• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 382
  • 255
  • 67
  • 30
  • 15
  • 9
  • 8
  • 7
  • 7
  • 7
  • 7
  • 7
  • 7
  • 6
  • 5
  • Tagged with
  • 960
  • 960
  • 338
  • 331
  • 163
  • 146
  • 103
  • 99
  • 95
  • 94
  • 92
  • 92
  • 88
  • 85
  • 76
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Diet, Body Fat Distribution, and Serum Leptin in Young Men with Undiagnosed Obstructive Sleep Apnea Syndrome

Jones, Emily Taylor 07 December 2008 (has links)
Background and Purpose: Little is known about influences of obstructive sleep apnea syndrome (OSAS) on dietary intake and body composition. The purpose of this study was to evaluate dietary status, body fat distribution and leptin in overweight young men with and without OSAS in comparison to published values for normal weight counterparts. Methods: Groups were comprised of 24 sedentary overweight young men with and without OSAS, who had a body mass index (BMI) greater than 25 kg/m². Serum leptin concentration was measured in the 24 subjects using radioimmunoassay, while OSAS assessment was done using nighttime home somnography. Analysis of 4-day diet recalls was performed using Nutritionist Pro (First DataBank, Inc., San Bruno, CA). A Healthy Eating Index (HEI) score was calculated for the 24 overweight subjects. Results: There were no differences between the two overweight groups for total fat mass, central abdominal fat, BMI, waist circumference, leptin, or the HEI. The HEI was not predictive of overall OSAS severity; however, BMI was moderately related to OSAS severity (r = 0.39; p=0.05). The normal weight group did have a 50% higher report of carbohydrate intake, and consumed on average, 500 more kilocalories per day. The normal weight group consumed 50% less sodium, and 50% more Vitamin's C and E including a 13% increase in the HEI. Conclusions: Regulation of eating behavior and related influences on diet composition may be affected by a number of neurohormonal disturbances associated with OSAS and/or obesity, itself. Further research is needed to quantify these possible differences on dietary status and the underlying mechanism involved. / Master of Science
202

Toward a Romanian version of the Three Factor Eating Questionnaire–R21 for children and adolescents (CTFEQr21): Preliminary psychometric analysis and relation with body composition

Steff, M., Verney, J., Marinau, M., Perte, S., Pereira, B., Bryant, Eleanor J., Drapeau, V., Chaput, J.P., Courteix, D., Thivel, D. 28 November 2018 (has links)
Yes / Purpose. The aim of this study was to develop and validate a Romanian version of the three factor eating questionnaire-r21 for children and adolescents (ctfeqr21), and to assess its psychometric properties and factor structure. Associations between this version of the ctfeqr21 and anthropometric measures as well as body composition were also examined. Design and methods. 153 children and adolescents (68 boys and 95 girls; 10.8 ± 3.5 years) took part in this study (bmi of 17.7 ± 3.1 kg/m²). The participants were first interviewed to ascertain their understanding of the ctfeq-r21 and were then asked to self-complete the questionnaire. Height and weight were measured and body composition assessed using bio impedance analyzers (Tanita MC 780). Results. The CTFEQr21 showed satisfactory internal consistency (cronbach’s α=0.78). Cronbach’s alpha coefficients were 0.55 for CR, 0.75 for UE, and 0.76 for EE separately. UE and EE were found to be significantly correlated (r=0.54, p<0.05). The three factors explained 43% of the total variance. Correlation between CR, UE and EE with body weight, BMI and FFM were significant but low to moderate with coefficients ranging from 0.20 to 0.37. The higher the CR, UE and EE tertiles, the higher the weight, fat mass (kg) and fat-free mass values. Conclusions. According to the psychometric analysis of the questionnaire, the proposed version of the CTFEQr21 proposed here is a satisfactory tool to assess eating behaviors in Romanian child population that remains to be further developed.
203

Quantitative measurement of body composition in individuals with acquired immune deficiency syndrome (AIDS)

Bergerson, Sara L. 30 December 2008 (has links)
Body composition parameters were measured in 48 males with AIDS who were classified as being HIV positive-asymptomatic (HIV+), HIV positive - Kaposis sarcoma (KS), and HIV positive -opportunistic infections (OI). The major conclusions derived from this study were based on the evaluation of body weight (BW) , body fat (BF) and body cell mass (BCM) alterations that were directly measured. Values for extracellular supporting tissue were inferred. The values for BCM were obtained from K-40 measurements and anthropometric measurements were used to obtain BF estimates. K-40 analysis and anthropometric measurements were performed in accordance with established methods. As expected, a difference in body composition parameters was detected among groups. The KS and OI groups had similar BCM levels. There was a small but significant decrease in BCM values when the KS and OI groups were compared to the HIV+ group. The OI group had lower BW and BF values compared to the other groups. However, the values for BF, BW and BCM from this sample were higher than anticipated. The results support the contention that body composition parameters change as the disease progresses, but that clinically stable individuals with HIV infection may be able to preserve or replete normal body stores. / Master of Science
204

Body frame measures and perceptions of frame size and weight

Merritt, Deborah Anne 17 November 2012 (has links)
The purpose of this research was to examine five methods of determining frame size. In addition, self perception of frame size and of desired weight was compared to two height-weight table recommendations. Pearson correlation coefficients were calculated to determine relationships between measurements used as criteria for frame measures and between the five frame measures studied. Agreement of frame size identification was examined by comparing percentages of small, medium and large frame for each method. While the Pearson correlation coefficient of wrist circumference with elbow breadth was greater than 0.5 for both men and women, the correlations between frame measures using wrist circumference criteria and frame measures using elbow breadth criteria were less than 0.5. Self-perceived frame size was not significantly correlated with any of the five frame measures examined or with weight perception variables. Comparison of weight perception with evaluation of measured weight using two height-weight tables indicated men appear to desire to be heavier and women appear to desire to be thinner than weights recommended for height and measured frame size. Results were discussed in relation to findings of other researchers. Recommendations were made concerning the frame measures examined, the relationship of frame size perception to self-evaluation of weight, and the use of height-weight tables in determining weight goals. / Master of Science
205

The use of bioelectrical impedance analysis for estimating the body composition of various fish species

Duncan, Michael Bennett 15 June 2009 (has links)
The reliable measurement of growth and condition is vital for effective fisheries assessments. Biologists have long attempted to estimate condition for their assessments, but a reliable method to nonlethally estimate body composition is lacking. Proximate analysis is the most dependable and accurate method for estimating internal composition, but it is lethal, time consuming, and expensive. Recent research has shown bioelectrical impedance analysis (BIA) to be an effective method for estimating proximate composition in some fishes. The technique is quick, inexpensive, and, most importantly, nonlethal, which is vital when examining endangered species or cultured fish. My research focused on developing BIA indices for several new species of fish, using those indices to evaluate the body composition of fish in the field, and determining whether water temperature influenced resistance and reactance measurements. I found that BIA accurately estimated the body composition of bluegill Lepomis macrochirus, redear sunfish Lepomis microlophus, brook trout Salvelinus fontinalis, and northern logperch Percina caprodes (r2 ≥ 0.71, p < 0.0001). I also determined that bluegill and redear regressions were not significantly different (P ≥ 0.10) suggesting they can be used interchangeably during future studies. Laboratory studies revealed that water temperature did not significantly influence resistance and reactance measurements of bluegill, redear, and largemouth bass Micropterus salmoides (P ≥ 0.18). These results, along with previous literature, indicate that BIA may be an accurate and reliable assessment tool for fisheries biologists. / Master of Science
206

Muscle deterioration due to rheumatoid arthritis: assessment by quantitative MRI and strength testing

27 April 2021 (has links)
Yes / RA patients often present with low muscle mass and decreased strength. Quantitative MRI offers a non-invasive measurement of muscle status. This study assessed whether MRI-based measurements of T2, fat fraction, diffusion tensor imaging and muscle volume can detect differences between the thigh muscles of RA patients and healthy controls, and assessed the muscle phenotype of different disease stages. Thirty-nine RA patients (13 'new RA'-newly diagnosed, treatment naïve, 13 'active RA'-persistent DAS28 >3.2 for >1 year, 13 'remission RA'-persistent DAS28 1 year) and 13 age and gender directly matched healthy controls had an MRI scan of their dominant thigh. All participants had knee extension and flexion torque and grip strength measured. MRI T2 and fat fraction were higher in the three groups of RA patients compared with healthy controls in the thigh muscles. There were no clinically meaningful differences in the mean diffusivity. The muscle volume, handgrip strength, knee extension and flexion were lower in all three groups of RA patients compared with healthy controls. Quantitative MRI and muscle strength measurements can potentially detect differences within the muscles between RA patients and healthy controls. These differences may be seen in RA patients who are yet to start treatment, those with persistent active disease, and those who were in clinical remission. This suggests that the muscles in RA patients are affected in the early stages of the disease and that signs of muscle pathology and muscle weakness are still observed in clinical remission. / National Institute for Health Research (NIHR) Leeds Biomedical Research Centre (BRC) and Health Education England
207

Korrigering av hemodialyspatienters torrvikt med vägledning av bioimpedansspektroskopi

Stenberg, Jenny January 2013 (has links)
Bakgrund: Felaktiga torrvikter är ett problem inom hemodialysvården. Det kan orsaka vårdskada i form av komplikationer och lidande, med symtom som trötthet, blodtrycksfall och sendrag för dialyspatienter. Det finns ett behov av implementering av evidensbaserade metoder som minskar risken för fel i torrviktsbestämning. Bioimpedansmätning beskrivs i litteraturen som ett lovande hjälpmedel för bestämning av torrvikt Syfte: Undersöka effekten av bioimpedansledd torrviktskorrigering, på symtom som hemodialyspatienter kan erfara under och efter dialysbehandling. Metod: Experimentell intervention, i form av veckovis korrigering av torrvikt med vägledning av bioimpedansspektroskopi, utförd med single-case-design och multiple base- line. Urvalet bestod av sex strategiskt utvalda hemodialyspatienter. Resultat: Interventionen hade ringa effekt på förekomst av intradialytiska symtom. Bland studiens deltagare förelåg sällan samvariation mellan förekomst av blodtrycksfall och/eller sendrag och felaktig torrvikt. Däremot förelåg positivt samband mellan symtombörda och differens mellan predialytisk vikt och torrvikt. Bioimpedansmätningarna avslöjade dessutom kliniskt relevant varians i torrvikt över tid. Slutsats: Även om interventionen inte hade bevisad effekt på de beroende variablerna, är det inte uteslutet att noga monitorering av vätskebalans med bioimpedansmätare och korrigering av torrvikt kan förebygga uppkomst av intradialytiska symtom. I vissa subgrupper kan bioimpedansmätning också bidra till förbättrad blodtryckskontroll. Dialyspatienters torrvikt visade sig kunna variera med flera kilogram per vecka, varför fixerad torrvikt kan vara ett dilemma för vissa individer. Bioimpedansmätning bland hemodialyspatienter kan underlätta identifiering av individuella riskfaktorer för intradialytiska symtom och vara ett verktyg som bidrar till utvecklingen mot personcentrerad vård med större patientdelaktighet och individualiserade mål. / Background: Inaccurate dry weight is a problem in hemodialysis care. It can cause health damage in the form of suffering and complications such as fatigue, intradialytic hypotension (IDH) and cramps for dialysis patients. There is a need for implementation of evidence-based practices that reduce the risk of error in dry weight assessment. Bioelectrical impedance is described in literature as a promising tool for assessment of dry weight.Objective: Examine the effect of bioimpedance guided dry weight correction on symptoms that hemodialysis patients may experience during and after dialysis. Method: Experimental intervention in the form of weekly assessment of dry weight with the guidance of bioimpedance spectroscopy, performed with single-case design and multiple baseline. The sample consisted of six strategically selected hemodialysis patients. Results: The intervention had little effect on the prevalence of intradialytic symptoms. Among the study participants, the occurrence of IDH and / or cramps and inaccurate dry weight rarely correlated. However, there was positive correlation between symptoms and the difference between predialytic weight and dry weight. Bioimpedance measurement also revealed clinically relevant variance in dry weight over time. Conclusion: Although the intervention had no proven effect on the dependent variables, it is possible that careful monitoring of fluid balance with bioimpedance measurement and correction of dry weight can help prevent intradialytic symptoms. In certain subgroups bioelectrical impedance may also contribute to improved blood pressure control. Dialysis patients' dry weight was found to vary several kilograms per week; fixated dry weight may therefore be a dilemma for some individuals. Bioelectrical impedance among hemodialysis patients may facilitate identification of individual risk factors for intradialytic symptoms and be a tool that contributes to the development of person-centered care with greater patient participation and individualized goals.
208

Body composition, bone health and vitamin D status of African adults in the North West Province / Olusola Funmilayo Sotunde

Sotunde, Olusola Funmilayo January 2014 (has links)
Background In South Africa, as in many other developing countries, obesity has become a major health problem causing an increase in the incidence and prevalence of various non-communicable diseases. Research has shown that excess adiposity is associated with low vitamin D status and detrimental to bone health. Low vitamin D status has been linked to various non-communicable diseases which includes osteoporosis, and also the metabolic syndrome. Information is scarce on the role of lean mass and fat mass on bone health in the black South African population. There is also a shortage of data on the association between vitamin D status and the metabolic syndrome in the South African population. Aim The main aim of this study was to examine factors (vitamin D status, socio-economic status [SES] and lifestyle risk factors) associated with body composition, including bone health, as well as predictors of change in body composition in African adults in the North West Province of South Africa. Methods The first study that forms part of this thesis was a longitudinal study aimed at examining the effects of urbanization, socio-economic status and lifestyle factors on changes in body composition over 5 years in rural and urban black South African adults. A total of 1058 men and women above age 30 years from the Prospective Urban Rural Epidemiology study were included in this study. The second study to form part of this thesis aimed to examine the association between body composition and bone health in urban black South African women. Structured questionnaires were used to collect socio-demographic and lifestyle information including medication and tobacco use. This second study is cross-sectional in design and it included 189 postmenopausal women aged > 43 years old. Dual X-ray absorptiometry was used to assess bone mineral density, lean mass and fat mass, while structured and specific questionnaires were used to assess the habitual physical activity, food frequency and fracture risk. Habitual activity energy expenditure was also measured using an accelerometer with a combined heart rate monitor. The third study aimed to examine the association of serum 25 hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) concentration, respectively, with the metabolic syndrome while controlling for adiposity in black women in the North West Province, South Africa. This third study is also cross-sectional in design and it included 209 HIV-negative urban women. Dual X-ray absorptiometry was used to assess adiposity, while habitual physical activity was accessed with questionnaire and habitual activity energy expenditure was also measured using an accelerometer with a combined heart rate monitor. Results Study 1: Over a 5-year period, body mass index (BMI) and waist circumference increased in both genders, but the change was significant for BMI (P<0.01) and waist circumference (P<0.001) in women only, indicating an increase in adiposity over time. Urban residency positively predicted changes in waist circumference in men (p < 0.05) and women (p < 0.001) as well as change in triceps skinfold thickness of men (p < 0.05). Being married positively predicted changes in BMI (p < 0.001) and waist circumference (p < 0.001) in men, while age negatively predicted changes in triceps skinfold thickness in women (p < 0.001). Study 2: Fat mass and lean mass were significantly positively associated with bone mineral density (BMD) and fracture risk when adjusted for potential confounders. However, lean mass and not fat mass remained significantly associated with femoral neck BMD (β = 0.49, p <0.001), spine BMD (β = 0.48, p< 0.0001) and hip BMD (β = 0.59, p< 0.0001). Lean mass was also negatively associated with fracture risk (β = -0.19 p =0.04) when both lean and fat mass were in the same model. Study 3: After adjusting for age, body fat, habitual physical activity, tobacco use and season, neither 25(OH)D nor PTH concentrations showed significant associations with having the metabolic syndrome. However, when body fat was replaced with waist circumference there was a weak positive association between 25(OH)D concentration and the metabolic syndrome. No significant association was found between PTH:25(OH)D ratio and the metabolic syndrome. Conclusion This thesis has highlighted that the prevalence of obesity among black South Africans is high particularly among women and urbanization played a significant role in the increasing adiposity of black South Africans in the North West province. Lean mass had a stronger association with bone health in comparison to fat mass in urban black South African women. Low 25(OH)D concentration was not associated with the metabolic syndrome while there was no significant association between PTH and the metabolic syndrome in our black South African women. / PhD (Dietetics), North-West University, Potchefstroom Campus, 2015
209

Body composition, bone health and vitamin D status of African adults in the North West Province / Olusola Funmilayo Sotunde

Sotunde, Olusola Funmilayo January 2014 (has links)
Background In South Africa, as in many other developing countries, obesity has become a major health problem causing an increase in the incidence and prevalence of various non-communicable diseases. Research has shown that excess adiposity is associated with low vitamin D status and detrimental to bone health. Low vitamin D status has been linked to various non-communicable diseases which includes osteoporosis, and also the metabolic syndrome. Information is scarce on the role of lean mass and fat mass on bone health in the black South African population. There is also a shortage of data on the association between vitamin D status and the metabolic syndrome in the South African population. Aim The main aim of this study was to examine factors (vitamin D status, socio-economic status [SES] and lifestyle risk factors) associated with body composition, including bone health, as well as predictors of change in body composition in African adults in the North West Province of South Africa. Methods The first study that forms part of this thesis was a longitudinal study aimed at examining the effects of urbanization, socio-economic status and lifestyle factors on changes in body composition over 5 years in rural and urban black South African adults. A total of 1058 men and women above age 30 years from the Prospective Urban Rural Epidemiology study were included in this study. The second study to form part of this thesis aimed to examine the association between body composition and bone health in urban black South African women. Structured questionnaires were used to collect socio-demographic and lifestyle information including medication and tobacco use. This second study is cross-sectional in design and it included 189 postmenopausal women aged > 43 years old. Dual X-ray absorptiometry was used to assess bone mineral density, lean mass and fat mass, while structured and specific questionnaires were used to assess the habitual physical activity, food frequency and fracture risk. Habitual activity energy expenditure was also measured using an accelerometer with a combined heart rate monitor. The third study aimed to examine the association of serum 25 hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) concentration, respectively, with the metabolic syndrome while controlling for adiposity in black women in the North West Province, South Africa. This third study is also cross-sectional in design and it included 209 HIV-negative urban women. Dual X-ray absorptiometry was used to assess adiposity, while habitual physical activity was accessed with questionnaire and habitual activity energy expenditure was also measured using an accelerometer with a combined heart rate monitor. Results Study 1: Over a 5-year period, body mass index (BMI) and waist circumference increased in both genders, but the change was significant for BMI (P<0.01) and waist circumference (P<0.001) in women only, indicating an increase in adiposity over time. Urban residency positively predicted changes in waist circumference in men (p < 0.05) and women (p < 0.001) as well as change in triceps skinfold thickness of men (p < 0.05). Being married positively predicted changes in BMI (p < 0.001) and waist circumference (p < 0.001) in men, while age negatively predicted changes in triceps skinfold thickness in women (p < 0.001). Study 2: Fat mass and lean mass were significantly positively associated with bone mineral density (BMD) and fracture risk when adjusted for potential confounders. However, lean mass and not fat mass remained significantly associated with femoral neck BMD (β = 0.49, p <0.001), spine BMD (β = 0.48, p< 0.0001) and hip BMD (β = 0.59, p< 0.0001). Lean mass was also negatively associated with fracture risk (β = -0.19 p =0.04) when both lean and fat mass were in the same model. Study 3: After adjusting for age, body fat, habitual physical activity, tobacco use and season, neither 25(OH)D nor PTH concentrations showed significant associations with having the metabolic syndrome. However, when body fat was replaced with waist circumference there was a weak positive association between 25(OH)D concentration and the metabolic syndrome. No significant association was found between PTH:25(OH)D ratio and the metabolic syndrome. Conclusion This thesis has highlighted that the prevalence of obesity among black South Africans is high particularly among women and urbanization played a significant role in the increasing adiposity of black South Africans in the North West province. Lean mass had a stronger association with bone health in comparison to fat mass in urban black South African women. Low 25(OH)D concentration was not associated with the metabolic syndrome while there was no significant association between PTH and the metabolic syndrome in our black South African women. / PhD (Dietetics), North-West University, Potchefstroom Campus, 2015
210

Health-related physical fitness and risk factors associated with obesity among primary school children in the Limpopo and Mpumalanga provinces of South Africa / Violet Kankane Moselakgomo

Moselakgomo, Violet Kankane January 2014 (has links)
It is well documented that behavioural and biological risk factors for Chronic Diseases of Lifestyle (CDL) such as overweight and high blood pressure persist from childhood into adulthood. CDL is considered to be a group of diseases that shares similar risk factors as a result of exposure over many decades to physical inactivity, unhealthy diets, smoking, lack of regular exercise, and possibly stress. This study assessed health-related physical fitness and risk factors associated with obesity among 1361 (boys: n=678; girls: n=683) primary school children aged 9-12 years in the Limpopo (LP) and Mpumalanga (MP) Provinces, South Africa. Anthropometric and physical fitness measurements were taken using the protocol of the International Society for the Advancement of Kinanthropometry (ISAK) (Marfell-Jones, et al., 2006) and EUROFIT (1988) test batteries. Body composition measures included body mass index (BMI) (weight/height2), percentage body fat (%BF) and waist-to-hip ratio, respectively. BMI for age and gender was used to classify the children as underweight, overweight or obese (Cole et al., 2007), whilst %BF calculated from the sum of two skinfolds (triceps and subscapular) using the equation of Slaughter et al. (1988) indicated adiposity. The International Physical Activity Questionnaire (IPAQ) was used to categorise the children’s physical activity (PA) level as follows: Low (METs scores of less than 500); Moderate (METs scores from 500 to 1499) or High (METs >1500). In general, 75% of the children were underweight/stunted and 1.6% overweight. Frequencies of underweight, normal weight and overweight were 77%, 22.4% and 0.2% in MP and 72%, 24% and 3% in LP province. Boys were generally taller and heavier than girls. At age 10 the MP boys performed significantly (p=0.05) better in sit-ups (SUP: 20.5 ±5.4) than the LP boys (18.6±6.56). However, the LP boys performed significantly better than the MP boys in sit-and-reach (SAR) at ages 10 and 11. The MP boys performed significantly (p=0.00) better in SBJ (121.6±9.1cm) compared to the Limpopo (118.4±11.00cm) boys at age 9. Generally, LP boys were significantly (p=0.00) better than the MP boys across all ages. The PA results showed that 27.7% (377), 58.5% (796) and 13.8% (188) of the children participate in low, moderate and high PA, respectively. Children in the MP province had higher PA (28.6%) in comparison to the low PA participation in LP children (26.7%). Furthermore, 59.7% of MP children compared to the LP children (57.3%) participate in moderate PA. A higher PA participation rate (15.8%) was found among the LP than MP children (11.6%). The girls had non-significantly higher BP values (systolic: 112.94±11.28mmHg; diastolic: (79.40±12.80mmHg) than boys (systolic: 110.71±14.95mmHg; diastolic: (75.53±12.53mmHg) who had higher PA levels (METs =1286.72±317.47) than girls (METs =397.28±30.14) (p<0.01). A total of 81% (n=1089) and 19% (n=253) of the combined samples had normal BP and prehypertension, respectively. When controlled for provinces, gender and age, results indicated that BMI was negatively associated with systolic BP (SBP) (-0.54) (p<0.01), but positively correlated with %BF (0.133) (p<0.01), whilst SBP related positively with %BF (0.125) (p<0.01). The children’s PA level correlated positively with BMI (0.86) (p<0.01) but negatively with %BF (-0.67); weight circumference (WC) (-0.41); SUP (sit-up) (-0.22); and predicted 2max • VO (-0.17) (p<0.05). The high percentage of underweight and pre-hypertensive children in the study warrants an urgent need to periodically evaluate PA levels among South African children and design appropriate intervention programmes to alleviate concerns over body weight disorders and low PA levels in children, thus optimising health outcomes. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2015

Page generated in 0.0795 seconds