Hypothesis / aims of study
Obstructive Sleep Apnea syndrome (OSAS) is associated with hypoxia, cardiovascular complications, and metabolic syndrome, all of which have been linked to overactive bladder syndrome (OAB) and erectile dysfunction. Considering a possible common pathophysiology between OSAS and OAB, we aimed to identify the prevalence of OAB symptoms among patients with OSAS, and to describe the relationship between OSAS, OAB, and erectile dysfunction in a community-based population of Canadian men.
Study design, materials and methods
This is a cross-sectional study of 988 male participants of the Men’s Health Day during three consecutive years (2013-2015). Participants underwent clinical evaluation (including demographic and metabolic profile), provided urine analysis and blood sampling (testosterone levels) and completed validated questionnaires of sexual health inventory (SHIM and ADAM) and lower urinary tract symptoms (OAB-V8 and IPSS). Berlin questionnaire was also completed to classify participants into high and low risk of OSAS. Patients with persistent and frequent symptoms in any two of three domains were considered to be at high risk for sleep apnea. Patients with total OAB-V8 score ≥8 were considered to have OAB.
A total of 988 men with a mean age of 55 (±12.8) years were included in the study. The prevalence was 22.8% for OSAS, 36% for OAB, 50% for erectile dysfunction (mild to severe), and 60% for androgen deficiency. The high risk OSAS group demonstrated significantly higher BMI, blood pressure, triglycerides, and OAB-V8 score, while their testosterone level was significantly lower than the low risk group. The incidence of diabetes mellitus, hypogonadism (ADAM), and severe lower urinary tract symptoms (IPSS) were also higher among the high-risk group. The OAB-V8 score positively correlated with age (r =0.234), IPSS score (r =0.721) and Berlin score (r =0.111). SHIM score inversely correlated with OAB score (r = -0.263), IPSS (r = -0.259), and age (r = - 0.418).
Interpretation of results
The current study assessed the prevalence of OAB symptoms in patients with low and high risk of OSAS in adult males using the OAB-V8 questionnaire in a community-based population grouped according to Berlin grading. OAB syndrome remains underdiagnosed in numerous geographic regions and medical specialties. Thus, the major target is to identify patients with OSAS at risk for developing OAB, metabolic syndrome and erectile dysfunction. Additionally, this study has the largest series of patients reported so far in the literature evaluating OAB symptoms in OSAS patients. We identified a higher OAB prevalence in this population syndrome in patients with high risk OSAS. Furthermore, our data demonstrated an important association in terms of OAB-V8, Berlin, IPSS and SHIM between the groups.
Among the multitude of conditions that can appear with OSAS, OAB and metabolic syndrome are two of the strongest in terms of statistical association with OSAS diagnosis. The underlying mechanisms linking OAB and OSAS rely mostly on the existence of urinary dysfunction secondary to hypoxia or associated polyuria, which also may explain the interaction between OSAS and metabolic syndrome.