preventive and therapeutic strategies against cachexia, sarcopenia, and wasting disorders is perceived as an urgent need by healthcare professionals. The treatment of body wasting remains an unresolved challenge to this day. As CC is a multifactorial disorder, it is unlikely that any single agent will be completely effective in treating this condition. Among all investigated therapeutic strategies, aerobic exercise training in HF patients is the most proved to counteract skeletal muscle wasting and is recommended by treatment guidelines for HF.

Effects of 96 Weeks of Rosuvastatin on Bone, Muscle, and Fat in HIV-Infected Adults on Effective Antiretroviral Therapy

Heightened inflammation and immune activation are associated with lower bone mineral density (BMD) and lean body mass (LBM) among HIV-infected persons. We hypothesized that a reduction in inflammation with rosuvastatin would be associated with improvements in BMD and LBM. HIV-infected participants on stable antiretroviral therapy without statin indication and with heightened immune activation (≥19% CD8(+)CD38(+)HLA-DR(+) T cells) or inflammation (hsCRP ≥2 mg/liter) were randomized to rosuvastatin 10 mg daily or placebo for 96 weeks. Among 72 participants randomized to rosuvastatin and 75 to placebo, there were no significant differences in the relative changes in BMD (p > 0.29) or in fat (p ≥ 0.19). A trend toward increased LBM (p = 0.059) was seen in the rosuvastatin arm without differences in creatinine kinase or self-reported physical activity (p ≥ 0.10). In a multivariable regression model, rosuvastatin was associated with a significant positive effect on LBM after adjusting for age, sex, race, smoking status, and detectable HIV-1 viral load. Higher baseline sCD163 correlated with increases in LBM from weeks 0 to 96 (p = 0.023); greater changes in total and leg lean mass were seen among statin users with higher compared to lower baseline IP-10 levels (LBM 1.8 vs. -0.3%; p = 0.028 and leg lean mass 2.9 vs. -1.7%; p = 0.012). Rosuvastatin is associated with an absence of toxicity on BMD and a potential benefit on LBM over 96 weeks of therapy. The preservation of LBM in the rosuvastatin arm over the 2 years of the study is of major clinical relevance in delaying loss of muscle mass with aging.

Effect of Statin Use on Mobility Disability and its Prevention in At-risk Older Adults: The LIFE Study

BACKGROUND

HMG-CoA reductase inhibitors (statins) are among the most commonly prescribed classes of medications. Although their cardiovascular benefits and myalgia risks are well documented, their effects on older adults initiating an exercise training program are less understood.

METHODS

1,635 sedentary men and women aged 70-89 years with Short Physical Performance Battery (SPPB) score of 9 or below and were able to walk 400 m were randomized to a structured, moderate-intensity physical activity (PA) program consisting of both center-based (twice/wk) and home-based (3-4 times/wk) aerobic, resistance, and flexibility training or to a health education (HE) program combined with upper extremity stretching.

RESULTS

Overall, the PA intervention was associated with lower risk of major mobility disability (hazard ratio [HR] = 0.82; 95% confidence interval [CI] = 0.69-0.98). The effect was similar (p value for interaction = .62) in both statin users (PA n = 415, HE n = 412; HR = 0.86, 95% CI = 0.67-1.1) and nonusers (PA n = 402, HE n = 404; HR = 0.78, 95% CI = 0.61-1.01). Attendance was similar for statin users (65%) and nonusers (63%). SPPB at 12 months was slightly greater for PA (8.35±0.10) than for HE (7.94±0.10) in statin users but not in nonusers (PA 8.25±0.10, HE 8.16±0.10), though the interaction effect was not statistically significant. Self-reported PA levels were not different between statin users and nonusers.

CONCLUSIONS

Although statins have been associated with adverse effects on muscle, data from the LIFE Study show that statin users and nonusers both benefit from PA interventions. Older adults who require statin medications to manage chronic medical conditions and are sedentary will be able to benefit from interventions to increase PA.

High Intensity Resistance Training Methods with and without Protein Supplementation to Fight Cardiometabolic Risk in Middle-Aged Males: A Randomized Controlled Trial

Time-effective protocols may potentially increase people's compliance with exercise. The purpose of this paper was to compare the relative effects of 16 weeks of high intensity (resistance) training (HIT) with and without protein supplementation (HIT&P) and HVHIT (high volume/high intensity training) versus a nontraining control group on cardiometabolic risk factors. One hundred and twenty untrained males 30–50 years old were randomly assigned to 3 subgroups: (a) a HIT group; (b) a HIT&P group, and (c) a waiting-control group (phase I) that crossed over to (d) high volume/high intensity training (HVHIT) during the second study phase. HIT was defined as “single set to failure protocol” while HVHIT consistently applied two sets. Protein supplementation provided an overall intake of 1.5 g/kg/body mass. Primary study endpoint was the metabolic syndrome Z-Score (MetS-Z-Score). MetS-Z-Score significantly improved in all exercise groups (p ≤ 0.001) with no significant difference between HIT, HIT&P, and HVHIT (p ≥ 0.829). However, all the exercise groups differed significantly from the CG (p < 0.001) which deteriorated significantly (p = 0.039). In conclusion, all exercise protocols were similarly effective in improving cardiometabolic risk factors. Thus, HIT may be the best choice for people with low time budgets looking to improve their cardiometabolic health.

[Statin intolerance and associated muscular dysfunctions]

Hypercholesterolemia is a major risk factor for cardiovascular diseases. The 2012-2013 survey of Canada's public health measures revealed that dyslipidemia was present in 38% of the respondents aged between 18 and 79 years. According to the American College of Cardiology, the American Heart Association, the Canadian Cardiovascular Society and the Canadian Working Group Consensus, statins remain the treatment of choice for dyslipidemia and the reduction of cardiovascular risk. However, concerns and questions persist regarding statins use and safety, potential and harmful muscular side-effects, interactions with exercise, and molecular mechanisms of myotoxicity. The goal of the present review is to provide a clear picture of the clinical situation and to investigate possible mechanisms of statin-induced myopathy. A better understanding of muscle pathology in statin users is absolutely essential to minimize their muscle symptoms and to provide a sound clinical basis for the management of cardiovascular risk.

Cardiac cachexia: hic et nunc: "hic et nunc" - here and now

Cardiac cachexia (CC) is the clinical entity at the end of chronic natural course of heart failure (HF). Despite the efforts, even the most recent definition of cardiac cachexia has been challenged, more precisely the addition of new criteria on top of obligatory weight loss. The pathophysiology of CC is complex and multifactorial. Better understanding of pathophysiological pathways in body wasting will contribute to establish potentially novel treatment strategies. The complex biochemical network related with CC and HF pathophysiology underlines that a single biomarker cannot reflect all of the features of the disease. Biomarkers that could pick-up the changes in body composition before they convey into clinical manifestations of CC would be of great importance. The development of preventive and therapeutic strategies against cachexia, sarcopenia and wasting disorders is perceived as an urgent need by healthcare professionals. The treatment of body wasting remains an unresolved challenge to this day. As CC is a multifactorial disorder, it is unlikely that any single agent will be completely effective in treating this condition. Among all investigated therapeutic strategies, aerobic exercise training in HF patients is the most proved to counteract skeletal muscle wasting and is recommended by treatment guidelines for HF.

Skeletal muscle microRNA and messenger RNA profiling in cofilin-2 deficient mice reveals cell cycle dysregulation hindering muscle regeneration

Congenital myopathies are rare skeletal muscle diseases presenting in early age with hypotonia and weakness often linked to a genetic defect. Mutations in the gene for cofilin-2 (CFL2) have been identified in several families as a cause of congenital myopathy with nemaline bodies and cores. Here we explore the global messenger and microRNA expression patterns in quadriceps muscle samples from cofillin-2-null mice and compare them with sibling-matched wild-type mice to determine the molecular pathways and mechanisms involved. Cell cycle processes are markedly dysregulated, with altered expression of genes involved in mitotic spindle formation, and evidence of loss of cell cycle checkpoint regulation. Importantly, alterations in cell cycle, apoptosis and proliferation pathways are present in both mRNA and miRNA expression patterns. Specifically, p21 transcript levels were increased, and the expression of p21 targets, such as cyclin D and cyclin E, was decreased. We therefore hypothesize that deficiency of cofilin-2 is associated with interruption of the cell cycle at several checkpoints, hindering muscle regeneration. Identification of these pathways is an important step towards developing appropriate therapies against various congenital myopathies.

Effects of randomized rosuvastatin compared with placebo on bone and body composition among HIV-infected adults

BACKGROUND

Statins have a beneficial effect on bone mineral density (BMD) and lean mass in some studies of HIV-uninfected adults; however, this has never been investigated in the setting of HIV infection.

DESIGN

HIV-infected individuals on stable antiretroviral therapy with a low-density lipoprotein cholesterol level of 130 mg/dl or less and evidence of heightened immune activation or inflammation were randomized to rosuvastatin 10 mg daily or placebo for 96 weeks.

METHODS

This was a prespecified interim analysis at 48 weeks. Between-group and within-group differences were compared; multivariable regression models were constructed.

RESULTS

Seventy-two individuals were randomized to statin therapy and 75 to placebo. Modest 48-week relative increases in trochanter BMD [0.9%; 95% confidence interval (95% CI) -0.9 to 0.6] and total hip BMD (0.6%; 95% CI 0.0-1.1) in the statin arm were significantly greater than placebo (P < 0.05). The relationship between statin use and total hip BMD change was robust to adjustment of age, sex, race and smoking status (P = 0.02) and strengthened by inclusion of baseline (P = 0.01) and week 48 change in soluble tumour necrosis factor-α receptor (sTNFR)-1 (P = 0.009). Relative increases in total body, trunk and limb fat were similar between statin and placebo arms (P ≥ 0.58). Although a significant gain in leg lean mass was seen in the statin arm, this was not significantly different compared with placebo (P = 0.36).

CONCLUSION

The improvements seen in total hip BMD after 48 weeks of rosuvastatin therapy support further potential benefits of statin therapy in HIV, beyond a reduction of cardiovascular risk.

Association between statin use at admission to inpatient rehabilitation and functional status at discharge among older patients

The effect of statins on functional status in older patients is unclear. Statins might carry a deleterious effect on muscle function leading to myopathy and therefore affecting functional recovery. We evaluated the relationship between statin exposure at in-hospital rehabilitation admission and functional outcome at discharge. This was a retrospective cohort study of older patients 70 years and older consecutively admitted to an in-hospital rehabilitation after an acute hospitalization. Statin exposure was measured at the time of rehabilitation admission. Functional status was defined with the Barthel Index (BI) score at the time of discharge. A multi-variable linear regression model was used to evaluate the association between statin exposure and functional status at discharge adjusting for potential confounders through a propensity score for statin exposure. A total of 2435 patients were included. The cohort had a mean age of 81.1 years. Of these 9% (n=220) were on statins at the time of admission. In the multi-variable analysis, the use of statins at the time of admission was independently associated with an improved functional status at discharge (point estimate 5.2; 95% confidence interval 1.5-8.9; p<0.01) after adjusting for relevant confounders. Patients who were receiving statins at the time of admission had a BI score 5 points higher compared to those who were not receiving statins. The use of statins was overall safe in a group of co-morbid older patients undergoing rehabilitation training after an acute hospitalization. Additionally, a possible benefit was found given the positive association between statin use and higher functional status at discharge.

An approach to identify SNPs in the gene encoding acetyl-CoA acetyltransferase-2 (ACAT-2) and their proposed role in metabolic processes in pig

The novel liver protein acetyl-CoA acetyltransferase-2 (ACAT2) is involved in the beta-oxidation and lipid metabolism. Its comprehensive relative expression, in silico non-synonymous single nucleotide polymorphism (nsSNP) analysis, as well as its annotation in terms of metabolic process with another protein from the same family, namely, acetyl-CoA acyltransferase-2 (ACAA2) was performed in Sus scrofa. This investigation was conducted to understand the most important nsSNPs of ACAT2 in terms of their effects on metabolic activities and protein conformation. The two most deleterious mutations at residues 122 (I to V) and 281 (R to H) were found in ACAT2. Validation of expression of genes in the laboratory also supported the idea of differential expression of ACAT2 and ACAA2 conceived through the in silico analysis. Analysis of the relative expression of ACAT2 and ACAA2 in the liver tissue of Jeju native pig showed that the former expressed significantly higher (P<0.05). Overall, the computational prediction supported by wet laboratory analysis suggests that ACAT2 might contribute more to metabolic processes than ACAA2 in swine. Further associations of SNPs in ACAT2 with production traits might guide efforts to improve growth performance in Jeju native pigs.

Fat-free mass and fasting glucose values in patients with and without statin therapy assigned to age groups between <60 and >75 years

OBJECTIVE

The aging-associated changes in body composition result in an increased cardiometabolic risk. A tremendous reduction of cardiovascular morbidity and mortality can be obtained by statin therapy. Statins are well tolerated, with myopathy as the most serious negative side effect. Some recently published studies indicate that the incidence of type 2 diabetes might be increased during intensified statin therapy. The aim of our study was to investigate whether statin therapy has an influence on the aging-associated changes in fat-free mass (FFM).

METHODS

A total of 3,280 persons attending a medical outdoor center between January 2005 and July 2011 were assigned to 3 age groups from <60 to >75 years. Clinical data, body mass index (BMI), and body composition were evaluated in the different age groups in patients with and without statin therapy. To analyze the impact of statin use on FFM, we regressed a patient's FFM on an interaction term between statin use and age and other control variables.

RESULTS

Aging was associated with a decrease in BMI and FFM, while fat mass continuously increased up to the age of >75 years. This was paralleled by a continuous increase in fasting glucose levels in patients with and without statin therapy. The loss of FFM between the age group <60 years and >75 years was more pronounced in statin-treated patients (10.88%) than in non-statin users (8.47%). Creatine phosphokinase values revealed a decrease of 7.77 U/l between the age groups <60 and >75 years in non-statin users and of 14.75 U/l in statin users. Statistical analysis indicated that the effect of statin therapy on FFM is more pronounced in younger than in older patients.

CONCLUSIONS

Patients under statin therapy seem to be more vulnerable to the aging-associated lowering of FFM. Diagnostic procedures and interventions to prevent a loss of muscle mass might be of particular advantage in elderly patients under statin therapy.

The effects of high-intensity resistance exercise on the blood lipid profile and liver function in hypercholesterolemic hamsters

It is well established that atherogenic dyslipidemia, characterized by high levels of triglycerides (TG), total cholesterol (TC), and low-density lipoprotein (LDL) cholesterol and low levels of high-density lipoprotein (HDL) cholesterol, constitutes important risk factors for cardiovascular disease. Regular exercise has been associated with a reduced risk for metabolic diseases. However, studies supporting the concept that resistance exercise is a modifier of blood lipid parameters are often contradictory. The aim of this study was to investigate the effects of high-intensity resistance exercise on the serum levels of TG, TC, HDL and non-HDL cholesterol, glucose, and the liver function enzymes alanine aminotransferase (ALT, EC 2.6.1.2) and aspartate aminotransferase (AST, EC 2.6.1.1) in golden Syrian hamsters (Mesocricetus auratus (Waterhouse, 1839)) fed a hypercholesterolemic diet. Sedentary groups (S) and exercise groups (E) were fed a standard diet (SS and ES) or a cholesterol-enriched diet (standard plus 1% cholesterol, SC and EC). Resistance exercise was performed by jumps in the water, carrying a load strapped to the chest, representing 10 maximum repetitions (10 RM, 30 s rest, five days per week for five weeks). Mean blood sample comparisons were made by ANOVA + Tukey or ANOVA + Kruskal-Wallis tests (p < 0.05) to compare parametric and nonparametric samples, respectively. There were no differences in blood lipids between the standard diet groups (SS and ES) (p > 0.05). However, the EC group increased the glucose, non-HDL, and TC levels in comparison with the ES group. Moreover, the EC group increased the TG levels versus the SC group (p < 0.05). In addition, the ALT levels were increased only by diet treatment. These findings indicated that high-intensity resistance exercise contributed to dyslipidemia in hamsters fed a hypercholesterolemic diet, whereas liver function enzymes did not differ in regards to the exercise protocol.

Sarcopenia: designing phase IIB trials

Sarcopenia is the age-related involuntary loss of skeletal muscle mass and functionality that can lead to the development of disability, frailty and increased health care costs. The development of interventions aimed at preventing and/or treating sarcopenia is complex, requiring the adoption of assumptions and standards that are not well established scientifically or clinically. A number of investigators and clinicians (both from academia and industry) met in Rome (Italy) in 2009 to develop a consensus definition of sarcopenia. Subsequently, in Albuquerque (New Mexico, USA) in 2010, the same group met again to consider the complex issues necessary for designing Phase II clinical trials for sarcopenia. Current clinical trial data indicate that fat-free mass (FFM) parameters are responsive to physical activity/nutritional treatment modalities over short time periods, but pharmacological trials of sarcopenia have yet to show significant efficacy. In order to conduct a clinical trial within a reasonable time frame, groups that model or display accelerated aging and loss of FFM are necessary. Few studies have used acceptable designs for testing treatment effects, sample sizes or primary outcomes that could provide interpretable findings or effects across studies. Dual energy x-ray absorptiometry (DXA) is the measure of choice for assessing FFM, but sufficient time is needed for changes to be detected accurately and reliably. A tool set that would allow clinical, basic and epidemiological research on sarcopenia to advance rapidly toward diagnosis and treatment phases should be those reflecting function and strength.

Current and future pharmacologic treatment of sarcopenia

Sarcopenia is a complex multifactorial condition that can by treated with multimodal approaches. No pharmacologic agent to prevent or treat sarcopenia has been as efficacious as exercise (mainly resistance training) in combination with nutritional intervention (adequate protein and energy intake). However, performing resistance training sessions and following nutritional advice can be challenging, especially for frail, sarcopenic, elderly patients, and results remain only partial. Therefore, new pharmacologic agents may substantially reduce the functional decline in older people. This article reviews the new pharmacologic agents currently being assessed for treating sarcopenia.

Influence of resistance exercise on lean body mass in aging adults: a meta-analysis

PURPOSE

sarcopenia plays a principal role in the pathogenesis of frailty and functional impairment that occur with aging. There are few published accounts that examine the overall benefit of resistance exercise (RE) for lean body mass (LBM) while considering a continuum of dosage schemes and/or age ranges. Therefore, the purpose of this meta-analysis was to determine the effects of RE on LBM in older men and women while taking these factors into consideration.

METHODS

this study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. Randomized controlled trials and randomized or nonrandomized studies among adults ≥ 50 yr were included. Heterogeneity between studies was assessed using the Cochran Q and the I statistics, and publication bias was evaluated through physical inspection of funnel plots as well as formal rank-correlation statistics. Mixed-effects meta-regression was incorporated to assess the relationship between RE dosage and changes in LBM.

RESULTS

data from 49 studies, representing a total of 1328 participants, were pooled using random-effect models. Results demonstrated a positive effect for LBM, and there was no evidence of publication bias. The Cochran Q statistic for heterogeneity was 497.8, which was significant (P < 0.01). Likewise, I was equal to 84%, representing rejection of the null hypothesis of homogeneity. The weighted pooled estimate of mean LBM change was 1.1 kg (95% confidence interval = 0.9-1.2 kg). Meta-regression revealed that higher-volume interventions were associated (β = 0.05, P < 0.01) with significantly greater increases in LBM, whereas older individuals experienced less increase (β = -0.03, P = 0.01).

CONCLUSIONS

RE is effective for eliciting gains in LBM among aging adults, particularly with higher-volume programs. Findings suggest that RE participation earlier in life may provide superior effectiveness.

Does habitual dietary intake influence myofiber hypertrophy in response to resistance training? A cluster analysis

Although resistance exercise training (RT) is a common intervention to stimulate muscle protein synthesis and increase skeletal muscle mass, the optimal daily protein and total energy intakes sufficient to support RT-mediated muscle growth are as yet unclear. Further, the efficacy of RT varies widely among adults of all ages and whether this is attributable to interindividual differences in nutrition is not known. To determine if self-selected daily intake of macronutrients and specific components of dietary protein and fat are predictive of the magnitude of RT-mediated muscle growth, detailed 4-day dietary records were analyzed on 60 subjects previously clustered (K-means cluster analysis) as non-, modest, and extreme responders (non, n = 16; mod, n = 29; xtr, n = 15), based on the magnitudes of change in vastus lateralis myofiber cross-sectional area following a 16-week, 3-day-per-week, high-intensity RT. Despite the marked contrast between 60% myofiber hypertrophy in xtr and zero growth in non, we found no differences among response clusters in daily intakes of energy (mean +/- SEM: non 102 +/- 8; mod 111 +/- 6; xtr 109 +/- 5 kJ.kg-1.day-1), protein (non 0.97 +/- 0.08; mod 1.07 +/- 0.07; xtr 1.05 +/- 0.06 g.kg-1.day-1), carbohydrate (non 3.02 +/- 0.24; mod 3.18 +/- 0.20; xtr 3.14 +/- 0.17 g.kg-1.day-1), and fat (non 0.95 +/- 0.09; mod 1.05 +/- 0.08; xtr 1.03 +/- 0.08 g.kg-1.day-1), which generally met or exceeded dietary recommendations. There were no cluster differences in intakes of branched chain amino acids known to stimulate muscle protein synthesis. Using the novel K-means clustering approach, we conclude from this preliminary study that protein and energy intakes were sufficient to facilitate modest and extreme muscle growth during RT and intrinsic or extrinsic factors other than nutrient ingestion apparently impaired the anabolic response in nonresponders.

Validated treatments and therapeutics prospectives regarding pharmacological products for sarcopenia

Loss of physical function in older adults may be, at least in part, explained by sarcopenia, a phenomenon characterized by a reduction in number and size of muscle fibres and by increase in interstitial fat and connective tissue. Lifestyle intervention (i.e. physical activity and nutrition) have shown to impact on sarcopenia. However, several drugs were suggested, with various levels of scientific evidence, to have an impact on muscle outcomes. In this study we reviewed the effect of six classes of drugs on sarcopenia and muscular outcomes in older adults. We decided to focus our review on two commonly drugs which have recently showed promising effects on muscular outcomes in older adults (ACE inhibitors and statins) and on four drugs whose effect on skeletal muscle was already largely studied (creatine, Growth Hormone, testosterone, estrogens and tibolone).

Statin therapy, muscle function and falls risk in community-dwelling older adults

BACKGROUND

Statin therapy can cause myopathy, however it is unclear whether this exacerbates age-related muscle function declines.

AIM

To describe differences between statin users and non-users in muscle mass, muscle function and falls risk in a group of community-dwelling older adults.

DESIGN

A prospective, population-based cohort study with a mean follow-up of 2.6 years.

METHODS

Total 774 older adults [48% female; mean (standard deviation) age = 62 (7) years] were examined at baseline and follow-up. Differences in percentage appendicular lean mass (%ALM), leg strength, leg muscle quality (LMQ; specific force) and falls risk were compared for statin users and non-users.

RESULTS

There were 147 (19%) statin users at baseline and 179 (23%) at follow-up. Longitudinal analyses revealed statin use at baseline predicted increased falls risk scores over 2.6 years (0.14, 95% CI 0.01 to 0.27) and a trend towards increased %ALM (0.45%, 95% CI -0.01 to 0.92). Statin users at both time points demonstrated decreased leg strength (-5.02 kg, 95% CI -9.65 to -0.40) and LMQ (-0.30 kg/kg, 95% CI -0.59 to -0.01), and trended towards increased falls risk (0.13, 95% CI -0.01 to 0.26) compared to controls. Finally, statin users at both baseline and follow-up demonstrated decreased leg strength (-16.17 kg, 95% CI -30.19 to -2.15) and LMQ (-1.13 kg/kg, 95% CI -2.02 to -0.24) compared to those who had ceased statin use at follow-up.

CONCLUSION

Statin use may exacerbate muscle performance declines and falls risk associated with aging without a concomitant decrease in muscle mass, and this effect may be reversible with cessation.

A randomized controlled trial of Kung Fu training for metabolic health in overweight/obese adolescents: the "martial fitness" study

Twenty overweight/obese adolescents underwent six months of Kung Fu or placebo (Tai Chi) training, 3x.wk(-1). Outcomes included fasting insulin and insulin resistance, lipids, glucose and HbA(1c), and C-reactive protein (CRP). CRP decreased significantly (p = 0.03) in both groups over time at six months. Although insulin sensitivity did not change, HbA(1c) tended to decrease over time (p = 0.09), again with no group difference (p = 0.60). Reduced CRP was related to increased upper body strength (p = 0.01). Increased lean body mass was related to reductions in HbA(1c), insulin resistance, triglycerides, and total cholesterol. Improvements in lean body mass appear to have a potential role in favorable metabolic outcomes, independent of changes in fat mass. Further research in this area is warranted before definite conclusions can be drawn about the efficacy of martial arts training for metabolic outcomes in this cohort.

Moderately increased protein intake predominately from egg sources does not influence whole body, regional, or muscle composition responses to resistance training in older people

The effects of increased dietary protein on resistance training (RT)-induced changes in body composition and skeletal muscle fiber size are uncertain in older people.

OBJECTIVES

We hypothesized that the ingestion of more animal-based foods, especially eggs, to achieve a higher protein intake would enhance RT-induced changes in body composition.

SETTING

West Lafayette, IN.

PARTICIPANTS

36 older people (age 61 +/- 1 y; mean +/- SEM).

INTERVENTION

Subjects completed RT three d/wk for 12 weeks, and consumed omnivorous diets that contained either 0.9 +/- 0.1 (lower protein) or 1.2 +/- 0.0 (higher protein) g protein x kg(-1) x d(-1) (12 +/- 3 and 17 +/- 5% of energy intakes, respectively), with the higher protein intake achieved by consuming more eggs, meats, and dairy foods. The lower and higher protein diets contained 213 +/- 21 and 610 +/- 105 mg cholesterol/d, respectively.

MEASUREMENTS

Strength, body composition, serum lipid-lipoprotein profile, urinary creatinine, skeletal muscle fiber type and size.

RESULTS

Among all subjects, over time (i.e. with RT) body weight was unchanged, lean mass (1.1 +/- 0.2 kg) increased, and fat mass (-1.4 +/- 0.2 kg) decreased (all changes P < 0.05). Regional (i.e. trunk, legs, arms) lean mass increased and fat mass decreased. Whole body muscle mass (24-h urinary creatinine excretion) increased, but skeletal muscle (vastus lateralis) type 1, type 2a, and type 2x fiber cross-sectional areas did not change from baseline. Serum total and LDL cholesterol decreased (P < 0.05) and HDL cholesterol and triacylglycerol were unchanged. Dietary protein and cholesterol intakes did not influence these responses to RT.

CONCLUSION

Consumption of diets that contained moderately higher protein and variable amounts of cholesterol did not differentially affect body composition, skeletal muscle fiber size, or serum lipid-lipoprotein profile responses to resistance training in older people.