Circadian Timing, Information processing and Metabolism (TIME) study: protocol of a longitudinal study of sleep duration, circadian alignment and cardiometabolic health among overweight adults.

BACKGROUND: Both short sleep duration and circadian rhythm misalignment are risk factors for metabolic dysfunction, but the underlying mechanisms are unknown. The goal of this study is to examine how sleep duration and circadian alignment predict changes in cardiometabolic risk factors over a 12-month period, and test cognitive function and hedonic eating tendencies as potential mechanisms. METHODS: We will recruit a sample of 120 working aged adults with BMI 25-35 kg/m2 (overweight to class I obesity). The protocol includes 5 visits over a 12-month period. Study visits include wrist actigraphy to measure sleep behaviors, 24-h diet recalls, dim light melatonin collection, a computerized neurobehavioral assessment, eating in the absence of hunger task, and frequently sampled IV glucose tolerance test. DISCUSSION: The results of the TIME study will advance the understanding of how both short sleep duration and circadian misalignment contribute to behavioral aspects of obesity and metabolic dysfunction. TRIAL REGISTRATION: ClinicalTrials.Gov, NCT04759755 , registered retrospectively February 13, 2021.

Sleep quality and glycaemic variability in a real-life setting in adults with type 1 diabetes.

AIMS/HYPOTHESIS: Suboptimal subjective sleep quality is very common in adults with type 1 diabetes. Reducing glycaemic variability is a key objective in this population. To date, no prior studies have examined the associations between objectively measured sleep quality and overnight glycaemic variability in adults with type 1 diabetes. We aimed to test the hypothesis that poor sleep quality would be associated with greater overnight glycaemic variability. METHODS: Data were collected in the home setting from 20 adults (ten male and ten female participants) with type 1 diabetes who were current insulin pump users. Simultaneous assessments of objective sleep quality (Zmachine Insight+) and continuous glucose monitoring (CGM) were performed over multiple nights (up to 15 nights) in each participant. Due to the real-life nature of this study, the participants kept their usual CGM alerts for out-of-range glucose values. Sleep quality was categorised as 'good' or 'poor' using a composite of objective sleep features (i.e. sleep efficiency, wake after sleep onset and number of awakenings) based on the National Sleep Foundation's consensus criteria. Glycaemic variability was quantified using SD and CV of overnight glucose values based on overnight CGM profiles. RESULTS: A total of 170 nights were analysed. Overall, 86 (51%) nights were categorised as good sleep quality, and 84 (49%) nights were categorised as poor sleep quality. Using linear mixed-effects models, poor sleep quality was significantly associated with greater glycaemic variability as quantified by SD (coefficient: 0.39 [95% CI 0.10, 0.67], p = 0.009) and CV (coefficient: 4.35 [95% CI 0.8, 7.9], p = 0.02) of overnight glucose values, after accounting for age, sex, BMI and overnight insulin dose. There was large inter- and intra-individual variability in sleep and glycaemic characteristics. Both pooled and individual-level data revealed that the nights with poor sleep quality had larger SDs and CVs, and, conversely, the nights with good sleep quality had smaller SDs and CVs. No associations were found between sleep quality and time spent in the target glucose range, or above or below the target glucose range, where CGM alarms are most likely to occur. CONCLUSIONS/INTERPRETATION: Objectively measured sleep quality is associated with overnight glycaemic variability in adults with type 1 diabetes. These findings highlight an important role of sleep quality in overnight glycaemic control in type 1 diabetes. They also provide a strong incentive to both patients and healthcare providers for considering sleep quality in personalised type 1 diabetes glycaemic management plans. Future studies should investigate the mechanisms linking sleep quality to glycaemic variability.

Psychometric properties of the Korean version of the Pittsburgh Fatigability Scale in breast cancer survivors.

BACKGROUND: Fatigability has recently emerged in oncology as a concept that anchors patients' perceptions of fatigue to defined activities of specified duration and intensity. This study aimed to examine the psychometric properties of the Korean version of the Pittsburgh Fatigability Scale (K-PFS) for women with breast cancer. METHODS: This cross-sectional study involved 196 women with breast cancer recruited from a tertiary hospital in Seoul, Korea. Reliability was evaluated using Cronbach's alpha, and confirmatory factor analysis was conducted to examine the factor structure of the K-PFS. Four goodness-of-fit values were evaluated: (1) the comparative fit index (CFI), (2) the Tucker-Lewis index (TLI), (3) the root mean square error of approximation (RMSEA), and (4) the standardized root mean square residual (SRMR). RESULTS: Of the 196 survivors, 71.1% had greater physical fatigability (K-PFS Physical score ≥ 15) and 52.6% had greater mental fatigability (K-PFS Mental score ≥ 13). The Cronbach's alpha coefficient for the total K-PFS scale was 0.926, and the coefficients for the physical and mental fatigability domains were 0.870 and 0.864, respectively. In the confirmatory factor analysis for physical fatigability, the SRMR value (0.076) supported goodness of fit, but other model fit statistics did not (CFI = 0.888, TLI = 0.826, and RMSEA = 0.224). For mental fatigability, although three goodness-of-fit values were acceptable (CFI = 0.948, TLI = 0.919, and SRMR = 0.057), the RMSEA value (0.149) did not indicate good model fit. However, each item coefficient was statistically significant (> 0.5), and the K-PFS was therefore found to be valid from a theoretical perspective. CONCLUSION: This study provides meaningful information on the reliability and validity of the K-PFS instrument, which was developed to meet an important need in the context of breast cancer survivors. Additional research should examine its test-retest reliability and construct validity with performance measures.

Cognitive and vascular function in older adults with and without CKD.

BACKGROUND: Cognitive impairment is a common complication of aging that is also associated with chronic kidney disease (CKD). Vascular dysfunction has been implicated as a potential cause of cognitive impairment in older adults, with particular deficits noted in those with CKD. AIMS: To determine the differences in cognitive function and vascular compliance in older adults with and without CKD with preclinical cognitive impairment and the relationship between these factors. METHODS: Utilizing a cross-sectional approach, 48 older adults with preclinical cognitive impairment (24 with and 24 without CKD) were evaluated for performance on a test of global cognition and executive function, and vascular compliance via tonometry and ultrasound. RESULTS: Cognitive function and some indicators of vascular function were significantly different in older adults with and without CKD. Global cognition was correlated with carotid-femoral pulse wave velocity (r = - 0.36, p = 0.02) in the entire sample. Vascular function was not correlated with executive function. DISCUSSION: Older adults with preclinical cognitive impairment and CKD had different cognitive and vascular function than those without CKD, and an indicator of vascular function may have a relationship with cognitive function in older adults. CONCLUSIONS: The findings of this study support the assessment of cognitive and vascular function in older adults with and without CKD with preclinical cognitive impairment.

Sedentary Behavior in Older Adults With Preclinical Cognitive Impairment With and Without Chronic Kidney Disease.

Older adults with preclinical cognitive impairment can have chronic conditions and lifestyle factors that influence health. Sedentary behavior is common in older adults with and without chronic kidney disease (CKD). The objective of the current study was to determine the differences in sedentary behavior for older adults with preclinical cognitive impairment with and without CKD. Our study evaluated 48 older adults with preclinical cognitive impairment with and without CKD who underwent assessment of sedentary behavior via accelerometry. We found that older adults with preclinical cognitive impairment with and without CKD were sedentary, but there were no significant differences between groups. Fragmentation index was different (p < 0.05), with a lower fragmentation index found in those with CKD. Sedentary behavior should be assessed and evaluated as a potential target for interventions to improve health in these at-risk older adults; however, further investigation is needed. [Journal of Gerontological Nursing, 47(6), 35-42.].

The Influence of Sedentary Behavior on the Relationship Between Cognitive Function and Vascular Function in Older Adults with and without Chronic Kidney Disease.

Cognitive impairment and vascular dysfunction are common in older adults with and without chronic kidney disease (CKD). Older adults with and without CKD are also sedentary - a behavior associated with cognitive and vascular function. The objective of this study was to explore whether sedentary behavior influenced the relationship between cognitive and vascular function in older adults with preclinical cognitive impairment with and without CKD. In our study, 48 older adults underwent assessment of cognition, vascular compliance, and sedentary behavior, and relationships were explored with regression moderation analysis. Sedentary time and breaks did not moderate the relationship between vascular and cognitive function. Although significant moderation was not found, cognition, vascular function, and sedentary behavior are important to assess when evaluating older adults with and without CKD.

Factors affecting trust in healthcare among middle-aged to older Korean American women.

BACKGROUND: Predictors of trust in healthcare providers and the healthcare system have never been studied in Korean Americans (KA) despite the fact that trust plays an important role in health behaviors. The purpose of this study is to examine factors influencing trust in the healthcare system and providers among KA women. METHODS: Data were collected in 196 KA women examining the effects of perceived discrimination and trust on breast cancer screening in the Chicago metropolitan area. Path analysis was used to identify factors influencing trust in the healthcare system and providers. RESULTS: Acculturation was positively related to trust in healthcare providers (ß = .15, p =. 002), and discrimination in the healthcare system was inversely related to trust in healthcare providers (ß = -.60, p <. 001). Length of stay in the US was inversely related to distrust in the healthcare system (ß = -.14, p <. 001), and discrimination in healthcare was positively related to distrust in the healthcare system (ß = .60, p <. 001). Trust in healthcare providers and distrust in the healthcare system were moderately correlated (r = .51, p < .001). CONCLUSION: Higher levels of acculturation and lower levels of perceived discrimination were identified as predictors of higher levels of trust in healthcare providers. A shorter stay in the US and higher levels of discrimination were identified as predictors of higher levels of distrust in the healthcare system. Perceived discrimination is a target for interventions to enhance trust in the healthcare system, and therefore reduce healthcare disparities in KAs.

Oxytocin levels are lower in premenopausal women with type 1 diabetes mellitus compared with matched controls.

BACKGROUND: Oxytocin, a hormone most commonly associated with parturition and lactation, may have additional roles in diabetes complications. We determined oxytocin levels in premenopausal women with type 1 diabetes mellitus (T1DM) compared with non-diabetic controls and examined associations of oxytocin with health behaviours, clinical factors, biomarkers, kidney function and bone health. Lower oxytocin was hypothesized for T1DM. METHODS: A cross-sectional study of premenopausal women with T1DM (n = 88) from the Wisconsin Diabetes Registry Study, a population-based cohort of incident T1DM cases, and matched non-diabetic controls (n = 74) was conducted. RESULTS: Women with T1DM had lower oxytocin levels than controls adjusting for caffeine and alcohol use (p = 0.03). Health behaviours associated with oxytocin differed between women with and without T1DM: oxytocin was negatively associated with hormonal contraceptive use (quantified as lifetime contraceptive oestrogen exposure) in women with T1DM (p = 0.003), whereas positively related to hormonal contraceptive use (quantified as never/former/current) in controls (p < 0.001). Oxytocin had a positive association with adiposity (waist-to-hip ratio and leptin) in women with T1DM and a negative relationship with adiposity (weight gain) in controls. In T1DM only, oxytocin was positively associated with caffeine intake (p = 0.01) and negatively associated with alcohol use (p = 0.01). Oxytocin was not related to glycemic control, kidney function or bone health in T1DM. CONCLUSIONS: Oxytocin levels are lower in women with T1DM than matched controls. Oxytocin also has opposing associations with hormonal contraceptives and adiposity in women with and without T1DM. Research is needed to determine if the altered oxytocin milieu in T1DM is associated with oxytocinher health outcomes.

Different health behaviours and clinical factors associated with bone mineral density and bone turnover in premenopausal women with and without type 1 diabetes.

BACKGROUND: Women with type 1 diabetes (T1DM) have an elevated fracture risk. We therefore compared the associations of health behaviours and clinical factors with bone mineral density (BMD) and bone remodelling between premenopausal women with and without T1DM to inform potential interventions. METHODS: Participants included women with T1DM (n = 89) from the Wisconsin Diabetes Registry Study and age-matched and race-matched controls without diabetes (n = 76). Peripheral (heel and forearm) and central (hip and spine) BMD, markers of bone resorption and formation, bone cell signalling, glycaemic control, and kidney function were assessed. Health behaviours and medical history were self-reported. RESULTS: In controls, but not in women with T1DM, older age was associated with lower bone resorption (p ≤ 0.006) and formation (p = 0.0007). Body mass index was positively associated with heel and forearm BMD in both controls and T1DM women (all p < 0.0001), but with hip and spine BMD only in controls (p ≤ 0.005). Worse glycaemic control during the previous 10 years, greater alcohol intake, history of smoking, and lack of physical activity were associated with poorer bone outcomes only in women with T1DM (all p ≤ 0.002), whereas use of hormonal contraceptives was related to low bone formation in both women with and without T1DM (all p ≤ 0.006). Diabetes duration, insulin dose, residual C-peptide, and kidney function were not associated with bone in T1DM. CONCLUSIONS: Age and body mass index may not predict bone health in T1DM women. However, modifiable behaviours such as optimizing glycaemic control, limiting substance and hormonal contraceptive use, and increasing physical activity may improve bone health in T1DM women.

Physical Activity After Heart Surgery: Associations With Psychosocial and Sleep Factors.

BACKGROUND: Heart surgery is an effective intervention for managing heart disease, the leading cause of death globally. After surgery, physical activity is key to improving patients' quality of life and decreasing mortality, but patients are frequently physically inactive after heart surgery. OBJECTIVE: This cross-sectional pilot study aimed to examine how psychosocial and sleep factors influenced physical activity in patients after heart surgery. The mediating role of sleep factors between psychosocial factors and physical activity was also examined. METHODS: Thirty-three patients who had undergone heart surgery were recruited. Psychosocial and sleep factors and physical activity were measured using an online survey and a wrist-worn ActiGraph for 7 days and nights. RESULTS: The participants had heart surgery an average of about 7 years previously. They exceeded the recommended 150 minutes per week of moderate-intensity physical activity for Americans; however, 64% of them showed poor sleep quality (Pittsburgh Sleep Quality Index >5). Higher anxiety and depressive symptoms, lower self-efficacy, and greater sleep disturbances were associated with lower physical activity. Moreover, self-efficacy, sleep duration, sleep disturbance, sleep efficiency, and wake after sleep onset were predictors for physical activity. No mediating role of sleep factors was observed between psychosocial factors and physical activity. CONCLUSIONS: Psychosocial and sleep factors should be considered when developing and implementing physical activity strategies for patients after heart surgery. Researchers should examine the relationships among the study variables with larger samples of postsurgical cardiac patients during different periods after heart surgery.

Health Behavior Adherence in a Metropolitan-Based Metabolic Syndrome Management Program during the COVID-19 Pandemic.

Background: The COVID-19 pandemic increased the worldwide prevalence of metabolic syndrome. The purpose of this study was to assess health behavior adherence during the pandemic in adults who had engaged in a metabolic syndrome management program for at least 6 months. This assessment included an evaluation of health behavior changes, factors influencing adherence, and clinical parameters. The city-wide program was operated by the Seoul Metropolitan Government. Methods: Baseline and follow-up data were compared in 116 participants who engaged in the program for at least 6 months prior to the pandemic. Health behaviors and clinical parameters were examined. Generalized estimating equation analysis was used to identify sociodemographic variables influencing health behavior adherence over time. Results: Systolic blood pressure, waist circumference, and blood glucose improved (all P<0.05), and risk factors decreased (P<0.001) from baseline to follow-up (mean±standard deviation, 1.13±0.91 years). All six health behaviors, physical activity and weight control, eating habits, alcohol consumption and smoking, stress management, sleep and rest, and medication compliance and medical examination improved (all P<0.001) from baseline to follow-up (2.37±1.05 years). Smoking and employment negatively influenced adherence to health behaviors (P<0.05). Participants felt the most beneficial part of the program was receiving sequential medical examination results with follow-up consultations by public health professionals without charge. Conclusion: Our study demonstrated the durability of the impact of the Seoul Program on all six targeted health behaviors as well as clinical parameters. Findings encourage participation in such broad-based programs and development of novel approaches to facilitate success for smokers and employed participants.

Effects of daily sleep on physical activity after cardiac surgery.

BACKGROUND: Maintaining physical activity is challenging after cardiac surgery. Postsurgical cardiac patients often experience sleep problems showing a reciprocal interaction with physical activity. As sleep and physical activity show day-to-day variations, their daily relationships need to be assessed. However, no studies have examined daily sleep-physical activity relationships in postsurgical cardiac patients. OBJECTIVES: This study aimed to examine the effects of daily sleep factors on daily physical activity after cardiac surgery. METHODS: Among 33 patients who underwent cardiac surgery at least 10 weeks earlier, 5 sleep and 4 physical activity variables were measured using a wrist-worn ActiGraph for 7 days. Mixed-effects models were applied for data analyses. RESULTS: Most participants were male (57.6 %), non-Hispanic whites (63.6 %) who had coronary artery bypass graft surgery (54.6 %). Participants averaged 60.8 ± 10.1 years of age and 85.7 ± 91.2 months since surgery. They slept for an average of 385.6 ± 74.6 min (6.4 ± 1.2 h). Among sleep factors, greater number of awakenings (NOA) predicted lower next-day sedentary time. Higher sleep efficiency (SE) was associated with lower next-day sedentary time when not controlling for covariates. Among the psychosocial, demographic, and clinical covariates, higher comorbidity index was associated with fewer kcals expended, less daily moderate-to-vigorous physical activity, and more daily sedentary time. CONCLUSIONS: Daily SE and NOA and individual health status, including comorbidity, should be assessed over time to support improvement of daily physical activity after cardiac surgery. Researchers should examine the relationship between NOA and next-day sedentary time with larger samples. Such research should address multiple psychosocial, demographic, and clinical factors and the potential mediating role of sleep.

Effects of acute aerobic exercise on circulating sTLR and sRAGE profiles in normal- and abnormal-glucose-tolerant individuals.

BMI-matched normal- (NGT, n = 10, 41 ± 4y, 35.6 ± 3.0 kg/m2 ) and abnormal-glucose-tolerant (AGT, n = 16, 51 ± 3y, 34.3 ± 1.5 kg/m2 ) participants were evaluated for body composition, metabolic health (oral glucose tolerance test [OGTT]), and VO2 max. Participants also completed a treadmill walking test at 65% VO2 max for 30 min. Total sRAGE, esRAGE, sTLR2, and sTLR4 were assessed via ELISA, and cRAGE was calculated. AGT exhibited greater (p < 0.05) body fat % (+24%), fasting plasma glucose (+37%), OGTT AUC (+59%), and HOMA-IR (+55%) and lower (p < 0.05) VO2 max (-24%). sTLR2 was 33% lower in AGT than NGT (main effect, p = 0.034). However, sTLR2 did not change (p > 0.05) following AE. sTLR4 tended to be 36% lower in AGT than NGT (main effect, p = 0.096) and did not change following AE (p > 0.05). Total sRAGE and isoforms were similar (p > 0.05) between groups and did not change following AE (p > 0.05). sTLR2 was correlated with (p < 0.05) basal BG (r = -0.505) and OGTT AUC (r = -0.687). sTLR4 was correlated with basal BG (p < 0.10, r = -0.374) and OGTT AUC (p < 0.05, r = -0.402). Linear regressions were predictive of sTLRs in the basal state (sTLR2: R2 = 0.641, p = 0.01; sTLR4: R2 = 0.566, p = 0.037) and after acute exercise state (sTLR2: R2 = 0.681, p = 0.004, sTLR4: R2 = 0.568, p = 0.036).These findings show circulating sTLR profiles are disrupted in AGT and acute AE minimally modulates their levels.

Translation of the diabetes prevention program's lifestyle intervention: role of community health workers.

Approximately 8.3% of the US population has diabetes and estimates indicate that 79 million adults have prediabetes and 33.8% are obese, increasing their risk of diabetes. The national Diabetes Prevention Program (DPP) and subsequent translation studies have demonstrated the efficacy of the DPP lifestyle intervention (DPPLI) on lowering weight and reducing risk of type 2 diabetes over 10 years. Innovative strategies are needed to translate the DPPLI to reach people at risk of diabetes. Community health workers represent a group of individuals poised to play a role in supporting the translation of the DPPLI, especially in underserved populations. This article aims to 1) describe community health workers in general; 2) describe their role and impact on diabetes care in general; and 3) provide a detailed overview of studies involving community health workers in the translation of the DPPLI.

Adaptive System Identification for Estimating Future Glucose Concentrations and Hypoglycemia Alarms.

Many patients with diabetes experience high variability in glucose concentrations that includes prolonged hyperglycemia or hypoglycemia. Models predicting a subject's future glucose concentrations can be used for preventing such conditions by providing early alarms. This paper presents a time-series model that captures dynamical changes in the glucose metabolism. Adaptive system identification is proposed to estimate model parameters which enable the adaptation of the model to inter-/intra-subject variation and glycemic disturbances. It consists of online parameter identification using the weighted recursive least squares method and a change detection strategy that monitors variation in model parameters. Univariate models developed from a subject's continuous glucose measurements are compared to multivariate models that are enhanced with continuous metabolic, physical activity and lifestyle information from a multi-sensor body monitor. A real life application for the proposed algorithm is demonstrated on early (30 min in advance) hypoglycemia detection.

Effects of Sleep-Extend on glucose metabolism in women with a history of gestational diabetes: a pilot randomized trial.

OBJECTIVES: Women with a history of gestational diabetes (GDM) are at 7-fold increase in the risk of developing diabetes. Insufficient sleep has also been shown to increase diabetes risk. This study aimed to explore the feasibility of a sleep extension in women with a history of GDM and short sleep, and effects on glucose metabolism. METHODS: Women age 18-45 years with a history of GDM and actigraphy confirmed short sleep duration (<7 h/night) on weekdays were randomized at a ratio of 1 control (heathy living information) to 2 cases (6 weeks of "Sleep-Extend" intervention: use of a Fitbit, weekly digital content, and weekly coaching to increase sleep duration). An oral glucose tolerance test (OGTT), 7-day actigraphy recording, and questionnaires were obtained at baseline and 6 weeks. Mean differences between baseline and end-of-intervention parameters were compared using independent samples t-tests. RESULTS: Mean (SD) sleep duration increased within the Sleep-Extend group (n=9, +26.9 (42.5) min) but decreased within the controls (n=5, - 9.1 (20.4) min), a mean difference (MD) of 35.9 min (95% confidence interval (CI) - 8.6, 80.5). Fasting glucose increased, but less in Sleep-Extend vs. control groups (1.6 (9.4) vs 10.4 (8.2) mg/dL, MD - 8.8 mg/dL (95% CI - 19.8, 2.1), while 2-h glucose levels after an OGTT did not differ. Compared to controls, Sleep-Extend had decreased fatigue score (MD - 10.6, 95%CI - 20.7, - 0.6), and increased self-report physical activity (MD 5036 MET- minutes/week, 95%CI 343, 9729. Fitbit compliance and satisfaction in Sleep-Extend group was high. CONCLUSION: Sleep extension is feasible in women with a history of GDM, with benefits in fatigue and physical activity, and possibly glucose metabolism. These data support a larger study exploring benefits of sleep extension on glucose metabolism in these high-risk women. TRIAL REGISTRATION: ClinicalTrials.gov , NCT03638102 (8/20/2018).

Quality of Life and Prolonged Symptoms in Korean Breast Cancer Survivors.

BACKGROUND: A culture of serious overwork in South Korea, more than other developed countries, may impact symptoms and quality of life (QOL) experienced by Korean breast cancer survivors (BCS). OBJECTIVES: The aim of this study was to examine health-related QOL and influencing factors in BCS in Seoul, Korea, who have recovered from treatment for at least 1 year and returned to normal life and work. METHODS: In a cross-sectional study, 199 BCS completed a self-administered questionnaire in Seoul, Korea. RESULTS: Mean QOL scores were lower than expected, with 49% of the variance explained by depressive symptoms, physical fatigability, cognitive impairment, and social support. Psychological distress was high (67.8%), along with anxiety (47.2%) and depressive symptoms (36.7%). Participants reported a high prevalence of physical fatigability (71.1%), sleeping an average of only 6 hours per night, with 58.9% reporting poor quality sleep. CONCLUSIONS: Quality of life was lower in Korean BCS than comparable studies in the United States, although participants received care at a premiere medical center. Depressive symptoms and anxiety were common and did not taper off over the 5 years after diagnosis, unlike BCS elsewhere. Korean survivors experienced significant physical fatigability, much higher than reported in a US study of mixed male and female cancer survivors. Overwork was not a significant predictor of QOL, although 30% of employed women reported working 45 to 90 hours weekly. IMPLICATIONS FOR PRACTICE: Findings demonstrate the importance of continued efforts to mitigate these symptoms in clinical survivorship care, as well as future research, to provide avenues for improving QOL for BCS, particularly in Korea.

Rhythmic auditory stimulation increases 6-Minute walk distance in individuals with COPD: A repeated measures study.

OBJECTIVE: To evaluate if there is an increase in 6-minute walk distance in individuals with chronic obstructive pulmonary disease (COPD) while walking to rhythmically enhanced music. BACKGROUND: Individuals with COPD are less active. Walking with rhythmically enhanced music may help Participant's walk farther while simultaneously distracting from symptoms of dyspnea. METHODS: Twenty-five men (age = 70.7 ± 4.5 yr), with moderate-to-severe COPD (FEV1 = 47.4 ± 9.7% predicted) completed three, 6 min walk tests (6MWT) in random order. Walks were completed with music, with music that was rhythmically enhanced, or without music. Walking distance and perceived dyspnea were measured. RESULTS: Participant's walked 12 m, 95% CI [20.5-, 2.6], p = 0.015 further during the 6MWT when listening to rhythmically enhanced music when compared to no music. Onset of dyspnea was not different between the three walking conditions. CONCLUSIONS: Rhythmically-enhanced music may be a useful tool to increase walking distance in Participant's with COPD.

Enriching the quality of cross-cultural instrument development through cognitive interviewing: Implications for nursing research.

AIM: During cross-cultural instrument development, a gap commonly exists between the intended meaning of questionnaire items and the extent to which the participant understands that meaning. Because cognitive interviewing can provide such a powerful means for ensuring an accurate interpretation of items, the purpose of this report is to provide a practical guide to encourage its use in nursing research. METHODS: This report provides in-depth information describing: (a) advantages of cognitive interviewing, particularly for cross-cultural instrument development; (b) specific problems it can identify and solve; (c) strategies for performing cognitive interviews, including the four-step model of the question-and-answer process; (d) practical guidance for conducting successful cognitive interviews. RESULTS: To achieve linguistic validity as well as cultural relevance, a variety of factors need to be considered in addition to language, such as cultural interpretations, attitudes, and values. Examples of health-related studies are presented, demonstrating the advantages of cognitive interviewing for instrument development and cross-cultural research. These examples show how cognitive interviewing can be productively used to verify question clarity, patient comprehension, and patients' ease of response and judgment while also helping to establish content validity based on patients' perspectives. CONCLUSIONS: Cognitive interviewing can help nurse researchers discover potential instrument flaws and correct them in advance, subsequently avoiding collection of inaccurate data. Thus, cognitive interviewing should be considered an effective pretesting method for development of accurate instruments, particularly in cross-cultural nursing research.

Estimation of future glucose concentrations with subject-specific recursive linear models.

BACKGROUND: Estimation of future glucose concentrations is a crucial task for diabetes management. Predicted glucose values can be used for early hypoglycemic/hyperglycemic alarms or for adjustment of insulin injections or insulin infusion rates of manual or automated pumps. Continuous glucose monitoring (CGM) technologies provide glucose readings at a high frequency and consequently detailed insight into the subject's glucose variations. The objective of this research is to develop reliable subject-specific glucose prediction models using CGM data. METHODS: Two separate patient databases collected under hospitalized (disturbance-free) and normal daily life conditions are used for validation of the proposed glucose prediction algorithm. Both databases consist of glucose concentration data collected at 5-min intervals using a CGM device. Using time-series analysis, low-order linear models are developed from patients' own CGM data. The time-series models are integrated with recursive identification and change detection methods, which enables dynamic adaptation of the model to inter-/intra-subject variability and glycemic disturbances. Prediction performance is evaluated in terms of glucose prediction error and Clarke Error Grid analysis (CG-EGA). RESULTS: Prediction errors are significantly reduced with recursive identification of the models, and predictions are further improved with inclusion of a parameter change detection method. CG-EGA analysis results in accurate readings of 90% or more. CONCLUSIONS: Subject-specific glucose prediction strategy has been developed. Including a change detection method to the recursive algorithm improves the prediction accuracy. The proposed modeling algorithm with small number of parameters is a good candidate for installation in portable devices for early hypoglycemic/hyperglycemic alarms and for closing the glucose regulation loop with an insulin pump.