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Introduction: Actigraphy is a useful tool for the assessment of the sleep pattern being mainly addressed by means of the Sadeh’s algorithm; hence several aspects of sleep, such as regularity, have not been appropriately studied so far. This paper strives for showing the utility of both analysis of the sleep registries to complement the sleep pattern characterization. The discriminant capability of some statistical and nonlinear features has been evaluated over two cohorts (institutionalized and non-institutionalized elderly) in which the features resulting from the Sadeh’s algorithm do not show significant differences. Materials and methods: Case/control study of elderly patients (65years older). The case group was 144 institutionalized patients, while the control group were 124 patient home-living. Subjects were monitored with the Actigraph GT3x device, 24h a day from Monday to Thursday, using 1s epochs. Statistical features are composed by the mean, median, standard deviation, the interquartile range and the variation coefficient (VC). Nonlinear features are formed by those extracted through the analysis with the central tendency measure (CTM) and symbolic dynamics (SD). CTM evaluates the regularity at the ro scale (ro=0, typically), while the SD (3 symbols long alphabet; 2 symbols/word) provides a set of word appearance probabilities that indicates either regularity or variability; Besides, the Shannon’s entropy (ES) has been also included as complexity measure. All these features have been analysed by means of the U-test of Mann–Whitney to determine the existence of significant differences between the cohorts. Results: As for the statistical features, only the VC shows significant differences, being higher in the control group (p <0.05). Regarding the nonlinear features, both CTM and SD give out discriminant features; specifically, the control group shows higher values of CTM (p <0.04), P02, P20 and P22 (p <0.02), whereas higher values of ES are achieved in the case group (p <0.05). Conclusion: Both the VC, the CTM and the SD are useful to complement the characterization of the sleep pattern. In the current study, these features allow for the assessment of the regularity and the intensity of activity during sleep. Results of both the CTM and the ES point out that the activity of institutionalized elderly is less regular than the activity of those who live at home, which is in line with the results of P22. Acknowledgement: Research supported by the Health Service of the Regional Government of Castilla y Leon. [Copyright &y& Elsevier]

Introduction: Obstructive sleep apnea (OSA) has been associated with increased mortality. It is not known, however, how sleep apnea affects the relation between short and long sleep duration and mortality risk. Despite the existence of many studies, the association between sleep duration and mortality is still unclear due to the large number of confounders, such as OSA. In the context, the relationship between mortality and sleep efficiency in sleep apnea patients remained less studied. The present study aims to investigate the association between survival time, sleep apnea severity, and sleep efficiency in patients with sleep disorders who underwent full night polysomnography. Materials and methods: A list with 17,778 names and demographics of people who underwent polysomnography between January 1985 and June 2012 was sent to the Health Information Group of the State Health Department. The search in the database of death certificates from 2000 to 2012 obtained 227 patients. Subjects had signed a form consenting in the anonymous use of their data. The subjects were divided at the median survival time in SHORT (<5years) and LONG survival (>5years). Results: Among the deceased, 173 were men and 54 women, with ages of (mean SD) 58 14 and 59 12years, respectively. Two cases had sleep apnea as cause of death. The mean survival time was similar for men and women (6.2 4.3 and 6.3 4.4 years). Comparing the SHORT and LONG survival, all variables examined were similar, including the apnea-hypopnea index (37 28 and 39 31 events/hour; P = 0.6), gender, age, body mass index, systolic and diastolic blood pressure, waist and neck circumference, average and minimum oxygen saturation, as well as time and cause of death. The number of years of survival only correlates significantly with sleep efficiency (rho= 0.17; P = 0.01). The sleep efficiency, however, was lower in the LONG survival group (76 16% and 80 16%; P = 0.049) and the total sleep time was 27min shorter (P = 0.01). In the linear regression to predict survival time, sleep efficiency remains the only variable with a significant beta value (−0.16; P = 0.03). The odds ratio for SHORT survival was 2.8 times higher in the group with sleep efficiency >84% (95% CI 1.5-5.0). Conclusion: In the present study, the only variable that explains years of survival is sleep efficiency. This may suggest that hyperexcitability evidenced in the polysomnography by reduced sleep efficiency is a feature that enhances survival. Acknowledgements: This study was supported in part by CNPq, CAPES, and FIPE-HCPA (Brazil). [Copyright &y& Elsevier]

Introduction: Obstructive sleep apnea (OSA) affects the sleep quality and is associated with psychosocial problems. Testosterone participates both in the pathophysiology of OSA, affecting the upper airway collapsibility, and is the leading hormone related to aggressive conduct. The relationship between decreased sleep quality and irritability or aggressiveness is a frequent anecdotal quote, but the experimental evidence validating this relation is still scarce. Thus, we hypothesized that OSA severity influences aggressiveness in men, independently of the sleepiness and testosterone levels. The present study aimed to evaluate the association of OSA with aggressivity scores on a questionnaire, controlling for sleepiness and testosterone level. Materials and methods: A case-control study was conducted from August 2012 to February 2013 in patients who underwent full overnight polysomnography to investigate sleep disorders. Inclusion criteria were: men aged 18 to 50 years, without organic or mental disorders, social problems, and use of behavior-altering medication, alcohol or illicit drugs. All answered the Brazilian version of the Kurzfragebogen zur Erfassung von Aggressivitatsfaktoren (K-FAF) and of the Epworth Sleepiness Scale (ESS). In this analysis, seven questions scoring peaceful manners were excluded. In the morning after the polysomnography, blood was sampled for the dosage of testosterone. Cases had an apnea hypopnea index (AHI) 15 events/hour and controls, an AHI <15/h. Results: The 127 men included, 87 cases and 40 controls, were aged (mean SD) 37 8.5 years. In uncontrolled analyses, cases are older than controls (P <0.001), had higher body mass index (P <0.001), had lower testosterone levels (p =0.001), and lower K-FAF scores (P =0.005) than controls. In bivariate correlation, the AHI correlates significantly with testosterone levels (ρ =−0.40; P <0.001) and with scores in K-FAF questionnaire (ρ =−0.23; P =0.008). The only significant variable to predict K-FAF scores was AHI (β =−0.27; P =0.022), adjusting for age, body mass index, ESS scores, and testosterone levels in the linear regression model (adjusted R2=0.103; p =0.008). Conclusion: The results of this study demonstrate an effect of sleep apnea in reducing scores of aggressive behavior in a specific questionnaire, controlling for confounders. Acknowledgement: Casa do Psicologo, Capes, CNPq, and FIPE- HCPA. [Copyright &y& Elsevier]

Introduction: More common health complaints in institutionalized patients are insomnia and sleep disorders comparing with home-living elderly patient. The aim of this study was for analyze sleep pattern in elderly population, comparing institutionalized elderly and home-living elderly. Materials and methods: Case and control study comparison between 266 elderly patients (65year older), 142 institutionalized whereas the control group was 124 patients living at home. Subjects were monitored with the Actigraph GT3x device (placed on the right wrist) 24h a day during seven consecutive days, using 1s lasted epochs. The sleep patterns of both groups have been extracted through the well known Sadeh’s algorithm and analysed by means of the U-test of Mann–Whitney (a non-parametric variant of the Student’s t-test) in order to determine the existence of statistically significant differences between the groups under analysis. Results: Statistically significant differences arise only during the three last days of the week (Friday, Saturday and Sunday). The number of minutes awake (p <0.02) and the average awakening (p <0.04) are higher in the case group on both Friday and Saturday, whilst the total sleep time (p <0.03) and the largest sleep time (p <0.05) are higher in the control group on Sunday. We not found statistically significant differences during working days in the analyzed variables. Conclusion: The effects of institutionalization over the sleep pattern in elderly population are only significant on weekends (Friday, Saturday and Sunday). Institutionalized subjects suffer from either less or poorer sleep than those subjects that live at home. Working days, significant differences are not observed in the sleep pattern between both groups of patients. A possible explanation for this fact stems from the disruption of the institutionalized subject’s daily routine as a consequence of both their weekend habits (activities with their families, for instance) and some variations on the schedule of the staff (on-call staff instead of regular staff, for instance). Acknowledgements: Research supported by the Health Service (SACYL) of the Regional Government of Castilla y Leon in Spain. [Copyright &y& Elsevier]

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 60years, 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) >140mm 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 >140mm Hg was 1.6 times higher in the group with SBT90 (95% CI 1.3–2.0). Conclusion: These data suggest that, in severe OSA, the effect of desaturation on blood pressure is weak, probably, because it “saturates” at low severity levels. The duration of the STB90 and the lowest saturation are similarly weak predictors of hypertension in severe OSA. This is in agreement with epidemiological and pathophysiological data indicating that arousals in mild and moderate OSA are the main factors in the pathogenesis of hypertension in OSA. Acknowledgements: This study was supported in part by CNPq, CAPES, and FIPE-HCPA (Brazil). [Copyright &y& Elsevier]