Protein Supplementation Has Minimal Effects on Muscle Adaptations during Resistance Exercise Training in Young Men: A Double-Blind Randomized Clinical Trial.

BACKGROUND: To our knowledge the efficacy of soy-dairy protein blend (PB) supplementation with resistance exercise training (RET) has not been evaluated in a longitudinal study. OBJECTIVE: Our aim was to determine the effect of PB supplementation during RET on muscle adaptation. METHODS: In this double-blind randomized clinical trial, healthy young men [18-30 y; BMI (in kg/m(2)): 25 ± 0.5] participated in supervised whole-body RET at 60-80% 1-repetition maximum (1-RM) for 3 d/wk for 12 wk with random assignment to daily receive 22 g PB (n = 23), whey protein (WP) isolate (n = 22), or an isocaloric maltodextrin (carbohydrate) placebo [(MDP) n = 23]. Serum testosterone, muscle strength, thigh muscle thickness (MT), myofiber cross-sectional area (mCSA), and lean body mass (LBM) were assessed before and after 6 and 12 wk of RET. RESULTS: All treatments increased LBM (P < 0.001). ANCOVA did not identify an overall treatment effect at 12 wk (P = 0.11). There tended to be a greater change in LBM from baseline to 12 wk in the PB group than in the MDP group (0.92 kg; 95% CI: -0.12, 1.95 kg; P = 0.09); however, changes in the WP and MDP groups did not differ. Pooling data from combined PB and WP treatments showed a trend for greater change in LBM from baseline to 12 wk compared with MDP treatment (0.69 kg; 95% CI: -0.08, 1.46 kg; P = 0.08). Muscle strength, mCSA, and MT increased (P < 0.05) similarly for all treatments and were not different (P > 0.10) between treatments. Testosterone was not altered. CONCLUSIONS: PB supplementation during 3 mo of RET tended to slightly enhance gains in whole-body and arm LBM, but not leg muscle mass, compared with RET without protein supplementation. Although protein supplementation minimally enhanced gains in LBM of healthy young men, there was no enhancement of gains in strength. This trial was registered at clinicaltrials.gov as NCT01749189.

Soy Protein Compared with Milk Protein in a Western Diet Increases Gut Microbial Diversity and Reduces Serum Lipids in Golden Syrian Hamsters.

BACKGROUND: Diet is a major factor influencing the composition and metabolic activity of the gut microbiota. OBJECTIVE: This study investigated the effect of soy compared with dairy protein on the gut microbiota of hamsters to determine whether changes in microbiota could account for soy protein's lipid lowering properties. METHODS: Thirty-two 6- to 8-wk-old, male Golden Syrian hamsters were fed a Western diet containing 22% (%wt) milk protein isolate (MPI) as the single protein source for 3 wk followed by 6 wk of one of 4 diets containing either [22% protein (%wt)]: MPI, soy protein concentrate (SPC), partially hydrolyzed soy protein isolate (SPI1), or intact soy protein isolate. Serum lipids, hepatic gene expression, and gut microbial populations were evaluated. RESULTS: Serum total and LDL-cholesterol concentrations were lower in the SPC-fed group (183 ± 9.0 and 50 ± 4.2 mg/dL, respectively) than in the MPI group (238 ± 8.7 and 72 ± 3.9 mg/dL, respectively) (P< 0.05). Triglyceride (TG) concentrations were lower (P< 0.05) in the SPI1-fed group (140 ± 20.8 mg/dL) than in the MPI-fed group (223 ± 14.2 mg/dL). VLDL and non-HDL-cholesterol concentrations were lower (by 40-49% and 17-33%, respectively) in all soy-fed groups than in the MPI-fed group (P< 0.05). Sequencing of the 16S ribosomal RNA gene revealed greater microbial diversity in each soy-fed group than in the MPI-fed group (P< 0.05). The cholesterol- and TG-lowering effect of soy protein was associated with higher expression of 3-hydroxy-3-methylglutaryl-CoA reductase (Hmgcr), lanosterol synthase (Lss), and farnesyl-diphosphosphate farnesyl-transferase 1 (Fdft1) (1.6-2.5-fold higher), and lower steroyl-CoA desaturase-1 (Scd1) expression (37-46% lower) in all soy-fed groups (P< 0.05) compared with the MPI-fed group. Gut microbes that showed significant diet differences were significantly correlated (ρ = -0.68 to 0.65,P< 0.05) with plasma lipids and hepatic gene expression. CONCLUSION: Dietary protein sources in male Golden Syrian hamsters fed a Western diet affect the gut microbiota, and soy protein may reduce lipogenesis through alterations of the gut microbial community.

The effect of two benzodiazepine receptor agonist hypnotics on sleep-dependent memory consolidation.

INTRODUCTION: Numerous studies have demonstrated that sleep promotes memory consolidation, but there is little research on the effect of hypnotics on sleep-dependent memory consolidation. We compared bedtime administration of zolpidem-ER 12.5 mg (6- to 8-h duration of action), middle-of-the-night administration of zaleplon 10 mg (3- to 4-h duration of action), and placebo to examine the effect of different durations of hypnotic drug exposure on memory consolidation during sleep. METHODS: Twenty-two participants with no sleep complaints underwent 3 conditions in a counterbalanced crossover study: (1) zolpidem-ER 12.5 mg (bedtime dosing), (2) zaleplon 10 mg (middle-of-the-night dosing), and (3) placebo. Memory testing was conducted before and after an 8-h sleep period, using a word pair association task (WPT; declarative memory) and a finger-tapping task (FTT; procedural memory). RESULTS: ANOVA revealed a significant condition effect for the WPT (p = 0.025) and a trend for the FTT (p = 0.067), which was significant when sex was added to the model (p = 0.014). Improvement in memory performance following sleep was lower with bedtime dosing of zolpidem-ER compared to placebo and middle-of-the-night dosing of zaleplon. There were no differences between placebo and zaleplon. CONCLUSIONS: The results suggest that in some circumstances hypnotics may have the potential to reduce the degree of sleep-dependent memory consolidation and that drug-free sleep early in the night may ameliorate this effect.

A convenient expiratory positive airway pressure nasal device for the treatment of sleep apnea in patients non-adherent with continuous positive airway pressure.

BACKGROUND: While continuous positive airway pressure (CPAP) effectively treats obstructive sleep apnea (OSA), adherence to CPAP is suboptimal. The short-term efficacy of and adherence with a convenient expiratory positive airway pressure (EPAP) nasal device was evaluated in OSA patients non-adherent with CPAP. METHODS: Participants were OSA patients who refused CPAP or used CPAP less than 3 h per night. After demonstrating tolerability to the EPAP device during approximately 1 week of home use, patients underwent a screening/baseline polysomnogram (PSG1) and a treatment PSG (PSG2). Patients meeting prespecified efficacy criteria underwent PSG3 after about 5 weeks of EPAP treatment. RESULTS: Forty-seven of 59 eligible patients (80%) tolerated the device and underwent PSG1. Forty-three patients (27 m, 16f; 53.7±10.9 years) met AHI entry criteria and underwent PSG2. Mean AHI decreased from 43.3±29.0 at baseline to 27.0±26.7 (p<0.001) at PSG2. Twenty-four patients (56%) met efficacy criteria; their mean AHI was 31.9±19.8, 11.0±7.9, 16.4±12.2 at PSG1, PSG2, and PSG3, respectively (p<0.001, PSG1 vs. both PSG2 and PSG3). Mean Epworth Sleepiness Scale (ESS) scores were 12.3±4.8 at baseline, 11.1±5.1 at PSG1, and 8.7±4.4 at PSG3 (p=0.001 compared to baseline). Device use was reported an average of 92% of all sleep hours. CONCLUSIONS: The improvements in AHI and ESS, combined with the high degree of treatment adherence observed, suggest that the convenient EPAP device tested may become a useful therapeutic option for OSA.

Enhancing slow wave sleep with sodium oxybate reduces the behavioral and physiological impact of sleep loss.

STUDY OBJECTIVES: To investigate whether enhancement of slow wave sleep (SWS) with sodium oxybate reduces the impact of sleep deprivation. DESIGN: Double-blind, parallel group, placebo-controlled design SETTING: Sleep research laboratory PARTICIPANTS: Fifty-eight healthy adults (28 placebo, 30 sodium oxybate), ages 18-50 years. INTERVENTIONS: A 5-day protocol included 2 screening/baseline nights and days, 2 sleep deprivation nights, each followed by a 3-h daytime (08:00-11:00) sleep opportunity and a recovery night. Sodium oxybate or placebo was administered prior to each daytime sleep period. Multiple sleep latency test (MSLT), psychomotor vigilance test (PVT), Karolinska Sleepiness Scale (KSS), and Profile of Mood States were administered during waking hours. MEASUREMENTS AND RESULTS: During daytime sleep, the sodium oxybate group had more SWS, more EEG spectral power in the 1-9 Hz range, and less REM. Mean MSLT latency was longer for the sodium oxybate group on the night following the first daytime sleep period and on the day following the second day sleep period. Median PVT reaction time was faster in the sodium oxybate group following the second day sleep period. The change from baseline in SWS was positively correlated with the change in MSLT and KSS. During recovery sleep the sodium oxybate group had less TST, SWS, REM, and slow wave activity (SWA) than the placebo group. CONCLUSIONS: Pharmacological enhancement of SWS with sodium oxybate resulted in a reduced response to sleep loss on measures of alertness and attention. In addition, SWS enhancement during sleep restriction appears to result in a reduced homeostatic response to sleep loss.