Researchers note the severity of the disease significantly impacts patients’ sleep habits, medication intake, and general mental and physical health.
Research from the Rasul Akram Hospital of Iran found that the severity of chronic obstructive pulmonary disease (COPD) strongly influenced sleep quality in patients. Factors such as coughing at night, shortness of breath, reliance on medications, and sleep apnea have all been associated with COPD and have a significant effect on patients’ sleep quality, health status, and overall breathlessness.
The study was conducted primarily in Iran, where the prevalence of COPD is estimated to be 9-10%.
Considered by some health professionals to be the “forgotten dimension” of COPD, sleep disturbance has affected a myriad of patients. The disease is also expected to be the third leading cause of death globally in the coming decade.
Leading author Mirfarhad Ghalehbandi, MD and colleagues felt the severity of COPD and its effect on sleep quality in patients warranted research, which gave rise to the recent prospective, cross-sectional study.
They team investigated the potential links between forced exhalation volume (FEV1) and forced vital capacity (FVC) ratio with the quality of sleep and described the potential relationships between subjective sleep quality and the severity of COPD in individual patients.
From April 2019-March 2021, the investigators enrolled 158 patients into the study.
Participants were 18 years or older in age and had been diagnosed with COPD. They were also required to be current or ex-smokers with a history of more than 10 years.
The investigators excluded patients who required routine oxygen therapy, had underlying or concurrent disorders other than COPD, recent history of cerebrovascular accidents, obesity of any kind, or acute psychiatry disorder.
Each participant engaged with 2 questionnaires during the study: the Pittsburgh Sleep Quality Index (PSQI) and a Persian version of the COPD Assessment Test (CAT).
The PSQI was comprised of 7 different components: sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medications, and daytime dysfunction that measures sleep complexity. Variables within the PSQI were scored on a scale of 0-3
The CAT questionnaire included 8 items intended to measure health-related quality of life (HRQoL). There were 4 stages that were developed based on the overall CAT scores: Stage 1 (mild), Stage 2 (moderate), Stage 3 (severe), and Stage 4 (very severe).
Finally, a modified Medical Research Council (mMRC) Dyspnea Scale was used to focus on the different physical activities that could cause dyspnea, and measured the severity of dyspnea in patients using a scale from 0-4 (4 being the most severe).
The investigators recorded the data presented in PSQI, FEV1, and CAT scores, as well as the FEV1/FVC ratio.
The FEV1/FVC scores were 62.6 ± 11.5 and 65.6 ± 14.9 %, while the CAT scores were 16.2 ± 7%. Scores for PSQI was 8.2 ± 3.8.
Ghalehbandi and colleagues noted that the association between PSQI score with FEV1 and FEV1/FVC ratio was not statistically significant (P = 0.64 and 0.58, respectively), but the association between PSQI score with CAT score and dyspnea severity were statistically significant.
The study confirmed that patients with severe COPD sleep poorly, with a majorty of participants recording longer sleep latency, lower sleep efficiency, higher disturbance rates, and higher sleep medication intake.
Additionally, the CAT scores indicated that dyspnea, an independent factor, could also be linked to poor sleep quality and negative effects on the QoL during daytime for patients, results that were reported in previous studies as well.
“It is recommended for pulmonologists to ask COPD patients in routine clinical assessment about sleep quality, sleep disturbance, and daytime dysfunction,” the investigators concluded.
The study, “The association between sleep quality, health status, and disability due to breathlessness in COPD patients,” was published online in The Clinical Respiratory Journal