- Email: [email protected]
Psychomotor assessment in sleep breathing disorder children – pilot study
e124
Abstracts / Sleep Medicine 14S (2013) e93–e164
sented higher spectral power in parieto-occipital regions for A1 (p = 0.049 – BF1) and temporal posterior for A2 (p = 0.015 – FB 1) and B (p = 0.049 – FB 1 e p = 0.033 – FB 2) possibly as a result of cerebral modifications due to deafness. Deaf subjects seem more sensitive to provoked sleep interruption with remarkable decrease of A1 (p = 0/015) in AA periods. Conclusion: Deaf subjects have more unstable sleep and higher sensitivity to provoked sleep interruption; compromised CAP rhythmicity as well as cortical and spectral modifications in posterior regions, possibly related to their clinical condition. Acknowledgements: Funded by: Fundação BIAL (No. 107/02). Work supported by Helder Bértolo, Joana Pires and Rosa Santos. http://dx.doi.org/10.1016/j.sleep.2013.11.277
Congenital central hypoventilation syndrome presenting as pulmonary hypertension T. Nunes 1, R. Ferreira 1, R. Anjos 2, O. Moldovan 3, T. Bandeira 1 1 Pneumology Unit, Department of Pediatrics, Santa Maria Hospital – CHLN, Academic Medical Center of Li, Portugal 2 Santa Cruz Hospital, Portugal 3 Genetic Service, Department of Pediatrics, Santa Maria Hospital – CHLN, Academic Medical Center of Li, Portugal
Introduction: Congenital Central Hypoventilation Syndrome (CCHS) is part of a diffuse autonomic nervous system deregulation. Usually it presents as sleep hypoventilation with impaired responses to hypoxemia and hypercapnia. Noninvasive ventilation (NIV) has been described as an option in older children. We describe a case of an infant in whom pulmonary hypertension (PHT) was the first signal of disease, being NIV a successful option. Materials and methods: Chart review. Results: M.D., was a 2 month old female infant, the 3rd child of a healthy, non-related, young couple. Gestation, delivery and neonatal period were uneventfully. She was on exclusive breastfeeding with good weight gain. Parents described prostration in the previous 3 days, food refusal and cyanosis in the day before. She was examined by a pediatric cardiologist who diagnosed severe PHT and referred her to our hospital. Physical examination confirmed central and peripheral cyanosis and satO2 was 91% breathing room air; other aspects were unremarkable including alertness, tonus, thorax examination and pulmonary auscultation. Hematological and biochemistry evaluations were normal except capillary blood gases that revealed respiratory acidosis (pH 7,26 mmHg) with pCO2 79,6 mmHg; chest X-ray was normal. There was no polipneia and during sleep apneic episodes were identified. Polysomnography revealed central apneas with severe desaturation in NREM sleep and hypercapnia, with delayed arousal response. After an initial decompensation period with increasingly high pCO2 that needed invasive ventilation, she was started on nasal mask NIV with good adaptation and blood gases normalization, permitting rapid transition to home care. A genetic mutation on PHOX 2B confirmed CCHS. Actually, at one year old, she is clinically stable on sleep NIV with normal neurodevelopment and somatic progression and without PHT on cardiac evaluation. Conclusion: Sleep central apneas are the most frequent presentation of CCHS in childhood but it can presents differently as shown on this patient. This case highlights the importance of clinical suspicion to diagnose this rare disease. The NIV support is a less common approach in younger patients, but it may be a successful option, avoiding tracheostomy and prolonged hospitalization and improving quality of life. http://dx.doi.org/10.1016/j.sleep.2013.11.278
Impact of diagnosis and treatment of obstructive sleep apnea syndrome (OSAS) with non-invasive ventilation (NIV) V. Ferreira 1, R. Nêveda 1, E. Lombardıa 1, R. Pimenta 2, J. Condeço 2, H. Curado 2 1 Local Health Unit of Alto Minho (ULSAM), Portugal 2 Polytechnic Institute of Oporto – School of Health Tecnhnology, Portugal
Introduction: OSAS is a serious public health problem. This study attempted to measure the benefits of one year of treatment with NIV in patients with moderate-severe OSAS, as well as the economic impact for both the patient and the Portuguese National Healthcare System (NHS). Specifically, we tried to assess if the treatment with NIV reduces: daytime sleepiness; road traffic accidents; number of hospitalizations; number of days of hospitalization; number of emergency visits; number of medical specialty consultations; and respective costs. We studied all patients with moderate-severe OSAS who visited the Pulmonology Services of the Local Health Unit of Alto Minho (ULSAM) and used NIV for at least one year. Materials and methods: To assess outcomes and costs, we used the Epworth Sleepiness Scale and the Homogeneous Diagnostic Groups (HDG’s) approved by law and contracted between the ULSAM and the NHS. Statistical data analysis was conducted by using descriptive and inferential techniques (t-test for paired samples and Spearman’s correlation coefficient), with a significance level of 5%. Patients with mild OSAS, weight reduction, subject to otolaryngology surgery and without one year of NIV treatment were excluded from the study. Results: The sample consisted of 153 individuals, 20.9% female and 79.1% male between the ages of 33 and 90. Our results show a significant reduction in daytime sleepiness (p < 0.001), road traffic accidents (p < 0.001), number of emergency visits (p < 0.001), number of hospitalizations (p < 0.001), and number of hospitalization days (p < 0.001). They also reveal a significant reduction in emergency costs (p < 0.001) and medical specialty consultations (p < 0.001) for the patient, as well as in emergency (p < 0.001) and hospitalization costs (p < 0.001) for the NHS. There was no significant reduction on the number of medical specialty visits (p = 0.269) and costs to the NHS (p = 0.269). The results were also not significant with regard to the relationship between the severity of OSAS and the number of road traffic accidents and daytime sleepiness. Conclusion: Treatment of OSAS with NIV, even in the short time period of one year, reduces the use of health services and associated costs, as well as daytime sleepiness and road traffic accidents. It was also found that the value of HDG’s medical hospitalization for OSAS contracted between ULSAM and NHS was insufficient, compared to HDG’s medical hospitalization for the same pathology as defined by law, which represents an added burden for the health institution. Acknowledgements: To the Local Health Unit of Alto Minho, Portugal (ULSAM), who made possible this study with real data of their patients. http://dx.doi.org/10.1016/j.sleep.2013.11.279
Psychomotor assessment in sleep breathing disorder children – pilot study V. Ferreira 1, J. Leite 2, L. Prado 3, G. Prado 3, L. Carvalho 3 1 Federal University of Sao Paulo, Neuro-Sono, Brazil 2 Federal University of Sao Paulo, Fisioterapy, Neuro-Sono, Brazil 3 University of Sao Paulo, Neuro-Sono, Brazil
Introduction: The Sleep Disordered Breathing (SDB) affects important cognitive functions concerning to the learning process as atten-
Abstracts / Sleep Medicine 14S (2013) e93–e164
tion, memory, and creativity, but just a little is known about the motor performance in those children. Suitable psychomotor development promotes better school learning. An assessment of the development and motor pattern contributes as preventive and reeducative to help or delete factors impeding the learning potential of the child. Objective: The aim of this study was to evaluate whether the psychomotor bases (fine motor coordination, global motor coordination, static and dynamic balance, body and image scheme, spatial and temporal organization) are impaired in SDB children. Materials and methods: We studied 9 children (5 girls) from 7 to 11 years, attending elementary school in São Paulo city, Brazil. All children had SBD diagnosed with polysomnography and the psychomotor assessment was evaluated with Motor Development Scale (MDS). We compared children‘s motor performance with the expected for children at the same age. Results: The children had, on average, Total Sleep Time 412 ± 47.6 min, minimal oxygen saturation of 89% ± 0.05, arousal index of 8.1 ± 8.8 events/h, and sleep latency of 48 ± 56 min. The average age of the children was 9.2 ± 1.1 years. The results showed that the psychomotor assessment with MDS was lower than expected for their age in all children: 8 children (89%) in fine motor coordination, 6 children (67%) in global motor coordination, 8 children (89%) in static and dynamic balance, 5 (55.5%) in body and image scheme, 7 (78%) in spatial organization, and 5 (55.5%) in temporal organization. The laterality (eye, hand, and foot) of children was full left-handed or right-handed in 55% of them and cross lateralization in 45%. Conclusion: Children with SDB showed lower performance than expected for children of the same age in all psychomotor bases, and it was more impaired in relation to fine motor coordination, global motor coordination static and dynamic balance, and spatial organization. Acknowledgements: Acknowledgements for all children and families who took part in the study. http://dx.doi.org/10.1016/j.sleep.2013.11.280
Obstructive sleep apnea and P300 abnormalities in children with attention deficit P. Henriques Filho 1, R. Pratesi 1, L. Gandolfi 1, Y. Nobrega 1, R. Tristao 2 1 Laboratory of Pediatrics, Faculty of Medicine, University of Brasilia, Brazil 2 University of Brasilia, Medicine Faculty, Brazil
Introduction: Obstructive sleep apnea (OSA), that causes abnormal breathing or chronic intermittent hypoxia during sleep, can cause attention and working memory deficits which can be related to cognitive impairment throughout the developing nervous system. Aims: To verify the ability to sustain attention in children and adolescents diagnosed with OSA compared to a control group. Materials and methods: 80 participants of a local school (49 boys and 31 girls) aged 6 to 17 years (mean 10.85 , ±2.25), with attention complaints by the school, accepted to participate in this study and underwent overnight polysomnography and P300 evoked potential test. This test was divided into three repeated series with 10 min interval between series and lasting 15 min each series. None of the participants had been using medication or had previous diagnoses of developing mental disorder. Results: Among the 80 participants, 26 (32.5%) received the diagnosis of OSA and 61 (76.3) had varied abnormalities at P300 tests, from these 26 met both OSA and ADD deficit attention disorder criteria, 19 participants had no altered results and composed the control group. Considering the entire sample, OSA was significantly
e125
correlated with lower amplitudes (r = .79; r = .77 and r = .81, p = .000) and longer latencies (r = .60; r = .57; r = 76, p = .000) in all three tests, respectively. Two-Way ANOVA and repeated measures analyses showed no effect of age and gender on the P300 waves, though boys had a greater variability in all values. The apnea and hypoapnea index (IAH) had mainly effect on amplitudes of all tests and at latency of test 3 (F > 2.23, p < .010) and OSA diagnosis had effect over all P300 variables (F > 34.39, p < .000). Also, the group with OSA also presented decay in amplitude along the three tests, as showed by the repeated measures analyses, over all the three P300 amplitude measures (F = 297.57, p = .000), but not to latency, differently from the group without OSA that kept the values at the same levels during the three tests. Conclusion: This study has found evidence of the relationship between OSA and P300 evoked potentials, amplitudes and latencies. These findings are in accordance with the literature showing that sleep disturbances might disrupt sustaining attention abilities leading to school complaints of learning capacity. Also, this may help to clarify the diagnosis of attention deficit disorder, when sleep disorder is present. Acknowledgements: To the University of Brasilia, FAHUB and CNPq. http://dx.doi.org/10.1016/j.sleep.2013.11.281
Hypoxia predicts high blood pressure in patients with severe obstructive sleep apnea C. Fiori 1, E. Martins 1, P. Lopez 2, D. Martinez 3 1 Hospital de Clínicas de Porto Alegre (HCPA), Graduate Program in Cardiology and Cardiovascular Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil 2 Hospital de Clínicas de Porto Alegre (HCPA), Undergraduate Program in Nursing, UFRGS, Brazil 3 UFRGS, Cardiology Division, Hospital de Clinicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil
Introduction: Among the mechanisms causing hypertension in obstructive sleep apnea (OSA) patients, the roles of hypoxia and of arousals, leading to intermittent oxidative stress and repeated elevations of blood pressure, have been difficult to disentangle. The apnea–hypopnea index (AHI) reflects the number of arousals. The minimum arterial oxygen saturation (SaO2min) and the percent of total sleep time with SaO2 below 90% (STB90) reflect the degree of hypoxic insult. Mild and moderate OSA are established causes of hypertension. Intense desaturation, however, occurs only in severe OSA. Most of the literature on the OSA-hypertension link uses only the AHI as OSA severity marker. The aim of this study was to quantify, in severe OSA, the influence of desaturation on blood pressure levels. Materials and methods: We analyzed retrospectively a total of 1517 polysomnographies of patients with AHI > 30, ages between 18 and 60 years, of both genders, who underwent baseline polysomnography in a sleep clinic. Area under the ROC curve was used to identify desaturation cut points for prediction of systolic blood pressure (SBP) >140 mm Hg. Multivariate models with SBP as dependent variable, using, AHI, SaO2min, and SBT90 as regressors were attempted. Results: In the linear regression model to predict SBP in severe OSA (adjusted R square 0.04; P < 0.001), all three regressors are weakly but significantly associated, being the beta for lnAHI (0.08; P = 0.006) STB90 (0.09; P = 0.008) and SaO2min ( 0.06; P = 0.048). The binary logistic model, adjusted for age, BMI, and gender, the odds ratio for SBP >140 mm Hg was 1.6 times higher in the group with SBT90 (95% CI 1.3–2.0).
Abstracts / Sleep Medicine 14S (2013) e93–e164
sented higher spectral power in parieto-occipital regions for A1 (p = 0.049 – BF1) and temporal posterior for A2 (p = 0.015 – FB 1) and B (p = 0.049 – FB 1 e p = 0.033 – FB 2) possibly as a result of cerebral modifications due to deafness. Deaf subjects seem more sensitive to provoked sleep interruption with remarkable decrease of A1 (p = 0/015) in AA periods. Conclusion: Deaf subjects have more unstable sleep and higher sensitivity to provoked sleep interruption; compromised CAP rhythmicity as well as cortical and spectral modifications in posterior regions, possibly related to their clinical condition. Acknowledgements: Funded by: Fundação BIAL (No. 107/02). Work supported by Helder Bértolo, Joana Pires and Rosa Santos. http://dx.doi.org/10.1016/j.sleep.2013.11.277
Congenital central hypoventilation syndrome presenting as pulmonary hypertension T. Nunes 1, R. Ferreira 1, R. Anjos 2, O. Moldovan 3, T. Bandeira 1 1 Pneumology Unit, Department of Pediatrics, Santa Maria Hospital – CHLN, Academic Medical Center of Li, Portugal 2 Santa Cruz Hospital, Portugal 3 Genetic Service, Department of Pediatrics, Santa Maria Hospital – CHLN, Academic Medical Center of Li, Portugal
Introduction: Congenital Central Hypoventilation Syndrome (CCHS) is part of a diffuse autonomic nervous system deregulation. Usually it presents as sleep hypoventilation with impaired responses to hypoxemia and hypercapnia. Noninvasive ventilation (NIV) has been described as an option in older children. We describe a case of an infant in whom pulmonary hypertension (PHT) was the first signal of disease, being NIV a successful option. Materials and methods: Chart review. Results: M.D., was a 2 month old female infant, the 3rd child of a healthy, non-related, young couple. Gestation, delivery and neonatal period were uneventfully. She was on exclusive breastfeeding with good weight gain. Parents described prostration in the previous 3 days, food refusal and cyanosis in the day before. She was examined by a pediatric cardiologist who diagnosed severe PHT and referred her to our hospital. Physical examination confirmed central and peripheral cyanosis and satO2 was 91% breathing room air; other aspects were unremarkable including alertness, tonus, thorax examination and pulmonary auscultation. Hematological and biochemistry evaluations were normal except capillary blood gases that revealed respiratory acidosis (pH 7,26 mmHg) with pCO2 79,6 mmHg; chest X-ray was normal. There was no polipneia and during sleep apneic episodes were identified. Polysomnography revealed central apneas with severe desaturation in NREM sleep and hypercapnia, with delayed arousal response. After an initial decompensation period with increasingly high pCO2 that needed invasive ventilation, she was started on nasal mask NIV with good adaptation and blood gases normalization, permitting rapid transition to home care. A genetic mutation on PHOX 2B confirmed CCHS. Actually, at one year old, she is clinically stable on sleep NIV with normal neurodevelopment and somatic progression and without PHT on cardiac evaluation. Conclusion: Sleep central apneas are the most frequent presentation of CCHS in childhood but it can presents differently as shown on this patient. This case highlights the importance of clinical suspicion to diagnose this rare disease. The NIV support is a less common approach in younger patients, but it may be a successful option, avoiding tracheostomy and prolonged hospitalization and improving quality of life. http://dx.doi.org/10.1016/j.sleep.2013.11.278
Impact of diagnosis and treatment of obstructive sleep apnea syndrome (OSAS) with non-invasive ventilation (NIV) V. Ferreira 1, R. Nêveda 1, E. Lombardıa 1, R. Pimenta 2, J. Condeço 2, H. Curado 2 1 Local Health Unit of Alto Minho (ULSAM), Portugal 2 Polytechnic Institute of Oporto – School of Health Tecnhnology, Portugal
Introduction: OSAS is a serious public health problem. This study attempted to measure the benefits of one year of treatment with NIV in patients with moderate-severe OSAS, as well as the economic impact for both the patient and the Portuguese National Healthcare System (NHS). Specifically, we tried to assess if the treatment with NIV reduces: daytime sleepiness; road traffic accidents; number of hospitalizations; number of days of hospitalization; number of emergency visits; number of medical specialty consultations; and respective costs. We studied all patients with moderate-severe OSAS who visited the Pulmonology Services of the Local Health Unit of Alto Minho (ULSAM) and used NIV for at least one year. Materials and methods: To assess outcomes and costs, we used the Epworth Sleepiness Scale and the Homogeneous Diagnostic Groups (HDG’s) approved by law and contracted between the ULSAM and the NHS. Statistical data analysis was conducted by using descriptive and inferential techniques (t-test for paired samples and Spearman’s correlation coefficient), with a significance level of 5%. Patients with mild OSAS, weight reduction, subject to otolaryngology surgery and without one year of NIV treatment were excluded from the study. Results: The sample consisted of 153 individuals, 20.9% female and 79.1% male between the ages of 33 and 90. Our results show a significant reduction in daytime sleepiness (p < 0.001), road traffic accidents (p < 0.001), number of emergency visits (p < 0.001), number of hospitalizations (p < 0.001), and number of hospitalization days (p < 0.001). They also reveal a significant reduction in emergency costs (p < 0.001) and medical specialty consultations (p < 0.001) for the patient, as well as in emergency (p < 0.001) and hospitalization costs (p < 0.001) for the NHS. There was no significant reduction on the number of medical specialty visits (p = 0.269) and costs to the NHS (p = 0.269). The results were also not significant with regard to the relationship between the severity of OSAS and the number of road traffic accidents and daytime sleepiness. Conclusion: Treatment of OSAS with NIV, even in the short time period of one year, reduces the use of health services and associated costs, as well as daytime sleepiness and road traffic accidents. It was also found that the value of HDG’s medical hospitalization for OSAS contracted between ULSAM and NHS was insufficient, compared to HDG’s medical hospitalization for the same pathology as defined by law, which represents an added burden for the health institution. Acknowledgements: To the Local Health Unit of Alto Minho, Portugal (ULSAM), who made possible this study with real data of their patients. http://dx.doi.org/10.1016/j.sleep.2013.11.279
Psychomotor assessment in sleep breathing disorder children – pilot study V. Ferreira 1, J. Leite 2, L. Prado 3, G. Prado 3, L. Carvalho 3 1 Federal University of Sao Paulo, Neuro-Sono, Brazil 2 Federal University of Sao Paulo, Fisioterapy, Neuro-Sono, Brazil 3 University of Sao Paulo, Neuro-Sono, Brazil
Introduction: The Sleep Disordered Breathing (SDB) affects important cognitive functions concerning to the learning process as atten-
Abstracts / Sleep Medicine 14S (2013) e93–e164
tion, memory, and creativity, but just a little is known about the motor performance in those children. Suitable psychomotor development promotes better school learning. An assessment of the development and motor pattern contributes as preventive and reeducative to help or delete factors impeding the learning potential of the child. Objective: The aim of this study was to evaluate whether the psychomotor bases (fine motor coordination, global motor coordination, static and dynamic balance, body and image scheme, spatial and temporal organization) are impaired in SDB children. Materials and methods: We studied 9 children (5 girls) from 7 to 11 years, attending elementary school in São Paulo city, Brazil. All children had SBD diagnosed with polysomnography and the psychomotor assessment was evaluated with Motor Development Scale (MDS). We compared children‘s motor performance with the expected for children at the same age. Results: The children had, on average, Total Sleep Time 412 ± 47.6 min, minimal oxygen saturation of 89% ± 0.05, arousal index of 8.1 ± 8.8 events/h, and sleep latency of 48 ± 56 min. The average age of the children was 9.2 ± 1.1 years. The results showed that the psychomotor assessment with MDS was lower than expected for their age in all children: 8 children (89%) in fine motor coordination, 6 children (67%) in global motor coordination, 8 children (89%) in static and dynamic balance, 5 (55.5%) in body and image scheme, 7 (78%) in spatial organization, and 5 (55.5%) in temporal organization. The laterality (eye, hand, and foot) of children was full left-handed or right-handed in 55% of them and cross lateralization in 45%. Conclusion: Children with SDB showed lower performance than expected for children of the same age in all psychomotor bases, and it was more impaired in relation to fine motor coordination, global motor coordination static and dynamic balance, and spatial organization. Acknowledgements: Acknowledgements for all children and families who took part in the study. http://dx.doi.org/10.1016/j.sleep.2013.11.280
Obstructive sleep apnea and P300 abnormalities in children with attention deficit P. Henriques Filho 1, R. Pratesi 1, L. Gandolfi 1, Y. Nobrega 1, R. Tristao 2 1 Laboratory of Pediatrics, Faculty of Medicine, University of Brasilia, Brazil 2 University of Brasilia, Medicine Faculty, Brazil
Introduction: Obstructive sleep apnea (OSA), that causes abnormal breathing or chronic intermittent hypoxia during sleep, can cause attention and working memory deficits which can be related to cognitive impairment throughout the developing nervous system. Aims: To verify the ability to sustain attention in children and adolescents diagnosed with OSA compared to a control group. Materials and methods: 80 participants of a local school (49 boys and 31 girls) aged 6 to 17 years (mean 10.85 , ±2.25), with attention complaints by the school, accepted to participate in this study and underwent overnight polysomnography and P300 evoked potential test. This test was divided into three repeated series with 10 min interval between series and lasting 15 min each series. None of the participants had been using medication or had previous diagnoses of developing mental disorder. Results: Among the 80 participants, 26 (32.5%) received the diagnosis of OSA and 61 (76.3) had varied abnormalities at P300 tests, from these 26 met both OSA and ADD deficit attention disorder criteria, 19 participants had no altered results and composed the control group. Considering the entire sample, OSA was significantly
e125
correlated with lower amplitudes (r = .79; r = .77 and r = .81, p = .000) and longer latencies (r = .60; r = .57; r = 76, p = .000) in all three tests, respectively. Two-Way ANOVA and repeated measures analyses showed no effect of age and gender on the P300 waves, though boys had a greater variability in all values. The apnea and hypoapnea index (IAH) had mainly effect on amplitudes of all tests and at latency of test 3 (F > 2.23, p < .010) and OSA diagnosis had effect over all P300 variables (F > 34.39, p < .000). Also, the group with OSA also presented decay in amplitude along the three tests, as showed by the repeated measures analyses, over all the three P300 amplitude measures (F = 297.57, p = .000), but not to latency, differently from the group without OSA that kept the values at the same levels during the three tests. Conclusion: This study has found evidence of the relationship between OSA and P300 evoked potentials, amplitudes and latencies. These findings are in accordance with the literature showing that sleep disturbances might disrupt sustaining attention abilities leading to school complaints of learning capacity. Also, this may help to clarify the diagnosis of attention deficit disorder, when sleep disorder is present. Acknowledgements: To the University of Brasilia, FAHUB and CNPq. http://dx.doi.org/10.1016/j.sleep.2013.11.281
Hypoxia predicts high blood pressure in patients with severe obstructive sleep apnea C. Fiori 1, E. Martins 1, P. Lopez 2, D. Martinez 3 1 Hospital de Clínicas de Porto Alegre (HCPA), Graduate Program in Cardiology and Cardiovascular Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil 2 Hospital de Clínicas de Porto Alegre (HCPA), Undergraduate Program in Nursing, UFRGS, Brazil 3 UFRGS, Cardiology Division, Hospital de Clinicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil
Introduction: Among the mechanisms causing hypertension in obstructive sleep apnea (OSA) patients, the roles of hypoxia and of arousals, leading to intermittent oxidative stress and repeated elevations of blood pressure, have been difficult to disentangle. The apnea–hypopnea index (AHI) reflects the number of arousals. The minimum arterial oxygen saturation (SaO2min) and the percent of total sleep time with SaO2 below 90% (STB90) reflect the degree of hypoxic insult. Mild and moderate OSA are established causes of hypertension. Intense desaturation, however, occurs only in severe OSA. Most of the literature on the OSA-hypertension link uses only the AHI as OSA severity marker. The aim of this study was to quantify, in severe OSA, the influence of desaturation on blood pressure levels. Materials and methods: We analyzed retrospectively a total of 1517 polysomnographies of patients with AHI > 30, ages between 18 and 60 years, of both genders, who underwent baseline polysomnography in a sleep clinic. Area under the ROC curve was used to identify desaturation cut points for prediction of systolic blood pressure (SBP) >140 mm Hg. Multivariate models with SBP as dependent variable, using, AHI, SaO2min, and SBT90 as regressors were attempted. Results: In the linear regression model to predict SBP in severe OSA (adjusted R square 0.04; P < 0.001), all three regressors are weakly but significantly associated, being the beta for lnAHI (0.08; P = 0.006) STB90 (0.09; P = 0.008) and SaO2min ( 0.06; P = 0.048). The binary logistic model, adjusted for age, BMI, and gender, the odds ratio for SBP >140 mm Hg was 1.6 times higher in the group with SBT90 (95% CI 1.3–2.0).