Physical activity and sedentary behaviour and their associations with clinical measures in axial spondyloarthritis

Engaging in physical activity (PA) is a key aspect in the management of axial spondyloarthritis (axial SpA), however, its relationship with clinical measures is unknown. Previous research has mainly focused on subjective methods of measuring PA and sedentary behaviour (SB). The aim of this study was to explore the associations between objectively measured PA and SB with clinical measures in people with established axial SpA. Fifty participants were recruited from secondary-care rheumatology outpatient services in Glasgow, UK. Clinical measures collected included; Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Metrology Index (BASMI), Ankylosing Spondylitis Quality of Life (ASQOL) and the Six Minute Walk Test (6MWT). PA and SB were measured using the activPAL3 tri-axial accelerometer. Data from forty-five participants were included (23 males, average age 49 ± 12 years). Participants accumulated an average of 93.2 ± 41.5 min/day walking with an average of 7200 ± 3397 steps/day. The majority of the day (65%) was spent sitting, accumulated in prolonged bouts. Walking time and steps taken/day were associated with better BASFI (r = − 0.395, p = 0.007 and r = − 0.404, p = 0.006), ASQOL (r = − 0.375, p = 0.011 and r = − 0.361, p = 0.015) and 6MWT (r = 0.396, p = 0.007 and r = 0.421, p = 0.004); while longer walking events were associated with better BASMI (rho = − 0.352, p = 0.018), BASFI (rho = − 0.316, p = 0.034) and 6MWT (rho = 0.404, p = 0.006). SB was associated with worse ASQOL (r = 0.380, p = 0.010) and 6MWT (6MWT, r = − 0.357, p = 0.016). In people with axial SpA PA is associated with better function, exercise capacity and spinal mobility, while SB is associated with lower exercise capacity and poor quality of life. These findings support the promotion of PA and reduction of SB in people with axial SpA

Level of, and factors affecting adherence to prescribed exercise in people with spondyloarthritis

Background: Spondyloarthritis is a group of chronic inflammatory musculoskeletal diseases for which exercise is considered an essential part of their management. Adherence is a primary determinant of the effectiveness of any intervention and can be influenced by multiple factors. The World Health Organisation proposes that when studying adherence, an approach where adherence is determined by interplay of factors relating to five construct; socioeconomic, healthcare, condition, treatment and patient-related can be used. Currently the level of adherence and factors affecting adherence to prescribed physiotherapy programmes in people with SpA is unknown. Objectives: The aim of the research within this thesis was to investigate the level of, and factors affecting, adherence in people with SpA. Methods: Three studies were undertaken. Firstly, a systematic review of the current literature investigating adherence to prescribed exercise in SpA. Secondly a cohort study to investigate the level of, and factors affecting, adherence to a web-based physiotherapy programme in patients with axial SpA (axSpA), the prototypic SpA condition. Finally, a survey of physiotherapists in the United Kingdom (UK) delivering prescribed exercise programmes to people with SpA, investigating the factors they perceive as affecting adherence and barriers to adopting methods to improve adherence. Results: The systematic review identified and included ten studies with a total of 690 participants. Rates of adherence ranged from 51% to 95%, and in the main were poorly reported. The interventions and measurement of adherence varied across studies, making comparisons difficult. Two studies identified that adherence was improved following educational programmes and one study identified that higher disease severity and longer diagnostic delays were associated with higher adherence rates. One study indicated supervised group exercise increased adherence to HEP whilst another found no difference. Three linked studies by the same authors with the same participants demonstrated that adherence reduced over time. No study within the systematic review measured adherence to a web-based physiotherapy programme. The cohort study found adherence to web-based physiotherapy exercise in people with axSpA was 27.6% of all sessions for all participants over 12-months. When participants started a session, they were likely to complete all the individual exercises within the session (74% versus 26% of the time). Adherence reduced over the course of the intervention. No quantitative factors were found to influence adherence, however participant interviews found that disease symptoms, getting into a routine and support have an important role in influencing adherence. The online survey identified that physiotherapists believe that adherence to prescribed exercises can be low. There were high levels of agreement of the factors affecting adherence to exercise. Within the WHO-proposed healthcare- related construct, good access to physiotherapy and effective medication for symptom control were perceived to improve adherence. Within the disease- related construct, concurrent mental health problems, high disease symptoms and multiple co-morbidities were considered to reduce adherence. Within the socio-economic domain, support increased adherence, while social deprivation reduced adherence. Within the person related construct, the belief the exercise would help and being physically active improved adherence, whilst lack time, interest or confidence and low self-efficacy reduced adherence. Within the treatment related construct, several strategies such as individualising the intervention, including goal setting, providing patient education, could increase adherence. Time was the most common barrier to physiotherapists implementing strategies to improve adherence. Conclusions: This thesis has provided data that adherence to prescribed exercise in people with SpA can be variable, often low and reduces over the course of interventions. This thesis has identified multiple interacting factors within the five constructs suggested by the WHO adherence model which may influence adherence. When prescribing exercise, physiotherapists should consider which factors are potentially affecting adherence within each WHO domain and address key modifiable factors in order to optimise adherence for that individual. Further research is required to compare rates of adherence across different modes of programmes, identifying which factors are most important in influencing adherence on a group level. Finally improving and standardising the measurement of adherence is crucial to facilitate progress and comparisons in this field

Enhanced Maternal Origin of the 22q11.2 Deletion in Velocardiofacial and DiGeorge Syndromes

Velocardiofacial and DiGeorge syndromes, also known as 22q11.2 deletion syndrome (22q11DS), are congenital-anomaly disorders caused by a de novo hemizygous 22q11.2 deletion mediated by meiotic nonallelic homologous recombination events between low-copy repeats, also known as segmental duplications. Although previous studies exist, each was of small size, and it remains to be determined whether there are parent-of-origin biases for the de novo 22q11.2 deletion. To address this question, we genotyped a total of 389 DNA samples from 22q11DS-affected families. A total of 219 (56%) individuals with 22q11DS had maternal origin and 170 (44%) had paternal origin of the de novo deletion, which represents a statistically significant bias for maternal origin (p = 0.0151). Combined with many smaller, previous studies, 465 (57%) individuals had maternal origin and 345 (43%) had paternal origin, amounting to a ratio of 1.35 or a 35% increase in maternal compared to paternal origin (p = 0.000028). Among 1,892 probands with the de novo 22q11.2 deletion, the average maternal age at time of conception was 29.5, and this is similar to data for the general population in individual countries. Of interest, the female recombination rate in the 22q11.2 region was about 1.6–1.7 times greater than that for males, suggesting that for this region in the genome, enhanced meiotic recombination rates, as well as other as-of-yet undefined 22q11.2-specific features, could be responsible for the observed excess in maternal origin

Enhanced Maternal Origin of the 22q11.2 Deletion in Velocardiofacial and DiGeorge Syndromes

Velocardiofacial and DiGeorge syndromes, also known as 22q11.2 deletion syndrome (22q11DS), are congenital-anomaly disorders caused by a de novo hemizygous 22q11.2 deletion mediated by meiotic nonallelic homologous recombination events between low-copy repeats, also known as segmental duplications. Although previous studies exist, each was of small size, and it remains to be determined whether there are parent-of-origin biases for the de novo 22q11.2 deletion. To address this question, we genotyped a total of 389 DNA samples from 22q11DS-affected families. A total of 219 (56%) individuals with 22q11DS had maternal origin and 170 (44%) had paternal origin of the de novo deletion, which represents a statistically significant bias for maternal origin (p = 0.0151). Combined with many smaller, previous studies, 465 (57%) individuals had maternal origin and 345 (43%) had paternal origin, amounting to a ratio of 1.35 or a 35% increase in maternal compared to paternal origin (p = 0.000028). Among 1,892 probands with the de novo 22q11.2 deletion, the average maternal age at time of conception was 29.5, and this is similar to data for the general population in individual countries. Of interest, the female recombination rate in the 22q11.2 region was about 1.6–1.7 times greater than that for males, suggesting that for this region in the genome, enhanced meiotic recombination rates, as well as other as-of-yet undefined 22q11.2-specific features, could be responsible for the observed excess in maternal origin

Internal rib structure can be predicted using mathematical models: an anatomic study comparing the chest to a shell dome with application to understanding fractures

The human rib cage resembles a masonry dome in shape. Masonry domes have a particular construction that mimics stress distribution. Rib cortical thickness and bone density were analyzed to determine whether the morphology of the rib cage is sufficiently similar to a shell dome for internal rib structure to be predicted mathematically. A finite element analysis (FEA) simulation was used to measure stresses on the internal and external surfaces of a chest-shaped dome. Inner and outer rib cortical thickness and bone density were measured in the mid-axillary lines of seven cadaveric rib cages using computerized tomography scanning. Paired t tests and Pearson correlation were used to relate cortical thickness and bone density to stress. FEA modeling showed that the stress was 82% higher on the internal than the external surface, with a gradual decrease in internal and external wall stresses from the base to the apex. The inner cortex was more radio-dense, P < 0.001, and thicker, P < 0.001, than the outer cortex. Inner cortical thickness was related to internal stress, r = 0.94, P < 0.001, inner cortical bone density to internal stress, r = 0.87, P = 0.003, and outer cortical thickness to external stress, r = 0.65, P = 0.035. Mathematical models were developed relating internal and external cortical thicknesses and bone densities to rib level. The internal anatomical features of ribs, including the inner and outer cortical thicknesses and bone densities, are similar to the stress distribution in dome-shaped structures modeled using FEA computer simulations of a thick-walled dome pressure vessel. Fixation of rib fractures should include the stronger internal corte

Enhanced Maternal Origin of the 22q11.2 Deletion in Velocardiofacial and DiGeorge Syndromes

Velocardiofacial and DiGeorge syndromes, also known as 22q11.2 deletion syndrome (22q11DS), are congenital-anomaly disorders caused by a de novo hemizygous 22q11.2 deletion mediated by meiotic nonallelic homologous recombination events between low-copy repeats, also known as segmental duplications. Although previous studies exist, each was of small size, and it remains to be determined whether there are parent-of-origin biases for the de novo 22q11.2 deletion. To address this question, we genotyped a total of 389 DNA samples from 22q11DS-affected families. A total of 219 (56%) individuals with 22q11DS had maternal origin and 170 (44%) had paternal origin of the de novo deletion, which represents a statistically significant bias for maternal origin (p = 0.0151). Combined with many smaller, previous studies, 465 (57%) individuals had maternal origin and 345 (43%) had paternal origin, amounting to a ratio of 1.35 or a 35% increase in maternal compared to paternal origin (p = 0.000028). Among 1,892 probands with the de novo 22q11.2 deletion, the average maternal age at time of conception was 29.5, and this is similar to data for the general population in individual countries. Of interest, the female recombination rate in the 22q11.2 region was about 1.6-1.7 times greater than that for males, suggesting that for this region in the genome, enhanced meiotic recombination rates, as well as other as-of-yet undefined 22q11.2-specific features, could be responsible for the observed excess in maternal origin.publisher: Elsevier articletitle: Enhanced Maternal Origin of the 22q11.2 Deletion in Velocardiofacial and DiGeorge Syndromes journaltitle: The American Journal of Human Genetics articlelink: http://dx.doi.org/10.1016/j.ajhg.2013.01.018 content_type: article copyright: Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.status: publishe