The use of near infrared spectroscopy (NIRS) to measure vascular haemodynamics in human bone tissue in vivo

Rationale: Poor cardiovascular health is associated with reduced bone strength and increased risk of fragility fracture. However, direct measurement of intraosseous vascular health is difficult due to the density and mineral content of bone. The aim of this PhD project was to investigate the feasibility of near infrared spectroscopy (NIRS) for the investigation of vascular haemodynamics in human bone in vivo. NIRS provides inexpensive, non-invasive, safe, and real time data on changes in oxygenated and deoxygenated haemoglobin concentration at superficial anatomical sites. NIRS utilises a source optode of near infrared (NIR) light and detector optode that obtains representative data of the interactions of NIR photons with tissue. Method: A systematic review was performed identifying the current existing applications of NIRS (and similar technologies) for measuring human bone tissue in vivo. This review informed the development of an arterial occlusion protocol for obtaining haemodynamic measurements of the proximal tibia and lateral calf, including assessment of the protocol’s reliability. For thirty-six participants, NIRS results were also compared to alternative tests of bone haemodynamics involving dynamic contrast enhanced MRI (DCE-MRI), and measures of general bone health based on dual x-ray absorptiometry testing and blood markers of bone metabolism. Results: This thesis presents novel data demonstrating NIRS can obtain acceptably reliable markers of haemodynamics at the proximal tibia in vivo, comparable with reliability assessments of alternative modalities measuring intraosseous haemodynamics, and the use of NIRS for measuring muscle. Novel associations have been demonstrated between haemodynamic markers measured with NIRS and DCE-MRI, giving confidence NIRS truly represents bone haemodynamics. Increased NIRS markers of oxygen extraction during occlusion, and greater post-ischaemic vascular response to occlusion, were both associated with greater bone mineral density. Conclusion: As a feasibility study, this PhD project has demonstrated the potential for NIRS to contribute to research around the potential pathophysiological role of vascular dysfunction within bone tissue, but also the limitations and need for further development of NIRS technology.The Royal College of Radiologist

Variation in Habitual Activity and Body Composition: A Segmental Body Comparison of Runners and Swimmers

There is considerable evidence that differences in patterns of habitual activity influence the distribution of skeletal tissue within the human skeleton, but little is known about variation in soft tissue. This thesis examines body composition and surface scan data from runners, swimmers, and a ‘recreational control’ population to investigate differences in the properties of limb segment surface areas and volumes, muscle mass, and fat mass. It also explores the relationship between activity and aging through the examination of body composition and volumetric measurements in older-adult habitual swimmers. The findings show that resulting limb segment properties support assumptions of running as a lower-limb dominant and swimming as an upper limb dominant activity. Habitual swimming also displays a positive effect on the preservation of skeletal muscle mass across the life course. This thesis suggests non-impact loading results in demonstrable differences in body morphology, emphasizing the importance of activity throughout the life course

Body Composition and Physical Health in Sports Practice

Research on human body composition has gained relevance given the recognized health impact of several body components. Many contemporary scientists have contributed to the field of body composition research as it exists today, even though interest in the topic extends back several thousand years. Quantifying human body composition in sports practice plays an important role in monitoring athletes' health status, performances, and training regimens. Such analysis can be performed in different contexts and with different approaches—e.g., in cross-sectional studies that aim to characterize sporting group samples and in longitudinal research finalized to define short-term or long-term changes and implications for physical health and performance. Body composition is also fundamental for a correct interpretation of body mass and weight status to plan specific interventions. This book adds new information on the effect of body composition on physical health and sport performance, current body composition measurement techniques and strategies for improving physical health through sports practice

Do East Asians Achieve Greater Knee Flexion than Caucasian North Americans, and are East Asian Kneeling and Squatting Styles Kinetically Different from North American Norms?

High flexion postures (specifically, kneeling and squatting) are used with greater regularity in East Asian (Chinese, Japanese, Korean, and Vietnamese) cultures for many activities of daily living (ADL). Furthermore, the favored style of kneeling and squatting is different between ethnicities: Caucasians typically flex their forefoot while kneeling and squatting, whereas East Asians tend to keep the top or bottom of the foot flat to the ground. Most, but not all, research suggests that East Asians are able to achieve a greater knee flexion angle during high flexion postures, but it is unknown if any differences between ethnicity extends to kinetic outcomes. A direct comparison between ethnicities with respect to kinetics has not been made. Where a difference in maximal attainable flexion angle exists, it is unclear whether the cause is cultural or innate. Therefore, this thesis project aimed to answer three related questions: 1) Do East Asian populations achieve a greater flexion angle than North American Caucasians; 2) If there is in fact a difference, is it a result of cultural upbringing or innate ability?; and, 3) Do different styles of kneeling and squatting alter the moments of force at the knee? To accomplish these aims, 43 participants were recruited from the University of Waterloo and fit into one of three groups: Caucasian, born and raised in North America (20 participants); East Asian, born and raised in North America (18 participants); or, East Asian, born in East Asia, living in North America for less than two years (five participants) (however, the East Asian born in East Asia group was excluded from statistical processing since the group size was considerably smaller). Kinetic, kinematic, neuromuscular, and passive range of motion data were collected and compared between different ethnicity groups. East Asians did not achieve a greater mean knee flexion angle during kneeling compared to Caucasians (Canadian born East Asians=152.01° (±4.85°); Caucasians=153.07° (±7.46°), p=0.2859), but a greater mean flexion angle was found during squatting (Canadian born East Asians =147.96° (±6.62°); Caucasians = 141.69° (±17.48°), p=0.0014). Between Caucasians and Canadian born East Asians, there was also no difference in peak knee flexion angle during passive range of motion testing (Canadian born East Asians = 152.05° (±8.16°); Caucasians = 149.54° (±7.75°)), which indicates that there is no difference in ability to achieve greater high flexion between groups. Finally, it was found that different styles of squatting altered the kinetics at the knee, but different styles of kneeling were not significantly different. Flat foot squatting, a posture more commonly seen in East Asian cultures, had significantly (p<0.05) lower flexion and adduction moments at the knee than heels raised squatting (which is more commonly used by Caucasian North Americans) during descent, ascent, and static squatting. The mean static flexion moment (which is similar in magnitude to the peak flexion moment during descent and ascent) for flat foot squatting was 4.37 (±1.47) %BW*Ht, and for heels raised squatting was 5.99 (±1.84) %BW*Ht. The mean static frontal plane moment for flat foot squatting was -0.45 (±1.33) and for heels raised squatting was 0.59 (±1.02). (Negative values indicate an external abduction moment and positive values indicate an external adduction moment.) When performing high flexion postures, reduced knee moments are desirable since higher moments are associated with greater joint loading and injury risk

Cortical Bone Health in African Ancestry Men

As the population ages, more non-white men will develop osteoporosis and its associated fractures, yet little is known about skeletal aging in African ancestry men. Studies using quantitative computed tomography (QCT)-measured Bone Mineral Density (BMD) have exposed the incomplete nature of the current understanding of age-related bone loss. Furthermore, studies of the relationship between body fat and BMD have challenged the traditional paradigm that adiposity is beneficial for skeletal health. Moreover, even though cortical bone constitutes 80% of the skeleton, its epidemiology has rarely been described. To address these knowledge gaps, this dissertation examined the rates of change and correlates for cortical thickness, periosteal and endosteal circumferences, and torsional bone strength (SSI) at the radius and tibia in middle-aged and older African ancestry men from the Tobago Bone Health Study over an average follow-up period of 6.2 years. Secondly, inflammation markers — high sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL6) — were examined in relation to rates of change in cortical bone measures in both limbs. Lastly, total calf adipose tissue area (TAT) and its components, percentage subcutaneous (%SAT) and non-subcutaneous fat (%NSAT), were assessed in relation to changes in cortical bone measures at the tibia. The main findings were: endosteal expansion outpaced periosteal bone formation, such that there was net cortical thinning and reductions in SSI in both limbs. HsCRP was not associated with rates of change in cortical bone measures, while higher baseline serum IL6 was significantly associated with slower rates of loss of cortical BMD and SSI at both limbs. Higher calf TAT was associated with higher rates of cortical BMD loss at the tibia. Higher %SAT and % NSAT were associated with lower and higher rates of cortical BMD loss respectively Higher %SAT was also associated with significantly greater rates of periosteal expansion. These findings have public health significance due to their focus on an under-studied population, detailed description of changes and correlates of cortical bone structure, particularly periosteal circumference, which is a promising therapeutic target for osteoporosis. Moreover, the relationship between adiposity and skeletal health is especially timely considering the alarming rates of obesity worldwide

Osteoporosis in Parkinson’s disease and the role of lean body mass: a cross-sectional study in a Brazilian tertiary center

BackgroundParkinson’s disease (PD) is the second most common neurodegenerative illness and has the highest increase rate in recent years. There is growing evidence to suggest that PD is linked to higher osteoporosis rates and risk of fractures.ObjectiveThis study aims to estimate the prevalence and factors associated with osteoporosis as defined by the National Osteoporosis Foundation (NOF) and World Health Organization in patients with mild to moderate PD.MethodsWe performed a cross-sectional study at a tertiary public hospital in Fortaleza, Brazil, dating from May 2021 until April 2022. The study sample was comprised of patients with mild to moderate PD who were at least 40 years old and who had the ability to walk and stand unassisted. Bone Mineral Density (BMD) of both the hip (neck of the femur) and the lumbar spine were obtained via properly calibrated Dual Energy X-ray Absorptiometry (DXA) scanning. The FRAX (Fracture Risk Assessment Tool) score was used to determine a person’s 10-year risk of major osteoporotic fracture. The Revised European Working Group on Sarcopenia in Older People (EWGSOP 2) was used as a basis to confirm a sarcopenia diagnosis with the following parameters: low muscle strength gauged by handgrip strength and low muscle quantity by DXA. Physical performance was carefully evaluated by using the Short Physical Performance Battery test. Osteoporosis and osteopenia were diagnosed following the NOF guidelines and WHO recommendations.ResultsWe evaluated 107 patients in total, of whom 45 (42%) were women. The group’s mean age was 68 ± 9 years, and the mean disease time span was 9.9 ± 6.0 years and mean motor UPDRS was 43 ± 15. We found that 42.1% and 34.6% of the sample had osteopenia and osteoporosis following NOF criteria, respectively, and 43% and 33.6% following the WHO recommendations. Lower lean appendicular mass was associated to osteopenia and osteoporosis in multinomial logistic regression analysis in both diagnostic criteria.ConclusionOur findings provide additional evidence for the protective role of lean mass against osteoporosis in patients with PD

A Machine-Learning Approach to Target Clinical and Biological Features Associated with Sarcopenia: Findings from Northern and Southern Italian Aging Populations

Epidemiological and public health resonance of sarcopenia in late life requires further research to identify better clinical markers useful for seeking proper care strategies in preventive medicine settings. Using a machine-learning approach, a search for clinical and fluid markers most associated with sarcopenia was carried out across older populations from northern and southern Italy. A dataset of adults >65 years of age (n = 1971) made up of clinical records and fluid markers from either a clinical-based subset from northern Italy (Pavia) and a population-based subset from southern Italy (Apulia) was employed (n = 1312 and n = 659, respectively). Body composition data obtained by dual-energy X-ray absorptiometry (DXA) were used for the diagnosis of sarcopenia, given by the presence of either low muscle mass (i.e., an SMI 2 for males or 2 for females) and of low muscle strength (i.e., an HGS < 27 kg for males or <16 kg for females) or low physical performance (i.e., an SPPB ≤ 8), according to the EWGSOP2 panel guidelines. A machine-learning feature-selection approach, the random forest (RF), was used to identify the most predictive features of sarcopenia in the whole dataset, considering every possible interaction among variables and taking into account nonlinear relationships that classical models could not evaluate. Then, a logistic regression was performed for comparative purposes. Leading variables of association to sarcopenia overlapped in the two population subsets and included SMI, HGS, FFM of legs and arms, and sex. Using parametric and nonparametric whole-sample analysis to investigate the clinical variables and biological markers most associated with sarcopenia, we found that albumin, CRP, folate, and age ranked high according to RF selection, while sex, folate, and vitamin D were the most relevant according to logistics. Albumin, CRP, vitamin D, and serum folate should not be neglected in screening for sarcopenia in the aging population. Better preventive medicine settings in geriatrics are urgently needed to lessen the impact of sarcopenia on the general health, quality of life, and medical care delivery of the aging population

Nutrición y ejercicio: efectos en la composición corporal, condición física, capacidad funcional y calidad de vida de personas mayores Nutrition and exercise: effects on body composition, physical fitness, functional capacity, and quality of life in older adults

Los cambios asociados al envejecimiento pueden afectar a la condición física y la composición corporal e influyen negativamente en la capacidad funcional de la persona mayor. La actividad y el ejercicio físico, así como unos buenos hábitos de alimentación contribuyen a un envejecimiento saludable que ayudará a prevenir y revertir estos cambios negativos disminuyendo el riesgo de discapacidad y mejorando la calidad de vida en el adulto mayor. Los principales objetivos de esta tesis doctoral son: 1) Evaluar las asociaciones entre la condición física, actividad física y diferentes variables de salud ósea en personas mayores (artículo 1 y 2); 2) Estudiar los efectos de un programa de ejercicio multicomponente y 4 meses de desentrenamiento sobre la composición corporal y el estado nutricional de personas mayores con capacidad funcional limitada (artículos 3, 4 y 5); 3) Analizar la relación existente entre la ingesta y el estado nutricional, la capacidad funcional, y los efectos del entrenamiento (artículos 5 y 6); y 4) Evaluar como la relación entre la condición física, la composición corporal, el estado nutricional y el entrenamiento se asocia con la calidad de vida relacionada con la salud (artículo 7).La presente tesis doctoral está compuesta por 7 artículos. La muestra pertenece al proyecto EXERNET-Elder. Este proyecto consta de dos estudios, uno con una cohorte multicéntrica española de 3136 personas mayores de 65 años y el segundo, de intervención, en una muestra complementaria de 126 con capacidad funcional limitada. La intervención constaba de un programa de ejercicio multicomponente. Se evaluó la composición corporal mediante antropometría, impedancia bioeléctrica y tomografía axial computerizada periférica. La condición física se midió a través de una serie de pruebas validadas e incluidas en las baterías: «Senior Fitness Test» y «Eurofit». Se recogió información sobre los niveles de actividad física a partir de dispositivos de acelerometría. La ingesta alimentaria y otros datos relacionados con la salud se recogieron a partir de cuestionarios validados. Se usaron, entre ellos, un cuestionario de frecuencia de consumo de alimentos semicuantitativo, el cuestionario de Adherencia a la Dieta Mediterránea de 14 puntos y el «Mini Nutritional Assessment». Una buena condición física, así como los patrones de actividad física más activos, con mayores niveles de actividad moderada a vigorosa, contribuyen a mejores valores de hueso cortical. Además, a través de un programa de ejercicio multicomponente se consigue disminuir el deterioro asociado al envejecimiento de los niveles de este hueso cortical en personas mayores con capacidad funcional limitada. La adiposidad parece disminuir con este tipo de entrenamiento, mientras que no se observan mejoras en la masa muscular. Sin embargo, independientemente de haber entrenado o no, periodos de 4 meses de desentrenamiento empeoran la masa muscular y la adiposidad. Por otra parte, encontramos una prevalencia alta de personas en riego de malnutrición (36,5%) y este estado parece condicionar el efecto del ejercicio; de hecho, el entrenamiento resulta más efectivo en personas mayores que tienen un buen estado nutricional. También la capacidad funcional está muy relacionada con el estado nutricional de las personas mayores y se ve afectada por diferentes nutrientes implicados en el metabolismo muscular como la vitamina D, los ácidos grasos n-3 o las proteínas. Finalmente, se observa que el entrenamiento mejora la calidad de vida, pero vuelve a niveles basales cuando este se interrumpe. Mayores niveles de condición física y actividad física están asociados a una mejor salud ósea. El entrenamiento multicomponente parece ser efectivo para la mejora de la adiposidad y la calidad de vida de las personas mayores con capacidad funcional limitada. Sin embargo, no parece ser la mejor estrategia cuando el objetivo es mejorar la salud ósea y la masa muscular, o al menos se debe avanzar en la dosis óptima para cada objetivo. Tanto la alimentación como el estado nutricional parecen ser claves en los efectos que tiene el entrenamiento sobre la composición corporal. Los deterioros observados tras el desentrenamiento en las variables estudiadas alertan de que este tipo de intervenciones no deberían interrumpirse en esta población.<br /