The public health burden of obstructive sleep apnea

Quantitative detection of sleep apnea in adults using inertial measurement unit embedded in wristwatch wearable devices

Sleep apnea (SA) is associated with risk of cardiovascular disease, cognitive decline, and accidents due to sleepiness, yet the majority (over 80%) of patients remain undiagnosed. Inertial measurement units (IMUs) are built into modern wearable devices and are capable of long-term continuous measurement with low power consumption. We examined if SA can be detected by an IMU embedded in a wristwatch device. In 122 adults who underwent polysomnography (PSG) examinations, triaxial acceleration and triaxial gyro signals from the IMU were recorded during the PSG. Subjects were divided into a training group and a test groups (both n = 61). In the training group, an algorithm was developed to extract signals in the respiratory frequency band (0.13-0.70 Hz) and detect respiratory events as transient (10-90 s) decreases in amplitude. The respiratory event frequency estimated by the algorithm correlated with the apnea-hypopnea index (AHI) of the PSG with r = 0.84 in the test group. With the cutoff values determined in the training group, moderate-to-severe SA (AHI ≥ 15) was identified with 85% accuracy and severe SA (AHI ≥ 30) with 89% accuracy in the test group. SA can be quantitatively detected by the IMU embedded in wristwatch wearable devices in adults with suspected SA.

An exploratory study on the association between serotonin and sleep breathing disorders

This exploratory observational study aimed to evaluate whether the blood levels of serotonin and enzymes involved in serotonin synthesis are associated with sleep breathing parameters. A total of 105 patients were included in this study, who were subjected to single-night polysomnography with simultaneous audio-video recordings. Peripheral blood samples were collected to estimate the serum levels of serotonin, tryptophan hydroxylase 1 (TPH1), and aromatic l-amino acid decarboxylase (AADC). Results showed a negative correlation between blood serotonin levels, and oxygen desaturation index (ODI) (p = 0.027), central apnea (p = 0.044) and obstructive apnea (OA) (p = 0.032) scores. Blood TPH1 levels were negatively correlated with average (p = 0.003) and minimal saturation (p = 0.035) and positively correlated with apnea-hypopnea index (p = 0.010), OA (p = 0.049), and hypopnea index (p = 0.007) scores. A tendency to sleep-disordered breathing seemed to co-occur with lower blood serotonin and higher TPH1 levels.Clinical Trial Registration : www.ClinicalTrials.gov , identifier NCT04214561.

The association between long working hours and obstructive sleep apnea assessed by STOP-BANG score: a cross-sectional study

PURPOSE

The relationship between night-shift work and obstructive sleep apnea (OSA) is well known, but that between OSA and long working hours is still unknown. This study explores the association between long working hours and OSA.

METHODS

Using cross-sectional Korean National Health and Nutrition Examination Survey 2020 data, we made multiple logistic regression models to calculate odds ratios (ORs) between weekly working hours and STOP-BANG scores for OSA screening. Stratified regression models by night or rotating shift work were also made.

RESULTS

In an adjusted model of STOP-BANG high-risk versus low-risk groups, the OR in the group exceeding 40 h/wk was higher but not statistically significant, 1.19 [95% confidence interval (CI) 0.66-2.15] compared to the group working 40 h/wk (standard working hours) or less. In the group exceeding 52 h/wk, the OR was 2.03 with statistical significance (95% CI 1.08-3.80). In the stratification analysis of daytime and night-shift work, the daytime worker results were similar to those in the non-stratified model. The point estimation values of ORs in the night-shift workers were higher than in the daytime workers; however, we did not observe a statistical significance.

CONCLUSION

Long working hours can increase the risk of OSA assessed by STOP-BANG scores.