Assessing fatigue and sleep in chronic diseases using physiological signals from wearables: A pilot study

Problems with fatigue and sleep are highly prevalent in patients with chronic diseases and often rated among the most disabling symptoms, impairing their activities of daily living and the health-related quality of life (HRQoL). Currently, they are evaluated primarily via Patient Reported Outcomes (PROs), which can suffer from recall biases and have limited sensitivity to temporal variations. Objective measurements from wearable sensors allow to reliably quantify disease state, changes in the HRQoL, and evaluate therapeutic outcomes. This work investigates the feasibility of capturing continuous physiological signals from an electrocardiography-based wearable device for remote monitoring of fatigue and sleep and quantifies the relationship of objective digital measures to self-reported fatigue and sleep disturbances. 136 individuals were followed for a total of 1,297 recording days in a longitudinal multi-site study conducted in free-living settings and registered with the German Clinical Trial Registry (DRKS00021693). Participants comprised healthy individuals (N = 39) and patients with neurodegenerative disorders (NDD, N = 31) and immune mediated inflammatory diseases (IMID, N = 66). Objective physiological measures correlated with fatigue and sleep PROs, while demonstrating reasonable signal quality. Furthermore, analysis of heart rate recovery estimated during activities of daily living showed significant differences between healthy and patient groups. This work underscores the promise and sensitivity of novel digital measures from multimodal sensor time-series to differentiate chronic patients from healthy individuals and monitor their HRQoL. The presented work provides clinicians with realistic insights of continuous at home patient monitoring and its practical value in quantitative assessment of fatigue and sleep, an area of unmet need.

Left ventricular diastolic dysfunction and diseases severity contribute to impaired exercise capacity in systemic lupus erythematosus

OBJECTIVES

Patients with systemic lupus erythematosus (SLE) have a higher risk of myocardial involvement, which can result in ventricular dysfunction. The aim of our study was to estimate potential relationship between exercise capacity assessed by six minute walk test (6MWT) and echocardiographic parameters of left and right ventricular function in SLE patients.

METHODS

We prospectively studied 66 SLE patients (57 F, age 44 (20-75) years) and 27 age matched healthy subjects. In addition to routine evaluation, 6MWT and transthoracic echocardiography including LV diastolic dysfunction parameters (E/A, E/É) were performed.

RESULTS

While E/A was similar in both groups, E/E' was higher in patients with SLE than in controls, 7.5 (4-22) vs 6.8 (1.6-9.4), p = 0.018. The mean 6MWT distance was significantly shorter in SLE (561.6 ± 150.7 vs 682.6 ± 98.1 m, p < 0.002). Among SLE patients only 53 (80.3%) were capable to walk at least 450 m, while in controls 27 (100%) (p = 0.013). We observed significant correlations between 6MWT distance and SLICC/ACR-DI (rho=-0.44, p < 0.001), E/A (rho = 0.30, p = 0.004), E/E' (rho=-0.36, p < 0.001) in SLE patients. Univariable logistic regression models revealed that SLICC/ACR-DI, E/E', tricuspid regurgitant peak gradient (TRPG), and right ventricular systolic pressure (RVSP) were associated with 6MWT distance lower than < 450 m. ROC curves shown high predictive value of E/E' ratio, TRPG, RVSP in the prediction for 6MWT distance < 450 m.

CONCLUSION

Impaired exercise tolerance seems to result mainly from the severity of SLE and LV diastolic dysfunction.

Heart Rate Variability in Women with Systemic Lupus Erythematosus: Association with Health-Related Parameters and Effects of Aerobic Exercise

Abnormal heart rate variability (HRV) has been observed in patients with systemic lupus erythematosus (SLE). In a combined cross-sectional and interventional study approach, we investigated the association of HRV with inflammation and oxidative stress markers, patient-reported outcomes, and the effect of 12 weeks of aerobic exercise in HRV. Fifty-five women with SLE (mean age 43.5 ± 14.0 years) were assigned to either aerobic exercise (n = 26) or usual care (n = 29) in a non-randomized trial. HRV was assessed using a heart rate monitor during 10 min, inflammatory and oxidative stress markers were obtained, psychological stress (Perceived Stress Scale), sleep quality (Pittsburg Sleep Quality Index), fatigue (Multidimensional Fatigue Inventory), depressive symptoms (Beck Depression Inventory), and quality of life (36-item Short-Form Health Survey) were also assessed. Low frequency to high frequency power (LFHF) ratio was associated with physical fatigue (p = 0.019). Sample entropy was inversely associated with high-sensitivity C-reactive protein (p = 0.014) and myeloperoxidase (p = 0.007). There were no significant between-group differences in the changes in HRV derived parameters after the exercise intervention. High-sensitivity C-reactive protein and myeloperoxidase were negatively related to sample entropy and physical fatigue was positively related to LFHF ratio. However, an exercise intervention of 12 weeks of aerobic training did not produce any changes in HRV derived parameters in women with SLE in comparison to a control group.

The impact of delayed heart rate recovery on prevalent hypertension

Objectives: Delayed heart rate recovery (HRR) is considered an indicator of autonomic nervous dysfunction, which is a primary pathological mechanism of hypertension. The present study aimed to explore the independent association between delayed HRR and prevalent hypertension.Methods: In this cross-sectional study, 314 inpatients were recruited between January 2018 and December 2019. HRR was defined as the peak heart rate during exercise minus the 2^nd-minute heart rate after exercise in the treadmill exercise test.Results: The mean HRR in the hypertension group was lower than that in the non-hypertension group (41 bpm vs. 46 bpm; P < 0.001). After full adjustment, each standard deviation increase in HRR was associated with a 35% decrease in the risk of prevalent hypertension (OR: 0.65, 95% CI: 0.48-0.87; P = 0.004). When the HRR was divided into quartiles, the risk in the top quartile was 26% of that in the bottom quartile (OR: 0.26, 95% CI: 0.12-0.56; P = 0.001). Furthermore, smooth curve fitting showed that the risk of prevalent hypertension decreased linearly with the increase in HRR.Conclusion: Delayed HRR was independently associated with prevalent hypertension. The association was linear and robust over the entire range of HRR. The present study suggested that delayed HRR could be used to optimize hypertension risk stratification.

Value of heart rate recovery in female patients with pulmonary arterial hypertension due to systemic lupus erythematosus

OBJECTIVE

This study intended to explore the relation between heart rate recovery at 1 minutes (HRR1) during the recovery phase of cardiopulmonary exercise test (CPET) and exercise capacity in female systemic lupus erythematosus associated pulmonary arterial hypertension (SLE-PAH) patients.

METHODS

Twenty-one female SLE-PAH patients underwent right heart catheterization (RHC), pulmonary function test (PFT) and CPET. Forty-two healthy subjects matched with SLE-PAH patients in age, sex and BMI were recruited as a control group. The correlations between HRR1 with clinical and CPET parameters were performed.

RESULTS

Peak HR, ΔHR, HRR1, Peak HR-warm HR_1min , Peak HR-warm HR_2min and CR were significantly lower in SLE-PAH than in controls (P < .01). Increased incidence of CRI was seen in SLE-PAH. Except for the Peak P_ET O₂ , which was higher in controls, all other CPET parameters were lower in SLE-PAH. SLE-PAH patients with HRR1 ≥ 16 had longer 6MWD, lower NT-proBNP, better percent of predicted gas transfer index or diffusing capacity for carbon monoxide (DLco% pred) as well as better CO and CI. Peak HR, ΔHR, HRR1, Peak HR-warm HR_1min , Peak HR-warm HR_2min , CR, Peak Load, Peak VO₂ , Peak P_ET CO₂ , OUEP and OUES were lower and duration of exercise was shorter in patients with HRR1 < 16. HRR1 had positive correlation with 6MWD, DLco% pred, CO, CI and some key CPET parameters.

CONCLUSIONS

HRR1 is an easily obtained auxiliary parameter in SLE-PAH patients to reflect an altered autonomic tone. SLE-PAH patients with HRR1 < 16 have more severe hemodynamics, worse clinical findings and marked oxygen uptake inefficiency than those with HRR1 ≥ 16.

Comparison of non-invasive assessment of arrhythmias, conduction disturbances and cardiac autonomic tone in systemic sclerosis and systemic lupus erythematosus

Systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are connective tissue diseases presenting cardiac complications including different arrhythmias, then direct electrocardiographic comparison may be useful in everyday clinical decision making. We examined 86 adult SSc patients, 76 with SLE and 45 healthy controls. Among other examinations all subjects underwent 24-h Holter monitoring with time-domain heart rate variability and heart rate turbulence evaluation. Patients with various co-existing conditions which might markedly influence arrhythmias and autonomic modulation were excluded from further analysis (SSc n = 12, SLE n = 6). Finally, 76 SSc and 70 SLE subjects were eligible for this study, mean age 51.9 ± 13.1 and 46.5 ± 12.7 years (p = 0.11), with median disease duration 6.0 and 8.5 years (p = 0.15), respectively. As compared to SLE, patients with SSc were characterised by more frequent incidence of various supraventricular and ventricular arrhythmias. As compared to SSc, patients with SLE presented prolonged corrected QT intervals and also significant correlations between corrected QT length and heart rate variability indices. Both SSc and SLE subjects presented impaired sympathetic cardiac autonomic modulation, while indices associated with parasympathetic activity in SLE were not diminished. Disease duration was not associated with arrhythmias' occurrence (except for ventricular tachycardia in SSc, p = 0.02) and also with autonomic function in both groups of patients. Patients with SSc and SLE differ in terms of arrhythmias, conduction disturbances and cardiac autonomic tone. Regular Holter monitoring should be considered as a part of routine evaluation in connective tissue diseases patients, especially in systemic sclerosis.

Heart rate variability in patients with systemic lupus erythematosus: a systematic review and methodological considerations

Aim The aim of this review was to summarize current knowledge about the scientific findings and potential clinical utility of heart rate variability measures in patients with systemic lupus erythematosus. Methods PubMed, Embase and Scopus databases were searched for the terms associated with systemic lupus erythematosus and heart rate variability, including controlled vocabulary, when appropriate. Articles published in English and available in full text were considered. Finally, 11 publications were selected, according to the systematic review protocol and were analyzed. Results In general, heart rate variability, measured in the time and frequency domains, was reported to be decreased in patients with systemic lupus erythematosus compared with controls. In some systemic lupus erythematosus studies, heart rate variability was found to correlate with inflammatory markers and albumin levels. A novel heart rate variability measure, heart rate turbulence onset, was shown to be increased, while heart rate turbulence slope was decreased in systemic lupus erythematosus patients. Reports of associations of changes in heart rate variability parameters with increasing systemic lupus erythematosus activity were inconsistent, showing decreasing heart rate variability or no relationship. However, the low/high frequency ratio was, in some studies, reported to increase with increasing disease activity or to be inversely correlated with albumin levels. Conclusions Patients with systemic lupus erythematosus have abnormal heart rate variability, which reflects cardiac autonomic dysfunction and may be related to inflammatory cytokines but not necessarily to disease activity. Thus measurement of heart rate variability could be a useful clinical tool for monitoring autonomic dysfunction in systemic lupus erythematosus, and may potentially provide prognostic information.