Exercise bouts at three different intensities fail to potentiate concentric power

Postactivation potentiation (PAP) has been hypothesized previously to occur during voluntary, concentric actions. We tested the hypothesis that one of at least three different intensities of conditioning exercises would evoke potentiation of power during the concentric, bench press throw (BPT). Twelve men (age = 22.9 &#; 2.7 years, bench press 1 repetition maximum (1RM) = 1.20 ± 0.12 kg•kg-1 body weight) completed five isotonic conditioning presses at ~55, 70, and 86% 1RM, in counterbalanced order, and on separate days. Average and peak power of the BPT using a load of 55% 1RM along with surface electromyography (EMG) of the triceps brachii were collected prior to and 4-minutes following each conditioning bout. Both average and peak power and EMG values (mean ± SD), respectively, were evaluated using two-way analyses of variance with repeated measures. Significant main effect decreases (p \u3c 0.05) in average (-18.6 ± 4.9 W) and peak power (-37.4 ± 9.9 W) occurred across the three different intensities evaluated. No main effects or interactions were observed with the EMG data. Contrary to the previously reported hypothesis, we were unable to demonstrate that conditioning exercise, with three different intensities, can evoke potentiation of power using a load equating to that which is optimum for power production

The impact of methylxanthines on muscle carbohydrate metabolism

Etude comparée de l'effet des substances dérivés de la xanthine, c'est à dire la caféine (extraite du café) et la théophylline (extraite du thé), sur le métabolisme musculaire lors d'un exercice d'endurance

Preferences for and Experiences of Shared and Informed Decision Making Among Patients Choosing Kidney Replacement Therapies in Nephrology Care.

RATIONALE & OBJECTIVE: Chronic kidney disease (CKD) can progress rapidly, and patients are often unprepared to make kidney failure treatment decisions. We aimed to better understand patients preferences for and experiences of shared and informed decision making (SDM) regarding kidney replacement therapy before kidney failure. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: Adults receiving nephrology care at CKD clinics in rural Pennsylvania. PREDICTORS: Estimated glomerular filtration rate, 2-year risk for kidney failure, duration and frequency of nephrology care, and preference for SDM. OUTCOMES: Occurrence and extent of kidney replacement therapy discussions and participants satisfaction with those discussions. ANALYTIC APPROACH: Multivariable logistic regression to quantify associations between participants characteristics and whether they had discussions. RESULTS: The 447 study participants had a median age of 72 (IQR, 64-80) years and mean estimated glomerular filtration rate of 33 (SD, 12) mL/min/1.73 m2. Most (96%) were White, high school educated (67%), and retired (65%). Most (72%) participants preferred a shared approach to kidney treatment decision making, and only 35% discussed dialysis or transplantation with their kidney teams. Participants who had discussions (n = 158) were often completely satisfied (63%) but infrequently discussed potential treatment-related impacts on their lives. In multivariable analyses, those with a high risk for kidney failure within 2 years (OR, 3.24 [95% CI, 1.72-6.11]; P < 0.01), longer-term nephrology care (OR, 1.12 [95% CI, 1.05-1.20] per 1 additional year; P < 0.01), and more nephrology visits in the prior 2 years (OR, 1.34 [95% CI, 1.20-1.51] per 1 additional visit; P < 0.01) had higher odds of having discussed dialysis or transplantation. LIMITATIONS: Single health system study. CONCLUSIONS: Most patients preferred sharing CKD treatment decisions with their providers, but treatment discussions were infrequent and often did not address key treatment impacts. Longitudinal nephrology care and frequent visits may help ensure that patients have optimal SDM experiences

Advanced CKD Care and Decision Making: Which Health Care Professionals Do Patients Rely on for CKD Treatment and Advice?

RATIONALE & OBJECTIVE: Chronic kidney disease (CKD) care is often fragmented across multiple health care providers. It is unclear whether patients rely mostly on their nephrologists or non-nephrologist providers for medical care, including CKD treatment and advice. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: Adults receiving nephrology care at CKD clinics in Pennsylvania. PREDICTORS: Frequency, duration, and patient-centeredness (range, 1 [least] to 4 [most]) of participants nephrology care. OUTCOME: Participants reliance on nephrologists, primary care providers, or other specialists for medical care, including CKD treatment and advice. ANALYTICAL APPROACH: Multivariable logistic regression to quantify associations between participants reliance on their nephrologists (vs other providers) and their demographics, comorbid conditions, kidney function, and nephrology care. RESULTS: Among 1,412 patients in clinics targeted for the study, 676 (48%) participated. Among these, 453 (67%) were eligible for this analysis. Mean age was 71 (SD, 12) years, 59% were women, 97% were white, and 65% were retired. Participants were in nephrology care for a median of 3.8 (IQR, 2.0-6.6) years and completed a median of 4 (IQR, 3-5) nephrology appointments in the past 2 years. Half (56%) the participants relied primarily on their nephrologists, while 23% relied on primary care providers, 18% relied on all providers equally, and 3% relied on other specialists. Participants adjusted odds of relying on their nephrologists were higher for those in nephrology care for longer (OR, 1.08 [95% CI, 1.02-1.15]; P = 0.02), those who completed more nephrology visits in the previous 2 years (OR, 1.16 [95% CI, 1.05-1.29]; P = 0.005), and those who perceived their last interaction with their nephrologists as more patient-centered (OR, 2.63 [95% CI, 1.70-4.09]; P < 0.001). LIMITATIONS: Single health system study. CONCLUSIONS: Many nephrology patients relied on non-nephrologist providers for medical care. Longitudinal patient-centered nephrology care may encourage more patients to follow nephrologists recommendations

Association Between Bilirubin, Atazanavir, and Cardiovascular Disease Events Among People Living With HIV Across the United States.

ObjectiveBilirubin is an antioxidant that may suppress lipid oxidation. Elevated bilirubin is associated with decreased cardiovascular events in HIV-uninfected populations. We examined these associations in people living with HIV (PLWH).MethodsPotential myocardial infarctions (MIs) and strokes were centrally adjudicated. We examined MI types: type 1 MI (T1MI) from atherosclerotic plaque instability and type 2 MI (T2MI) in the setting of oxygen demand/supply mismatch such as sepsis. We used multivariable Cox regression analyses to determine associations between total bilirubin levels and outcomes adjusting for traditional and HIV-specific risk factors. To minimize confounding by hepatobiliary disease, we conducted analyses limited to bilirubin values <2.1 mg/dL; among those with fibrosis-4 values <3.25; and among everyone. We repeated analyses stratified by hepatitis C status and time-updated atazanavir use.ResultsAmong 25,816 PLWH, there were 392 T1MI and 356 T2MI during follow-up. Adjusted hazard ratios for the association of higher bilirubin levels with T1MI were not significant. Higher bilirubin levels were associated with T2MI. By contrast, among PLWH on atazanavir, higher bilirubin levels were associated with fewer T2MI (hazard ratio 0.56:0.33-1.00). Higher bilirubin levels among those on atazanavir were associated with fewer T1MI combined with ischemic stroke.LimitationsAnalyses were conducted with total rather than unconjugated bilirubin.ConclusionsAmong PLWH, higher bilirubin levels were associated with T2MI among some subgroups. However, among those on atazanavir, there was a protective association between bilirubin and T2MI. These findings demonstrate different associations between outcomes and elevated bilirubin due to diverse causes and the importance of distinguishing MI types

Types of Stroke Among People Living With HIV in the United States.

BackgroundMost studies of stroke in people living with HIV (PLWH) do not use verified stroke diagnoses, are small, and/or do not differentiate stroke types and subtypes.SettingCNICS, a U.S. multisite clinical cohort of PLWH in care.MethodsWe implemented a centralized adjudication stroke protocol to identify stroke type, subtype, and precipitating conditions identified as direct causes including infection and illicit drug use in a large diverse HIV cohort.ResultsAmong 26,514 PLWH, there were 401 strokes, 75% of which were ischemic. Precipitating factors such as sepsis or same-day cocaine use were identified in 40% of ischemic strokes. Those with precipitating factors were younger, had more severe HIV disease, and fewer traditional stroke risk factors such as diabetes and hypertension. Ischemic stroke subtypes included cardioembolic (20%), large vessel atherosclerosis (13%), and small vessel (24%) ischemic strokes. Individuals with small vessel strokes were older, were more likely to have a higher current CD4 cell count than those with cardioembolic strokes and had the highest mean blood pressure of the ischemic stroke subtypes.ConclusionIschemic stroke, particularly small vessel and cardioembolic subtypes, were the most common strokes among PLWH. Traditional and HIV-related risk factors differed by stroke type/subtype. Precipitating factors including infections and drug use were common. These results suggest that there may be different biological phenomena occurring among PLWH and that understanding HIV-related and traditional risk factors and in particular precipitating factors for each type/subtype may be key to understanding, and therefore preventing, strokes among PLWH