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Jordan Robertson, ND
Understanding the link between nocturia and obstructive sleep apnea (OSA) can improve screening and treatment outcomes, especially in women.
Although awareness and screening for sleep apnea in non-snoring patients have improved in the last decade, research is only beginning to explore the importance of identifying and treating sleep apnea. The STOP-BANG questionnaire is the most widely used and straightforward clinical screening tool for identifying patients, but its accuracy diminishes in lean patients who may have central apnea, female patients, and those with comorbid insomnia from other causes.1
Biochemical Mechanisms
Sleep apnea and hypoxia events trigger biochemical cascades that elevate cardiovascular risks and lead to other negative health consequences associated with sleep apnea. A lesser-known effect is the impact of hypoxic events on the urinary system, resulting in increased nighttime urination (nocturia) in patients, which worsens with the severity of OSA.2
In a large review of over 19,000 OSA patients, 46% experienced comorbid nocturia, defined as more than one nighttime urination event.
Proposed Pathophysiology
The exact mechanism behind increased urine output in patients with OSA is still being elucidated. However, it is currently believed that blocked airways elevate intrathoracic pressure, which places additional pressure on the heart, increases venous return, and consequently triggers chemoreceptors. This leads to an increased secretion of atrial natriuretic peptide (ANP) and heightened urine production. This nocturnal polyuria is the primary proposed mechanism through which OSA leads to nighttime awakenings for urination. Additionally, secondary mechanisms involving central hypoxia and brain natriuretic peptide (BNP) release have also been suggested.5,7,12
As OSA severity increases, so does the risk of comorbid health conditions that also elevate nocturnal urine production, such as hypertension and increased BMI.2 Distinguishing the impact of OSA alone from that of comorbid conditions on nocturnal urination has posed a research challenge; however, even patients without comorbid conditions face a higher risk of nighttime urination due to OSA. Furthermore, patients with comorbid conditions may be prescribed medications, particularly diuretics, that exacerbate 24-hour polyuria, potentially intensifying nighttime awakenings in patients who are partially aroused by OSA.
Evidence from Urogynecology Clinics
A prominent paper examining the prevalence of sleep apnea in patients presenting with nocturnal urination to a urogynecology clinic found that 20% of these patients qualified for further sleep apnea testing using the STOP-BANG questionnaire. Of those screened with polysomnography, 80% qualified for sleep apnea treatment.3 Notably, in this study, the gynecologists were asked to screen all patients for apnea, and over the course of the 18-month study, not only were patients identified who would have been otherwise missed, but simply educating the gynecologists about the connection between nocturnal urination and OSA increased screening compliance among their patients. These results are similar to another study in a urogynecology setting that found a retrospective chart analysis of more than 2 nocturia events per night had an 86% sensitivity for the diagnosis of OSA in women.9 Furthermore, 38% of patients presenting to a urogynecology clinic screened as high risk for OSA at baseline, with 76% of patients with OSA experiencing nocturia and 46% suffering from nocturnal enuresis.11
Sex Differences in Risk and Symptoms
Goyal8 identified a sex-specific difference in the effect of nocturnal urination on OSA diagnosis. Among a population with more than two episodes per night, 28% were diagnosed with OSA. In contrast, 41% of women presenting with more than two episodes were diagnosed with OSA upon further assessment.8 Furthermore, female patients were more likely to experience headaches and daytime fatigue compared to male patients. This suggests the potential benefit of using nighttime urination as a screening tool for female patients who may not meet the criteria for testing using STOP-BANG alone.
Although not standard practice, Narwade tested a more comprehensive screening tool in patients with suspected OSA who do not present with fatigue. Their scoring system included the hemodynamic changes associated with OSA, such as hypertension and nocturia. This novel scoring system increased the sensitivity of clinical screening and identified more cases of OSA than the STOP-BANG assessment alone.7
A subset of patients may demonstrate greater chemosensitivity to changes in intrathoracic pressure that trigger nighttime urination. In the paper by Dai, the authors suggest screening patients for OSA who experience nocturia before they meet the criteria for screening based only on STOP-BANG.4 While this may not be a practical solution and contradicts current standard care guidelines, it could benefit patients with other causes of nocturnal urination ruled out, such as reduced bladder capacity, 24-hour polyuria, or other reasons for nocturnal polyuria. Assessing for OSA in patients with polyuria and fatigue may help identify those who traditional screening guidelines might overlook.
Emerging research indicates that using CPAP to treat apnea impacts nocturia events, with CPAP use reducing nocturia by approximately 50% in most studies.5,10,12 A large meta-analysis revealed that both CPAP and surgery (uvulopalatopharyngoplasty) decreased nocturia episodes in the majority of patients. In a second meta-analysis, clinically significant nocturia (more than two episodes per night) was reduced from 73% to 51% with adherence to CPAP.6 Treating OSA and nocturia requires a multidisciplinary approach that includes cardiometabolic risk reduction, medication reviews, and screening for alcohol use.5 These studies highlight the importance of screening for OSA in patients with nocturia and provide evidence that effective treatment of OSA may alleviate nocturia symptoms.
Looking ahead, it’s crucial for clinicians to recognize the link between OSA and nocturia, serving both as a possible screening tool for at-risk individuals and as a treatment target for OSA therapy. The potential sex differences in nocturia incidence among OSA patients also present an opportunity for clinicians to investigate OSA as a possible cause of nighttime awakenings, even in patients who may not meet the traditional screening criteria outlined by STOP-BANG.
Dr. Jordan Robertson, ND, is on a mission to create a standard of care of evidence-based naturopathic medicine while reducing the unpaid research labour of naturopathic clinicians. She is the founder of The Confident Clinician, a clinical decision-making tool and database explicitly built for Naturopathic Doctors. She is a graduate of CCNM (2008) and has a 15-year career teaching critical appraisal, research in integrative medicine, and clinical nutrition at McMaster University, Canada. Jordan can be reached at [email protected]
1. Shi C, Wang Y, Luo J, Huang R, Xiao Y. Performance of Four Screening Tools for Identifying Obstructive Sleep Apnea Among Patients with Insomnia. Nat Sci Sleep. 2025;17(0):379-390. doi:10.2147/nss.s494804
2. Lu CH, Chang HM, Chang KH, et al. Effect of nocturia in patients with different severity of obstructive sleep apnea on polysomnography: A retrospective observational study. Asian J Urol. 2024;11(3):486-496. doi:10.1016/j.ajur.2023.02.003
3. Douglass KM, Laus K, DeAndrade S, et al. Enhancing Obstructive Sleep Apnea Screening and Nocturia Treatment: A Quality Improvement Study. Urogynecology. 2025;31(4):361-368. doi:10.1097/spv.0000000000001648
4. Dai L, Guo J, Wang X, Luo J, Huang R, Xiao Y. Nocturnal urination is associated with the presence of higher ventilatory chemosensitivity in patients with obstructive sleep apnea. Sleep Breath. 2024;28(5):1951-1959. doi:10.1007/s11325-024-03084-3
5. Vrooman OPJ, Kerrebroeck PEV van, Balken MR van, Koeveringe GA van, Rahnama’i MS. Nocturia and obstructive sleep apnoea. Nat Rev Urol. 2024;21(12):735-753. doi:10.1038/s41585-024-00887-7
6. Vrooman OPJ, Balken MR van, Koeveringe GA van, et al. The effect of continuous positive airway pressure on nocturia in patients with obstructive sleep apnea syndrome. Neurourol Urodyn. 2020;39(4):1124-1128. doi:10.1002/nau.24329
7. Narwade G, Madan M, Kumar R, et al. Clinical characteristics of non-sleepy obstructive sleep apnea patients: a study in a tertiary care sleep clinic in India. Monaldi Arch Chest Dis. Published online 2024. doi:10.4081/monaldi.2024.3031
8. Goyal A, Meena R, Gupta S, et al. Sex-specific differences in presenting symptoms of obstructive sleep apnea. Lung India : Off Organ Indian Chest Soc. 2024;41(2):115-120. doi:10.4103/lungindia.lungindia_235_22
9. Burr EF, Myer ENB, Kikuchi JY, Chen CCG. Nocturnal Urinary Symptoms as Screening Tools for Obstructive Sleep Apnea. Urogynecology. 2025;31(2):154-160. doi:10.1097/spv.0000000000001503
10. Margel D, Shochat T, Getzler O, Livne PM, Pillar G. Continuous positive airway pressure reduces nocturia in patients with obstructive sleep apnea. Urology. 2006;67(5):974-977. doi:10.1016/j.urology.2005.11.054
11. Myer ENB, Long A, Cooper C, Fashokun T, Abernethy M, Chen CCG. Prevalence of Screening High Risk of Obstructive Sleep Apnea Among Urogynecology Patients. Female Pelvic Med Reconstr Surg. 2020;26(8):503-507. doi:10.1097/spv.0000000000000801
12. Bello FD, Napolitano L, Abate M, et al. “Nocturia and obstructive sleep apnea syndrome: A systematic review.” Sleep Med Rev. 2023;69:101787. doi:10.1016/j.smrv.2023.101787
Jordan Robertson, ND
Understanding the link between nocturia and obstructive sleep apnea (OSA) can improve screening and treatment outcomes, especially in women.
Although awareness and screening for sleep apnea in non-snoring patients have improved in the last decade, research is only beginning to explore the importance of identifying and treating sleep apnea. The STOP-BANG questionnaire is the most widely used and straightforward clinical screening tool for identifying patients, but its accuracy diminishes in lean patients who may have central apnea, female patients, and those with comorbid insomnia from other causes.1
Biochemical Mechanisms
Sleep apnea and hypoxia events trigger biochemical cascades that elevate cardiovascular risks and lead to other negative health consequences associated with sleep apnea. A lesser-known effect is the impact of hypoxic events on the urinary system, resulting in increased nighttime urination (nocturia) in patients, which worsens with the severity of OSA.2
In a large review of over 19,000 OSA patients, 46% experienced comorbid nocturia, defined as more than one nighttime urination event.
Proposed Pathophysiology
The exact mechanism behind increased urine output in patients with OSA is still being elucidated. However, it is currently believed that blocked airways elevate intrathoracic pressure, which places additional pressure on the heart, increases venous return, and consequently triggers chemoreceptors. This leads to an increased secretion of atrial natriuretic peptide (ANP) and heightened urine production. This nocturnal polyuria is the primary proposed mechanism through which OSA leads to nighttime awakenings for urination. Additionally, secondary mechanisms involving central hypoxia and brain natriuretic peptide (BNP) release have also been suggested.5,7,12
As OSA severity increases, so does the risk of comorbid health conditions that also elevate nocturnal urine production, such as hypertension and increased BMI.2 Distinguishing the impact of OSA alone from that of comorbid conditions on nocturnal urination has posed a research challenge; however, even patients without comorbid conditions face a higher risk of nighttime urination due to OSA. Furthermore, patients with comorbid conditions may be prescribed medications, particularly diuretics, that exacerbate 24-hour polyuria, potentially intensifying nighttime awakenings in patients who are partially aroused by OSA.
Evidence from Urogynecology Clinics
A prominent paper examining the prevalence of sleep apnea in patients presenting with nocturnal urination to a urogynecology clinic found that 20% of these patients qualified for further sleep apnea testing using the STOP-BANG questionnaire. Of those screened with polysomnography, 80% qualified for sleep apnea treatment.3 Notably, in this study, the gynecologists were asked to screen all patients for apnea, and over the course of the 18-month study, not only were patients identified who would have been otherwise missed, but simply educating the gynecologists about the connection between nocturnal urination and OSA increased screening compliance among their patients. These results are similar to another study in a urogynecology setting that found a retrospective chart analysis of more than 2 nocturia events per night had an 86% sensitivity for the diagnosis of OSA in women.9 Furthermore, 38% of patients presenting to a urogynecology clinic screened as high risk for OSA at baseline, with 76% of patients with OSA experiencing nocturia and 46% suffering from nocturnal enuresis.11
Sex Differences in Risk and Symptoms
Goyal8 identified a sex-specific difference in the effect of nocturnal urination on OSA diagnosis. Among a population with more than two episodes per night, 28% were diagnosed with OSA. In contrast, 41% of women presenting with more than two episodes were diagnosed with OSA upon further assessment.8 Furthermore, female patients were more likely to experience headaches and daytime fatigue compared to male patients. This suggests the potential benefit of using nighttime urination as a screening tool for female patients who may not meet the criteria for testing using STOP-BANG alone.
Although not standard practice, Narwade tested a more comprehensive screening tool in patients with suspected OSA who do not present with fatigue. Their scoring system included the hemodynamic changes associated with OSA, such as hypertension and nocturia. This novel scoring system increased the sensitivity of clinical screening and identified more cases of OSA than the STOP-BANG assessment alone.7
A subset of patients may demonstrate greater chemosensitivity to changes in intrathoracic pressure that trigger nighttime urination. In the paper by Dai, the authors suggest screening patients for OSA who experience nocturia before they meet the criteria for screening based only on STOP-BANG.4 While this may not be a practical solution and contradicts current standard care guidelines, it could benefit patients with other causes of nocturnal urination ruled out, such as reduced bladder capacity, 24-hour polyuria, or other reasons for nocturnal polyuria. Assessing for OSA in patients with polyuria and fatigue may help identify those who traditional screening guidelines might overlook.
Emerging research indicates that using CPAP to treat apnea impacts nocturia events, with CPAP use reducing nocturia by approximately 50% in most studies.5,10,12 A large meta-analysis revealed that both CPAP and surgery (uvulopalatopharyngoplasty) decreased nocturia episodes in the majority of patients. In a second meta-analysis, clinically significant nocturia (more than two episodes per night) was reduced from 73% to 51% with adherence to CPAP.6 Treating OSA and nocturia requires a multidisciplinary approach that includes cardiometabolic risk reduction, medication reviews, and screening for alcohol use.5 These studies highlight the importance of screening for OSA in patients with nocturia and provide evidence that effective treatment of OSA may alleviate nocturia symptoms.
Looking ahead, it’s crucial for clinicians to recognize the link between OSA and nocturia, serving both as a possible screening tool for at-risk individuals and as a treatment target for OSA therapy. The potential sex differences in nocturia incidence among OSA patients also present an opportunity for clinicians to investigate OSA as a possible cause of nighttime awakenings, even in patients who may not meet the traditional screening criteria outlined by STOP-BANG.
Dr. Jordan Robertson, ND, is on a mission to create a standard of care of evidence-based naturopathic medicine while reducing the unpaid research labour of naturopathic clinicians. She is the founder of The Confident Clinician, a clinical decision-making tool and database explicitly built for Naturopathic Doctors. She is a graduate of CCNM (2008) and has a 15-year career teaching critical appraisal, research in integrative medicine, and clinical nutrition at McMaster University, Canada. Jordan can be reached at [email protected]
1. Shi C, Wang Y, Luo J, Huang R, Xiao Y. Performance of Four Screening Tools for Identifying Obstructive Sleep Apnea Among Patients with Insomnia. Nat Sci Sleep. 2025;17(0):379-390. doi:10.2147/nss.s494804
2. Lu CH, Chang HM, Chang KH, et al. Effect of nocturia in patients with different severity of obstructive sleep apnea on polysomnography: A retrospective observational study. Asian J Urol. 2024;11(3):486-496. doi:10.1016/j.ajur.2023.02.003
3. Douglass KM, Laus K, DeAndrade S, et al. Enhancing Obstructive Sleep Apnea Screening and Nocturia Treatment: A Quality Improvement Study. Urogynecology. 2025;31(4):361-368. doi:10.1097/spv.0000000000001648
4. Dai L, Guo J, Wang X, Luo J, Huang R, Xiao Y. Nocturnal urination is associated with the presence of higher ventilatory chemosensitivity in patients with obstructive sleep apnea. Sleep Breath. 2024;28(5):1951-1959. doi:10.1007/s11325-024-03084-3
5. Vrooman OPJ, Kerrebroeck PEV van, Balken MR van, Koeveringe GA van, Rahnama’i MS. Nocturia and obstructive sleep apnoea. Nat Rev Urol. 2024;21(12):735-753. doi:10.1038/s41585-024-00887-7
6. Vrooman OPJ, Balken MR van, Koeveringe GA van, et al. The effect of continuous positive airway pressure on nocturia in patients with obstructive sleep apnea syndrome. Neurourol Urodyn. 2020;39(4):1124-1128. doi:10.1002/nau.24329
7. Narwade G, Madan M, Kumar R, et al. Clinical characteristics of non-sleepy obstructive sleep apnea patients: a study in a tertiary care sleep clinic in India. Monaldi Arch Chest Dis. Published online 2024. doi:10.4081/monaldi.2024.3031
8. Goyal A, Meena R, Gupta S, et al. Sex-specific differences in presenting symptoms of obstructive sleep apnea. Lung India : Off Organ Indian Chest Soc. 2024;41(2):115-120. doi:10.4103/lungindia.lungindia_235_22
9. Burr EF, Myer ENB, Kikuchi JY, Chen CCG. Nocturnal Urinary Symptoms as Screening Tools for Obstructive Sleep Apnea. Urogynecology. 2025;31(2):154-160. doi:10.1097/spv.0000000000001503
10. Margel D, Shochat T, Getzler O, Livne PM, Pillar G. Continuous positive airway pressure reduces nocturia in patients with obstructive sleep apnea. Urology. 2006;67(5):974-977. doi:10.1016/j.urology.2005.11.054
11. Myer ENB, Long A, Cooper C, Fashokun T, Abernethy M, Chen CCG. Prevalence of Screening High Risk of Obstructive Sleep Apnea Among Urogynecology Patients. Female Pelvic Med Reconstr Surg. 2020;26(8):503-507. doi:10.1097/spv.0000000000000801
12. Bello FD, Napolitano L, Abate M, et al. “Nocturia and obstructive sleep apnea syndrome: A systematic review.” Sleep Med Rev. 2023;69:101787. doi:10.1016/j.smrv.2023.101787
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The point of using Lorem Ipsum is that it has a more-or-less normal distribution of letters, as opposed to using ‘Content here, content here’, making
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It is a long established fact that a reader will be distracted by the readable content of a page when looking at its layout. The point of using Lorem Ipsum is that it has a more-or-less normal distribution
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