Mark Orme

Can functional magnetic resonance imaging studies help with the optimization of health messaging for lifestyle behavior change? A systematic review

Unhealthy behaviors, including smoking, poor nutrition, excessive alcohol consumption, physical inactivity and sedentary lifestyles, are global risk factors for non-communicable diseases and premature death. Functional magnetic resonance imaging (fMRI) offers a unique approach to optimize health messages by examining how the brain responds to information relating to health. Our aim was to systematically review fMRI studies that have investigated variations in brain activation in response to health messages relating to (i) smoking; (ii) alcohol consumption; (iii) physical activity; (iv) diet; and (v) sedentary behavior. The electronic databases used were Medline/PubMed, Web of Science (Core Collection), PsychINFO, SPORTDiscuss, Cochrane Library and Open Grey. Studies were included if they investigated subjects aged ≥10years and were published before January 2017. Of the 13,836 studies identified in the database search, 18 studies (smoking k=15; diet k=2; physical activity/sedentary behavior k=1) were included in the review. The prefrontal cortex was activated in seven (47%) of the smoking-related studies and the physical activity study. Results suggest that activation of the ventromedial, dorsolateral and medial prefrontal cortex regions were predictive of subsequent behavior change following exposure to aversive anti-smoking stimuli. Studies investigating the neurological responses to anti-smoking material were most abundant. Of note, the prefrontal cortex and amygdala were most commonly activated in response to health messages across lifestyle behaviors. The review highlights an important disparity between research focusing on different lifestyle behaviors. Insights from smoking literature suggest fMRI may help to optimize health messaging in relation to other lifestyle behaviors.

Study protocol for Chronic Obstructive Pulmonary Disease-Sitting and ExacerbAtions Trial (COPD-SEAT): a randomised controlled feasibility trial of a home-based self-monitoring sedentary behaviour intervention

Introduction An acute exacerbation of chronic obstructive pulmonary disease (COPD) marks a critical life event, which can lower patient quality of life and ability to perform daily activities. Patients with COPD tend to lead inactive and highly sedentary lifestyles, which may contribute to reductions in functional capacity. Targeting sedentary behaviour (SB) may be more attainable than exercise (at a moderate-to-vigorous intensity) for behaviour change in patients following an exacerbation. This study aims to evaluate the feasibility and acceptability of a 2-week at-home intervention providing education and self-monitoring to reduce prolonged periods of SB in patients with COPD discharged following an acute exacerbation. Methods and analysis Patients will be randomised into 1 of 3 conditions: usual care (control), education or education+feedback. The education group will receive information and suggestions about reducing long periods of sitting. The education+feedback group will receive real-time feedback on their sitting time, stand-ups and step count at home through an inclinometer linked to a smart device app. The inclinometer will also provide vibration prompts to encourage movement when the wearer has been sedentary for too long. Data will be collected during hospital admission and 2 weeks after discharge. Qualitative interviews will be conducted with patients in the intervention groups to explore patient experiences. Interviews with healthcare staff will also be conducted. All data will be collected January to August 2016. The primary outcomes are feasibility and acceptability, which will be assessed by qualitative interviews, uptake and drop-out rates, reasons for refusing the intervention, compliance, app usage and response to vibration prompts. Ethics and dissemination The research ethics committee East Midlands Leicester-Central has provided ethical approval for the conduct of this study. The results of the study will be disseminated through appropriate conference proceedings and peer-reviewed journals. Trial registration number ISRCTN13790881; Pre-results.

Sensing interstitial glucose to nudge active lifestyles (SIGNAL): feasibility of combining novel self-monitoring technologies for persuasive behaviour change

Introduction Increasing physical activity (PA) reduces the risk of developing diabetes, highlighting the role of preventive medicine approaches. Changing lifestyle behaviours is difficult and is often predicated on the assumption that individuals are willing to change their lifestyles today to reduce the risk of developing disease years or even decades later. The self-monitoring technologies tested in this study will present PA feedback in real time, parallel with acute physiological data. Presenting the immediate health benefits of being more physically active may help enact change by observing the immediate consequences of that behaviour. The present study aims to assess user engagement with the self-monitoring technologies in individuals at moderate-to-high risk of developing type 2 diabetes. Methods and analysis 45 individuals with a moderate-to-high risk, aged ≥40 years old and using a compatible smartphone, will be invited to take part in a 7-week protocol. Following 1 week of baseline measurements, participants will be randomised into one of three groups: group 1— glucose feedback followed by biobehavioural feedback (glucose plus PA); group 2—PA feedback followed by biobehavioural feedback; group 3—biobehavioural feedback. A PA monitor and a flash glucose monitor will be deployed during the intervention. Participants will wear both devices throughout the intervention but blinded to feedback depending on group allocation. The primary outcome is the level of participant engagement and will be assessed by device use and smartphone usage. Feasibility will be assessed by the practicality of the technology and screening for diabetes risk. Semistructured interviews will be conducted to explore participant experiences using the technologies. Trial registration number ISRCTN17545949. Registered on 15/05/2017.

Influence of muscle mass in the assessment of lower limb strength in COPD: validation of the prediction equation

Absence of established reference values limits application of quadriceps maximal voluntary contraction (QMVC) measurement. The impact of muscle mass inclusion in predictions is unclear. Prediction equations encompassing gender, age and size with (FFM+) and without (FFM−), derived in healthy adults (n=175), are presented and compared in two COPD cohorts recruited from primary care (COPD-PC, n=112) and a complex care COPD clinic (COPD-CC, n=189). Explained variance was comparable between the prediction models (R2: FFM+: 0.59, FFM−: 0.60) as were per cent predictions in COPD-PC (88.8%, 88.3%). However, fat-free mass inclusion reduced the prevalence of weakness in COPD, particularly in COPD-CC where 11.9% fewer were deemed weak.

The influence of South Asian ethnicity on the incremental shuttle walk test in UK adults

The objective of this study was to compare incremental shuttle walking test (ISWT) performance between South Asian and Caucasian British adults, identify predictors of ISWT distance and produce ethnicity-specific reference equations. Data from a mixed gender sample aged 40–75 years from Leicestershire, United Kingdom, were selected for analyses. Analysis of covariance determined differences in ISWT performance between South Asian and Caucasian British ethnic groups. Linear regressions identified predictors of ISWT distance, which determined the reference equations. In total, 144 participants took part in the study (79 South Asian (54 ± 8 years, 71% female) and 65 Caucasian British (58 ± 9 years, 74% female)). Distance walked for the ISWT was shorter for South Asian individuals compared with Caucasian British (451 ± 143 vs. 575 ± 180 m, p < 0.001). The ethnicity-specific reference equations for ISWT distance explained 33–50% of the variance (standard error of the estimate (SEE): 107–119 m) for South Asians and explained 14–58% of the variance (SEE: 121–169 m) for Caucasian British. Ethnicity univariately explained 12.9% of the variance in ISWT distance and was significantly associated with ISWT distance after controlling for age, gender, height, weight, dyspnoea and lung function (B = −70.37; 1 = Caucasian British, 2 = South Asian), uniquely explaining 3.7% of the variance. Predicted values for ISWT performance were lower in South Asian people than in Caucasian British. Ethnicity-specific reference equations should account for this.

S82 Daily stepping does not recover as an inpatient: standardising the measurement of physical activity during hospitalisation for respiratory disease

Introduction and Objectives Hospitalisation for an exacerbation of chronic respiratory disease has a major impact on physical activity (PA). However, criteria to derive reliable inpatient PA data do not exist and current recommendations are unlikely to account for variations in length of hospital stay (LOHS) and the hospital environment. The aims were to identify the minimum wear time and number of days required to obtain reliable inpatient PA data; to use these criteria to determine how PA changes during recovery as an inpatient; and to compare PA across patients stratified by LOHS. Methods 259 individuals hospitalised with an exacerbation of chronic respiratory disease were recruited as part of an early rehabilitation trial previously reported (Greening et al, BMJ 2014). Participants (mean (SD) age 70.0±9.7 years, 58.3% female) wore a physical activity monitor (SenseWear) during their stay. Daily step count and walking time during waking hours was analysed. Inpatient PA was assessed across a range of minimum wear time criteria (≥1–12 hours). Repeated measures analysis of covariance was used to compare between days and between times of day. Single-day intraclass correlation coefficients (ICCs) were calculated across the range of wear time criteria. The minimum number of days required to obtain an ICC ≥0.80 was estimated using the Spearman-Brown prophecy formula. Abstract S82 Figure 1 Step count per hour as a proportion of total daily step count across an average 24 hour period. Data are reported as mean (95% CI). Results A minimum wear time of 11 hours (≥1 valid day) allowed 80% of the sample to be retained. All minimum wear time thresholds produced an ICC ≥0.80, resulting in 1 day of wear required to produce representative inpatient PA. Mornings and afternoons were more active than evenings and overnight (32.1% and 32.0% vs. 25.2% and 10.7% of steps/day, respectively, p<0.001) (figure 1). No changes in PA were observed during the hospital stay; ranging 585–707 steps/day and 72–83 min/day of walking. After controlling for wear time, patients admitted for 2–3 days took more steps on average than patients staying 7–14 days (997±125 vs. 597±91, p=0.036). Conclusions One full day (24 hours) of monitoring is required at the individual-level to obtain representative inpatient PA. A minimum wear time criteria of ≥11 waking hours is recommended for sample-level data. Wear time and LOHS should be accounted for in analyses.

The influence of muscle mass in the assessment of lower limb strength in COPD [Abstract]

Introduction and objectives Lower limb muscle strength measured by Quadriceps Maximal Voluntary Contraction (QMVC) provides valuable functional and prognostic information in people with COPD. Reference equations providing normal values for QMVC have been reported, some requiring measurement of muscle mass. It is unclear whether including muscle mass in the calculation significantly alters predicted values in COPD. We addressed this question by deriving reference equations for QMVC with and without the inclusion of whole body assessment of muscle mass in a cohort of healthy volunteers and subsequently comparing QMVC assessment using these reference equations in two separate cohorts of patients with COPD. Methods Prediction equations were derived through multiple linear regression in a healthy control (HC) group. Age, gender, height and weight were inputted into the first model (FFM– model) and fat-free mass (FFM) added for the other (FFM+ model). The prediction equations were then applied to a Primary Care COPD (PCC) group and Complex Care COPD (CCC) group of patients where percentage predicted values were calculated and weakness determined using a threshold of the lower limit of normal. Results 175 HC subjects (median (IQR) age: 54 (14) years, 31% male) were recruited. The PCC group comprised 87 patients (median (IQR) age: 68 (9) years, 71% male, FEV1 62 (20)% predicted) and the CCC group 189 patients (median (IQR) 66 (12) years, 57% male, FEV1: 29 (16)% predicted). Prediction values for the HC and PCC were similar between the FFM– and FFM+ models as shown in the table. In the CCC percentage predicted values were lower and there were 11.9% more classed as weak by the FFM– model compared to the FFM+ model. Abstract P47 Table 1 QMVC values expressed as percent predicted values and number classed as weak using the FFM− and FFM+ models for the COPD cohorts Healthy control Primary care COPD Complex care COPD n = 175 n = 87 n = 189 FFM− Model- %pred QMVC: 100.3 (24.1) 86.0 (22.0) 54.0 (16.4) Number classed as weak (%): 6 (3.4%) 14 (16.3%) 101 (53.2%) FFM+ Model% pred QMVC: 100.2 (24.1) 86.7 (20.6) 59.2 (17.8) Number classed as weak (%): 8 (4.6%) 10 (11.6%) 78 (41.3%) Mean (SD) values presented as a percentage of the values predicted (%pred) using the FFM– and FFM+ models. Abbreviations: FFM+: fat-free mass included, FFM− fat-free mass not included. Conclusion The inclusion of fat-free mass did not significantly alter prediction of muscle weakness in the healthy cohort. In the COPD cohorts, including FFM in the model altered the proportion classified as having muscle weakness, most notably in the CCC cohort. This is likely to be due to a higher prevalence of muscle wasting in this population which resulted in an underestimate of predicted strength when muscle mass is included in the model.