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

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

Introduction : Ce programme de recherche visait à étudier l'impact d'une intervention de 8 mois entrainant une perte de poids induite par l'activité physique et la nutrition sur la santé osseuse chez des adolescents obèses. L'objectif global de cette thèse était d'examiner l'impact d'une intervention de perte de poids sur les paramètres osseux chez les adolescents obèses.Méthode : Soixante-cinq adolescents ont été recrutés : 31 (6 garçons) obèses pour le groupe intervention (âge : 13,61 (1,27)), 23 adolescents de poids normal (NW) (âge : 15,90 (0,43)) et 11 (4 hommes) adolescents obèses pour le groupe témoin (14.02 (1.39)). Le critère d’évaluation principal concernait la densitométrie osseuse par DXA (corps entier, colonne vertébrale, hanche). Les critères d'évaluation secondaires comprenaient la composition corporelle (DXA), la géométrie et la résistance des os (analyse structurelle de la hanche) et des biomarqueurs osseux (propeptide N-terminal (P1NP) procollagène de type 1, estradiol C-télopeptide (CTx), leptine). Les données ont été collectées au départ à 4 mois et à 8 mois. Les données ont été ajustées en fonction des changements de poids corporel, de masse grasse et de masse maigre.Résultats : Comparés au groupe contrôle de poids normal, les adolescents obèses présentaient une densité osseuse non ajustée et ajustée inférieure. Suite à la perte de poids (~ -11%), les adolescents obèses ont augmentés leur densité osseuse au corps entier (% Ob 3,22 (3,58) p <0,001) et à la colonne lombaire (% Ob 6,27 (12,45) p = 0,014). Cependant, ces valeurs restent inférieures à celles de leurs homologues contrôle de poids normal après ajustement aux variations de poids corporel. Après l’intervention entrainant une perte de poids, les estimations du risque de fracture sont restées élevée, en particulier au niveau du col étroit (buckling ratio (BR) 8,25 (2,00) p = 0,005) et ce malgré des adaptations positives de certaines propriétés géométriques (i.e. NN CSA, NN Z). De plus, les modifications de l'accrétion osseuse chez les adolescents obèses suivent une adaptation de type androgènes, cela est démontrée par une expansion périostée (% NW ∆ 0,69 (3,71); Ob ∆ 1,67 (9,11)) et une résorption endocorticale (% NW ∆ -2,11 (11,79); Ob ∆ 4,42 (10,56)). Dans le groupe intervention, les différences au regard des marqueurs osseux favorisent la formation osseuse au cours des 4 premiers mois alors que par la suite la résorption osseuse est favorisée.Conclusion : La fragilité osseuse chez les adolescents obèses a été démontrée par (1) une densité minérale osseuse inférieure corps entier et régionale pré et post-intervention par rapport aux contrôles normo-pondérés, (2) un indice de risque de fracture élevé après intervention au niveau du cou étroit, (3) des biomarqueurs osseux démontrant des z-scores, indices de découplage (uncoupling indices) et représentations qualitatives de la distribution du remodelage osseux inférieures. Les résultats de cette thèse contribuent aux recherches futures sur les liens entre os et obésité à l’adolescence. / Introduction: This program of research targeted the impact of an 8-month weight loss intervention induced by physical activity and nutrition on bone health in adolescents with obesity. The overall aim of this thesis was to examine the impact of a lifestyle weight loss intervention on the bone parameters in adolescents with obesity. Method: Sixty-five adolescents were recruited: 31 (6 males) adolescents with obesity in the weight loss intervention (age: 13.61 (1.27)), 23 normal weight (NW) adolescents (age: 15.90 (0.43)) and 11 (4 males) adolescents with obesity in another control group (14.02 (1.39)). Primary outcomes targeted bone densitometry (whole body, spine, hip DXA). Secondary outcomes included body composition, bone geometry and strength (hip structural analysis) and bone biomarkers (procollagen type 1 N-terminal propeptide (P1NP), C telopeptide (CTx) estradiol, leptin). Data were collected at baseline, 4 months and 8 months. Data were adjusted for body weight, fat mass and lean mass changes.Results: Compared with the NW controls, adolescents with obesity displayed lower unadjusted and adjusted bone density. Following successful weight loss (~ -11%) adolescents with obesity increased whole body (%Ob ∆ 3.22 (3.58) p<0.001) and lumbar spine (%Ob ∆ 6.27 (12.45) p=0.014) BMD. However, values remain lower than their NW peers after adjustment to body weight changes. After the weight loss intervention, compromised estimates of fracture risk remained especially at the narrow neck (buckling ratio (BR) 8.25 (2.00) p=0.005), despite positive adaptations of some geometric properties (i.e. NN CSA, NN Z). Also, bone accretion changes in adolescents with obesity followed an androgen-like adaptation demonstrated by periosteal expansion (% NW ∆ 0.69 (3.71); Ob ∆ 1.67 (9.11)) and endocortical resorption (% NW ∆ -2.11 (11.79); Ob ∆ 4.42 (10.56)). Among the intervention group, differences in bone markers favoured formation during the first 4 months and favoured resorption in the remaining months.Conclusion: Bone fragility in adolescents with obesity was demonstrated by (1) baseline and post intervention lower whole body and regional BMD than NW controls, (2) post-intervention higher fracture risk index at the narrow neck, (3) bone biomarkers showing reduced z-scores, uncoupling indices and qualitative representations of the distribution of bone remodeling. Future investigations of links between bone and obesity during adolescence can be well informed by the results of this thesis.

Orientador: Dalton Muller Pessoa Filho / Resumo: O processo de modelação e remodelação óssea pela influência dos impactos mecânicos não contribui para o aumento da massa e da força óssea em esportes onde a gravidade é baixa, como em atividades aquáticas. O objetivo do estudo foi comparar a massa e a densidade mineral (BMC/BMD) corporal e regional de nadadores (ambos os sexos) com outros atletas da mesma faixa etária, pessoas sedentárias e idosas. Participaram do estudo 114 indivíduos, sendo 87 do sexo masculino, divididos em seis grupos: natação (n=12), Kendo (n=10), Jiu-Jitsu (n=10), musculação (n=14), sedentários (n=30) e idosos (n=11); e 27 do sexo feminino, divididos em dois grupos: sedentárias (n=13) e nadadoras (n=14). Os participantes foram avaliados quanto à composição regional e corporal através de absorciometria de raio-X com duplo feixe (DXA), fornecendo informações sobre o conteúdo mineral ósseo (BMC) e densidade mineral óssea (BMD). As diferenças entre os grupos quanto à BMC e BMD foram analisadas pela ANOVA (uma entrada e Sidak como post-hoc) estabelecendo-se p≤0,05. Os resultados obtidos mostraram que os valores de BMC do corpo todo (2442,81 ± 359,45 g), membros inferiores (MI) (909,78 ± 136,53 g), membros superiores (MS) (326,85 ± 51,61 g) e pélvis (P) (261,73 ± 49,13 g) para nadadores homens, mostraram-se diferentes do grupo de musculação (3148,29 ± 314,07 g/cm2, p<0,001; 1217,64 ± 161,08 g/cm2, p<0,001; 444,34 ± 58,82 g/cm2, p<0,001; 405,20 ± 75,06 g/cm2, p<0,001, respectivamente). Em relação aos valores d... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The process of modeling and bone remodeling by the influence of mechanical impacts does not contribute to the increase of mass and bone strength in sports where gravity is low, such as in aquatic activities. The objective of the study was to compare the body mass and mineral density (BMC/BMD) of swimmers (both sexes) with other athletes of the same age group, sedentary and elderly people. The 114 individuals, 87 males, were divided into six groups: swimming (n=12), Kendo (n=10), Jiu-Jitsu (n=10), Resistance Training (n=14), sedentary (n=30) and olders (n=11); and 27 females were divided into two groups: sedentary (n=13) and swimmers (n=14). Participants were evaluate for regional and whole-body composition by dual energy X-ray absorptiometry (DXA), providing information on bone mineral content (BMC) and bone mineral density (BMD). The differences between the groups for BMC and BMD were analyzed by ANOVA (one way with Sidak as post-hoc), setting p≤0.05. The results showed that the BMC values for whole-body (2442.81 ± 359.45 g), lower limbs (LL) (909.78 ± 136.53 g), upper limbs (UL) (326.85 ± 51,61 g) and pelvis (P) (261.73 ± 49.13 g) for male swimmers were different from resistance training group (3148.29 ± 314.07, p<0.001, 1217.64 ± 161.08, p<0.001, 444.34 ± 58.82, p<0.001, 405.20 ± 75.06, p<0.001, respectively). Regarding BMD values for whole-body (1.09 ± 0.07 g/cm2), LL (1.12 ± 0.07 g/cm2), UL (0.78 ± 0.04 g/cm2), P (1.07 ± 0.08 g/cm2) male swimmers also differed from resis... (Complete abstract click electronic access below) / Mestre

In the United States, about 8.5 million women live with osteoporosis. Osteoporosis is a debilitating systemic skeletal disorder characterized by low bone mass and reduced bone mineral density that occurs with the loss of estrogen. The mortality rate for this group is about 3 to 4 times higher than other women and as many as 1 in 3 experience a fracture. Guided by the Health Belief Model, this project evaluated how a bone health fact sheet impacts knowledge about osteoporosis and self-efficacy for preventative behavioral change in premenopausal women (age 40-58 years). The project also evaluated if an electronic medical record (EMR) alert system with an additional bone health education in the patient instruction menu can improve participation by 11 health care providers (HCPs). Prior to the participants receiving the fact sheet, the knowledge, health beliefs, and perceived risks for developing osteoporosis were measured using the Revised Osteoporosis Knowledge Test (ROKT) and the Osteoporosis Health Belief Scale (OHBS). Although 87% of participants identified menopause as a major osteoporosis risk factor, fewer women (33%) knew that surgical removal of the ovaries was also a risk factor and half agreed or strongly agreed that calcium and exercise can prevent osteoporosis. After receiving the fact sheet, the participants had an average confidence score of 62% on the Osteoporosis Self-Efficacy Scale (OSES) for engaging in exercise and an average confidence score of 65% for adhering to calcium intake guidelines. Furthermore, the EMR alert system facilitated 100% documentation by HCPs. These results indicated the fact sheet can motivate premenopausal women to engage in osteoporosis preventive behaviors. Importantly, the EMR reminder with education fact sheet can facilitate the active involvement of HCPs in patient education.

Introduction: About 80% of those affected by osteoporosis are postmenopausal women. Therefore, identifying beneficial or harmful dietary factors for postmenopausal osteoporosis may have a significant public health impact. Objectives: The overall objective of this thesis was to examine the relations between various dietary factors and bone health in postmenopausal women aged ≥ 45 years using different analytical approaches. Methods: First, the associations between fruit and vegetables (F&V) intake and indicators of bone health were assessed using a systematic review approach. Electronic databases were searched and peer-reviewed observational and interventional studies published in English with F&V intake as a main dietary exposure were included. Data selection, extraction and evaluation of risk of bias were performed independently by two reviewers. Second, the associations between an overall diet quality index (HEI-2005) and its components with bone turnover markers (BTMs) were examined. Third, the relationships between alpha-tocopherol intake, serum alpha- and gamma-tocopherol, two concentration biomarkers of vitamin E intake, and their ratio and BTMs were assessed. For the second and third studies, cross-sectional data from the National Health and Nutrition Examination Survey 1999-2002 were used. Weighted multiple regression models with adjustments for relevant confounders were used to examine the relationship between exposures and serum bone-specific alkaline phosphatase (BAP), a biomarker of bone formation, and urinary N-Telopeptides/Creatinine (uNTx/Cr), a biomarker of bone resorption. Results: There was significant between-study heterogeneity in design, definition and amount of F&V intake, outcomes, analyses and reporting of results in the eight included studies. Overall, cross-sectional and case-control analyses reported protective associations between F&V intake and bone health, whereas interventional and prospective cohort analyses did not. There were no associations between total HEI-2005 scores and BTMs. However, the Milk Group component of HEI-2005 had a significant inverse relationship with uNTx/Cr. Higher serum gamma-tocopherol and lower ratio of serum alpha- to gamma-tocopherol were associated with higher BAP concentrations but had no associations with NTx/Cr concentrations. Conclusions: The results confirm the existing knowledge that a diet with adequate intake of dairy may reduce bone loss. Further research is needed to examine the potential anabolic effects of gamma-tocopherol on bone in postmenopausal women.

Introduction: About 80% of those affected by osteoporosis are postmenopausal women. Therefore, identifying beneficial or harmful dietary factors for postmenopausal osteoporosis may have a significant public health impact. Objectives: The overall objective of this thesis was to examine the relations between various dietary factors and bone health in postmenopausal women aged ≥ 45 years using different analytical approaches. Methods: First, the associations between fruit and vegetables (F&V) intake and indicators of bone health were assessed using a systematic review approach. Electronic databases were searched and peer-reviewed observational and interventional studies published in English with F&V intake as a main dietary exposure were included. Data selection, extraction and evaluation of risk of bias were performed independently by two reviewers. Second, the associations between an overall diet quality index (HEI-2005) and its components with bone turnover markers (BTMs) were examined. Third, the relationships between alpha-tocopherol intake, serum alpha- and gamma-tocopherol, two concentration biomarkers of vitamin E intake, and their ratio and BTMs were assessed. For the second and third studies, cross-sectional data from the National Health and Nutrition Examination Survey 1999-2002 were used. Weighted multiple regression models with adjustments for relevant confounders were used to examine the relationship between exposures and serum bone-specific alkaline phosphatase (BAP), a biomarker of bone formation, and urinary N-Telopeptides/Creatinine (uNTx/Cr), a biomarker of bone resorption. Results: There was significant between-study heterogeneity in design, definition and amount of F&V intake, outcomes, analyses and reporting of results in the eight included studies. Overall, cross-sectional and case-control analyses reported protective associations between F&V intake and bone health, whereas interventional and prospective cohort analyses did not. There were no associations between total HEI-2005 scores and BTMs. However, the Milk Group component of HEI-2005 had a significant inverse relationship with uNTx/Cr. Higher serum gamma-tocopherol and lower ratio of serum alpha- to gamma-tocopherol were associated with higher BAP concentrations but had no associations with NTx/Cr concentrations. Conclusions: The results confirm the existing knowledge that a diet with adequate intake of dairy may reduce bone loss. Further research is needed to examine the potential anabolic effects of gamma-tocopherol on bone in postmenopausal women.

The purpose of this longitudinal repeated measures experimental study was to determine the effects of bone health testing using dual energy X-ray absorptiometry (DXA) on outcomes of intentions toward and actual engagement in bone health behaviors (calcium intake, vitamin D intake, physical activity) among perimenopausal women. The Perimenopausal Bone Health Behaviors Model was developed based on the Theory of Planned Behavior and guided this study to determine how perimenopausal women respond to DXA and bone health information compared to bone health information only.One hundred fifty community-based perimenopausal women (ages 35-55) were randomly assigned to an intervention group (n=75 DXA and bone health information) or to a comparison group (n=75 bone health information). Baseline demographic data were collected. The Prevention Intentions Questionnaire and Behaviors Questionnaire were administered at baseline, at two weeks, and at two months after both groups received assigned interventions.Results showed 32% (n = 24) of intervention group women had low bone density. The intervention of DXA and bone health information showed near-significance (p = .068) over the intervention of bone health information alone in affecting women's intentions, and showed near-significance in affecting calcium intake (p = .052). Lower bone density test scores were related to higher intentions (r(74) = -.23, p = .046) at two weeks after DXA and bone health information, and were related to improved vitamin D intake (r(73) = -.25, p = .03) at two months after DXA and bone health information. At study end, Attitudes contributed 27.0% of the variance in Intentions among women who received DXA and bone health information; Attitudes, Subjective Norms, and Perceived Behavioral Control contributed 62.0% of the variance in Intentions among women who received bone health information only.Nursing interventions focusing on perimenopausal women should include providing bone health information to all perimenopausal women. Interventions targeting attitudes toward bone health behaviors may motivate some perimenopausal women to participate in behaviors that contribute to decreased risk of osteoporosis. Early detection and intervention in perimenopausal bone loss may reduce osteoporosis morbidity and may impact women's quality of life, reduce financial consequences to individuals, families, communities, and the nation.

BACKGROUND: Bariatric surgery is an effective weight loss treatment modality for people with morbid obesity, however, there may be a negative impact on postoperative bone health. This review summarizes changes of different bone mineral density dual-energy x-ray absorptiometry measurements, with specific attention to the laparoscopic sleeve gastrectomy and the roux-en-y gastric bypass. METHODS: PubMed and the Cochrane Library searches yielded 156 articles published before November 2017. The articles were evaluated based on the following inclusion criteria: focus on laparoscopic sleeve gastrectomy or roux-en-y gastric bypass and bone health, written in English, full-length article, studied participants for one-to-two years, and included statistical measurements. RESULTS: Of the 156 studies that were initially screened, 16 full-length articles were included in the final analysis. The articles described a lower loss of bone density at the lumbar spine, femoral neck, forearm, and total hip after laparoscopic sleeve gastrectomy when compared to roux-en-y gastric bypass, however, these studies lack statistical power due to the small sample sizes of less than 10 participants. CONCLUSION: The number of bariatric surgeries continues to increase worldwide, however, the literature provides limited studies that evaluate the effects of bariatric surgery on bone health, more than two-years postoperative. Further study is necessary to determine the mechanisms of bone loss after bariatric surgery, with great attention to differences in bone health between sexes.

abstract: The Human Gut Microbiome (GM) modulates a variety of structural, metabolic, and protective functions to benefit the host. A few recent studies also support the role of the gut microbiome in the regulation of bone health. The relationship between GM and bone health was analyzed based on the data collected from a group of twenty-three adolescent boys and girls who participated in a controlled feeding study, during which two different doses (0 g/d fiber and 12 g/d fiber) of Soluble Corn Fiber (SCF) were added to their diet. This analysis was performed by predicting measures of Bone Mineral Density (BMD) and Bone Mineral Content (BMC) which are indicators of bone strength, using the GM sequence of proportions of 178 microbes collected from 23 subjects, by building a machine learning regression model. The model developed was evaluated by calculating performance metrics such as Root Mean Squared Error, Pearson’s correlation coefficient, and Spearman’s rank correlation coefficient, using cross-validation. A noticeable correlation was observed between the GM and bone health, and it was observed that the overall prediction correlation was higher with SCF intervention (r ~ 0.51). The genera of microbes that played an important role in this relationship were identified. Eubacterium (g), Bacteroides (g), Megamonas (g), Acetivibrio (g), Faecalibacterium (g), and Paraprevotella (g) were some of the microbes that showed an increase in proportion with SCF intervention. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2020