Doctoral thesis defended with a view to obtaining the Grade of Associate of Higher Education in Medicine

By

Boniface TETE OKAKA K'ELOTA
Pulmonologist-Internist

Promoter: Professor Doctor Jean-Marie KAYEMBE NTUMBA

Co-promoter: Professor Doctor Jean-Robert MAKULO RISSASSI

SUMMARY

Background and Objectives
In the Democratic Republic of Congo (DRC), the extent of obstructive sleep apnea hypopnea syndrome (OSAHS) is not known. With a view to developing a management strategy for this pathology in the country, the present work carried out during the period from July 2017 to March 2022 had the following objectives: to assess the level of knowledge of Congolese doctors on OSAHS (study 1), to determine the prevalence and risk factors of OSAHS in the population of Kinshasa (study 2), to assess the compliance and effectiveness of continuous positive airway pressure (CPAP) treatment (study 3) and to know the diagnostic performance of nocturnal oximetry (NO).
Methods
The first study analyzed responses to items in a questionnaire in
administered online to 821 final year medical students, general practitioners and specialists using the 3 main platforms of Congolese doctors in social networks. In the second study, the prevalence of symptoms suggestive of OSAHS and risk factors were determined on a sample of 4162 subjects aged ~ 18 years living in the city of Kinshasa and selected following a stratified random sampling at three levels (neighborhood, street, plot/household). The third study (interventional) evaluated the adherence and efficacy of CPAP treatment (modification of the Pichot and Epworth scales after 6 months of treatment) in 323 patients. In the 4th study, the sensitivity and specificity of the ON were investigated in relation to ventilatory polygraphy (VP). OSAHS was suspected when the Stop-bang score was > 3. The diagnosis was confirmed by PV when the apnea hypopnea index (AHI) was > 5. CPAP treatment was initiated following the recommendations of the French Society for Sleep Research and Medicine (SFRMS). OSAHS was considered severe, moderate, or mild if the apnea hypopnea index (AHI) values were > 30, between 15 and 30, and between 5 and 15, respectively.
Results
The level of knowledge of finalist students on SAHOS was poor at 85.7% vs 67.1 % in general practitioners and 46.1 % in specialists (p <0.001). The prevalence of SAHOS in the general population was 13.1 % including 17.4% in men and 7.9% in women. Risk factors for OSAHS were: male gender (OR=4.21; 1C: 3.20-5.54), THTA (OR=6.73; CI: 4.87-9.30), age 40 years (OR=2.36; CI: 1.15-4.81), obesity/overweight (OR=1.94; CI: 1.13-3.78), excessive daytime sleepiness (OR=2.63; CI: 2.05-3.56). In patients with confirmed OSAHS, PV showed severe OSAHS at 71.2% and moderate at 22%. CPAP adherence was good (90%). Pichot (21.8±3.2 vs. 17.1±2.7; p <0.001) and Epworth (12.9±2.5 vs. 7.1±1.8; p <0.001) scales improved after 6 months of PPC treatment. Compared with PV, ON showed a sensitivity of 94.4% and a specificity of 88.9%.
Conclusion
Congolese physicians have a low level of knowledge about OSAHS. In the general population, approximately one in seven adults presents symptoms of OSAHS, the risk of which is higher in men over 40 years of age, obese individuals, and hypertensive individuals. CPAP treatment is well tolerated and effective in the vast majority of patients. In an environment where CPAP is unavailable, ON remains a reliable alternative for diagnosing OSAHS.

Keywords : Level of knowledge, sleep apnea, prevalence, nocturnal oximetry, ventilatory polygraphy