scholarly journals Elite male Flat jockeys display lower bone density and lower resting metabolic rate than their female counterparts: implications for athlete welfare

2015 ◽  
Vol 40 (12) ◽  
pp. 1318-1320 ◽  
Author(s):  
George Wilson ◽  
Jerry Hill ◽  
Craig Sale ◽  
James P. Morton ◽  
Graeme L. Close
Keyword(s):  
Lumbar Spine ◽  
Bone Density ◽  
Metabolic Rate ◽  
Lean Mass ◽  
Resting Metabolic Rate ◽  
Male And Female ◽  
Z Scores

To test the hypothesis that daily weight-making is more problematic to health in male compared with female jockeys, we compared the bone density and resting metabolic rate (RMR) in weight-matched male and female Flat jockeys. RMR (kcal·kg−1 lean mass) was lower in males compared with females as well as lower bone-density Z scores at the hip and lumbar spine. Data suggest the lifestyle of male jockeys compromise health more severely than females, possibly because of making weight more frequently.

scholarly journals Association Between Body Composition and Bone Density in Morbidly Obese Women According to Menopausal Status (P01-023-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Marise Crivelli ◽  
Amina Chain ◽  
Flavia Bezerra
Keyword(s):  
Body Composition ◽  
Lumbar Spine ◽  
Soft Tissue ◽  
Bone Density ◽  
Bone Turnover ◽  
Postmenopausal Women ◽  
Lean Mass ◽  
Severe Obesity ◽  
Menopausal Status ◽  
Morbidly Obese

Abstract Objectives The study aim was to assess bone mineral density (BMD) and bone turnover in pre- and postmenopausal women with severe obesity. Additionally, we explored the association between soft tissue body composition and BMD according to menopausal status. Methods This is a cross-sectional study conducted in pre- (n = 37) and postmenopausal (n = 22) morbid obese (BMI >40 kg/cm2) women. Body composition and BMD at different sites (lumbar spine, proximal femur and forearm) were assessed by dual energy X-ray absorptiometry (DXA). Biochemical markers of bone metabolism (serum CTX and osteocalcin) and serum 25(OH)D were also measured. Differences between pre- and postmenopausal women were analyzed by Student´s t-test. Body composition [lean mass, visceral (VAT) and subcutaneous (SAT) adipose tissue] and other potential factors associated with BMD were investigated by multiple regression. Results BMD at all sites evaluated was similar in pre- and postmenopausal women (P > 0.05). Also, no differences between groups were observed for bone turnover markers (P > 0.05). In postmenopausal women, years after menopause was inversely associated with BMD at total body (β = −0.010, P < 0.01) and total femur (β = −0.009, P < 0.05). Serum 25(OH)D was also associated with total femur BMD (β = 0.008, P < 0.01) in postmenopausal women. Lean mass was not associated with BMD in both groups. VAT was directly associated with lumbar spine BMD in postmenopausal women (β = 0.135, P < 0.05). Conclusions Our results suggest that severe obesity may weaken the impact of menopause on bone mass and turnover. Also, soft tissue body composition appears to poorly influence bone density in these women. Funding Sources Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ, Grant number E26/110.764/2013 for FFB).

EFFECT OF THERMOGENIC DIETARY SUPPLEMENTS ON RESTING METABOLIC RATE IN HEALTHY MALE AND FEMALE VOLUNTEERS

1999 ◽  
Vol 31 (Supplement) ◽  
pp. S164 ◽  
Author(s):  
A. E. Shugarman ◽  
E. W. Askew ◽  
D. D. Stadler ◽  
M. J. Luetkemeier ◽  
R. C. Bullough ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Dietary Supplements ◽  
Resting Metabolic Rate ◽  
Healthy Male ◽  
Male And Female

scholarly journals Older age at Initiation of Antiretroviral Therapy Predicts Low Bone Mineral Density in Children with perinatally-infected HIV in Zimbabwe

2019 ◽  
Author(s):  
Celia L Gregson ◽  
April Hartley ◽  
Edith Majonga ◽  
Grace Mchugh ◽  
Nicola Crabtree ◽  
...  
Keyword(s):  
Antiretroviral Therapy ◽  
Bone Density ◽  
Bone Mineral ◽  
Lean Mass ◽  
Muscle Development ◽  
Z Score ◽  
Mineral Density ◽  
Bone Mineral Apparent Density ◽  
Art Initiation ◽  
Z Scores

AbstractBackgroundPerinatally-acquired HIV infection commonly causes stunting in children, but how this affects bone and muscle development is unclear. We investigated differences in bone and muscle mass and muscle function between children with HIV (CWH) and uninfected children.SettingCross-sectional study of CWH (6–16 years) receiving antiretroviral therapy (ART) for >6 months and children in the same age-group testing HIV-negative at primary health clinics in Zimbabwe.MethodsFrom Dual-energy X-ray Absorptiometry (DXA) we calculated total-body less-head (TBLH) Bone Mineral Content (BMC) for lean mass adjusted-for-height (TBLH-BMCLBM) Z-scores, and lumbar spine (LS) Bone Mineral Apparent Density (BMAD) Z-scores.ResultsThe 97 CWH were older (mean age 12.7 vs. 10.0 years) and therefore taller (mean height 142cm vs. 134cm) than those 77 uninfected. However, stunting (height-for-age Z-score≤-2) was more prevalent in CWH (35% vs. 5%, p<0.001). Amongst CWH, 15% had low LS-BMAD (Z-score ≤-2) and 13% had low TBLH-BMCLBM, vs. 1% and 3% respectively in those uninfected (both p≤0.02). After age, sex, height and puberty adjustment, LS-BMAD was 0.33 SDs (95%CI −0.01, 0.67; p=0.06) lower in CWH, with no differences in TBLH-BMCLBM, lean mass or grip strength by HIV status. However, there was a strong relationship between age at ART initiation and both LS-BMAD Z-score (r=-0.33, p=0.001) and TBLH-BMCLBM Z-score (r=-0.23, p=0.027); for each year ART initiation was delayed a 0.13 SD reduction in LS-BMAD was seen.ConclusionSize-adjusted low bone density is common in CWH. Delay in initiating ART adversely affects bone density. Findings support immediate ART initiation at HIV diagnosis.

scholarly journals Metabolic reduction after long-duration flight is not related to fat-free mass loss or flight duration in a migratory passerine

2020 ◽  
Vol 223 (19) ◽  
pp. jeb215384
Author(s):  
Alexander R. Gerson ◽  
Joely G. DeSimone ◽  
Elizabeth C. Black ◽  
Morag F. Dick ◽  
Derrick J. Groom
Keyword(s):  
Metabolic Rate ◽  
Mass Loss ◽  
Body Mass ◽  
Lean Mass ◽  
Migratory Birds ◽  
Resting Metabolic Rate ◽  
Fat Free Mass ◽  
Flight Duration ◽  
Long Duration ◽  
Resting Metabolism

ABSTRACTMigratory birds catabolize large quantities of protein during long flights, resulting in dramatic reductions in organ and muscle mass. One of the many hypotheses to explain this phenomenon is that decrease in lean mass is associated with reduced resting metabolism, saving energy after flight during refueling. However, the relationship between lean body mass and resting metabolic rate remains unclear. Furthermore, the coupling of lean mass with resting metabolic rate and with peak metabolic rate before and after long-duration flight have not previously been explored. We flew migratory yellow-rumped warblers (Setophaga coronata) in a wind tunnel under one of two humidity regimes to manipulate the rate of lean mass loss in flight, decoupling flight duration from total lean mass loss. Before and after long-duration flights, we measured resting and peak metabolism, and also measured fat mass and lean body mass using quantitative magnetic resonance. Flight duration ranged from 28 min to 600 min, and birds flying under dehydrating conditions lost more fat-free mass than those flying under humid conditions. After flight, there was a 14% reduction in resting metabolism but no change in peak metabolism. Interestingly, the reduction in resting metabolism was unrelated to flight duration or to change in fat-free body mass, indicating that protein metabolism in flight is unlikely to have evolved as an energy-saving measure to aid stopover refueling, but metabolic reduction itself is likely to be beneficial to migratory birds arriving in novel habitats.

Energy Conservation in Amenorrheic Ballet Dancers

2006 ◽  
Vol 21 (3) ◽  
pp. 97-104
Author(s):  
Beth Glace ◽  
Ian Kremenic ◽  
Marijeanne Liederbach
Keyword(s):  
Eating Disorders ◽  
Energy Conservation ◽  
Metabolic Rate ◽  
Body Fat ◽  
Lean Mass ◽  
Resting Metabolic Rate ◽  
Ballet Dancers ◽  
Thermic Effect Of Food ◽  
Effect Of Food ◽  
Thermic Effect

Ballet dancers may be at risk of eating disorders, and women with eating disorders are at increased risk for menstrual dysfunction. Caloric intakes of amenorrheic dancers have been reported to be less than those of eumenorrheic dancers, indicating a possible conservation of energy. We evaluated resting metabolic rate and the thermic effect of food following ingestion of a 500-kcal liquid supplement in 8 amenorrheic dancers and 10 eumenorrheic dancers. Body fat was higher for the eumenorrheic group (20%) than the amenorrheic group (15%). Resting metabolic rate did not differ between groups when corrected for body mass (24.2 ± 1.1 kcal/kg/day for amennorheic dancers vs. 25.0 ± 0.9 kcal/kg/day for eumennorheic dancers), nor did resting metabolic rate differ when adjusted for lean mass. However, amennorheic dancers expended significantly less energy post-prandially once adjusted for lean mass (ANOVA, effect of group p = 0.035). Dancers were asked to complete the Eating Disorder Inventory, a self-report scale that measures symptoms of disordered eating; 9 of 10 eumennorheic but only 4 of 8 amennorheic women were willing to complete the questionnaire. Eumennorheic dancers had profiles similar to or less pathologic than those of non-eating-disordered populations. Greater dissatisfaction was expressed by eumennorheic women as body fat increased. Contrary to the findings in previous studies, amennorheic ballet dancers did not exhibit energy conservation via reductions in resting metabolic rate but did expend slightly less energy in thermic effect of food compared to normally menstruating women.

scholarly journals The Effect of Gender and Body Composition Method on the Apparent Decline in Lean Mass-Adjusted Resting Metabolic Rate With Age

2000 ◽  
Vol 55 (12) ◽  
pp. M757-M760 ◽  
Author(s):  
R. Roubenoff ◽  
V. A. Hughes ◽  
G. E. Dallal ◽  
M. E. Nelson ◽  
C. Morganti ◽  
...  
Keyword(s):  
Body Composition ◽  
Metabolic Rate ◽  
Lean Mass ◽  
Resting Metabolic Rate ◽  
Composition Method

scholarly journals Low resting metabolic rate in exercise-associated amenorrhea is not due to a reduced proportion of highly active metabolic tissue compartments

2016 ◽  
Vol 311 (2) ◽  
pp. E480-E487 ◽  
Author(s):  
Karsten Koehler ◽  
Nancy I. Williams ◽  
Rebecca J. Mallinson ◽  
Emily A. Southmayd ◽  
Heather C. M. Allaway ◽  
...  
Keyword(s):  
Body Size ◽  
Energy Conservation ◽  
Metabolic Rate ◽  
Lean Mass ◽  
Resting Metabolic Rate ◽  
Tissue Level ◽  
Highly Active ◽  
Exercising Women ◽  
Lower Ratio ◽  
Tissue Compartments

Exercising women with menstrual disturbances frequently display a low resting metabolic rate (RMR) when RMR is expressed relative to body size or lean mass. However, normalizing RMR for body size or lean mass does not account for potential differences in the size of tissue compartments with varying metabolic activities. To explore whether the apparent RMR suppression in women with exercise-associated amenorrhea is a consequence of a lower proportion of highly active metabolic tissue compartments or the result of metabolic adaptations related to energy conservation at the tissue level, RMR and metabolic tissue compartments were compared among exercising women with amenorrhea (AMEN; n = 42) and exercising women with eumenorrheic, ovulatory menstrual cycles (OV; n = 37). RMR was measured using indirect calorimetry and predicted from the size of metabolic tissue compartments as measured by dual-energy X-ray absorptiometry (DEXA). Measured RMR was lower than DEXA-predicted RMR in AMEN (1,215 ± 31 vs. 1,327 ± 18 kcal/day, P < 0.001) but not in OV (1,284 ± 24 vs. 1,252 ± 17, P = 0.16), resulting in a lower ratio of measured to DEXA-predicted RMR in AMEN (91 ± 2%) vs. OV (103 ± 2%, P < 0.001). AMEN displayed proportionally more residual mass ( P < 0.001) and less adipose tissue ( P = 0.003) compared with OV. A lower ratio of measured to DXA-predicted RMR was associated with lower serum total triiodothyronine ( ρ = 0.38, P < 0.001) and leptin ( ρ = 0.32, P = 0.004). Our findings suggest that RMR suppression in this population is not the result of a reduced size of highly active metabolic tissue compartments but is due to metabolic and endocrine adaptations at the tissue level that are indicative of energy conservation.

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