European Journal of Cardiovascular Medicine

Obstructive Sleep Apnea (OSA) is a common sleep disorder characterized by recurrent episodes of upper airway obstruction during sleep, leading to intermittent hypoxia and fragmented sleep [1]. It has been increasingly recognized that OSA frequently coexists with asthma, a chronic inflammatory airway disease marked by variable airflow obstruction and bronchial hyperresponsiveness [2]. The coexistence of OSA and asthma is of clinical importance, as both conditions may exacerbate each other, resulting in poor disease control and increased morbidity [3]. Several studies have demonstrated that the prevalence of OSA is higher in patients with asthma compared to the general population, with estimates ranging from 20% to 60% depending on the severity of asthma and study population characteristics [4,5]. Mechanistically, the chronic airway inflammation, increased nasal resistance, and use of corticosteroids in asthma may contribute to upper airway collapsibility, thereby predisposing patients to OSA [6]. Conversely, untreated OSA may worsen asthma symptoms through nocturnal hypoxemia, systemic inflammation, and altered autonomic regulation [7]. Furthermore, emerging evidence suggests a correlation between the severity of asthma and the presence or severity of OSA. Patients with severe asthma tend to have a higher prevalence of OSA, and coexisting OSA has been linked to poor asthma control, increased exacerbations, and reduced quality of life [8, 9]. Identifying OSA in asthma patients could, therefore, have therapeutic implications, as treatment of OSA with continuous positive airway pressure (CPAP) has been shown to improve asthma symptoms and lung function [10]. Given these observations, this study aims to assess the prevalence of OSA in asthma patients and evaluate its correlation with asthma severity, which may help in early recognition and comprehensive management of this comorbid condition.

Study Type: Observational Cross-Sectional Study

Study Place: Kamla Nehru Chest Hospital, Dr S N Medical College, Department of Pulmonary Medicine, Jodhpur, Rajasthan

Study Period: The present study was conducted from February 2024 to July 2024

Study Subject: Patients diagnosed asthma as per GINA guidelines attending OPD of department of respiratory medicine of tertiary care center.

Sample Size: 78 asthma patients.

Sampling Technique: Consecutive sampling till sample size is achieved

Inclusion Criteria

• Bronchial asthma diagnosis as per recent GINA guidelines with spirometry proven reversible airway obstruction with age group 18 to 80 years old.

Exclusion Criteria

• Current smoker or history of smoking.
• Pregnant females.
• Any patient who had acute exacerbation in last 4weeks or presently in exacerbation.
• Uncooperative patient and not given consent.
• Significant comorbidities of CLD, ESRD, decompensated heart failure.
• Other known lung diseases such as interstitial lung diseases, chronic obstructive pulmonary disease, bronchiectasis, pulmonary embolism.
• Any diagnosed neurological or psychiatric diseases.
• Those not willing to study

Statistical Analysis:

Data were entered into Excel and analysed using SPSS and GraphPad Prism. Numerical variables were summarized using means and standard deviations, while categorical variables were described with counts and percentages. Two-sample t-tests were used to compare independent groups, while paired t-tests accounted for correlations in paired data. Chi-square tests (including Fisher’s exact test for small sample sizes) were used for categorical data comparisons. P-values ≤ 0.05 were considered statistically significant.

Table 1: Age distribution of study population

Table 2: Demographic Characteristics, Occupation, Residence, Comorbidities, BMI, Symptom Types, MMRC Grading, and Asthma Severity & Control among Study Participants (N=78)

Table 3: Gender-wise Distribution and Severity of Obstructive Sleep Apnea (OSA) Among Study Participants

Table 4: Distribution of Study Population On The Basis Of Their Stop-Bang Score

Table 5: Sleep Stage Duration

Figure 1: Distribution of Study Population On The Basis Of Their Stop-Bang Score

Figure 2: Gender-wise Distribution and Severity of Obstructive Sleep Apnea (OSA) Among Study Participants

Among the 78 study participants, the majority (53.85%) were aged between 41 and 60 years, followed by 24.36% who were 40 years or younger, and 21.79% above 60 years. There were 56 males and 22 females, with mean ages of 50.05 ± 13.88 years and 50.50 ± 16.29 years, respectively. The overall mean age of the study population was approximately 50 years.

In our study of 78 patients, the majority were male (56, 71.79%) compared to females (22, 28.21%). Regarding occupation, most patients were categorized as “others” (25, 32.05%), followed by businessmen (15, 19.23%), housewives (13, 16.67%), students (8, 10.25%), teachers (8, 10.25%), farmers (5, 6.41%), and shopkeepers (4, 5.12%). A large proportion of patients resided in urban areas (66, 84.62%) compared to rural areas (12, 15.38%). Common comorbidities included rhinitis (48, 34%), GERD (30, 21%), obesity (25, 18%), postnasal drip (PND) (20, 14%), hypothyroidism (10, 7%), and diabetes mellitus (8, 6%). BMI distribution showed 2 (2.56%) underweight patients, 26 (33.33%) with normal BMI, 23 (29.49%) overweight, and 27 (34.62%) obese. Regarding presenting symptoms, cough was reported in 44 (43%), wheeze in 41 (41%), chest tightness in 11 (11%), and sputum production in 5 (5%). MMRC grading revealed 30 (38.46%) patients in grade 0, 35 (44.87%) in grade 1, 3 (3.85%) in grade 2, 10 (12.82%) in grade 3, and none in grade 4. Clinically, 9 (11.54%) patients had severe asthma, while 69 (88.46%) had non-severe asthma. Assessment of asthma control showed 40 (51.28%) patients were well-controlled, 21 (26.92%) partially controlled, and 17 (21.79%) uncontrolled.

Among the 78 participants, 53.85% (n=42) were diagnosed with obstructive sleep apnea (OSA), with a higher prevalence in males (32) compared to females (10). The remaining 46.15% (n=36) did not have OSA. Regarding OSA severity, 14.1% had mild OSA, 23.07% had moderate OSA, and 16.66% were classified as severe cases. Males showed a higher proportion across all severity levels compared to females.

Among the 78 participants, 37.17% were classified as low risk (score 0–2), 28.20% as intermediate risk (score 3–4), and 34.61% as high risk (score 5–8) according to the risk scoring system. This distribution indicates a substantial proportion of patients at moderate to high risk.

The mean duration spent in different sleep stages among the study participants was as follows: awake time averaged 6.05 ± 2.65 minutes, stage 1 sleep constituted 22.91 ± 65.02 minutes, stage 2 sleep accounted for the majority at 52.11 ± 8.02 minutes, stage 3 sleep averaged 15.84 ± 4.32 minutes, and rapid eye movement (REM) sleep comprised 11.17 ± 6.32 minutes.

In our study of 78 participants, a significant overlap between asthma and obstructive sleep apnea (OSA) was observed, with 53.85% (n=42) diagnosed with OSA, predominantly affecting males (n=32) [11]. The severity distribution showed 14.1% with mild, 23.07% with moderate, and 16.66% with severe OSA [12]. Risk assessment indicated that 37.17% were at low risk, 28.20% at intermediate risk, and 34.61% at high risk for OSA [13]. Sleep architecture analysis revealed an average of 6.05 ± 2.65 minutes awake, 22.91 ± 65.02 minutes in stage 1, 52.11 ± 8.02 minutes in stage 2, 15.84 ± 4.32 minutes in stage 3, and 11.17 ± 6.32 minutes in REM sleep [14]. These findings indicate alterations in sleep patterns consistent with prior studies showing that OSA disrupts sleep architecture, particularly affecting REM and NREM sleep [15, 16]. The high prevalence of OSA among asthmatic individuals underscores the importance of routine screening in this population to improve health outcomes [17, 18]. Additionally, comorbidities such as obesity, GERD, and rhinitis were common and may exacerbate both asthma and OSA severity [19]. These observations align with previous reports emphasizing the need for integrated management of asthma-OSA overlap syndrome [20].

In conclusion, the study demonstrates a considerable overlap between asthma and obstructive sleep apnea (OSA), with a higher prevalence observed in males. Patients exhibited a range of OSA severities, with a notable proportion at moderate to high risk according to established scoring systems. Sleep architecture analysis indicated disruptions in normal sleep patterns, particularly affecting REM and NREM stages. Clinically, most patients had non-severe asthma, yet varying levels of asthma control were observed, highlighting the impact of comorbid conditions on disease management. The findings underscore the importance of routine screening for OSA in asthmatic individuals, as well as the need for integrated management strategies addressing both asthma and sleep-disordered breathing to improve overall patient outcomes.

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