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Item The gut‐bone axis in coeliac disease : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Manawatū, New Zealand(Massey University, 2022) Schraders, Katie Elizabeth Coad PedleyCoeliac Disease (CD) is a lifelong autoimmune disease, highly prevalent in New Zealand, triggered by ingestion of gluten in genetically susceptible individuals. It leads to villous atrophy and nutrient malabsorption which often compromises bone mineral density (BMD). Although a gluten‐free diet (GFD) usually improves symptoms, BMD is often not fully resolved. Persistent low BMD may be due to ongoing gut inflammation and malabsorption, or the uncoupling of bone formation and resorption. Previous research indicates that individuals with CD and low BMD may have altered bone signalling pathways, particularly in the expression of receptor activator of NF‐κβ ligand (RANKL) and osteoprotegerin. RANKL is implicated in both the initiation of the immune response and persistent low BMD because it has a role in bone resorption, via the differentiation of osteoclasts, and a possible role in translocating gluten across the gut, via the expression of microfold cells. The objective of this PhD was to examine underlying mechanisms underpinning low BMD in individuals with CD using a small intestinal organoid model which allows for investigation of otherwise inaccessible gut cells and signalling pathways implicated in the gut‐bone axis. A further study, Close to the Bone, investigated BMD in premenopausal women with CD compared to healthy controls. A third online A Gut Feeling study investigated dietary advice that individuals consuming a GFD in New Zealand receive, focusing on bone health. Although the organoid research was interrupted due to the SARS‐CoV‐2 pandemic, the model was established using murine tissue and future research opportunities were identified. The results of the Close to the Bone study demonstrated no differences in BMD between the coeliac group and healthy controls but identified further research into bone density in people with CD in New Zealand was warranted. This study raised concerns about iodine intake and status in people with CD. The A Gut Feeling study found inconsistencies in advice given to individuals diagnosed with CD. The research identified that the organoid model offers potential for future study of the gut‐bone axis and that individuals with CD are at risk of nutritional deficiencies but often are not advised well or referred for a bonescan.Item Broken shoulders in dairy heifers in New Zealand : investigating the relationship between live weight and bone morphology in the bovine forelimb : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, New Zealand(Massey University, 2021) Gibson, MichaelaSpontaneous humeral fractures in first lactation dairy heifers are a significant economic and welfare issue in the New Zealand dairy industry. With approximately 4% of dairy farms being affected and, within farm, up to 25% of replacement heifers lost, the cost to the dairy industry is estimated to be over $10 million. Preliminary observations from Dittmer et al. (2016), showed the presence of growth arrest lines in bones from affected heifers, indicating a period of malnutrition in the heifer’s life. However, with little known about how heifer’s bones grow within the New Zealand pastoral system, it is difficult to identify developmental time periods that have the greatest impact on long bone growth and, therefore, greatest potential to affect the risk of fracture. Therefore, the aim of this thesis was to investigate the relationship between live weight and bone morphology in the bovine forelimb to identify potential risk periods for spontaneous humeral fractures in first-lactation dairy heifers. In this thesis, the metacarpus and humerus were opportunistically collected from cattle from a variety of experiments carried out at Massey University and from samples submitted from farms throughout New Zealand. Measures of bone morphology in the metacarpus were highly correlated with the same measure in the humerus (R²=0.89-0.98). Measures of the humerus and metacarpus were also highly correlated with live weight at all ages. However, the relationship between bone and live weight changed over time demonstrating differences in bone maturity. Distal regions of the forelimb such as the metacarpus matured by one year of age as indicated by a different relationship between live weight and pQCT measures of the humerus at 24 months compared with 8-12 months of age. However, proximal regions of the forelimb such as the humerus continued to grow after a year of age. Differences in proximal and distal bone growth were reflected in the pattern of stature growth. A cohort of dairy heifers (Holstein Friesian, Jersey, and Holstein-Friesian cross Jersey) were measured for live weight, height, wither-rump length, girth, and distal and proximal forelimb length (stature) from birth to 15 months of age. As live weight increased, the contribution of the distal limb to increases in height decreased, which is consistent with knowledge that physeal closure in cattle occurs earlier in distal limb bones, such as the metacarpus, than in proximal limb bones, such as the humerus. Finally, bones collected from heifers affected and unaffected by spontaneous humeral fractures were compared and the effect of copper status on bone measures was examined. The mid diaphysis of the humerus of the affected group had reduced cortical bone mineral density (p<0.05) and a trend for reduced cortical content and total bone content which contributed to a reduced stress-strain index. A trend for reduced bone length in affected humeri provides additional support for the hypothesis of inhibited humeral growth. Heifers with low liver copper concentration had reduced humeral length and reduced cortical bone mineral density (p<0.05). Growth and fracture data presented in this thesis support the hypothesis that the most likely developmental period in which inadequate bone growth occurs in heifers subsequently affected by humeral fracture is in the months leading up to the event, which coincides with the animal’s second winter.Item The role of vegetables in the maintenance of acid-base balance and bone structure : a thesis presented in partial fulfillment of the requirements for the degree of Masters of Science in Nutritional Science at Massey University, Turitea, Palmerston North, New Zealand(Massey University, 2005) Singh, SewakhMetabolic acidosis may over time lead to osteoporosis by causing a release of calcium and other mineral phases from bone. The regular consumption of fruits and vegetables is believed to be associated with higher bone mineral density. In the last ten years various population-based studies have found positive effects of fruit and vegetable intakes on bone health. The aim of the present study was to investigate the effects of broccoli, onion, and potato on bone density and strength in male rats. Forty male Spraguc-Dawlcy rats were randomized into four equal groups of ten each. The animals were fed either a base, broccoli, onion, or potato diet for a period of eight weeks. The apparent percentage calcium and phosphorus retained, the serum type 1 collagen C-tclopcptide concentration, bone density and bone strength, and the urinary parameters i.e. ammonia, creatinine, urea, specific gravity and osmolality were determined. The groups on onion and potato diets had significantly higher apparent percentage calcium retained (over the balance period) than the group on control diet (p=0.02l and 0.008 respectively). Apparent percentage calcium retained was also significantly higher in the group on potato diet compared to the group on broccoli diet (p"0.037). There were no significant differences between groups for percentage phosphorus retained on ANOVA. However, the discriminant analysis (multivariate method) showed that the group on the broccoli diet retained significantly more phosphate over the balance period compared to the other groups. The urinary ammonia excretion (over the balance period) was significantly lower in the group on broccoli diet than in the groups on base and potato diets (p=0.040 and 0.055 respectively). As for the urinary urea excretion over the balance period, the group on base diet had significantly higher urea excretion than the groups on onion and potato diets (p=0.002 and p=0.000 respectively). Urinary urea excretion (over the balance period) was also significantly higher in the group on broccoli diet compared to the groups on onion and potato diets (p=0.005 and 0.000 respectively). The differences between groups for the volume of urine produced over the balance period were also significant i.e. the group on broccoli diet produced significantly more urine than the groups on base, onion, and potato diets (p=0.011. p=0.008. and p=0.00l respectively). However, there were no significant differences between groups for urinary specific gravity, osmolality, and creatinine, and bone density, bone breaking strength, and serum type I collagen C-telopeptide concentrations on ANOVA. In conclusion Ig of broccoli per day significantly reduced urinary ammonia excretion and increased apparent percentage phosphorus retained whereas Ig of onion or potato per day significantly increased apparent percentage calcium retained in growing male rats. The decrease in urinary ammonia excretion was most likely due to the buffering of metabolic acids by the bases present in broccoli resulting in decreased ammonia production and secretion. Similarly the increased apparent percentage phosphorus retained (in the group on broccoli diet) may be due to the bases present in broccoli that may have buffered metabolic acids thereby reducing the need for phosphate buffering. This increased apparent percentage phosphorus retained may also be due to a high pH which is known to enhance renal phosphate uptake. The buffering of metabolic acids by the bases present in onion and potato may have reduced the need for calcium buffering resulting in higher apparent percentage calcium retained in the groups on onion and potato diets. Thus broccoli, onion, and potato intake may protect against the bone depleting effects of an acidogenic diet and may also have the potential to increase bone mineral density.Item Bone mineral density and body composition in high-performing cricket players : an exploratory study : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics, at Massey University, Albany, New Zealand(Massey University, 2017) Payne, CoreyBackground/Aim: Cricket is a popular sport both in New Zealand, and internationally. Cricketers have a high prevalence of stress fractures, which may in part be linked to bone mineral density. However, little research exists investigating bone health in this group. The primary aim of this study was to investigate determinants of bone mineral density (BMD) in a group of highperforming cricketers. Secondary aims included measuring musculoskeletal differences in the dominant versus non-dominant arm, and monitoring pre and postseason body composition. Methods: Healthy male (n=27) and female (n=11) cricketers aged 16-33y were recruited. BMD was measured using DXA, and body composition was measured pre and post-season using bioelectrical impedance analysis (BIA). Food frequency questionnaires (FFQ’s) and a lifestyle & health questionnaire were completed. Determinants of BMD were tested using hierarchical multiple regression analysis. A dependent samples t-test was used to determine differences between dominant and non-dominant arms and changes in body composition over the season. Results: Skeletal muscle mass was a significant predictor of BMD and accounted for 31, 18, and 38 percent of BMD variation at the hip, spine, and total body, respectively. Age and calcium intake did not predict BMD at any site. BMD and lean mass were significantly greater (p<0.05) in the dominant arms of both males (+0.056g/cm2 and +308.4g) and females (+0.078g/cm2 and +254.2g). A 0.8kg reduction in post-season skeletal muscle mass was found in females (p<0.05), with no differences found in males. Conclusions: Skeletal muscle was the strongest predictor of BMD in this group, while age and calcium intake showed no effect. Significant differences in BMD and lean mass were observed between dominant and non-dominant arms. Skeletal muscle in males remained unchanged from beginning to end of season, and was reduced in females. Training methods in this group should target development and maintenance of muscle mass in order to optimise BMD.Item The relationship between nutritional adequacy and 24-month fracture occurence in Māori and non-Māori of advanced age : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Nutrition and Dietetics, Massey University, Albany, New Zealand(Massey University, 2015) Towgood, AliceAbstract Background The life expectancy of both Māori and non-Māori is continually increasing with more New Zealanders expected to live into advanced age. Adults over the age of 80 experience greater health loss than any other age group, with chronic disease and associated disability increasing substantially with age. Osteoporosis and the morbidity associated with fractures, particularly hip fracture, are of critical concern for an ageing population and may diminish quality of life and independence for older people, thus placing an increased burden on health and disability support services. The role of nutrition in the maintenance of bone mineral density (BMD), bone integrity, and subsequent fracture prevention, particularly in octogenarians is unclear. The ability to meet adequate energy requirements decrease with increasing age and may compromise intake of nutrients related to bone health. Nutrients necessary for bone health including: protein, calcium, vitamin D, phosphorous, magnesium and potassium are modifiable factors. Achieving optimal bone nutrient intakes may influence potential for maintenance of good bone health in adults of advanced age. This study aims firstly to investigate food and nutrient intakes of Māori and Non-Māori octogenarians to establish an understanding of nutrient adequacy. Secondly, to investigate the energy and nutrient intakes of participants who experience a fracture compared with those non-fractured to identify nutrient specific risk factors for fracture in adults of advanced age. Method Comprehensive nutritional parameters were collected using two separate 24-hour multi-pass recalls. FOOD files were used to analyse food sources and nutrient intake. Face to face interviews were conducted to ascertain specific social, demographic, health and fracture information. Fracture occurrence was measured over a 24 month period following the 2 x 24-hour Multi Pass Recall’s and included self-reported and hospitalised fracture occurrences. Hospitalisation data was obtained with permission from the participants. National Health Index New Zealand (NHI) numbers were used to identify fractures. Results There were 317 participants (113 Māori and 204 non-Māori), aged 80-90 years in this study. For men and women respectively the median energy intakes were 6,943kJ vs. 5,603kJ for Māori; and 8,203kJ vs. 6,225kJ for non-Māori; protein as a percentage of energy was 15.5% vs. 15.9% for Māori and 15.7% vs. 15.5% for non-Māori. The top foods contributing to energy were bread, butter and margarine for all Maori and non-Maori with beef and veal contributed the most protein for Māori men, bread for Māori women and milk for non-Māori, men and women. Compared to the Estimated Average Requirement (EAR) intakes of calcium, vitamin D, magnesium and potassium were inadequate for all participants. Compared to an EAR of 1100mg for men and women, median calcium intakes were low, 559mg vs. 539mg for Māori and 748mg vs. 672mg for non-Māori, men and women respectively. The primary food groups contributing to calcium were milk, cheese and bread. Compared to the EAR (15 μg/day in men and women) and vitamin D intake from food was low (≤ 4 μg) for all participants. Compared to the EAR (350mg/day men and 265mg/day women), median magnesium intakes were 259 mg/day vs. 204mg/day for Māori and 271 mg/day vs. 238 mg/day for non-Māori, men and women respectively. The primary food groups contributing to magnesium were bread, breakfast cereals and fruit. A total of 18.6% of Māori and 20.6% of non-Māori sustained a fracture over a 24 month period. One in five Māori and non-Māori women sustained fractures. Among non-Māori women those who fractured were 1.1 times more likely to be financially insecure than non-fractured women (p=0.033). For Māori women who were fractured, inability to afford to eat properly was 3.3 times more likely (p=0.012), and previous fractures were 1.5 times (p=0.015) more likely than for non-fractured women. Fractured Māori women consumed significantly less vitamin D (2.0μg vs 3.0μg) (P=0.01) and magnesium (143.0mg vs 211mg) (P=0.033) compared to non-fractured Māori women. Conclusion Energy intakes were low for all participants and may have manifested the suboptimal intakes of calcium, vitamin D, potassium and magnesium prevalent in Māori and non-Māori, men and women. Fractures were more frequent in women than men, and both Māori and non-Māori sustained similar rates of fracture over the 24 month period. Magnesium and vitamin D intakes were significantly related to fracture occurrence in Māori women; this relationship diminished with further regression analysis. Increased intake of energy in adults of advanced age, with a focus on protein rich and nutrient dense foods, particularly calcium and magnesium, should be encouraged through consuming a variety of foods from the major food groups. Greater intakes of calcium can be achieved through higher consumption of milk and dairy products including yoghurt and cheese; and magnesium through increased green leafy vegetables, seafood, dairy, mushrooms, avocado, beans and bananas. Vitamin D intakes were minimal from food; however it is possible participants were receiving supplementary vitamin D and further investigation is warranted. For fractured Māori women, magnesium intake was significantly lower than those with no fractures. Promoting increased intakes of culturally acceptable foods such as vegetables and seafood may be advantageous to increase magnesium intakes.Item Associations between physical activity, body composition, nutrient intake, and bone mineral density in pre-menopausal Pacific Island women living in New Zealand : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics at Massey University, Albany, New Zealand(Massey University, 2015) Casale, MariaBackground/Aim: Anecdotally it is suggested that Pacific Island women have good bone mineral density (BMD); however little evidence for this or for associated factors exists. The aim of this study is to explore associations between several key predictors of bone health with bone mineral density, as measured by BMD (g/cm2), in pre-menopausal Pacific Island women. Methods: Healthy pre-menopausal Pacific Island women (n=91; age 16-45y) were recruited. Participants’ body composition and total body BMD were assessed using DXA and air-displacement plethysmography (BodPod). A food frequency questionnaire (FFQ) and current bone-specific physical activity questionnaire (cBPAQ) were completed. Variables that significantly correlated with BMD were applied to a hierarchical multiple regression analysis. Results: The mean BMD was 1.1 g/cm2 ± 0.08. Bone-free, fat-free lean mass only (LMO, 52.4kg ± 6.9) and total mass (90.4kg ± 19) were the only factors to show a significant correlation with BMD. Body-fat (38.4% ± 7.6), cBPAQ score (1.7 (0.4,5.2)), and dietary calcium (1016mg ± 442), protein (18% ± 3.8) and vitamin C (125mg (94, 216)) showed no correlation with BMD. The regression analysis suggests that LMO is the most important predictor of BMD, explaining 13.4% of the variance, while total mass accounts for a further 2.5% of the variance. Together, these factors explain a total of 15.9% of the variability. Conclusions: LMO is the strongest predictor of BMD, while many established contributors to bone health (calcium, physical activity, protein, and vitamin C) do not appear to be associated with BMD in this population. As just 15.9% of the variability can be explained, further research is needed in this area.Item The effect of a milk lipid fraction on bone properties of growing female rats and the growth and function of bone cells : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Human Nutrition at Massey University, Manawatu, Palmerston North, New Zealand(Massey University, 2014) Cao, ZhonglingObjective: To investigate the effects of a milk lipid fraction (MLF) on the accruel of bone mass in growing rats by evaluating the effects of MLF on growth and bone parameters such as bone mineral content (BMC), bone mineral density (BMD) and biomechanical properties in growing rats and the effects of MLF on the development and activity of bone cells, including osteoblasts and osteoclasts. Methods: There were one hundred and eight 3-month old female Sprague-Dawley rats were randomly allocated into three groups: a control group (n=48), a low-dose MLF group (n=30) fed with 250 mg/rat/day of MLF, and a high-dose MLF group (n=30) fed with 500 mg/rat/day of MLF. Forty-five rats (n=15 for each group) were selected to terminate at month 3 for biomechanical testing while sixty-three continued into a second arm of the trial after ovariectomy. Body composition and bone parameters of animals (n=108) were measured in vivo by Dual Energy X-Ray Absorptiometry (DEXA) at baseline and week 12 of the study. Length and diaphyseal width and thickness of the left femur were measured. The three-point bending test was used to evaluate the biomechanical characteristics of the left femur of rat. The effect of MLF on proliferation, differentiation and mineralization of murine osteoblasts were investigated using the osteoblastic cell line MC3T3-E1. The cells were cultured with 0-1,000 µg/ml or 0-100 µg/ml MLF for 5, 9 and 24 days, respectively for proliferation, differentiation and mineralization. Cell proliferation was determined using the methyl-thiazolyl tetrazolium (MTT) assay. The differentiation of osteoblasts was detected using the alkaline phosphatase (ALP) activity assay. Mineralized nodules were examined using an Alizarin red histochemistry assay. The effect of MLF on RANKL-induced osteoclastogenesis was evaluated in the murine monocytic cell line RAW264.7. The cells were cultured with 0-100 µg/ml MLF for five days. Osteoclastogenesis was determined using the tartrate-resistant acid phosphatase (TRAP) staining assay and counting numbers of TRAP-positive multinucleated cells. Results: Rats fed with the high-dose MLF diet had a significant increase in body lean mass compared with those fed with the control and low-dose MLF diets. The high-dose MLF group also had significant gains in BMC at the femur and in BMD at the femur and lumbar spine compared with the control group. There were no significant differences in dimensional and biomechanical results among groups. The MLF significantly increased the proliferation of MC3T3-E1 at 0.1, 1.0 and 100 µg/ml. There was a dose-dependent, but not significant increase in the differentiation of osteoblasts cultured with MLF for 9 days. After 24-days of cell culture, the MLF at the low concentrations of 0.1 and 1.0 µg/ml led to non-significant increase in calcium deposition by the differentiated osteoblasts. MLF at 10 and 100 µg/ml significantly inhibited calcium nodule formation. RANKL-stimulated osteoclastogenesis was significantly increased in RAW 264.7 cells cultured with the MLF at concentrations up to 10 µg/ml. Conclusion: These results indicated that oral administration of MLF to the growing rats improved bone accrual and has a favourable effect on achievement of peak bone mass. The MLF increased the proliferation of MC3T3-E1 pre-osteoblast cell line, but there was no effect on osteoblast differentiation and the higher concentration of MLF may have inhibited the function of mature osteoblast. Additionally, the MLF stimulated osteoclastogenesis from RAW264.7 cells. Further studies are required to investigate some of the contradictory findings presented in this report.Item Bone mineral density characteristics of the third metacarpal /metatarsal distal epiphysis of thoroughbred horses : a thesis presented in partial fulfilment of the requirements for the degree of Master of Veterinary Science at Massey University, Manawatu, New Zealand(Massey University, 2012) Bogers, Sophie HelenThis thesis includes two studies using non-invasive imaging techniques to quantify, in detail, the bone mineral density (BMD) characteristics of the distal third metacarpal (Mc3) and metatarsal (Mt3) epiphyses of Thoroughbred horses associated with exercise exposure and condylar fracture. Additionally, the relationship between the bone structure of the distal Mc3/Mt3 epiphysis and incurred cyclic loading, as well as techniques for imaging the area non-invasively, are reviewed. Mt3 bones from fourteen trained or untrained Thoroughbred horses and Mc3 bones from fourteen Thoroughbred racehorses with or without condylar fracture were scanned using peripheral quantitative computed tomography (pQCT) at a site on the distal epiphysis. The relative proportions of volumetric bone mineral density (BMDV) and the spatial distribution of BMDV were quantitatively assessed using conventional and ArcGIS software. The relative proportion of voxels within nine threshold categories of BMDV and spatial statistics of BMDV distribution were compared for regions of interest in the palmar/plantar epiphysis between respective treatment groups; trained vs. untrained controls or fractured vs. non-fractured controls. In study one, trained horses had a significantly higher (P=0.006) proportion of high BMDV voxels and a significantly lower (P=0.006) relative proportion of low BMDV voxels than controls in the central condylar regions of the plantar Mt3 epiphysis. In other regions of the plantar epiphysis the trained horses also had a significantly higher (P=0.006) relative proportion of high BMDV voxels than controls; however, there were no significant differences for the relative proportion of low BMDV voxels. These relationships were also evident with multiple correspondence analysis. There was strong to marked clustering of high BMDV voxels in the central condylar region of all of the trained horses (I = 0.64 - 1.0, P = 0.01) and no clustering of low BMDV voxels. In contrast, half of the control horses had clustering of high BMDV voxels, which was weak to strong (I = 0.64 - 1.0, P = 0.01) and there was weak to moderate clustering of low BMDV voxels in the lateral and medial central condylar regions (I = 0.45-0.62, P = 0.01 and I = 0.45-0.57, P = 0.01, respectively). In study two, there were no significant differences between the median age (P = 0.7), number of race starts (P = 0.5), the relative proportion of BMDV voxels, or the spatial distribution of BMDV voxels in regions of the palmar Mc3 epiphysis between the fractured and control groups. The results of this thesis suggest that the response of bone to exercise is specific in relation to anatomical site, the thresholds of BMD that change, and the spatial distribution of BMD. In both studies the exercise exposure was responsible for much of the variation in the relative proportions and the spatial distributions of BMDV. The clinical relevance of these findings are that detailed quantification of previous exercise exposure needs to be considered when determining if a BMD response of the Mt3/Mc3 epiphysis is part of a physiological or pathological finding.