Relationship between REI and PSA in patients with obstructive sleep apnea: a prospective case-control study.

Background: Obstructive sleep apnea has been associated with various urinary system diseases, including prostatic hyperplasia and nocturia. Recently, it has been linked to prostate cancer. This study investigated the relationship between the apnea hypopnea index, prostate-specific antigen (PSA) levels, and changes in PSA.

Methods: A total of 673 male patients who received portable sleep monitoring were assessed. All participants underwent thorough health assessments, including PSA testing. Individuals in Study 1 were divided into OSA and control groups based on an REI (Respiratory event index) ≥ 15 events/h. In Study 2, 176participants from the initial study were retested for PSA after three years.

Results: In Study 1, patients with OSA had significantly higher ln-transformed PSA levels than controls (P < 0.05). Ln-transformed PSA levels showed a positive correlation with the REI (r = 0.184, p = 0.015). In Study 2, after three years, the ln-transformed PSA level increased by 0.13 ng/ml in the OSA group, while it decreased by -0.05 ng/ml in the control group. The change in ln-transformed PSA was significantly higher in patients with OSA (p = 0.014). Even after adjusting for age, body mass index (BMI), smoking, hypertension, and diabetes, REI remained a significant predictor of PSA level changes (β = 0.226, 95% CI = 0.001-0.009; p = 0.008).

Conclusions: This study highlights the close relationship between REI and PSA levels in individuals with obstructive sleep apnea, indicating that REI is an independent risk factor for PSA levels. Obstructive sleep apnea may be associated with the incidence of prostate cancer.