1.Sleep Tracking of Two Smartwatches Against Self-Reported Logs for Circadian Rhythm and Sleep Quality Assessment in Healthy Adults
Ji-Eun PARK ; Jayeun KIM ; Hoseok KIM ; Eunkyoung AHN ; Kyuhyun YOON
Journal of Sleep Medicine 2025;22(1):8-16
Although many wearable devices are used to assess sleep, their accuracy remains controversial. This study aimed to investigate the accuracy of the Actiwatch, a research-grade device, and the Fitbit, a consumer-grade device, against sleep diaries to assess sleep patterns. Methods: Twenty participants wore Fitbit and Actiwatch for two weeks and tracked their sleep patterns using sleep diaries. Total sleep time (TST), time-in-bed (TIB), sleep efficiency (SE), sleep onset latency (SOL), and wake after sleep onset (WASO) from the two devices and sleep diaries were analyzed using analysis of variance and Bland-Altman analysis. Results: The TIB measured by the sleep log, Fitbit, and Actiwatch were 420.9 minutes, 417.3 minutes, and 567.4 minutes, respectively. Compared to the sleep log, the Fitbit underestimated TST, TIB, and SE, with significant differences observed for TST (p<0.001) and SE (p<0.001), but not for TIB. The Actiwatch overestimated TIB (p<0.001) and TST (p=0.02) and underestimated SE (p<0.001) compared to the sleep log. The difference between the Fitbit and Actiwatch was significant for TST, TIB, and SE (all p<0.001). Conclusions: The Fitbit showed a smaller difference than the Actiwatch when compared with the sleep logs. The Fitbit could be used as a tool to assess sleep patterns in the clinic as well as in daily life.
2.Sleep Tracking of Two Smartwatches Against Self-Reported Logs for Circadian Rhythm and Sleep Quality Assessment in Healthy Adults
Ji-Eun PARK ; Jayeun KIM ; Hoseok KIM ; Eunkyoung AHN ; Kyuhyun YOON
Journal of Sleep Medicine 2025;22(1):8-16
Although many wearable devices are used to assess sleep, their accuracy remains controversial. This study aimed to investigate the accuracy of the Actiwatch, a research-grade device, and the Fitbit, a consumer-grade device, against sleep diaries to assess sleep patterns. Methods: Twenty participants wore Fitbit and Actiwatch for two weeks and tracked their sleep patterns using sleep diaries. Total sleep time (TST), time-in-bed (TIB), sleep efficiency (SE), sleep onset latency (SOL), and wake after sleep onset (WASO) from the two devices and sleep diaries were analyzed using analysis of variance and Bland-Altman analysis. Results: The TIB measured by the sleep log, Fitbit, and Actiwatch were 420.9 minutes, 417.3 minutes, and 567.4 minutes, respectively. Compared to the sleep log, the Fitbit underestimated TST, TIB, and SE, with significant differences observed for TST (p<0.001) and SE (p<0.001), but not for TIB. The Actiwatch overestimated TIB (p<0.001) and TST (p=0.02) and underestimated SE (p<0.001) compared to the sleep log. The difference between the Fitbit and Actiwatch was significant for TST, TIB, and SE (all p<0.001). Conclusions: The Fitbit showed a smaller difference than the Actiwatch when compared with the sleep logs. The Fitbit could be used as a tool to assess sleep patterns in the clinic as well as in daily life.
3.Sleep Tracking of Two Smartwatches Against Self-Reported Logs for Circadian Rhythm and Sleep Quality Assessment in Healthy Adults
Ji-Eun PARK ; Jayeun KIM ; Hoseok KIM ; Eunkyoung AHN ; Kyuhyun YOON
Journal of Sleep Medicine 2025;22(1):8-16
Although many wearable devices are used to assess sleep, their accuracy remains controversial. This study aimed to investigate the accuracy of the Actiwatch, a research-grade device, and the Fitbit, a consumer-grade device, against sleep diaries to assess sleep patterns. Methods: Twenty participants wore Fitbit and Actiwatch for two weeks and tracked their sleep patterns using sleep diaries. Total sleep time (TST), time-in-bed (TIB), sleep efficiency (SE), sleep onset latency (SOL), and wake after sleep onset (WASO) from the two devices and sleep diaries were analyzed using analysis of variance and Bland-Altman analysis. Results: The TIB measured by the sleep log, Fitbit, and Actiwatch were 420.9 minutes, 417.3 minutes, and 567.4 minutes, respectively. Compared to the sleep log, the Fitbit underestimated TST, TIB, and SE, with significant differences observed for TST (p<0.001) and SE (p<0.001), but not for TIB. The Actiwatch overestimated TIB (p<0.001) and TST (p=0.02) and underestimated SE (p<0.001) compared to the sleep log. The difference between the Fitbit and Actiwatch was significant for TST, TIB, and SE (all p<0.001). Conclusions: The Fitbit showed a smaller difference than the Actiwatch when compared with the sleep logs. The Fitbit could be used as a tool to assess sleep patterns in the clinic as well as in daily life.
4.Impact of Omicron-Variant SARS-CoV-2 Infection on Depression and Anxiety: A Community-Based Study in Korea
Youngsook KWON ; Jina PARK ; Eunkyoung AN ; Sukyoung JUNG ; Kukju KWEON
Psychiatry Investigation 2024;21(4):415-421
Objective:
This study seeks to evaluate the association between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the severity of depression and anxiety in the Korean community during the period dominated by the Omicron variant.
Methods:
We used data from the 2022 Daejeon Mental Health Survey, involving data of 985 participants aged 19–69 years. The data collected included SARS-CoV-2 infection experience, days post-infection, and depression and anxiety symptoms evaluated using the Patient Health Questionnaire-9 and the Generalized Anxiety Disorder Questionnaire-7, respectively. Additionally, physical health, social activity status, and sociodemographic characteristics such as gender, age, marital status, educational level, and household income were collected. The association between SARS-CoV-2 infection and depression and anxiety were examined. Further analyses explored association between days post- infection and the severity of depression and anxiety.
Results:
There was no significant correlation between SARS-CoV-2 infection and depression and anxiety in the overall population. Notably, participants under 50 years of age exhibited a transient worsening of depression and anxiety, followed by a decrease in symptoms within 40 days. Participants aged 51 years and older showed no significant change in depression and anxiety.
Conclusion
This study discerned transient effects of Omicron variant infection on depression and anxiety, particularly in younger individuals. A prospective study encompassing a larger sample size is imperative to investigate the influence of SARS-CoV-2 infection on depression and anxiety.
5.Hyperkalemia Detection in Emergency Departments Using Initial ECGs:A Smartphone AI ECG Analyzer vs. Board-Certified Physicians
Donghoon KIM ; Joo JEONG ; Joonghee KIM ; Youngjin CHO ; Inwon PARK ; Sang-Min LEE ; Young Taeck OH ; Sumin BAEK ; Dongin KANG ; Eunkyoung LEE ; Bumi JEONG
Journal of Korean Medical Science 2023;38(45):e322-
Background:
Hyperkalemia is a potentially fatal condition that mandates rapid identification in emergency departments (EDs). Although a 12-lead electrocardiogram (ECG) can indicate hyperkalemia, subtle changes in the ECG often pose detection challenges. An artificial intelligence application that accurately assesses hyperkalemia risk from ECGs could revolutionize patient screening and treatment. We aimed to evaluate the efficacy and reliability of a smartphone application, which utilizes camera-captured ECG images, in quantifying hyperkalemia risk compared to human experts.
Methods:
We performed a retrospective analysis of ED hyperkalemic patients (serum potassium ≥ 6 mmol/L) and their age- and sex-matched non-hyperkalemic controls. The application was tested by five users and its performance was compared to five board-certified emergency physicians (EPs).
Results:
Our study included 125 patients. The area under the curve (AUC)-receiver operating characteristic of the application’s output was nearly identical among the users, ranging from 0.898 to 0.904 (median: 0.902), indicating almost perfect interrater agreement (Fleiss’ kappa 0.948). The application demonstrated high sensitivity (0.797), specificity (0.934), negative predictive value (NPV) (0.815), and positive predictive value (PPV) (0.927). In contrast, the EPs showed moderate interrater agreement (Fleiss’ kappa 0.551), and their consensus score had a significantly lower AUC of 0.662. The physicians’ consensus demonstrated a sensitivity of 0.203, specificity of 0.934, NPV of 0.527, and PPV of 0.765. Notably, this performance difference remained significant regardless of patients’ sex and age (P < 0.001 for both).
Conclusion
Our findings suggest that a smartphone application can accurately and reliably quantify hyperkalemia risk using initial ECGs in the ED.
6.Detecting mpox infection in the early epidemic: an epidemiologic investigation of the third and fourth cases in Korea
Taeyoung KIM ; Eonjoo PARK ; Jun Suk EUN ; Eun-young LEE ; Ji Won MUN ; Yunsang CHOI ; Shinyoung LEE ; Hansol YEOM ; Eunkyoung KIM ; Jongmu KIM ; Jihyun CHOI ; Jinho HA ; Sookkyung PARK
Epidemiology and Health 2023;45(1):e2023040-
OBJECTIVES:
As few mpox cases have been reported in Korea, we aimed to identify the characteristics of mpox infection by describing our epidemiologic investigation of a woman patient (index patient, the third case in Korea) and a physician who was infected by a needlestick injury (the fourth case).
METHODS:
We conducted contact tracing and exposure risk evaluation through interviews with these 2 patients and their physicians and contacts, as well as field investigations at each facility visited by the patients during their symptomatic periods. We then classified contacts into 3 levels according to their exposure risk and managed them to minimize further transmission by recommending quarantine and vaccination for post-exposure prophylaxis and monitoring their symptoms.
RESULTS:
The index patient had sexual contact with a man foreigner during a trip to Dubai, which was considered the probable route of transmission. In total, 27 healthcare-associated contacts across 7 healthcare facilities and 9 community contacts were identified. These contacts were classified into high (7 contacts), medium (9 contacts), and low (20 contacts) exposure risk groups. One high-risk contact was identified as a secondary patient: a physician who was injured while collecting specimens from the index patient.
CONCLUSIONS
The index patient visited several medical facilities due to progressive symptoms prior to isolation. Although the 2022 mpox epidemic mainly affected young men, especially men who have sex with men, physicians should also consider mpox transmission in the general population for the timely detection of mpox-infected patients.
8.Immune Checkpoint Programmed Cell Death Protein-1 (PD-1) Expression on Bone Marrow T Cell Subsets in Patients With Plasma Cell Myeloma
Min Young LEE ; Chan-Jeoung PARK ; Young-Uk CHO ; Eunkyoung YOU ; Seongsoo JANG ; Eul Ju SEO ; Jung-Hee LEE ; Dok Hyun YOON ; Cheolwon SUH
Annals of Laboratory Medicine 2021;41(3):259-267
Background:
Plasma cell myeloma (PCM) is caused by immune dysregulation. We evaluated the expression of immune checkpoint programmed cell death protein-1 (PD-1) on T cell subsets in PCM patients according to disease course and cytogenetic abnormalities.This study aimed to find a target group suitable for therapeutic use of PD-1 blockade in PCM.
Methods:
A total of 188 bone marrow (BM) samples from 166 PCM patients and 32 controls were prospectively collected between May 2016 and May 2017. PD-1 expression on BM T cell subsets was measured using flow cytometry.
Results:
At diagnosis, the median PD-1 expression on CD4+ T cells was 24.6%, which did not significantly differ from that in controls. After stem cell transplantation, PD-1 expression on CD4+ T cells was higher than that at diagnosis (P < 0.001), regardless of residual disease. PD-1 expression on CD4+ T cells in patients with residual disease after chemotherapy was significantly higher than that at diagnosis (P = 0.001) and after complete remission following chemotherapy (P = 0.044). PD-1 expression on CD8+ T cells was higher in PCM patients with cytogenetic abnormalities, including monosomy 13, 1q gain, complex karyotype, and hypodiploidy.
Conclusions
PD-1 blockade might have therapeutic potential in refractory PCM patients after chemotherapy, especially in those with high- or intermediate-risk cytogenetic abnormalities.
9.The fruit of Acanthopanax senticosus Harms improves arterial stiffness and blood pressure: a randomized, placebo-controlled trial
Eunkyoung OH ; Youjin KIM ; Soo-yeon PARK ; Yeni LIM ; Ji-yoon SHIN ; Ji Yeon KIM ; Ji-Hyun KIM ; Moo-Yong RHEE ; Oran KWON
Nutrition Research and Practice 2020;14(4):322-333
BACKGROUND/OBJECTIVES:
Arterial stiffness and endothelial dysfunction are 2 of the independent predictors for cardiovascular disease, while Acanthopanax senticosus Harms (ASH) is a traditional medicinal plant that can improve cardiovascular health. This study aimed to investigate the efficacy of the fruit of ASH on vascular function in apparently healthy subjects.
SUBJECTS/METHODS:
A 12-week, randomized, double-blind, placebo-controlled design, consisting of healthy adults with at least 2 of the following 3 conditions: borderline high blood pressure (BP; 120 mmHg ≤ systolic BP ≤ 160 mmHg or 80 mmHg ≤ diastolic BP ≤ 100 mmHg), smoking (≥10 cigarettes/day), and borderline blood lipid levels (220 ≤ total cholesterol ≤ 240, 130 ≤ low density lipoprotein cholesterol ≤ 165, or 150 ≤ triglyceride ≤ 220 mg/dL). Randomly assigned 76 subjects who received a placebo or 2 doses of ASH fruit (low, 500 mg/day; high, 1,000 mg/day) completed the intervention. Brachial-ankle pulse wave velocity (baPWV), flow-mediated dilation, carotid intima-media thickness, and BP were measured both at baseline and following the 12-week intervention. Endothelial nitric oxide synthase (eNOS) phosphorylation was assessed by western blotting.
RESULTS:
Compared with the placebo group, the low-dose group showed more significant changes after the 12-week intervention period in terms of systolic BP (0.1 vs. −7.7 mmHg; P = 0.044), baPWV (31.3 vs. −98.7 cm/s; P = 0.007), and the ratio of phospho-eNOS/eNOS (0.8 vs. 1.22; P = 0.037).
CONCLUSIONS
These results suggest that ASH fruit extract at 500 mg/day has the potential to improve BP and arterial stiffness via endothelial eNOS activation in healthy adults with smoking and the tendency of having elevated BP or blood lipid parameters.
10.Recent Patient Health Monitoring Platforms Incorporating Internet of Things-Enabled Smart Devices.
Minhee KANG ; Eunkyoung PARK ; Baek Hwan CHO ; Kyu Sung LEE
International Neurourology Journal 2018;22(4):313-313
Due to a mistake in reference by the author submission in this article, an erroneous grant number had been published.

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