Validation of a sleep staging classification model for healthy adults based on two combinations of a single-channel EEG headband and wrist actigraphy.

STUDY OBJECTIVES: The aim of this study was to develop a sleep staging classification model capable of accurately performing on different wearable devices. METHODS: Twenty-three healthy participants underwent a full-night type I polysomnography and used two device combinations: (A) flexible single-channel electroencephalogram (EEG) headband + actigraphy (n = 12) and (B) rigid single-channel EEG headband + actigraphy (n = 11). The signals were segmented into 30-second epochs according to polysomnographic stages (scored by a board-certified sleep technologist; model ground truth) and 18 frequency and time features were extracted. The model consisted of an ensemble of bagged decision trees. Bagging refers to bootstrap aggregation to reduce overfitting and improve generalization. To evaluate the model, a training dataset under 5-fold cross-validation and an 80-20% dataset split was used. The headbands were also evaluated without the actigraphy feature. Participants also completed a usability evaluation (comfort, pain while sleeping, and sleep disturbance). RESULTS: Combination A had an F1-score of 98.4% and the flexible headband alone of 97.7% (error rate for N1: combination A = 9.8%; flexible headband alone = 15.7%). Combination B had an F1-score of 96.9% and the rigid headband alone of 95.3% (error rate for N1: combination B = 17.0%; rigid headband alone = 27.7%); in both, N1 was more confounded with N2. CONCLUSIONS: We developed an accurate sleep classification model based on a single-channel EEG device, and actigraphy was not an important feature of the model. Both headbands were found to be useful, with the rigid one being more disruptive to sleep. Future research can improve our results by applying the developed model in a population with sleep disorders. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Actigraphy, Wearable EEG Band and Smartphone for Sleep Staging; URL: https://clinicaltrials.gov/study/NCT04943562; Identifier: NCT04943562. CITATION: Melo MC, Vallim JRS, Garbuio S, et al. Validation of a sleep staging classification model for healthy adults based on 2 combinations of a single-channel EEG headband and wrist actigraphy. J Clin Sleep Med. 2024;20(6):983-990.

Impact on health outcomes associated with changing the clock 1 hour during fall and spring transitions in the Southern Hemisphere.

STUDY OBJECTIVES: Changing the clocks seasonally is potentially harmful because it interferes with normal daytime activities. Studies aimed at quantifying this association are scant. The objective of this study was to determine the effects of 1 year's worth of changing the clocks (fall and spring transitions) on healthy young men located in the Southern Hemisphere in South America. METHODS: We performed an observational prospective study. Thirty healthy male university students were evaluated from 2 weeks before to 2 weeks after both the fall and spring transitions. We administered an overall sleep questionnaire, assessed quality of life, recorded 7-day wrist actigraphy, and had participants perform a psychomotor vigilance task. We defined the 1-hour clock change as the primary exposure and the change in psychomotor vigilance task lapses of 500 milliseconds or more in response time as our primary outcome. Changes were evaluated by the Wilcoxon rank test (significance: P < .05). RESULTS: After the fall transition, we found a significant worsening in psychomotor vigilance task performance (median [interquartile range], 9.9 [6.0-14.3] lapses of ≥ 500 milliseconds in response time at baseline vs 16.8 [8.2-28.0] after transition; P < .002). Additionally, we found a median loss of about 1 hour of total sleep time and time in bed after the fall transition. Furthermore, participants presented with insomnia. Performance on the psychomotor vigilance task was also affected after the spring transition (16.7 [10-23] vs 23 [12.2-32.2]; P < .001). CONCLUSIONS: A decrease in performance in neurocognitive tests was found after both time transitions. The transition led to insomnia and a significant worsening of sleep variables. CITATION: Labarca G, Henriquez-Beltrán M, Sanhueza R, et al. Impact on health outcomes associated with changing the clock 1 hour during fall and spring transitions in the Southern Hemisphere. J Clin Sleep Med. 2024;20(6):887-893.

Sleep parameters assessed by actigraphy in Fabry's disease patients: a proof-of-concept.

BACKGROUND: In a previous study developed by our group, we identified a phase inversion in 6-sulfatoxymelatonin - melatonin metabolite in urine - daily profile in Fabry's disease patients. Since melatonin is an endogenous marker, it could also be accompanied by behavioral changes in sleep-wake cycle, which impairs the overall patient's life quality. OBJECTIVE: In this study, we evaluated sleep-wake cycle in Fabry disease patients. We hypothesized that patients would have increased daytime naps, given our previous results for urinary 6-sulfatoxymelatonin. PATIENTS/METHODS: This was a cross-sectional and case-control study, performed between October 2016 and May 2017. Volunteers recorded activity and rest rhythm by actigraphy and answered Pittsburgh Sleep Quality Index (PSQI). From actigraphy data, we calculated sleep parameters: sleep latency, wake after sleep onset, sleep (WASO) efficiency, awakenings index (PSQI), and the amount and duration of daytime naps. We included 16 Fabry disease patients with biochemical and molecular diagnosis and 10 control individuals matched by age and gender. RESULTS: We did not observe significant differences for any of the parameters analyzed (p > 0.05). However, evaluating the magnitude of the effect, we found that patients dozed, on average, about 42 min longer (d = 0.9 - large effect size) than control group. CONCLUSIONS: This is a preliminary study, a proof-of-concept, and our results indicate that changes in melatonin secretion phase may have behavioral consequences in sleep-wake cycle, with longer duration of daytime naps.

Validity of the Brief Infant Sleep Questionnaire (BISQ) in Brazilian children.

OBJECTIVE: To investigate the validity of the Brief Infant Sleep Questionnaire (BISQ), in assessing sleep quality in childhood. METHODS: This was a validation study with children from the Pelotas 2015 Birth Cohort. BISQ was applied to mothers when their children were 3, 6, 12, and 24 months of age. The poor sleep indicators analysed, as defined by BISQ, were >3 wakings per night, nocturnal wakefulness >1 h and total sleep duration <9/24 h, compared to number of wakings per night and nocturnal and total sleep duration defined by actigraphy taken as the gold standard. The Actiwatch wGT3X-BT device was used by the child consecutively during five days at three and six months and for three days at 12 and 24 months. At each age the prevalence, sensitivity, specificity, accuracy, and positive (PPV) and negative predictive values (NPV) of each sleep indicator was calculated. RESULTS: A total of 586 children were enrolled in the study. Nocturnal wakefulness >1 h was the most frequent indicator at all ages, with higher sensitivity (varying from 27.5% at six months to 54.8% at three) and lower specificity (53.4% at three months to 79.4% at six months), in comparison to the other sleep indicators. Specificity for >3 wakings and total sleep duration <9 h was greater than 85.0% at all the ages. Higher accuracies were observed for total sleep <9 h at 3 (85.6%), 6 (88.2%) and 12 months (73.6%) and for > 3 wakings at 24 months (84.5%). The sensitivity for the presence of at least one indicator decreased with age from 56.0% at three months to 35.8% at 24 months, whereas the specificity increased from 50.6% at three months to 63.8% at 24 months. CONCLUSION: The high specificity of the BISQ sleep parameters supports the validity of parents' reports on sleep-related problems in childhood for use in epidemiological studies.

Comparing ActiGraph equations for estimating energy expenditure in older adults.

Accurate estimation of energy expenditure (EE) from accelerometer outputs remains a challenge in older adults. The aim of this study was to validate different ActiGraph (AG) equations for predicting EE in older adults. Forty older adults (age = 77.4 ± 8.1 yrs) completed a set of household/gardening activities in their residence, while wearing an AG at the hip (GT3X+) and a portable calorimeter (MetaMax 3B - criterion). Predicted EEs from AG were calculated using five equations (Freedson, refined Crouter, Sasaki and Santos-Lozano (vertical-axis, vectormagnitude)). Accuracy of equations was assessed using root-mean-square error (RMSE) and mean bias. The Sasaki equation showed the lowest RMSE for all activities (0.47 METs) and across physical activity intensities (PAIs) (range 0.18-0.48 METs). The Freedson and Santos-Lozano equations tended to overestimate EE for sedentary activities (range: 0.48 to 0.97 METs), while EEs for moderate-to-vigorous activities (MVPA) were underestimated (range: -1.02 to -0.64 METs). The refined Crouter and Sasaki equations showed no systematic bias, but they respectively overestimated and underestimated EE across PAIs. In conclusion, none of the equations was completely accurate for predicting EE across the range of PAIs. However, the refined Crouter and Sasaki equations showed better overall accuracy and precision when compared with the other methods.

Tracking of physical activity during adolescence: the 1993 Pelotas Birth Cohort, Brazil / Atividade física ao longo da adolescência: Coorte de Nascimentos de Pelotas de 1993

OBJECTIVE To analyze physical activity during adolescence in participants of the 1993 Pelotas Birth Cohort Study, Brazil. METHODS Data on leisure time physical activity at 11, 15, and 18 years of age were analyzed. At each visit, a cut-off point of 300 min/week was used to classify adolescents as active or inactive. A total of 3,736 participants provided data on physical activity at each of the three age points. RESULTS A significant decline in the proportion of active adolescents was observed from 11 to 18 years of age, particularly among girls (from 32.9% to 21.7%). The proportions of girls and boys who were active at all three age points were 28.0% and 55.1%, respectively. After adjustment for sex, economic status, and skin color, participants who were active at 11 and 15 years of age were 58.0% more likely to be active at 18 years of age compared with those who were inactive at 11 and 15 years of age. CONCLUSIONS Physical activity declined during adolescence and inactivity tended to track over time. Our findings reinforce the need to promote physical activity at early stages of life, because active behavior established early tends to be maintained over time. .

OBJETIVO Analisar a participação em atividade física ao longo da adolescência na coorte de 1993 de Pelotas. MÉTODOS Estudo de coorte composta pelas crianças nascidas em Pelotas, RS, em 1993. Foram analisadas as informações sobre a prática de atividades físicas no lazer aos 11, 15 e 18 anos de idade. O ponto de corte de 300 min foi usado para classificar os adolescentes como ativos em cada período. Um total de 3.736 indivíduos forneceu dados sobre atividades físicas realizadas nos três momentos estudados. RESULTADOS Declínio significativo na proporção de adolescentes ativos foi observado entre 11 e 18 anos, especialmente entre as meninas (32,9% para 21,7%). A proporção de meninas e meninos ativos nos três momentos foi de 28,0% e 55,1%, respectivamente. Após ajuste por sexo, nível econômico e cor da pele, os indivíduos ativos aos 11 e 15 anos, quando comparados àqueles inativos nessa faixa etária, foram 58,0% mais prováveis de serem ativos aos 18 anos. CONCLUSÕES A prática de atividade física diminuiu entre os ١١ e ١٨ anos de idade e o comportamento inativo tendeu a se manter ao longo do período.Os resultados obtidos reforçam a importância de promover a atividade física nos estágios iniciais da adolescência, pois esse comportamento tende a ser mantido ao longo do tempo. .

Tracking of physical activity during adolescence: the 1993 Pelotas Birth Cohort, Brazil.

OBJECTIVE To analyze physical activity during adolescence in participants of the 1993 Pelotas Birth Cohort Study, Brazil. METHODS Data on leisure time physical activity at 11, 15, and 18 years of age were analyzed. At each visit, a cut-off point of 300 min/week was used to classify adolescents as active or inactive. A total of 3,736 participants provided data on physical activity at each of the three age points. RESULTS A significant decline in the proportion of active adolescents was observed from 11 to 18 years of age, particularly among girls (from 32.9% to 21.7%). The proportions of girls and boys who were active at all three age points were 28.0% and 55.1%, respectively. After adjustment for sex, economic status, and skin color, participants who were active at 11 and 15 years of age were 58.0% more likely to be active at 18 years of age compared with those who were inactive at 11 and 15 years of age. CONCLUSIONS Physical activity declined during adolescence and inactivity tended to track over time. Our findings reinforce the need to promote physical activity at early stages of life, because active behavior established early tends to be maintained over time.

Objectively measured physical activity in children from a southern Brazilian city: a population-based study.

BACKGROUND: The aim of this study was to assess physical activity (PA) patterns (intensity and prevalence) in children according to demographic, socioeconomic, and familiar characteristics. METHODS: In 2010, a cross-sectional study of 239 children aged 4-11 was conducted, in Pelotas, Southern Brazil. PA was measured by accelerometry and classified in different intensities. Insufficient physical activity was defined as less than 60 min/day of moderate-to-vigorous PA. Descriptive analyses of accelerometry-related variables were presented. Multivariate Poisson regression models were used to estimate the association between physical insufficient PA and covariates. RESULTS: For both sexes, around 65% of the registered time was spent in sedentary activities and less than 20 min/day in vigorous activity. Age and economic status were inversely associated to PA in all categories of PA. Moderate and vigorous activities means were higher in boys than in girls. The prevalence of insufficient PA was 34.5% in girls and 19.5% in boys. CONCLUSIONS: We found important differences in physical activity patterns according to sex and economic status, as well as a significant decline in time spent in moderate-to-vigorous PA with increasing age. Understanding the relationship between these sociodemographic factors is important to tackle low levels of PA.