Korean Circulation Journal 대한심장학회지 순환기 Kim J, et al. Korean Circ J. 2020 Nov;50(11):1013-1022. https://doi.org/10.4070/kcj.2020.0108

Objective. The purpose of this study was to establish the validity and reliability of the newly developed surface electromyography (sEMG) device (PSL-EMG-Tr1) compared with a conventional sEMG device (BTS-FREEEMG1000). Methods. In total, 20 healthy participants (10 males, age 30.3 ± 2.9 years; 10 females, age 22.3 ± 2.7 years) were recruited. EMG signals were recorded simultaneously on two devices during three different isometric contractions (maximal voluntary isometric contraction (MVIC, 40% MVIC, 80% MVIC)). Two trials were performed, and the same session was repeated after 1 week. EMG amplitude recorded from the dominant biceps brachii (BB) and rectus femoris (RF) muscles was analyzed for reliability using intrasession intraclass correlation coefficient (ICC). Concurrent validity of the two devices was determined using Pearson’s correlation coefficient. Results. Nonnormalized sEMG data showed moderate to very high reliability for all three contraction levels (ICC = 0.832–0.937 (BB); ICC = 0.814–0.957 (RF)). Normalized sEMG values showed no to high reliability (ICC = 0.030–0.831 (BB); ICC = 0.547–0.828 (RF)). sEMG signals recorded by the PSL-EMG-Tr1 showed good to excellent validity compared with the BTS-FREEEMG1000, at 40% MVIC (r = 0.943 (BB), r = 0.940 (RF)) and 80% MVIC (r = 0.983 (BB); r = 0.763 (RF)). Conclusions. The PSL-EMG-Tr1 was performed with acceptable validity. Furthermore, the high accessibility and portability of the device are useful in adjusting the type and intensity of exercise.

Purpose: We evaluate the relationship between Bruch's membrane opening minimum rim width (BMO-MRW) and peripapillary retinal nerve fiber layer thickness (pRNFLT) and develop a new parameter combining BMO-MRW and pRNFLT using a neural network to maximize their compensatory values. Methods: A total of 402 subjects were divided into two groups: 273 (validation group) and 129 (neural net training) subjects. Linear quadratic and broken-stick regression models were used to explore the relationship between BMO-MRW and pRNFLT. A multilayer neural network was used to create a combined parameter, and diagnostic performances were compared using area under the receiver operating characteristic curves (AUROCs). Results: Regression analyses between BMO-MRW and pRNFLT revealed that the broken-stick model afforded the best fit. Globally, the tipping point was a BMO-MRW of 226.5 μm. BMO-MRW and pRNFLT were correlated significantly with visual field. When differentiating normal from glaucoma subjects, the neural network exhibited the largest AUROC. When differentiating normal from early glaucoma subjects, the overall diagnostic performance decreased, but the neural network still exhibited the largest AUROC. Conclusions: The optimal relationship between BMO-MRW and pRNFLT was revealed using the broken-stick model. Considerable BMO-MRW thinning preceded pRNFLT thinning. The neural network significantly improved diagnostic power by combining BMO-MRW and pRNFLT. Translational Relevance: A combined index featuring BMO-MRW and pRNFLT data can aid clinical decision-making, particularly when individual parameters yield confusing results. Our neural network effectively combines information from separate parameters.

Albuminuria is generally accepted as a sensitive marker of diabetic nephropathy but has limitations in predicting its progression. The aim of this study was to evaluate the use of nonalbumin proteinuria in addition to albuminuria for predicting the progression of type 2 diabetic nephropathy. In this retrospective observational study, the urine albumin-to-creatinine ratio (ACR) and the nonalbumin protein-to-creatinine ratio (NAPCR) were measured in 325 patients with type 2 diabetes and estimated glomerular filtration rates (eGFR) ≥30 mL/min/1.73 m2. The patients were divided into four groups based on the cutoff points for the urinary ACR (30 mg/g) and NAPCR (120 mg/g). The renal outcomes were chronic kidney disease (CKD) progression and accelerated eGFR decline. During the 4.3-year follow-up period, 25 (7.7%) patients showed CKD progression and 69 (21.2%) patients showed accelerated eGFR decline. After adjusting for nine clinical parameters, the group with a NAPCR greater than 120 mg/g exhibited higher cumulative incidences of CKD progression (hazard ratio 6.84; P = 0.001) and accelerated eGFR decline (hazard ratio 1.95; P = 0.011) than the group with a NAPCR < 120 mg/g. In patients with normoalbuminuria, the group with NAPCR levels greater than 120 mg/g also exhibited a higher cumulative incidence than that with NAPCR levels <120 mg/g of CKD progression (hazard ratio 21.82; P = 0.005). The addition of NAPCR to ACR improved the model fit for CKD progression and accelerated eGFR decline. Nonalbumin proteinuria showed additional value over and above that of albuminuria for predicting the progression of CKD in patients with type 2 diabetes.

Park TS, et al. J Korean Med Sci. 2023 Oct;38(40):e325. https://doi.org/10.3346/jkms.2023.38.e325

Background: Caffeine, a widely consumed stimulant, affects sleep and mental health. Shift work disrupts the circadian rhythm and has been associated with various mental health issues, such as depression, anxiety, and suicidal ideation. Objective: This study explored the associations between caffeine consumption, sleep duration, and mental health outcomes, particularly suicidal ideation, among shift workers in Korea. Methods: Data from the 6th Korea National Health and Nutrition Examination Survey (2013, 2015), which comprised 4723 adults aged 19 and older, were analyzed. Participants were categorized into groups based on average daily coffee consumption and work patterns. Multiple logistic regression analyses were conducted to determine the impact of caffeine consumption and work patterns on mental health outcomes. Results: Participants worked longer hours, reported higher perceived stress levels, and slightly decreased sleep duration as daily coffee consumption increased. However, no significant differences were observed in depression or suicidal ideation across the coffee consumption groups. Logistic regression analysis indicated a trend towards higher suicidal ideation risk with increased coffee intake, particularly among those who consumed three or more cups per day (OR 5.67, 95% CI 1.82–17.59). Conclusion: This study suggests a complex relationship between caffeine consumption, work patterns, and mental health outcomes. Although caffeine intake is associated with increased work hours and stress, its impact on suicidal ideation is influenced by occupational factors.