| 1. |
- Garthwaite, Taru, et al.
(författare)
-
Associations of sedentary time, physical activity, and fitness with muscle glucose uptake in adults with metabolic syndrome
- 2022
-
Ingår i: Scandinavian Journal of Medicine and Science in Sports. - West Sussex : John Wiley & Sons. - 0905-7188 .- 1600-0838. ; 33:3, s. 353-358
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: The objective of the study was to investigate the associations of sedentary time, physical activity, and cardiorespiratory fitness with skeletal muscle glucose uptake (GU). Methods: Sedentary time and physical activity were measured with accelerometers and VO2max with cycle ergometry in 44 sedentary adults with metabolic syndrome. Thigh muscle GU was determined with [18F]FDG-PET imaging. Results: Sedentary time (β = −0.374), standing (β = 0.376), steps (β = 0.351), and VO2max (β = 0.598) were associated with muscle GU when adjusted for sex, age, and accelerometer wear time. Adjustment for body fat-% turned all associations non-significant. Conclusion: Body composition is a more important determinant of muscle GU in this population than sedentary time, physical activity, or fitness. © 2022 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.
|
|
| 2. |
- Garthwaite, Taru, et al.
(författare)
-
Standing is associated with insulin sensitivity in adults with metabolic syndrome
- 2021
-
Ingår i: Journal of Science and Medicine in Sport. - Chatswood : Elsevier. - 1440-2440 .- 1878-1861. ; 24:12, s. 1255-1260
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: To determine how components of accelerometer-measured sedentary behavior (SB) and physical activity (PA), and fitness are associated with insulin sensitivity in adults with metabolic syndrome. Design: Cross-sectional. Methods: Target population was middle-aged (40–65 years) sedentary adults with metabolic syndrome. SB, breaks in SB, standing, and PA were measured for four weeks with hip-worn accelerometers. VO2max (ml/min/kg) was measured with maximal cycle ergometry. Insulin sensitivity was determined by hyperinsulinaemic-euglycaemic clamp (M-value) and fasting blood sampling (HOMA-IR, insulin). Multivariable regression was used for analyses. Results: Sixty-four participants (37 women; 58.3 [SD 6.8] years) were included. Participants spent 10.0 (1.0) h sedentary, 1.8 (0.6) h standing, and 2.7 (0.6) h in PA and took 5149 (1825) steps and 29 (8) breaks daily. In sex-, age- and accelerometer wear time-adjusted model SB, standing, steps and VO2max were associated with M-value (β = −0.384; β = 0.400; β = 0.350; β = 0.609, respectively), HOMA-IR (β = 0.420; β = −0.548; β = −0.252; β = −0.449), and insulin (β = 0.433; β = −0.541; β = −0.252; β = −0.453); all p-values < 0.05. Breaks associated only with M-value (β = 0.277). When further adjusted for body fat %, only standing remained significantly associated with HOMA-IR (β = −0.381) and insulin (β = −0.366); significance was maintained even when further adjusted for SB, PA and fitness. Light and moderate-to-vigorous PA were not associated with insulin sensitivity. Conclusions: Standing is associated with insulin sensitivity markers. The association with HOMA-IR and insulin is independent of adiposity, PA, SB and fitness. Further studies are warranted, but these findings encourage replacing sitting with standing for potential improvements in insulin sensitivity in adults at increased type 2 diabetes risk. © 2021 The Authors.
|
|
| 3. |
- Haapala, Eero A., et al.
(författare)
-
Association between cardiorespiratory fitness and metabolic health in overweight and obese adults
- 2022
-
Ingår i: Journal of Sports Medicine and Physical Fitness. - Turin : Edizioni Minerva Medica. - 0022-4707 .- 1827-1928. ; 62:11, s. 1526-1533
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cardiorespiratory fitness (CRF) has been inversely associated with insulin resistance and clustering of cardiometabolic risk factors among overweight and obese individuals. However, most previous studies have scaled CRF by body mass (BM) possibly inflating the association between CRF and cardiometabolic health. We investigated the associations of peak oxygen uptake (V?O2peak) and peak power output (Wpeak) scaled either by BM-1, fat free mass (FFM-1), or by allometric methods with individual cardiometabolic risk factors and clustering of cardiometabolic risk factors in 55 overweight or obese adults with metabolic syndrome. METHODS: VO2peak and Wpeak were assessed by a maximal cycle ergometer exercise test. FFM was measured by air displacement plethysmo- graph and glucose, insulin, HbA1c, triglycerides, and total, LDL, and HDL cholesterol from fasting blood samples. HOMA-IR and metabolic syndrome score (MetS) were computed. RESULTS: VO2peak and Wpeak scaled by BM-1 were inversely associated with insulin (β=-0.404 to -0.372, 95% CI: -0.704 to -0.048), HOMAIR (β=-0.442 to -0.440, 95% CI: -0.762 to -0.117), and MetS (β=-0.474 to -0.463, 95% CI: -0.798 to -0.127). Other measures of CRF were not associated with cardiometabolic risk factors. CONCLUSIONS: Our results suggest that using BM-1 as a scaling factor confounds the associations between CRF and cardiometabolic risk in overweight/obese adults with the metabolic syndrome. © 2022 EDIZIONI MINERVA MEDICA.
|
|
| 4. |
|
|
| 5. |
- Jukka-Pekka, Spets, et al.
(författare)
-
Test of Different Anode Electrocatalysts for Direct Glucose Anion Exchange Membrane Fuel Cell
- 2016
-
Ingår i: International Journal of Electrochemical Science. - : Electrochemical Science Group. - 1452-3981. ; 11:6, s. 4219-4230
-
Tidskriftsartikel (refereegranskat)abstract
- Direct glucose anion exchange membrane fuel cell (AEMFC) with near-neutral-state electrolyte of 0.1 M [PO4] (tot) was studied with five different anode electrocatalysts (Pt, PtRu, PtNi, Au, PdAu) at a temperature of 37 degrees C and at a glucose concentration of 0.1 M. The cathode catalyst in each test was Pt supported on carbon (60 wt.%). Four anode electrocatalysts (supported on carbon) had a total metal content of 40 wt.% while the fifth anode material of PtRu had a higher content of 60 wt.%. Moreover, in order to show the influence of the metallic content on the fuel cell performance, anode catalysts with 60 wt.% (Pt) and 10wt.% (PtNi) were tested. The operation of the AEMFC was controlled by means of an in-house-made electronic load with PI-controller (i.e. a feedback controller that has proportional and integral action on control error signal) either at constant current (CC) or at constant voltage (CV). The primary objective was to characterize the Coulombic efficiency (CE) based on the exchange of two electrons and compare the specific energy (Wh kg(-1)) for the direct glucose AEMFC related to the different electrode combinations and electrocatalysts. As a result of these screening tests, two most efficient anode electrodes with Pt and PtNi were selected to be used for further AEMFC studies.
|
|
| 6. |
- Jukka-Pekka, Spets, et al.
(författare)
-
Towards an Efficient Direct Glucose Anion Exchange Membrane Fuel Cell System with Several Electro-Oxidation Units
- 2017
-
Ingår i: International Journal of Electrochemical Science. - : ESG. - 1452-3981. ; 12:5, s. 3697-3708
-
Tidskriftsartikel (refereegranskat)abstract
- This work covers the direct glucose anion exchange membrane fuel cell (AEMFC) with near-neutralstate electrolyte of 0.1 M [PO4] (tot) having two high-performing anode electrocatalysts (Pt and PtNi) at 37 degrees C and at a glucose concentration of 0.1 M. The cathode catalyst in each test was a Pt supported on carbon (60 wt.%). The PtNi/C had a total metal content of 40 wt.% and the Pt/C 60 wt.%. The operation of the AEMFC was controlled by means of an in-house made electronic load with PI-controller (i.e. a feedback controller, which has proportional and integral action on control error signal). There were two primary objectives with this study. At first, to find out how the electrode modifications of the anode (i.e. by increasing the thicknesses of these electrodes by adding extra carbon) affect the Coulombic efficiency (CE, based on the exchange of two electrons) and the specific energy (SPE, Wh kg(-1)) values of the direct glucose AEMFC. Secondly, investigate how a two-stage fuel cell system with two fuel cells concatenated and used one after the other for the electrochemical oxidation of glucose, influence the CE and SPE values. The results show that the modified PtNi anode shows superior results for the AEMFC compared to our earlier results. As for the two-stage fuel cell system, it increased the average electric power (mWh) and SPE when compared to single fuel cell systems except when the higher selective anode catalyst (Pt) was used in the first fuel cell prior to the fuel cell in the second fuel cell containing the lower selective anode catalyst (PtNi).
|
|
| 7. |
|
|
| 8. |
- Norha, Jooa, et al.
(författare)
-
Effects of reducing sedentary behavior on cardiorespiratory fitness in adults with metabolic syndrome : A 6-month RCT
- 2023
-
Ingår i: Scandinavian Journal of Medicine and Science in Sports. - Chichester : Wiley-Blackwell Publishing Inc.. - 0905-7188 .- 1600-0838. ; 33:8, s. 1452-1461
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction:Poor cardiorespiratory fitness (CRF) is associated with adverse health outcomes. Previous observational and cross-sectional studies have suggested that reducing sedentary behavior (SB) might improve CRF. Therefore, we investigated the effects of a 6-month intervention of reducing SB on CRF in 64 sedentary inactive adults with metabolic syndrome in a non-blind randomized controlled trial.Materials and Methods:In the intervention group (INT, n = 33), the aim was to reduce SB by 1 h/day for 6 months without increasing exercise training. Control group (CON, n = 31) was instructed to maintain their habitual SB and physical activity. Maximal oxygen uptake (VO2max) was measured by maximal graded bicycle ergometer test with respiratory gas measurements. Physical activity and SB were measured during the whole intervention using accelerometers.Results:Reduction in SB did not improve VO2max statistically significantly (group × time p > 0.05). Maximal absolute power output (Wmax) did not improve significantly but increased in INT compared to CON when scaled to fat free mass (FFM) (at 6 months INT 1.54 [95% CI: 1.41, 1.67] vs. CON 1.45 [1.32, 1.59] Wmax/kgFFM, p = 0.036). Finally, the changes in daily step count correlated positively with the changes in VO2max scaled to body mass and FFM (r = 0.31 and 0.30, respectively, p < 0.05).Discussion:Reducing SB without adding exercise training does not seem to improve VO2max in adults with metabolic syndrome. However, succeeding in increasing daily step count may increase VO2max. © 2023 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.
|
|
| 9. |
- Woolway, R. Iestyn, et al.
(författare)
-
Geographic and temporal variations in turbulent heat loss from lakes : A global analysis across 45 lakes
- 2018
-
Ingår i: Limnology and Oceanography. - : WILEY. - 0024-3590 .- 1939-5590. ; 63:6, s. 2436-2449
-
Tidskriftsartikel (refereegranskat)abstract
- Heat fluxes at the lake surface play an integral part in determining the energy budget and thermal structure in lakes, including regulating how lakes respond to climate change. We explore patterns in turbulent heat fluxes, which vary across temporal and spatial scales, using in situ high-frequency monitoring data from 45 globally distributed lakes. Our analysis demonstrates that some of the lakes studied follow a marked seasonal cycle in their turbulent surface fluxes and that turbulent heat loss is highest in larger lakes and those situated at low latitude. The Bowen ratio, which is the ratio of mean sensible to mean latent heat fluxes, is smaller at low latitudes and, in turn, the relative contribution of evaporative to total turbulent heat loss increases toward the tropics. Latent heat transfer ranged from similar to 60% to > 90% of total turbulent heat loss in the examined lakes. The Bowen ratio ranged from 0.04 to 0.69 and correlated significantly with latitude. The relative contributions to total turbulent heat loss therefore differ among lakes, and these contributions are influenced greatly by lake location. Our findings have implications for understanding the role of lakes in the climate system, effects on the lake water balance, and temperature-dependent processes in lakes.
|
|
