Aims/hypotheses
Obesity is associated with decreased insulin sensitivity (IS) and elevated plasma branched-chain amino acids (BCAAs). The purpose of this study was to investigate the relationship ...between BCAA metabolism and IS in overweight (OW) individuals during exercise intervention.
Methods
Whole-body leucine turnover, IS by hyperinsulinaemic–euglycaemic clamp, and circulating and skeletal muscle amino acids, branched-chain α-keto acids and acylcarnitines were measured in ten healthy controls (Control) and nine OW, untrained, insulin-resistant individuals (OW-Untrained). OW-Untrained then underwent a 6 month aerobic and resistance exercise programme and repeated testing (OW-Trained).
Results
IS was higher in Control vs OW-Untrained and increased significantly following exercise. IS was lower in OW-Trained vs Control expressed relative to body mass, but was not different from Control when normalised to fat-free mass (FFM). Plasma BCAAs and leucine turnover (relative to FFM) were higher in OW-Untrained vs Control, but did not change on average with exercise. Despite this, within individuals, the decrease in molar sum of circulating BCAAs was the best metabolic predictor of improvement in IS. Circulating glycine levels were higher in Control and OW-Trained vs OW-Untrained, and urinary metabolic profiling suggests that exercise induces more efficient elimination of excess acyl groups derived from BCAA and aromatic amino acid (AA) metabolism via formation of urinary glycine adducts.
Conclusions/interpretation
A mechanism involving more efficient elimination of excess acyl groups derived from BCAA and aromatic AA metabolism via glycine conjugation in the liver, rather than increased BCAA disposal through oxidation and turnover, may mediate interactions between exercise, BCAA metabolism and IS.
Trial registration:
Clinicaltrials.gov NCT01786941
While the benefits of exercise are clear, many unresolved issues surround the optimal exercise prescription. Many organizations recommend aerobic training (AT) and resistance training (RT), yet few ...studies have compared their effects alone or in combination. The purpose of this study, part of Studies Targeting Risk Reduction Interventions Through Defined Exercise-Aerobic Training and/or Resistance Training (STRRIDE/AT/RT), was to compare the effects of AT, RT, and the full combination (AT/RT) on central ectopic fat, liver enzymes, and fasting insulin resistance homeostatic model assessment (HOMA). In a randomized trial, 249 subjects 18-70 yr old, overweight, sedentary, with moderate dyslipidemia (LDL cholesterol 130-190 mg/dl or HDL cholesterol ≤ 40 mg/dl for men or ≤ 45 mg/dl for women) performed an initial 4-mo run-in period. Of these, 196 finished the run-in and were randomized into one of the following 8-mo exercise-training groups: 1) RT, which comprised 3 days/wk, 8 exercises, 3 sets/exercise, 8-12 repetitions/set, 2) AT, which was equivalent to ∼19.2 km/wk (12 miles/wk) at 75% peak O(2) uptake, and 3) full AT + full RT (AT/RT), with 155 subjects completing the intervention. The primary outcome variables were as follows: visceral and liver fat via CT, plasma liver enzymes, and HOMA. AT led to significant reductions in liver fat, visceral fat, alanine aminotransferase, HOMA, and total and subcutaneous abdominal fat (all P < 0.05). RT resulted in a decrease in subcutaneous abdominal fat (P < 0.05) but did not significantly improve the other variables. AT was more effective than RT at improving visceral fat, liver-to-spleen ratio, and total abdominal fat (all P < 0.05) and trended toward a greater reduction in liver fat score (P < 0.10). The effects of AT/RT were statistically indistinguishable from the effects of AT. These data show that, for overweight and obese individuals who want to reduce measures of visceral fat and fatty liver infiltration and improve HOMA and alanine aminotransferase, a moderate amount of aerobic exercise is the most time-efficient and effective exercise mode.
Summary Background In previous clinical trials of patients with metastatic renal-cell carcinoma, patients treated with axitinib as second-line therapy had longer median progression-free survival than ...those treated with sorafenib. We therefore undertook a phase 3 trial comparing axitinib with sorafenib in patients with treatment-naive metastatic renal-cell carcinoma. Methods In this randomised, open-label, phase 3 trial, patients with treatment-naive, measurable, clear-cell metastatic renal-cell carcinoma from 13 countries were stratified by Eastern Cooperative Oncology Group performance status, and then randomly assigned (2:1) by a centralised registration system to receive axitinib 5 mg twice daily, or sorafenib 400 mg twice daily. The primary endpoint was progression-free survival, assessed by masked independent review committee in the intention-to-treat population. This ongoing trial is registered at ClinicalTrials.gov , NCT00920816. Findings Between June 14, 2010, and April 21, 2011, we randomly assigned 192 patients to receive axitinib, and 96 patients to receive sorafenib. The cutoff date for this analysis was July 27, 2012, when 171 (59%) of 288 patients died or had disease progression, as assessed by the independent review committee. There was no significant difference in median progression-free survival between patients treated with axitinib or sorafenib (10·1 months 95% CI 7·2–12·1 vs 6·5 months 4·7–8·3, respectively; stratified hazard ratio 0·77, 95% CI 0·56–1·05). Any-grade adverse events that were more common (≥10% difference) with axitinib than with sorafenib were diarrhoea (94 50% of 189 patients vs 38 40% of 96 patients), hypertension (92 49% vs 28 29%), weight decrease (69 37% vs 23 24%), decreased appetite (54 29% vs 18 19%), dysphonia (44 23% vs ten 10%), hypothyroidism (39 21% vs seven 7%), and upper abdominal pain (31 16% vs six 6%); those more common with sorafenib than with axitinib included palmar-plantar erythrodysaesthesia (PPE; 37 39% of 96 patients vs 50 26% of 189), rash (19 20% vs 18 10%), alopecia (18 19% vs eight 4%), and erythema (18 19% vs five 3%). The most common grade 3 or 4 adverse events in patients treated with axitinib included hypertension (26 14% of 189 patients), diarrhoea (17 9%), asthenia (16 8%), weight decrease (16 8%), and PPE (14 7%); common grade 3 or 4 adverse events in patients treated with sorafenib included PPE (15 16% of 96 patients), diarrhoea (five 5%), and asthenia (five 5%). Serious adverse events were reported in 64 (34%) of 189 patients receiving axitinib, and 24 (25%) of 96 patients receiving sorafenib. Interpretation Axitinib did not significantly increase progression-free survival in patients with treatment-naive metastatic renal-cell carcinoma compared with those treated with sorafenib, but did demonstrate clinical activity and an acceptable safety profile. Funding Pfizer Inc.
Summary Background In a phase 3 trial comparing the efficacy and safety of axitinib versus sorafenib as second-line treatment for metastatic renal cell carcinoma, patients given axitinib had a longer ...progression-free survival (PFS). Here, we report overall survival and updated efficacy, quality of life, and safety results. Methods Eligible patients had clear cell metastatic renal cell carcinoma, progressive disease after one approved systemic treatment, and an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0–1. 723 patients were stratified by ECOG PS and previous treatment and randomly allocated (1:1) to receive axitinib (5 mg twice daily; n=361) or sorafenib (400 mg twice daily; n=362). The primary endpoint was PFS assessed by a masked, independent radiology review committee. We assessed patient-reported outcomes using validated questionnaires. Baseline characteristics and development of hypertension on treatment were studied as prognostic factors. Efficacy was assessed in the intention-to-treat population, and safety was assessed in patients who received at least one dose of the study drug. This ongoing trial is registered on ClinicalTrials.gov , number NCT00678392. Findings Median overall survival was 20·1 months (95% CI 16·7–23·4) with axitinib and 19·2 months (17·5–22·3) with sorafenib (hazard ratio HR 0·969, 95% CI 0·800–1·174; one-sided p=0·3744). Median investigator-assessed PFS was 8·3 months (95% CI 6·7–9·2) with axitinib and 5·7 months (4·7–6·5) with sorafenib (HR 0·656, 95% CI 0·552–0·779; one-sided p<0·0001). Patient-reported outcomes scores were similar in the treatment groups at baseline, were maintained during treatment, but decreased at end-of-treatment. Common grade 3 or higher treatment-related adverse events were hypertension (60 17%), diarrhoea (40 11%), and fatigue (37 10%) in 359 axitinib-treated patients and hand–foot syndrome (61 17%), hypertension (43 12%), and diarrhoea (27 8%) in 355 sorafenib-treated patients. In a post-hoc 12-week landmark analysis, median overall survival was longer in patients with a diastolic blood pressure of 90 mm Hg or greater than in those with a diastolic blood pressure of less than 90 mm Hg: 20·7 months (95% CI 18·4–24·6) versus 12·9 months (10·1–20·4) in the axitinib group (p=0·0116), and 20·2 months (17·1–32·0) versus 14·8 months (12·0–17·7) in the sorafenib group (one-sided p=0·0020). Interpretation Although overall survival, a secondary endpoint for the study, did not differ between the two groups, investigator-assessed PFS remained longer in the axitinib group compared with the sorafenib group. These results establish axitinib as a second-line treatment option for patients with metastatic renal cell carcinoma. Funding Pfizer Inc.
Organisms are adapted to the relentless cycles of day and night, because they evolved timekeeping systems called circadian clocks, which regulate biological activities with ∼24-hour rhythms. The ...clock of cyanobacteria is driven by a three-protein oscillator composed of KaiA, KaiB, and KaiC, which together generate a circadian rhythm of KaiC phosphorylation. We show that KaiB flips between two distinct three-dimensional folds, and its rare transition to an active state provides a time delay that is required to match the timing of the oscillator to that of Earth's rotation. Once KaiB switches folds, it binds phosphorylated KaiC and captures KaiA, which initiates a phase transition of the circadian cycle, and it regulates components of the clock-output pathway, which provides the link that joins the timekeeping and signaling functions of the oscillator.
Purpose
Systemic exposure to rosuvastatin in Asian subjects living in Japan or Singapore is approximately twice that observed in Caucasian subjects in Western countries or in Singapore. This study ...was conducted to determine whether pharmacokinetic differences exist among the most populous Asian subgroups and Caucasian subjects in the USA.
Method
Rosuvastatin pharmacokinetics was studied in Chinese, Filipino, Asian-Indian, Korean, Vietnamese, Japanese and Caucasian subjects residing in California. Plasma concentrations of rosuvastatin and metabolites after a single 20-mg dose were determined by mass spectrometric detection. The influence of polymorphisms in
SLCO1B1
(T521>C Val174Ala and A388>G Asn130Asp) and in
ABCG2
(C421>A Gln141Lys) on exposure to rosuvastatin was also assessed.
Results
The average rosuvastatin area under the curve from time zero to time of last quantifiable concentration was between 64 and 84 % higher, and maximum drug concentration was between 70 and 98 % higher in East Asian subgroups compared with Caucasians. Data for Asian-Indians was intermediate to these two ethnic groups at 26 and 29 %, respectively. Similar increases in exposure to N-desmethyl rosuvastatin and rosuvastatin lactone were observed. Rosuvastatin exposure was higher in subjects carrying the
SLCO1B1
521C allele compared with that in non-carriers of this allele. Similarly, exposure was higher in subjects carrying the
ABCG2
421A allele compared with that in non-carriers.
Conclusion
Plasma exposure to rosuvastatin and its metabolites was significantly higher in Asian populations residing in the USA compared with Caucasian subjects living in the same environment. This study suggests that polymorphisms in the
SLCO1B1 and ABCG2
genes contribute to the variability in rosuvastatin exposure.
Shift work or transmeridian travel can desynchronize the body's circadian rhythms from local light–dark cycles. The mammalian suprachiasmatic nucleus (SCN) generates and entrains daily rhythms in ...physiology and behavior. Paradoxically, we found that vasoactive intestinal polypeptide (VIP), a neuropeptide implicated in synchrony among SCN cells, can also desynchronize them. The degree and duration of desynchronization among SCN neurons depended on both the phase and the dose of VIP. A model of the SCN consisting of coupled stochastic cells predicted both the phase- and the dose-dependent response to VIP and that the transient phase desynchronization, or “phase tumbling”, could arise from intrinsic, stochastic noise in small populations of key molecules (notably, Period mRNA near its daily minimum). The model also predicted that phase tumbling following brief VIP treatment would accelerate entrainment to shifted environmental cycles. We tested this using a prepulse of VIP during the day before a shift in either a light cycle in vivo or a temperature cycle in vitro. Although VIP during the day does not shift circadian rhythms, the VIP pretreatment approximately halved the time required for mice to reentrain to an 8-h shifted light schedule and for SCN cultures to reentrain to a 10-h shifted temperature cycle. We conclude that VIP below 100 nM synchronizes SCN cells and above 100 nM reduces synchrony in the SCN. We show that exploiting these mechanisms that transiently reduce cellular synchrony before a large shift in the schedule of daily environmental cues has the potential to reduce jet lag.
Summary Background The treatment of advanced renal cell carcinoma has been revolutionised by targeted therapy with drugs that block angiogenesis. So far, no phase 3 randomised trials comparing the ...effectiveness of one targeted agent against another have been reported. We did a randomised phase 3 study comparing axitinib, a potent and selective second-generation inhibitor of vascular endothelial growth factor (VEGF) receptors, with sorafenib, an approved VEGF receptor inhibitor, as second-line therapy in patients with metastatic renal cell cancer. Methods We included patients coming from 175 sites (hospitals and outpatient clinics) in 22 countries aged 18 years or older with confirmed renal clear-cell carcinoma who progressed despite first-line therapy containing sunitinib, bevacizumab plus interferon-alfa, temsirolimus, or cytokines. Patients were stratified according to Eastern Cooperative Oncology Group performance status and type of previous treatment and then randomly assigned (1:1) to either axitinib (5 mg twice daily) or sorafenib (400 mg twice daily). Axitinib dose increases to 7 mg and then to 10 mg, twice daily, were allowed for those patients without hypertension or adverse reactions above grade 2. Participants were not masked to study treatment. The primary endpoint was progression-free survival (PFS) and was assessed by a masked, independent radiology review and analysed by intention to treat. This trial was registered on ClinicalTrials.gov , number NCT00678392. Findings A total of 723 patients were enrolled and randomly assigned to receive axitinib (n=361) or sorafenib (n=362). The median PFS was 6·7 months with axitinib compared to 4·7 months with sorafenib (hazard ratio 0·665; 95% CI 0·544–0·812; one-sided p<0·0001). Treatment was discontinued because of toxic effects in 14 (4%) of 359 patients treated with axitinib and 29 (8%) of 355 patients treated with sorafenib. The most common adverse events were diarrhoea, hypertension, and fatigue in the axitinib arm, and diarrhoea, palmar-plantar erythrodysaesthesia, and alopecia in the sorafenib arm. Interpretation Axitinib resulted in significantly longer PFS compared with sorafenib. Axitinib is a treatment option for second-line therapy of advanced renal cell carcinoma. Funding Pfizer Inc.
It is not clear to what extent changes in blood pressure (BP) during hemodialysis affect or predict survival. Studying comparative outcomes of BP changes during hemodialysis can have major clinical ...implications including the impact on management strategies in hemodialysis patients. Here we undertook a retrospective cohort study of 113,255 hemodialysis patients over a 5-year period to evaluate an association between change in BP during hemodialysis and mortality. The change in BP was defined as post-hemodialysis minus pre-hemodialysis BP, and mean of BP change values during the hemodialysis session was used as a mortality predictor. The patients' average age was 61 years old and consisted of 45% women, 32% African-Americans and 58% diabetics. Over a median follow-up of 2.2 years, a total of 53,461 (47.2%) all-cause and 21,548 (25.7%) cardiovascular deaths occurred. In a fully adjusted Cox regression model with restricted cubic splines, there was a U-shaped association between change in systolic BP and all-cause mortality. Post-dialytic drops in systolic BP between -30 and 0mmHg were associated with greater survival, but large decreases of systolic BP (more than -30mmHg) and any increase in systolic BP (over 0mmHg) were related to increased mortality. Peak survival was found at a change in systolic BP of -14mmHg. The U-shaped association was also found for cardiovascular mortality. Thus, modest declines in BP after hemodialysis are associated with the greatest survival, whereas any rise or large decline in BP is associated with worsened survival.
Myocardial infarction secondary to spontaneous coronary artery dissection (SCAD) can be traumatic and potentially trigger posttraumatic stress disorder (PTSD). In a large, multicenter, registry-based ...cohort, we documented prevalence of lifetime and past-month SCAD-induced PTSD, as well as related treatment seeking, and examined a range of health-relevant correlates of SCAD-induced PTSD.
Patients with SCAD were enrolled in the iSCAD (International SCAD) Registry. At baseline, site investigators completed medical report forms, and patients reported demographics, medical/SCAD history, psychosocial factors (including SCAD-induced PTSD symptoms), health behaviors, and health status via online questionnaires. Of 1156 registry patients, 859 patients (93.9% women; mean age, 52.3 years) completed questionnaires querying SCAD-induced PTSD. Nearly 35% (n=298) of patients met diagnostic criteria for probable SCAD-induced PTSD in their lifetime, and 6.4% (n=55) met criteria for probable past-month PTSD. Of 811 patients ever reporting any SCAD-induced PTSD symptoms, 34.8% indicated seeking treatment for this distress. However, 46.0% of the 298 patients with lifetime probable SCAD-induced PTSD diagnoses reported never receiving trauma-related treatment. Younger age at first SCAD, fewer years since SCAD, being single, unemployed status, more lifetime trauma, and history of anxiety were associated with greater past-month PTSD symptom severity in multivariable regression models. Greater past-month SCAD-induced PTSD symptoms were associated with greater past-week sleep disturbance and worse past-month disease-specific health status when adjusting for various risk factors.
Given the high prevalence of SCAD-induced PTSD symptoms, efforts to support screening for these symptoms and connecting patients experiencing distress with empirically supported treatments are critical next steps.
URL: https://www.clinicaltrials.gov; Unique identifier: NCT04496687.
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