ORIGINAL ARTICLE: STUDY OF SLEEP PATTERNS IN PATIENTS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE: A SINGLE TERTIARY CARE CENTRE STUDY

Introduction: Chronic obstructive pulmonary disease (COPD) is a common, preventable and treatable disease that is characterized by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities usually caused by significant exposure to noxious particles or gases. Sleep problems and sleepiness are common in COPD patients, partly due to symptoms but also because of the medications used to treat COPD. Method: This was a cross-sectional observational study conducted at CD Hospital of GMC Jammu for a period of one year from December 2020 to November 2021. 60 subjects were taken for sleep study by polysomnography with Alice 5 sleep system. Aim: To find out total sleep period and sleep efficiency and to find out correlation between spirometric & polysomnoghraphic variables. Result: Mean age of study sample is 60 years with standard deviation of 6.9 years. No significant difference observed in age and sex of study sample. Conclusion: 18 (30%) having hypertension as co-morbid condition. 31 (51.7%) samples were having smoking history, while 112 (20%) were reformed smokers. Excessive daytime sleepiness were present in 10 (16.7%) of study sample, Snoring was present in 9 (15%) of study sample.

The prevalence of COPD reported from different population-based studies from India is highly variable. The prevalence rates in male subjects vary from 2.21% to 9.4% in the studies reported from North India and studies from South India reported the prevalence of 1.4% to 4.8% in male subjects 1 . Sleep-related disturbances and insomnia have been shown to be higher in chronic obstructive pulmonary disease (COPD) sufferers than in the general population, with between 50 and 70% of patients reporting difficulty in initiating or maintaining sleep, or poor sleep quality 2,3 . . In addition, changes in breathing patterns that occur during normal sleep that do not affect healthy people may lead to more severe consequences in people with COPD, which may worsen and complicate COPD since they reduce blood oxygen. 4  .215 * Correlation is significant at the 0.05 level (2-tailed) ** Correlation is significant at the 0.01 level (2-tailed).

Discussion:-Age and Gender wise distribution of study population:
In the study population, male were three times than females, there were 45 (75%) males and 15 (25%) females, which are much lower than sex ratio according Census Maharashtra state 2011(925 Females/1000 Males). In all age group males are more than females. Mean age in this study population was 60.82 yrs (SD 6.9) which is more than study population in Ajit Vigg 6 (mean 55, SD 2.5).

Daytime sleepiness & Snoring:
Excessive daytime sleepiness were present in 10 (16.7%) of study sample while Snoring was present in 9 (15%) of study sample. Septal deviation, macroglossia, Retrognathia & dental malocclusion were also observed in patient of COPD.
While other symptoms of sleep disturbances among COPD patients like problem falling asleep (87 patients), Nocturnal awakening (67 subjects), early morning wheezing & cough (44 subjects), Unrefreshing quality of Sleep (56 subjects), difficulty in sleeping flat on bed (50 subjects) was reported in a study conducted by Agit Vigg 6 . 91 subjects also reported snoring as problem in study conducted by Larsson LG, Lindberg A et al 9 . Daytime sleepiness (ESS >= 10) was present in 34.8% COPD patients in Ali Zohal M, Yazdi Z et al 10 .

Body Mass Index:
BMI in study sample was slightly lower than the samples of study conducted by Shridhar Venkateswaran, Augustine Tee 11 (BMI 23.7). The majority of patients in the study had overlap syndrome and minimal exacerbations, were not obese or sleepy. While study done by Carl P. Browman, Michael G. Sampsonet et al 12 shows the relation between apneas per hour of sleep and body weight. A modest decrease in weight was thus associated with a disproportionally larger decrease in the rate of apneas. The results suggested that dieting and weight loss lead to an improvement in sleep apnea and related sequelae.

Epworth Sleeping Scale:
Average ESS of study samples was 9.6 with standard deviation of 5.5, with the highest 24 and the lowest 0; 39 were having normal, 10 mild, 2 moderate and 9 sever ESS. The association between AHI and ESS were found to be statistically highly significant (p 0.0027). It means normal ESS samples having ≥ 5 AHI are statistically significant different from those with AHI < 5. Positive correlation is observed in ESS and AHI (0.749) in the study and it was highly significant (0.000).

ESS in this study is higher than ESS (Mean 7.3 SD 4.4) in study by Carlos Eduardo Ventura Gaio Dos Santos 13 .
While no significant correlation found in spirometeric variable and polysomnoghraphic variable in that study.
In Tang  There were 27 patients in study having ESS 15 or more when compare with 11 patients with ESS >10 of study by Claudia Enz, Stefanie Brighenti-Zogg et al 14 . It also states multiple linear regression age (β = −0.254, p< 0.05), AHI (β = 0.287, p< 0.05) and CAT score (β = 0.380, p< 0.01) were independent predictors of ESS. ESS score is lower in Shridhar Venkateswaran, Augustine Tee 11 study (Mean 5.6 SD 5.8), and in which majority of patients had overlap syndrome been not obese or sleepy.

GOLD Criteria (FEV 1 /FVC<0.7):
There were 16 subjects were having obstruction falling in mild group (GOLD stage 1), 32 moderate obstruction (GOLD stage 2), 11 severe obstruction (GOLD stage 3) and 1 was having very sever obstruction (GOLD stage 4) by spirometeric test. Fisher's exact test shows association between BMI and GOLD stage of COPD was not statistically significant (p 0.4215). Mean of FEV 1 /FVC 63.8% with SD 6.56% in Sanders MH, Newman AB et al 15 was slightly higher than Mean 54 in Carlos Eduardo Ventura Gaio Dos Santos 13 with SD 13%; which is further higher than Xavier Soler, Eduardo Gaio et al 16

Conclusions:-
Mean age of study sample is 60 years with standard deviation of 6.9 years. No significant difference observed in age and sex of study sample. 18 (30%) having hypertension as co-morbid condition. 31 (51.7%) samples were having smoking history, while 112 (20%) were reformed smokers. Excessive daytime sleepiness were present in 10 (16.7%) of study sample, Snoring was present in 9 (15%) of study sample. Mean sleep efficiency ((Total Sleep Time / Total Time) x 100) was 66 % with SD 29.21 %, with the highest 100 % and the lowest 4.9 %. Mean AHI was 23.02 with standard deviation of 25.6, with the highest 108 per minute and the lowest 0.4.

3) Pie chart 1 showing frequency distribution of study sample according to hypertension.
Above table shows 18 (30%) of study samples were having hypertension as co-morbid condition.