Background
Insulin resistance (IR) influences lipid metabolism, particularly small dense low-density lipoprotein cholesterol (sdLDL-C), a key feature of diabetic dyslipidemia and a predictor of cardiovascular disease. The single-point insulin sensitivity estimator (SPISE) index is an effective tool for assessing IR. This study explored the relationship between the SPISE index and average low-density lipoprotein cholesterol (LDL-C) particle size in obese Korean adults.
Methods
Cardiovascular risk was assessed in 161 obese individuals. The participants were divided into three groups based on SPISE index tertiles. Steiger’s Z test was used to assess the differences in correlation coefficients among various IR indices and average LDL-C particle size. Multivariate linear regression models were used to determine the independent association between the SPISE index and average LDL-C particle size. Receiver operating characteristic (ROC) curves established the SPISE index cut-off for sdLDL-C particle dominance.
Results
The SPISE index was positively correlated with mean LDL-C particle size after adjusting for confounders. It demonstrated a stronger independent association with average LDL-C particle size (r=0.679, P<0.001) than with fasting insulin, the homeostatic model assessment for IR, and the quantitative insulin sensitivity check index (P<0.001 for all). ROC analysis identified an optimal SPISE index cutoff for sdLDL-C predominance of 4.955, with an area under the curve of 0.745.
Conclusion
Our findings indicate a direct correlation between the SPISE index and average LDL-C particle size, suggesting that the SPISE index may complement labor-intensive IR indices and sdLDL-C measurement techniques for estimating IR-induced sdLDL-C predominance.

Background
Sleep disorders and insomnia are prevalent worldwide, with negative health outcomes. The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report assessment tool for evaluating sleep quality, comprising seven subdomains. The Korean version of the PSQI (PSQI-K) has been tested for reliability and validity in small sample sizes but lacks large-scale validation using objective measures.
Methods
This study was conducted with 268 Korean adults attending health check programs. Participants completed the PSQI-K questionnaire and wore Fitbit devices (Fitbit Inc., USA) to ascertain sleep parameters. Reliability was analyzed using the Cronbach’s α coefficient, and construct validity was determined through factor analysis. Criteria validity was assessed by correlating their index scores with Fitbit sleep parameters. We identified the optimal cutoff for detecting sleep disorders.
Results
The Cronbach’s α coefficient was 0.61, indicating adequate internal consistency. Factor analysis revealed three factors, explaining 48.2% of sleep quality variance. The index scores were negatively correlated with Fitbit sleep efficiency, total sleep time, and number of awakenings (P<0.05). The optimal cutoff point for identifying sleep disorder groups was ≥6.
Conclusion
The PSQI-K demonstrated good reliability and validity when correlated with Fitbit sleep parameters, offering a practical screening tool for identifying sleep disorders among Korean adults. Cutoff scores can help identify patients for sleep interventions. However, further large-scale studies are required to validate these findings.

Citations

• Association of work ability with job burnout and sleep quality among biosafety laboratory personnel in Xinjiang, China: a cross-sectional study
  Keke Ju, Ruikai Wu, Jing Yu, Lei Ding, Mengjie Xia, Jiwen Liu, Yaoqin Lu
  Frontiers in Public Health.2025;[Epub]     CrossRef
• Validation of the Korean version of the Sleep Hygiene Practice Scale in a Non-Clinical Population
  Dongyeop Kim, Ji Young Yun, Hye Ah Lee, Pamela Song, Heeyoung Ahn, Chien-Ming Yang, Jee Hyun Kim
  Behavioral Sleep Medicine.2024; 22(6): 791.     CrossRef
• The relationship between sleep quality and happiness among preclinical students in a medical school
  Rusdiah Ruzanna Jusoh, Kavimitha G Krishnasamy, Saila Dharishinee Alagu, Pretha Mohan, Jeslyn Tan Guan Qian, Elayevenee Elanthevan, Muhammad Zulfiqah Sadikan, Haryati Ahmad Hairi
  Journal of Education Technology in Health Sciences.2024; 11(3): 92.     CrossRef

Background
Physical activity (PA) is associated with a favorable metabolic risk profile in adults. However, its role in adolescents remains unclear. In this study, using data (2019–2021) from the 8th Korea National Health and Nutrition Examination Survey, we investigated the optimal exercise type for preventing metabolic complications in adolescents.
Methods
A total of 1,222 eligible adolescent participants (12–18-year-old) were divided into four groups as follows: aerobic exercise (AE), resistance exercise (RE), combined aerobic and resistance exercise (CE), and no exercise (NE). Daily PA was assessed using the international PA questionnaire. Blood samples were collected to measure lipid, glucose, and insulin levels. Additionally, the homeostasis model assessment for insulin resistance (HOMA-IR) and triglyceride-glucose (TyG) indices were measured. Multivariate regression analysis was used to compare the metabolic risk factors across the PA groups before and after propensity score matching (PSM) adjustment for confounding variables.
Results
The CE group exhibited improved fasting glucose levels, lower TyG index, reduced white blood cell count, and higher high-density lipoprotein (HDL) cholesterol levels than the NE group. The RE group exhibited lower mean blood pressure, triglyceride, fasting insulin, HOMA-IR, TyG index and a reduced risk of metabolic syndrome than the NE group. The AE group had higher total and HDL cholesterol levels. In detailed comparison of the AE and RE groups, the RE group consistently exhibited favorable metabolic parameters, including lower blood pressure and total and low-density cholesterol levels, which persisted after PSM.
Conclusion
These findings highlight the positive effects of PA on cardiovascular risk factors in adolescents. Thus, RE may have a more favorable metabolic effect than AE. Further studies are needed to validate the benefits of exercise according to the exercise type.

Citations

• Reflecting on progress and challenges: the Korean Journal of Family Medicine in 2024
  Seung-Won Oh
  Korean Journal of Family Medicine.2025; 46(2): 55.     CrossRef