scholarly journals Body fat does not affect venous bubble formation after air dives of moderate severity: theory and experiment

2013 ◽  
Vol 114 (5) ◽  
pp. 602-610 ◽  
Author(s):  
Nico A. M. Schellart ◽  
Tjeerd P. van Rees Vellinga ◽  
Rob A. van Hulst
Keyword(s):  
Body Fat ◽  
Decompression Sickness ◽  
Bubble Formation ◽  
Maximal Oxygen Consumption ◽  
Whole Body ◽  
Small Range ◽  
Gas Embolism ◽  
Blood Compartment ◽  
In Series ◽  
Venous Gas Embolism

For over a century, studies on body fat (BF) in decompression sickness and venous gas embolism of divers have been inconsistent. A major problem is that age, BF, and maximal oxygen consumption (V̇o2max) show high multicollinearity. Using the Bühlmann model with eight parallel compartments, preceded by a blood compartment in series, nitrogen tensions and loads were calculated with a 40 min/3.1 bar (absolute) profile. Compared with Haldanian models, the new model showed a substantial delay in N2 uptake and (especially) release. One hour after surfacing, an increase of 14–28% in BF resulted in a whole body increase of the N2 load of 51%, but in only 15% in the blood compartment. This would result in an increase in the bubble grade of only 0.01 Kisman-Masurel (KM) units at the scale near KM = I−. This outcome was tested indirectly by a dry dive simulation (air breathing) with 53 male divers with a small range in age and V̇o2max to suppress multicollinearity. BF was determined with the four-skinfold method. Precordial Doppler bubble grades determined at 40, 80, 120, and 160 min after surfacing were used to calculate the Kisman Integrated Severity Score and were also transformed to the logarithm of the number of bubbles/cm2 (logB). The highest of the four scores yielded logB = −1.78, equivalent to KM = I−. All statistical outcomes of partial correlations with BF were nonsignificant. These results support the model outcomes. Although this and our previous study suggest that BF does not influence venous gas embolism (Schellart NAM, van Rees Vellinga TP, van Dijk FH, Sterk W. Aviat Space Environ Med 83: 951–957, 2012), more studies with different profiles under various conditions are needed to establish whether BF remains (together with age and V̇o2max) a basic physical characteristic or will become less important for the medical examination and for risk assessment.

Hyperbaric treatment of air or gas embolism: current recommendations

2019 ◽  
pp. 673-683
Author(s):  
Richard E. Moon ◽  
Keyword(s):  
Animal Studies ◽  
Decompression Sickness ◽  
Bubble Formation ◽  
Endothelial Damage ◽  
Neurological Deficits ◽  
Breath Hold ◽  
Gas Embolism ◽  
Hyperbaric Treatment ◽  
Pulmonary Capillaries ◽  
Venous Gas Embolism

Gas can enter arteries (arterial gas embolism, AGE) due to alveolar-capillary disruption (caused by pulmonary over-pressurization, e.g. breath-hold ascent by divers) or veins (venous gas embolism, VGE) as a result of tissue bubble formation due to decompression (diving, altitude exposure) or during certain surgical procedures where capillary hydrostatic pressure at the incision site is subatmospheric. Both AGE and VGE can be caused by iatrogenic gas injection. AGE usually produces stroke-like manifestations, such as impaired consciousness, confusion, seizures and focal neurological deficits. Small amounts of VGE are often tolerated due to filtration by pulmonary capillaries; however VGE can cause pulmonary edema, cardiac “vapor lock” and AGE due to transpulmonary passage or right-to-left shunt through a patient foramen ovale. Intravascular gas can cause arterial obstruction or endothelial damage and secondary vasospasm and capillary leak. Vascular gas is frequently not visible with radiographic imaging, which should not be used to exclude the diagnosis of AGE. Isolated VGE usually requires no treatment; AGE treatment is similar to decompression sickness (DCS), with first aid oxygen then hyperbaric oxygen. Although cerebral AGE (CAGE) often causes intracranial hypertension, animal studies have failed to demonstrate a benefit of induced hypocapnia. An evidence-based review of adjunctive therapies is presented.

scholarly journals Ascent rate, age, maximal oxygen uptake, adiposity, and circulating venous bubbles after diving

2002 ◽  
Vol 93 (4) ◽  
pp. 1349-1356 ◽  
Author(s):  
D. Carturan ◽  
A. Boussuges ◽  
P. Vanuxem ◽  
A. Bar-Hen ◽  
H. Burnet ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Body Fat ◽  
Maximal Oxygen Uptake ◽  
Decompression Sickness ◽  
Bubble Formation ◽  
Rank Test ◽  
Percent Body Fat ◽  
Ascent Rate ◽  
Interaction Terms ◽  
Log Linear

Decompression sickness in diving is recognized as a multifactorial phenomenon, depending on several factors, such as decompression rate and individual susceptibility. The Doppler ultrasonic detection of circulating venous bubbles after diving is considered a useful index for the safety of decompression because of the relationship between bubbles and decompression sickness risk. The aim of this study was to assess the effects of ascent rate, age, maximal oxygen uptake (V˙o 2 max), and percent body fat on the production of bubbles after diving. Fifty male recreational divers performed two dives at 35 m during 25 min and then ascended in one case at 9 m/min and in the other case at 17 m/min. They performed the same decompression stops in the two cases. Twenty-eight divers were Doppler monitored at 10-min intervals, until 60 min after surfacing, and the data were analyzed by Wilcoxon signed-rank test to compare the effect of ascent rate on the kinetics of bubbles. Twenty-two divers were monitored 60 min after surfacing. The effect on bubble production 60 min after surfacing of the four variables was studied in 47 divers. The data were analyzed by multinomial log-linear model. The analysis showed that the 17 m/min ascent produced more elevated grades of bubbles than the 9 m/min ascent ( P < 0.05), except at the 40-min interval, and showed relationships between grades of bubbles and ascent rate and age and interaction terms betweenV˙o 2 max and age, as well asV˙o 2 max and percent body fat. Younger, slimmer, or aerobically fitter divers produced fewer bubbles compared with older, fatter, or poorly physically fit divers. These findings and the conclusions of previous studies performed on animals and humans led us to support that ascent rate, age, aerobic fitness, and adiposity are factors of susceptibility for bubble formation after diving.

Determinants of maximal whole-body fat oxidation in elite cross-country skiers: Role of skeletal muscle mitochondria

2018 ◽  
Vol 28 (12) ◽  
pp. 2494-2504 ◽  
Author(s):  
Sune Dandanell ◽  
Anne-Kristine Meinild-Lundby ◽  
Andreas B. Andersen ◽  
Paul F. Lang ◽  
Laura Oberholzer ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Fat ◽  
Fat Oxidation ◽  
Whole Body ◽  
Muscle Mitochondria ◽  
Skeletal Muscle Mitochondria ◽  
Cross Country

scholarly journals Increasing skeletal muscle carnitine content in older individuals increases whole‐body fat oxidation during moderate‐intensity exercise

Aging Cell ◽  
2021 ◽  
Vol 20 (2) ◽  
Author(s):  
Carolyn Chee ◽  
Chris E. Shannon ◽  
Aisling Burns ◽  
Anna L. Selby ◽  
Daniel Wilkinson ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Fat ◽  
Fat Oxidation ◽  
Whole Body ◽  
Moderate Intensity ◽  
Older Individuals ◽  
Moderate Intensity Exercise

scholarly journals Sex differences in the associations between adiposity distribution and cardiometabolic risk factors in overweight or obese individuals: a cross-sectional study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yide Yang ◽  
Ming Xie ◽  
Shuqian Yuan ◽  
Yuan Zeng ◽  
Yanhui Dong ◽  
...  
Keyword(s):  
Risk Factors ◽  
Sex Differences ◽  
Body Fat ◽  
Regression Models ◽  
Cardiometabolic Risk ◽  
Cardiometabolic Risk Factors ◽  
Whole Body ◽  
Anthropometric Measurement ◽  
Cardiometabolic Health ◽  
Lower Odds

Abstract Background We aimed to assess the associations between adiposity distribution and cardiometabolic risk factors among overweight and obese adults in China, and to demonstrate the sex differences in these associations. Methods A total of 1221 participants (455 males and 766 females) were included in this study. Percentage of body fat (PBF) of the whole body and regional areas, including arm, thigh, trunk, android, and gynoid, were measured by the dual-energy X-ray absorptiometry method. Central adiposity was measured by waist circumference. Clustered cardiometabolic risk was defined as the presence of two or more of the six cardiometabolic risk factors, namely, high triglyceride, low high density lipoprotein, elevated glucose, elevated blood pressure, elevated high sensitivity C-reactive protein, and low adiponectin. Linear regression models and multivariate logistic regression models were used to assess the associations between whole body or regional PBF and cardiometabolic risk factors. Results In females, except arm adiposity, other regional fat (thigh, trunk, android, gynoid) and whole-body PBF are significantly associated with clustered cardiometabolic risk, adjusting for age, smoking, alcohol drinking, physical activity, and whole-body PBF. One-SD increase in Z scores of the thigh and gynoid PBF were significantly associated with 80 and 78% lower odds of clustered cardiometabolic risk (OR: 0.20, 95%CI: 0.12–0.35 and OR: 0.22, 95%CI: 0.12–0.41). Trunk, android and whole-body PBF were significantly associated with higher odds of clustered risk with OR of 1.90 (95%CI:1.02–3.55), 2.91 (95%CI: 1.75–4.85), and 2.01 (95%CI: 1.47–2.76), respectively. While in males, one-SD increase in the thigh and gynoid PBF are associated with 94% (OR: 0.06, 95%CI: 0.02–0.23) and 83% lower odds (OR: 0.17, 95%CI: 0.05–0.57) of clustered cardiometabolic risk, respectively. Android and whole-body PBF were associated with higher odds of clustered cardiometabolic risk (OR: 3.39, 95%CI: 1.42–8.09 and OR: 2.45, 95%CI: 1.53–3.92), but the association for trunk PBF was not statistically significant (OR: 1.16, 95%CI: 0.42–3.19). Conclusions Adiposity distribution plays an important role in the clustered cardiometabolic risk in participants with overweight and obese and sex differences were observed in these associations. In general, central obesity (measured by android PBF) could be the best anthropometric measurement for screening people at risk for CVD risk factors for both men and women. Upper body fat tends to be more detrimental to cardiometabolic health in women than in men, whereas lower body fat is relatively more protective in men than in women.

scholarly journals Tissue-specific expression of Sprouty1 in mice protects against high-fat diet-induced fat accumulation, bone loss and metabolic dysfunction

2011 ◽  
Vol 108 (6) ◽  
pp. 1025-1033 ◽  
Author(s):  
Sumithra Urs ◽  
Terry Henderson ◽  
Phuong Le ◽  
Clifford J. Rosen ◽  
Lucy Liaw
Keyword(s):  
Adipose Tissue ◽  
Bone Loss ◽  
Bone Mass ◽  
Body Fat ◽  
High Fat Diet ◽  
Conditional Knockout ◽  
Whole Body ◽  
High Fat ◽  
Tissue Specific ◽  
Diet Induced Obesity

We recently characterised Sprouty1 (Spry1), a growth factor signalling inhibitor as a regulator of marrow progenitor cells promoting osteoblast differentiation at the expense of adipocytes. Adipose tissue-specific Spry1 expression in mice resulted in increased bone mass and reduced body fat, while conditional knockout of Spry1 had the opposite effect with decreased bone mass and increased body fat. Because Spry1 suppresses normal fat development, we tested the hypothesis that Spry1 expression prevents high-fat diet-induced obesity, bone loss and associated lipid abnormalities, and demonstrate that Spry1 has a long-term protective effect on mice fed a high-energy diet. We studied diet-induced obesity in mice with fatty acid binding promoter-driven expression or conditional knockout of Spry1 in adipocytes. Phenotyping was performed by whole-body dual-energy X-ray absorptiometry, microCT, histology and blood analysis. In conditional Spry1-null mice, a high-fat diet increased body fat by 40 %, impaired glucose regulation and led to liver steatosis. However, overexpression of Spry1 led to 35 % (P < 0·05) lower body fat, reduced bone loss and normal metabolic function compared with single transgenics. This protective phenotype was associated with decreased circulating insulin (70 %) and leptin (54 %; P < 0·005) compared with controls on a high-fat diet. Additionally, Spry1 expression decreased adipose tissue inflammation by 45 %. We show that conditional Spry1 expression in adipose tissue protects against high-fat diet-induced obesity and associated bone loss.

Blood platelet-derived microparticles release and bubble formation after an open-sea air dive

2012 ◽  
Vol 37 (5) ◽  
pp. 888-892 ◽  
Author(s):  
Jean-Michel Pontier ◽  
Emmanuel Gempp ◽  
Mihaela Ignatescu
Keyword(s):  
Platelet Aggregation ◽  
Decompression Sickness ◽  
Blood Platelets ◽  
Water Immersion ◽  
Bubble Formation ◽  
Blood Platelet ◽  
Field Conditions ◽  
Control Group ◽  
Open Sea ◽  
Experimental Group

Bubble-induced platelet aggregation offers an index for evaluating decompression severity in humans and in a rat model of decompression sickness. Endothelial cells, blood platelets, or leukocytes shed microparticles (MP) upon activation and during cell apoptosis. The aim was to study blood platelet MP (PMP) release and bubble formation after a scuba-air dive in field conditions. Healthy, experienced divers were assigned to 1 experimental group (n = 10) with an open-sea air dive to 30 msw for 30 min and 1 control group (n = 5) during head-out water immersion for the same period. Bubble grades were monitored with a pulsed doppler according to Kissman Integrated Severity Score (KISS). Blood samples for platelet count (PC) and PMP (annexin V and CD41) were taken 1 h before and after exposure in both groups. The result showed a decrease in post-dive PC compared with pre-dive values in experimental group with no significant change in the control group. We observed a significant increase in PMP values after the dive while no change was revealed in the control group. There was a significant positive correlation between the PMP values after the dive and the KISS bubble score. The present study highlighted a relationship between the post-dive decrease in PC, platelet MP release, and bubble formation. Release of platelet MPs could reflect bubble-induced platelet aggregation and could play a key role in alteration of the coagulation. Further studies must investigate endothelial and leukocyte MP release in the same field conditions.

Whole body fat: Content and distribution

2013 ◽  
Vol 73 ◽  
pp. 56-80 ◽  
Author(s):  
E.L. Thomas ◽  
J.A. Fitzpatrick ◽  
S.J. Malik ◽  
S.D. Taylor-Robinson ◽  
J.D. Bell
Keyword(s):  
Body Fat ◽  
Fat Content ◽  
Whole Body ◽  
Body Fat Content

Body Composition, Dietary Intake, and Iron Status of Female Collegiate Swimmers and Divers

2006 ◽  
Vol 16 (3) ◽  
pp. 281-295 ◽  
Author(s):  
Heidi L. Petersen ◽  
C. Ted Peterson ◽  
Manju B. Reddy ◽  
Kathy B. Hanson ◽  
James H. Swain ◽  
...  
Keyword(s):  
Body Composition ◽  
Dietary Intake ◽  
Body Fat ◽  
Lean Mass ◽  
Iron Status ◽  
Dietary Quality ◽  
Whole Body ◽  
Vitamin B ◽  
Percentage Body Fat ◽  
X Ray

This study determined the effect of training on body composition, dietary intake, and iron status of eumenorrheic female collegiate swimmers (n = 18) and divers (n = 6) preseason and after 16 wk of training. Athletes trained on dryland (resistance, strength, fexibility) 3 d/wk, 1.5 h/d and in-water 6 d/wk, nine, 2-h sessions per week (6400 to 10,000 kJ/d). Body-mass index (kg/m2; P = 0.05), waist and hip circumferences (P ≤ 0.0001), whole body fat mass (P = 0.0002), and percentage body fat (P ≤ 0.0001) decreased, whereas lean mass increased (P = 0.028). Using dual-energy X-ray absorptiometry, we found no change in regional lean mass, but fat decreased at the waist (P = 0.0002), hip (P = 0.0002), and thigh (P = 0.002). Energy intake (10,061 ± 3617 kJ/d) did not change, but dietary quality improved with training, as refected by increased intakes of fber (P = 0.036), iron (P = 0.015), vitamin C (P = 0.029), vitamin B-6 (P = 0.032), and fruit (P = 0.003). Iron status improved as refected by slight increases in hemoglobin (P = 0.046) and hematocrit (P = 0.014) and decreases in serum transferrin receptor (P ≤ 0.0001). Studies are needed to further evaluate body composition and iron status in relation to dietary intake in female swimmers.

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