Obstructive sleep apnoea in older people

Obstructive sleep apnoea (OSA) is common and the prevalence increases with age. When OSA leads to sleep disruption and excessive daytime sleepiness, it is referred to as obstructive sleep apnoea syndrome (OSAS). The aim of this thesis was to investigate the consequences of OSAS in older people (˃ 65 years) and the effect of continuous positive airway pressure (CPAP) therapy. CPAP is the treatment of choice in moderate to severe OSAS in middle aged people. However, there is a paucity of evidence on the therapeutic and economic benefits of CPAP in older people with OSAS. The two studies in this thesis aimed to address this by comparing outcomes in older people with OSAS before and after treatment with CPAP. The first study presented is the thesis is the PREDICT trial; a multicentre randomised controlled trial of CPAP in older people with OSAS. The trial studied the clinical efficacy of CPAP after 3 months, while determining the cost effectiveness of treatment over 12 months. The results of the trial showed that CPAP was an effective treatment for reducing excessive daytime sleepiness by -2.1 (95%CI -3.0 to -1.3); p<0.001 points as measured by the Epworth sleepiness scale. CPAP also improved quality of life, with a statistically significant increase in the quality adjusted life years calculated with the SF-6D, equating to one week. The CPAP group also accrued marginally lower health care costs over 12 months compared to the group treated with best supportive care alone. Overall the economic benefit of CPAP was linked to the reduced healthcare usage offsetting the cost of the equipment. The second study presented in the thesis was a single centre randomised controlled trial to investigate the impact of CPAP on cognitive function and brain morphology in older people with minimally symptomatic OSAS after 6 months of treatment. In this study I tested the hypothesis that older patients with OSAS have cognitive impairment and corresponding brain changes which would be modifiable with treatment. The results of this study suggested older people with minimally symptomatic OSAS had normal cognitive function but impaired attention and executive function. CPAP treatment improved one aspect of attention, although memory and overall cognitive function were unchanged. The results of the brain MRI scans are not presented, and are in the process of being analysed. In conclusion the data presented in this thesis support the use of CPAP therapy in older people with excessive daytime sleepiness due to OSAS.Open Acces

Dose-response between frequency of breaks in sedentary time and glucose control in type 2 diabetes: a proof of concept study

Objectives This study aimed to investigate dose-response between frequency of breaks in sedentary time and glucose control.DesignRandomised three-treatment, two-period balanced incomplete block trial.MethodsTwelve adults with type 2 diabetes (age, 60 ± 11 years; body mass index, 30.2 ± 4.7 kg/m2) participated in two of the following treatment conditions: sitting for 7 h interrupted by 3 min light-intensity walking breaks every (1) 60 min (Condition 1), (2) 30 min (Condition 2), and (3) 15 min (Condition 3). Postprandial glucose incremental area under the curves (iAUCs) and 21-h glucose total area under the curve (AUC) were measured using continuous glucose monitoring. Standardised meals were provided. Results Compared with Condition 1 (6.7 ± 0.8 mmol L−1 × 3.5 h−1), post-breakfast glucose iAUC was reduced for Condition 3 (3.5 ± 0.9 mmol L−1 × 3.5 h−1, p ˂ 0.04). Post-lunch glucose iAUC was lower in Condition 3 (1.3 ± 0.9 mmol L−1 × 3.5 h−1, p ˂ 0.03) and Condition 2 (2.1 ± 0.7 mmol L−1 × 3.5 h−1, p ˂ 0.05) relative to Condition 1 (4.6 ± 0.8 mmol L−1 × 3.5 h−1). Condition 3 (1.0 ± 0.7 mmol L−1 × 3.5 h−1, p = 0.02) and Condition 2 (1.6 ± 0.6 mmol L−1 × 3.5 h−1, p ˂ 0.04) attenuated post-dinner glucose iAUC compared with Condition 1 (4.0 ± 0.7 mmol L−1 × 3.5 h−1). Cumulative 10.5-h postprandial glucose iAUC was lower in Condition 3 than Condition 1 (p = 0.02). Condition 3 reduced 21-h glucose AUC compared with Condition 1 (p < 0.001) and Condition 2 (p = 0.002). However, post-breakfast glucose iAUC, cumulative 10.5-h postprandial glucose iAUC and 21-h glucose AUC were not different between Condition 2 and Condition 1 (p ˃ 0.05).Conclusions There could be dose-response between frequency of breaks in sedentary time and glucose. Interrupting sedentary time every 15 min could produce better glucose control

The relationship between sedentary bout duration and glucose in adults with type 2 diabetes

Physical activity is important for blood glucose management in people with Type 2 diabetes (T2D). Little research has explored the relationship between sedentary behaviour and mean glucose and glucose variability in people with T2D using objective and continuous measurements. Aims: To explore the relationship between sedentary bout duration and mean glucose and glucose variability in people with T2D using objective continuous measurement. Methods: 16 participants with T2D managed with diet, Metformin or DPP4 inhibitors were recruited (mean age 64.1±10.9 yr & BMI 29.4±6.9 kg/m2). Participants completed a demographic questionnaire and wore an activPAL accelerometer and FreeStyle Libre continuous glucose monitor for 3-14 days whilst documenting sleep, food and medication. Average proportion of time spent sitting/lying, during the waking day were calculated. Bouts of wake time sedentary behaviour were identified and defined as a period of at least 30 minutes continuous, uninterrupted sitting/lying during the waking day. Correlation analysis was conducted to investigate the relationships between sedentary bout duration and mean glucose, glucose range and glucose coefficient of variation. Results: On average, participants spent 65% of their day sitting/lying, 76% of sedentary bouts were ≥30minutes and 29% of bouts were ≥60minutes. Mean glucose was negatively (r = -0.08, p <0.01) associated with sedentary bout duration. Glucose range (r =0.47, p <0.001) and glucose coefficient of variation (r = 0.26, p <0.001) both positively correlated with sedentary bout duration. Participant characteristics such as age, gender and BMI appear to influence the relationship between sedentary bout duration and glucose response. Conclusions: Results indicate increased sedentary time leads to improved mean glucose and increased glucose variability

A systematic and integrated review of mobile-based technology to promote active lifestyles in people with Type 2 diabetes

Background: An active lifestyle is important for good Type 2 diabetes management. Mobile-based technology is increasingly being used to promote active lifestyles. Aim: To review studies examining the effectiveness, acceptability and feasibility of mobile-based technology for promoting active lifestyles in people with Type 2 diabetes. Methods: An integrated, systematic review method was used to allow inclusion of a variety of study designs. A comprehensive search of electronic databases including; PubMed, Medline, ScienceDirect and ACM Digital Library was conducted to retrieve studies promoting active lifestyles in people with Type 2 diabetes using mobile-based technology (apps and wearable technology). Studies had to assess; effectiveness, acceptability or feasibility of mobile based technology. Studies were categorised as 1)informing, 2)monitoring, 3)provoking or 4)sustaining behaviour. Results: A total of 9 papers from the 7662 sourced met inclusion criteria; 5 studies used smartphone or tablet apps, 1 a diabetes personal digital assistant, 1 a combination of continuous glucose monitor and accelerometer, 1 a pedometer and 1 a website delivered by a smartphone. The effectiveness of technology was assessed in 6 studies, feasibility examined in 3 studies and acceptability in 4 studies. Most (n=5) of the studies examined the effectiveness of using mobile-based technology to provoke lifestyle. The effectiveness of mobile-based technology in monitoring active lifestyles and the feasibility and acceptability of using mobile-based technology to sustained lifestyle change has not been investigated. Conclusions: To maintain health benefit from active lifestyles future research should explore the feasibility and acceptability of mobile based technology monitoring in sustaining active lifestyles

Objective, continuous measurement of sedentary behaviour and glucose in people with type 2 diabetes

Aims: To explore the relationship between daily levels of sitting/lying and glucose in people with Type 2 diabetes (T2D) using objective and continuous measurements. Methods: Ten participants with T2D managed with diet, Metformin or DPP4 inhibitors were recruited (mean age 63.5±9.4 years & BMI 30.8±6.9 kg/cm2). Participants completed a demographic questionnaire and wore an activPAL accelerometer and FreeStyle Libre continuous glucose monitor for 3-14 days whilst documenting sleep, food and medication. Average proportion of time spent sitting/lying, and daily mean glucose during the waking day were calculated. A multiple linear regression was calculated to explore the relationship between time spent sitting/lying, age, BMI, and daily mean glucose. Results: On average, participants spent 67.5% of their day sitting/lying and mean daily glucose was 7.7 (±1.8) mmol/l. Regression analysis suggested a significant effect (F(3,105) = 16.52, p <0.01) for sitting/lying time, age and BMI on daily mean glucose (R2 = 0.30). Participants’ predicted daily mean glucose is equal to -12.23 + 5.14(sitting/lying) + 0.16(age) + 0.21(BMI), with daily mean glucose increasing by 5.14mmol/l for each percent of daily sitting/lying, 0.16mmol/l for each increasing year of age and 0.21mmol/l for each increasing BMI unit. Conclusions: Average sitting/lying time was higher than has previously been reported and percentage sitting/lying time, age and BMI were identified as significant predictors of higher daily mean glucose in people with T2D. Results suggest that increased sedentariness is associated with increased daily mean glucose in those with T2D

Comparative effectiveness of cognitive therapies delivered face-to-face or over the telephone: an observational study using propensity methods.

OBJECTIVES: To compare the clinical and cost-effectiveness of face-to-face (FTF) with over-the-telephone (OTT) delivery of low intensity cognitive behavioural therapy. DESIGN: Observational study following SROBE guidelines. Selection effects were controlled using propensity scores. Non-inferiority comparisons assessed effectiveness. SETTING: IAPT (improving access to psychological therapies) services in the East of England. PARTICIPANTS: 39,227 adults referred to IAPT services. Propensity score strata included 4,106 individuals; 147 pairs participated in 1:1 matching. INTERVENTION: Two or more sessions of computerised cognitive behavioural therapy (CBT). MAIN OUTCOME MEASURES: Patient-reported outcomes: Patient Health Questionnaire (PHQ-9) for depression; Generalised Anxiety Disorder questionnaire (GAD-7); Work and Social Adjustment Scale (WSAS). Differences between groups were summarised as standardised effect sizes (ES), adjusted mean differences and minimally important difference for PHQ-9. Cost per session for OTT was compared with FTF. RESULTS: Analysis of covariance controlling for number of assessments, provider site, and baseline PHQ-9, GAD-7 and WSAS indicated statistically significantly greater reductions in scores for OTT treatment with moderate (PHQ-9: ES: 0.14; GAD-7: ES: 0.10) or small (WSAS: ES: 0.03) effect sizes. Non-inferiority in favour of OTT treatment for symptom severity persisted as small to moderate effects for all but individuals with the highest symptom severity. In the most stringent comparison, the one-to-one propensity matching, adjusted mean differences in treatment outcomes indicated non-inferiority between OTT versus FTF treatments for PHQ-9 and GAD-7, whereas the evidence was moderate for WSAS. The per-session cost for OTT was 36.2% lower than FTF. CONCLUSIONS: The clinical effectiveness of low intensity CBT-based interventions delivered OTT was not inferior to those delivered FTF except for people with more severe illness where FTF was superior. This provides evidence for better targeting of therapy, efficiencies for patients, cost savings for services and greater access to psychological therapies for people with common mental disorders

Methods for combining continuously measured glucose and activity data in people with Type 2 diabetes : challenges and solutions

Aims: To present the novel application of combining continuously measured glucose with continuous accelerometer measured physical activity and sedentary behaviour data and discusses the principles used and challenges faced in combining and analysing these two sets of data in the context of diabetes management. Methods: The background and rationale for exploring glucose, physical activity and sedentary behaviour in people with Type 2 diabetes is presented, the paper outlines the technologies used, the individual data extraction and finally the combined data analysis. A case study approach is used to illustrate the application of the combined data processing and analysis. Results: The data analytic principles used could be transferred to different conditions where continuous data sets are being combined to help individuals or health professionals better manage and care for people with long term conditions. Conclusions: Future work should focus on generating validated techniques to visualise combined data sets and explore ways to present data back to the individual in an effective way to support health care management and rehabilitation

A Lay Health Worker Intervention to Increase Uptake and Completion of Pulmonary Rehabilitation in Chronic Obstructive Pulmonary Disease: Assessing Fidelity of Intervention Delivery

“This is an Accepted Manuscript of an article published by Taylor & Francis Group in COPD: Journal of Chronic Obstructive Pulmonary Disease on 17 Aug 2020, available online: https://doi.org/10.1080/15412555.2020.1797658

Implementing Primordial Binaries in Simulations of Star Cluster Formation with a Hybrid MHD and Direct N-Body Method

The fraction of stars in binary systems within star clusters is important for their evolution, but what proportion of binaries form by dynamical processes after initial stellar accretion remains unknown. In previous work, we showed that dynamical interactions alone produced too few low-mass binaries compared to observations. We therefore implement an initial population of binaries in the coupled MHD and direct N-body star cluster formation code Torch. We compare simulations with, and without, initial binary populations and follow the dynamical evolution of the binary population in both sets of simulations, finding that both dynamical formation and destruction of binaries take place. Even in the first few million years of star formation, we find that an initial population of binaries is needed at all masses to reproduce observed binary fractions for binaries with mass ratios above the $q \geq 0.1$ detection limit. Our simulations also indicate that dynamical interactions in the presence of gas during cluster formation modify the initial distributions towards binaries with smaller primary masses, larger mass ratios, smaller semi-major axes and larger eccentricities. Systems formed dynamically do not have the same properties as the initial systems, and systems formed dynamically in the presence of an initial population of binaries differ from those formed in simulations with single stars only. Dynamical interactions during the earliest stages of star cluster formation are important for determining the properties of binary star systems.Comment: 15 pages, 14 figures, submitted to MNRAS and edited to address positive referee's repor