Jibril Mohammed

Evidence for Autonomic Function and Its Influencing Factors in Subjects With COPD: A Systematic Review

Cardiovascular autonomic neuropathy is one of the factors implicated in the high morbidity and mortality rate in patients with COPD. Thus, several studies and nonsystematic reviews have increasingly reported autonomic function impairment in these subjects. For a better understanding, this systematic review was performed to evaluate not only the evidence for autonomic function impairment, but also factors influencing it. The results of the studies reviewed showed a strong level of evidence to support the impairment of heart rate variability in the time domain. A similar evidence level was also found to support impairment in baroreceptor sensitivity and muscle sympathetic nerve activity. Furthermore, this review identified physical activity level, muscle function, and circadian rhythm as the major influencing factors (strong evidence) of autonomic function in subjects with COPD. However, no definite conclusion could be reached for factors such as dyspnea, anxiety, body composition, pulmonary function, age, breathing frequency, ventilatory effort, quality of life, and disease severity due to limited, conflicting, or lack of existing evidence. The results of this review highlight relevant clinical messages for clinicians and other health-care providers regarding the role autonomic function can play as an important physiological marker for prognostication and stratification. Hence, autonomic function outcomes should be identified and considered during management of patients with COPD. Moreover, this review can serve as basis for future research aimed at assessing the interventions for autonomic function abnormalities in these patients.

Evidence for aerobic exercise training on the autonomic function in patients with chronic obstructive pulmonary disease (COPD): a systematic review

OBJECTIVE To assess evidence for the effectiveness of aerobic exercise training (AET) on the autonomic function (AF) outcomes in patients with chronic obstructive pulmonary disease (COPD). DATA SOURCES Online databases of PubMed, CINAHL and Web of Science were systematically searched for all years till 26th of January, 2017. STUDY SELECTION Clinical studies assessing any measure of AF following exercise training in patients with COPD were included. DATA EXTRACTION AND SYNTHESIS Data were extracted from studies with high methodological quality for evidence synthesis. Rating of evidence quality was determined using the GRADE guidelines. RESULTS The Majority of the included studies utilized continuous exercise training mode with a vigorous level of intensity. Each exercise training session lasted between 30 to 40minutes, and the frequency of intervention was ≥3 times/week. Evidence synthesis of studies with high methodological quality revealed that a high quality evidence level supported a significant increase for time-domain heart rate variability (HRV) analyses and the heart rate recovery (HRR) following AET. The review also found that frequency domain HRV analyses were not significantly affected by AET. The evidence to support the effect of exercise training on baroreceptor sensitivity (BRS) in patients with COPD is very low. CONCLUSION Aerobic exercise training demonstrated beneficial but limited effects on the AF in COPD. Presently, it is not clear whether these effects are sustained in the long term. Only a limited number of RCTs were available indicating a significant gap in the literature.

Autonomic symptoms in patients with moderate and severe chronic obstructive pulmonary disease

Abstract Objectives: A synoptic description of the autonomic symptoms profile (ASP) of patients with COPD is not available. Therefore, we aimed to provide an overview of autonomic symptoms and its associates in COPD. Methods: We evaluated 89 subjects with COPD (65 ± 7.3 years; 66 males; GOLD II-IV) with an equal number of age- and sex-matched control subjects by means of the composite autonomic symptom score (COMPASS 31) questionnaire, which assesses autonomic symptoms across six domains (orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, urinary and pupillomotor). Lung function, medication use and health status variables (quality of life: physical/mental component summary [PCS/MCS], fatigue, anxiety, depression and dyspnea levels) were also assessed. Results: Compared to controls, all subjects with COPD reported significantly higher orthostatic intolerance, secretomotor and total autonomic symptom scores (p < .05). Additionally, subjects with moderate COPD also reported significantly higher scores for vasomotor, gastrointestinal, urinary and pupillomotor symptoms compared to controls (p < .05). Nevertheless, these symptoms were comparable between the moderate and severe COPD subgroups (p > .05). The COPD subjects had poorer health status compared to controls as exhibited by significantly higher scores for depression, anxiety, fatigue and dyspnea, and lower scores values for PCS and MCS scores (p < .05). These health status variables were mildly associated with autonomic symptoms (0.214 ≤ r ≥ 0.421; p < .05), but not with demographic and lung function (p > .05). The MCS was the only significant predictor of total autonomic symptoms score in COPD (p = 0.001; β = −0.430). Conclusion: Autonomic symptoms are present in all domains of the COMPASS-31 in COPD, irrespective of disease severity and demographic variables. Autonomic symptoms in COPD were mainly influenced by poor mental health.

Effect of respiratory rehabilitation techniques on the autonomic function in patients with chronic obstructive pulmonary disease : a systematic review

Patients with chronic obstructive pulmonary disease (COPD) show several extrapulmonary abnormalities such as impairment in the autonomic function (AF). Similarly, the use of respiratory training techniques such as controlled breathing techniques, noninvasive mechanical ventilation (NIMV), and oxygen supplementation for AF modulation in patients with COPD is popular in existing literature. However, the evidence to support their use is nonexistent. A systematic search of studies reporting on the effect of controlled breathing techniques, NIMV, and/or oxygen supplementation techniques on AF outcome parameters was conducted in three online databases: PubMed, Embase, and Web of Science. Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement, relevant studies were retained and qualitatively analyzed for evidence synthesis. The methodological quality in these studies was evaluated using the evidence based guideline development (EBRO) checklists per designs provided by the Dutch Cochrane Centre. Eighteen studies met the inclusion criteria of the review and were included and discussed. The evidence synthesis revealed that a strong and moderate level evidence supported oxygen supplementation and slow breathing techniques, respectively, in significantly enhancing the baroreceptor sensitivity (BRS) values in patients with COPD. The effect of the examined techniques on the heart rate variability and muscle sympathetic nerve activity was of a limited or inconsistent evidence. The findings from this review suggest that oxygen supplementation and controlled breathing techniques have profound positive influence on the BRS in patients with COPD. However, it is not fully clear whether these influence translates to any therapeutic benefit on the general AF of patients with COPD in the long term.

Short and long-term impairments of cardiopulmonary fitness level in previous childhood cancer cases: a systematic review

PurposeTo describe the impairments in physical fitness in individuals who were previously diagnosed and treated for childhood cancer.MethodsUsing the PRISMA-guidelines, a systematic search was performed in PubMed, Web of Science, and Embase using a combination of the following predefined keywords: “exercise capacity” OR “aerobic capacity” OR “fitness” OR “cardiorespiratory fitness” OR “cardiopulmonary fitness” OR “physical fitness” OR “exercise testing” OR “exercise tolerance” OR “exercise” OR “oxygen consumption” AND “leukemia” OR “childhood cancer” OR “childhood cancer survivors (CCS)”. Studies that met our inclusion criteria were reviewed on methodological quality, while the Newcastle-Ottawa Scale was used for evidence synthesis.ResultsA total of 2644 articles were identified from the database search. After screening based on the eligibility (abstracts) and inclusion (full texts) criteria, 49 articles remained. Even though the risk-of-bias scores in the studies were generally low, yet the results from those with high-quality studies revealed that poor fitness levels were prevalent in individuals with acute lymphoblastic leukemia, brain tumor, and mixed cancer histories, compared to healthy controls.ConclusionsA global glance at CCS shows poor levels of fitness that is continuous and life-long even after active cancer treatment has ended. Nevertheless, the results presented in this review were based on a limited number of high-quality studies suggesting the need to for additional clinical trials in the topic area.

Cardiac Autonomic Function and Reactivity Tests in Physically Active Subjects with Moderately Severe COPD

ABSTRACT Patients with chronic obstructive pulmonary disease (COPD) show impairments in the autonomic nervous systems (ANS) function, which is responsible for cardiac autonomic regulation. This study assessed the autonomic function and cardio-vagal reactivity in conveniently sampled subjects with COPD participating in a pulmonary rehabilitation (PR) program. Twenty-six subjects with COPD and 22 age and gender matched control subjects were evaluated. R-R intervals were collected at rest in supine position. Thereafter, resting autonomic function parameters comprising linear and nonlinear analyses of heart rate variability (HRV) and baroreceptor sensitivity (BRS) were calculated. Autonomic reactivity tests comprising deep breathing (DB), Valsalva maneuver (VM), and head up tilt (HUT) were also performed. The results of this study indicated that resting autonomic function variables were generally reduced in COPD compared to controls. However, this difference was only statistically significant for a few HRV parameters: mean RR intervals, low frequency (LF), standard deviation of dispersion of points perpendicular to the line-of-identity (SD1), and approximate entropy (ApEn) (p < 0.05). The results also indicated that all cardio-vagal indices following the autonomic reactivity tests were comparable between COPD and controls (p > 0.05). It was concluded that subtle autonomic impairments exists in physically active COPD patients, and these autonomic function deficits were mainly recognized by resting HRV indices and not autonomic reactivity tests.