Muscle Free Fatty-Acid Uptake Associates to Mechanical Efficiency During Exercise in Humans

Intrinsic factors related to muscle metabolism may explain the differences in mechanical efficiency (ME) during exercise. Therefore, this study aimed to investigate the relationship between muscle metabolism and ME. Totally 17 healthy recreationally active male participants were recruited and divided into efficient (EF; n = 8) and inefficient (IE; n = 9) groups, which were matched for age (mean +/- SD 24 +/- 2 vs. 23 +/- 2 years), BMI (23 +/- 1 vs. 23 +/- 2 kg m(-2)), physical activity levels (3.4 +/- 1.0 vs. 4.1 +/- 1.0 sessions/week), and (V)over dotO(2)peak (53 +/- 3 vs. 52 +/- 3 mL kg(-1) min(-1)), respectively, but differed for ME at 45% of (V)over dotO(2)peak intensity during submaximal bicycle ergometer test (EF 20.5 +/- 3.5 vs. IE 15.4 +/- 0.8%, P < 0.001). Using positron emission tomography, muscle blood flow (BF) and uptakes of oxygen (m(V)over dotO(2)), fatty acids (FAU) and glucose (GU) were measured during dynamic submaximal knee-extension exercise. Workload-normalized BF (EF 35 +/- 14 vs. IE 34 +/- 11 mL 100 g(-1) min(-1), P = 0.896), m(V)over dotO(2) (EF 4.1 +/- 1.2 vs. IE 3.9 +/- 1.2 mL 100 g(-1) min(-1), P = 0.808), and GU (EF 3.1 +/- 1.8 vs. IE 2.6 +/- 2.3 m mol 100 g(-1) min(-1), P = 0.641) as well as the delivery of oxygen, glucose, and FAU, as well as respiratory quotient were not different between the groups. However, FAU was significantly higher in EF than IE (3.1 +/- 1.7 vs. 1.7 +/- 0.6 m mol 100 g(-1) min(-1), P = 0.047) and it also correlated with ME (r = 0.56, P = 0.024) in the entire study group. EF group also demonstrated higher use of plasma FAU than IE, but no differences in use of plasma glucose and intramuscular energy sources were observed between the groups. These findings suggest that the effective use of plasma FAU is an important determinant of ME during exercise

Decreased insulin-stimulated brown adipose tissue glucose uptake after short-term exercise training in healthy middle-aged men

Aims: To test the hypothesis that high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) improve brown adipose tissue (BAT) insulin sensitivity.Participants and methods: Healthy middle-aged men (n = 18, age 47 years [95% confidence interval {CI} 49, 43], body mass index 25.3 kg/m(2) [95% CI 24.1-26.3], peak oxygen uptake (VO2peak) 34.8 mL/kg/min [95% CI 32.1, 37.4]) were recruited and randomized into six HIIT or MICT sessions within 2 weeks. Insulin-stimulated glucose uptake was measured using 2-[F-18] flouro-2-deoxy-D-glucose positron-emission tomography in BAT, skeletal muscle, and abdominal and femoral subcutaneous and visceral white adipose tissue (WAT) depots before and after the training interventions.Results: Training improved VO2peak (P =.0005), insulin-stimulated glucose uptake into the quadriceps femoris muscle (P =.0009) and femoral subcutaneous WAT (P =.02) but not into BAT, with no difference between the training modes. Using pre-intervention BAT glucose uptake, we next stratified subjects into high BAT (> 2.9 mu mol/100 g/min; n = 6) or low BAT (< 2.9 mu mol/100 g/min; n = 12) groups. Interestingly, training decreased insulin-stimulated BAT glucose uptake in the high BAT group (4.0 [2.8, 5.5] vs 2.5 [1.7, 3.6]; training*BAT, P =.02), whereas there was no effect of training in the low BAT group (1.5 [1.2, 1.9] vs 1.6 [1.2, 2.0] mu mol/100 g/min). Participants in the high BAT group had lower levels of inflammatory markers compared with those in the low BAT group.Conclusions: Participants with functionally active BAT have an improved metabolic profile compared with those with low BAT activity. Short-term exercise training decreased insulin-stimulated BAT glucose uptake in participants with active BAT, suggesting that training does not work as a potent stimulus for BAT activation

[11C]acetate PET/CT Visualizes Skeletal Muscle Exercise Participation, Impaired Function, and Recovery after Hip Arthroplasty; First Results

Based on skeletal muscle acetate physiology we aimed studying muscle function after hip arthroplasty with [(11)C]acetate PET

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Pulmonary blood flow and its distribution in highly trained endurance athletes and healthy control subjects

Heinonen I, Savolainen AM, Han C, Kemppainen J, Oikonen V, Luotolahti M, Duncker DJ, Merkus D, Knuuti J, Kalliokoski KK. Pulmonary blood flow and its distribution in highly trained endurance athletes and healthy control subjects. J Appl Physiol 114: 329-334, 2013. First published December 6, 2012; doi:10.1152/japplphysiol.00710.2012.-Pulmonary blood flow (PBF) is an important determinant of endurance sports performance, yet studies investigating adaptations of the pulmonary circulation in athletes are scarce. In the present study, we investigated PBF, its distribution, and heterogeneity at baseline and during intravenous systemic adenosine infusion in 10 highly trained male endurance athletes and 10 untrained but fit healthy controls, using positron emission tomography and [ O-15] water at rest and during adenosine infusion at supine body posture. Our results indicate that PBF at rest and during adenosine stimulation was similar in both groups (213 +/- 55 and 563 +/- 138 ml.100 ml(-1).min(-1) in athletes and 206 +/- 83 and 473 +/- 212 ml.100 ml(-1).min(-1) in controls, respectively). Although the PBF response to adenosine was thus unchanged in athletes, overall PBF heterogeneity was reduced from rest to adenosine infusion (from 84 +/- 18 to 70 +/- 19%, P < 0.05), while remaining unchanged in healthy controls (77 +/- 16 to 85 +/- 33%, P = 0.4). Additionally, there was a marked gravitational influence on general PBF distribution so that clear dorsal dominance was observed both at rest and during adenosine infusion, but training status did not have an effect on this distribution. Regional blood flow heterogeneity was markedly lower in the high-perfusion dorsal areas, both at rest and during adenosine, in all subjects, but flow heterogeneity in dorsal area tended to further decrease in response to adenosine in athletes. In conclusion, reduced blood flow heterogeneity in response to adenosine in endurance athletes may be a reflection of capillary reserve, which is more extensively recruitable in athletes than in matched healthy control subjects