Background
Insulin resistance contributes to the development of cardiovascular disease and type 2 diabetes mellitus. Smoking leads to an increase in triglyceride levels, which, in turn, increases insulin resistance. Although the number of e-cigarette users has increased in recent years, few studies have investigated the association between ecigarette use and insulin resistance. Therefore, this study aimed to determine the association between e-cigarette use and insulin resistance using the triglyceride-glucose (TyG) index in Korean adults.
Methods
This study included 4,404 healthy adults aged ≥20 years who participated in the Korea National Health and Nutrition Examination Survey between 2019 and 2020. Participants were categorized as never-smokers or ecigarette users, and the TyG index was categorized into low- and high-TyG index groups according to the median value (9.22). A logistic regression analysis was performed to determine the association between e-cigarette smoking and insulin resistance.
Results
E-cigarette users had a higher TyG index than never smokers (e-cigarette: mean=3.95; never: mean=9.18; P<0.001). The e-cigarette users had a higher risk of being in the high TyG index group than never-smokers (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.03–1.84). In the subgroup analysis stratified by sex, age, and body mass index, a higher OR for a high TyG index was observed in men (OR, 1.46; 95% CI, 1.03–2.08) and individuals aged 60 years or older (OR, 3.74; 95% CI, 1.14–12.30).
Conclusion
Our findings suggest that e-cigarette use is significantly associated with insulin resistance.

Background
Skipping breakfast is associated with an increased risk of chronic inflammatory diseases. This study aimed to examine the association between breakfast-eating habits and inflammation, using high-sensitivity C-reactive protein (hs-CRP) as a marker.
Methods
A total of 4,000 Korean adult males with no history of myocardial infarction, angina, stroke, diabetes, rheumatoid arthritis, cancer, or current smoking were included. Data from the 2016–2018 Korea National Health and Nutrition Examination Survey were used for analysis. The frequency of breakfast consumption was assessed through a questionnaire item in the dietary survey section asking participants about their weekly breakfast consumption routines over the past year. Participants were categorized into two groups, namely “0–2 breakfasts per week” and “3–7 breakfasts per week”; hs-CRP concentrations were measured through blood tests.
Results
Comparing between the “infrequent breakfast consumption (0–2 breakfasts per week)” and “frequent breakfast consumption (3–7 breakfasts per week)” groups, the mean hs-CRP was found to be significantly higher in the “infrequent breakfast consumption” group, even after adjusting for age, body mass index, physical activity, alcohol consumption, systolic blood pressure, blood pressure medication, fasting blood glucose, and triglycerides (mean hs-CRP: frequent breakfast consumption, 1.36±0.09 mg/L; infrequent breakfast consumption, 1.17±0.05 mg/L; P-value=0.036).
Conclusion
Less frequent breakfast consumption was associated with elevated hs-CRP levels. Further large-scale studies incorporating adjusted measures of daily eating patterns as well as food quality and quantity are required for a deeper understanding of the role of breakfast in the primary prevention of chronic inflammatory diseases.

Background
Sleep duration is associated with hearing loss, especially presbycusis, which is the most common type of hearing loss; however, there is limited evidence regarding this association among the Korean population. We aimed to determine the relationship between sleep duration and high-frequency hearing loss in Korean adults aged ≥40 years.
Methods
We examined 5,547 Korean adults aged ≥40 years who completed audiometric tests and questionnaires regarding sleep duration during the 2010–2012 cycle of the Korea National Health and Nutrition Examination Survey. Mild presbycusis was defined as >25 decibels (dB) and <40 dB, whereas moderate-to-severe presbycusis was defined as >40 dB pure tone averages at high frequencies (3,000, 4,000, and 6,000 Hz) for both ears. Additionally, the sleep duration was divided into quartiles. Odds ratios and 95% confidence intervals were estimated using multivariable logistic regression after adjusting for covariates.
Results
The prevalence of presbycusis in South Korean adults was 62.1%, of which 61.4% showed moderate to severe presbycusis. The incidence of moderate-to-severe, but not mild, presbycusis showed a significant positive correlation with sleep duration.
Conclusion
Our findings suggest that sleep duration is associated with the prevalence of presbycusis.

Citations

• Joint association of sleep duration and depression with new-onset hearing loss: a national cohort study
  Fang Wang, Yu-Jun Xiong, Da-Ming Shao, Tian Lv, Shiqin Chen, Qian-Yuan Zhu
  Frontiers in Nutrition.2025;[Epub]     CrossRef
• Sleep characteristics and hearing loss in middle-aged and older adults: The National Health and Nutrition Examination Survey 2015–2018
  Kening Jiang, Adam P. Spira, Nicholas S. Reed, Frank R. Lin, Jennifer A. Deal
  Sleep Epidemiology.2024; 4: 100082.     CrossRef
• Age-related hearing loss and its potential drug candidates: a systematic review
  Shiyu Hu, Qingru Sun, Fei Xu, Ninghua Jiang, Jianli Gao
  Chinese Medicine.2023;[Epub]     CrossRef

Background
The aim of this study was to evaluate the association between near work time and depression.
Methods
Data of 1,551 workers aged 19–49 years from the sixth Korea National Health and Nutrition Examination Survey were examined. The Patient Health Questionaire-9 scores were used to screen for depression. Participants who scored a total of 10 or above, which is suggestive of the presence of depression, were classified as the depression group; the rest were classified as normal. The correlation between daily near work time and depression was analyzed using multivariate logistic analysis after adjusting for other sociodemographic and health behavior-related variables.
Results
Multivariate logistic analysis found that workers with 3 or more hours of near work were more likely to report depression compared to the reference group who had 2 or fewer hours per day of near work (adjusted odds ratio, 2.471; 95% confidence interval, 1.062–5.747).
Conclusion
Longer near work time was associated with depression among South Korea’s workers. Therefore, it is necessary to reduce near work time to prevent depression.

Background
The prevalence of chronic kidney disease is increasing worldwide. Several studies have suggested that obesity is associated with early renal dysfunction. However, little is known about the relationship between obesity phenotypes and early renal function decline. Therefore, this study aimed to identify the relationship between obesity phenotypes and early renal function decline in adults without hypertension, dyslipidemia, and diabetes.
Methods
We conducted a cross-sectional analysis of clinical and anthropometric data from 1,219 patients who underwent a routine health checkup in 2014. We excluded adults with cardiovascular disease, renal disease, diabetes, hypertension, dyslipidemia, or low glomerular filtration rate (<60 mL/min/1.73 m2). Renal function was determined according to the estimated glomerular filtration rate calculated using the Chronic Kidney Disease Epidemiology Collaboration creatinine-cystatin C equation.
Results
Age, sex, body mass index, waist circumference, triglyceride, low-density lipoprotein, and fasting glucose had an association with the estimated glomerular filtration rate. After adjusting for age, sex, smoking status, and alcohol intake, the odds ratios of the metabolically abnormal normal weight and metabolically abnormal obese phenotypes for the presence of low estimated glomerular filtration rates were 1.807 (95% confidence interval, 1.009– 3.236) and 1.834 (95% confidence interval, 1.162–2.895), compared with the metabolically healthy normal weight phenotype. However, the metabolically healthy obese phenotype did not show a significant association with early renal function decline.
Conclusion
In this cross-sectional study, we confirmed the association between the metabolically abnormal normal weight and metabolically abnormal obese phenotypes and early kidney function decline in adults without hypertension, dyslipidemia, and diabetes.

Citations

• Obesity as a Risk Factor for Hyperglycemia, Electrolyte Disturbances, and Acute Kidney Injury in the Emergency Department
  Iulia Najette Crintea, Alexandru Cristian Cindrea, Ovidiu Alexandru Mederle, Teodor Florin Fulga, Adina Maria Marza, Alina Petrica, Cosmin Iosif Trebuian, Romulus Timar
  Biomedicines.2025; 13(2): 349.     CrossRef
• Obesity Class and Severity of Metabolic Emergencies: A Single-Center Retrospective Five-Year Study
  Iulia Najette Crintea, Alexandru Cristian Cindrea, Teodor Florin Fulga, Cosmin Iosif Trebuian, Adina Maria Marza, Alina Petrica, Ovidiu Alexandru Mederle, Romulus Timar
  Healthcare.2025; 13(6): 617.     CrossRef
• Metabolically healthy obesity and chronic kidney disease risk: exploring the dynamics
  Mustafa GULDAN, Lasin OZBEK, Ahmet U. TOPCU, Adrian COVIC, Mehmet KANBAY
  Panminerva Medica.2024;[Epub]     CrossRef
• Visceral Adiposity Index and Lipid Accumulation Product as Effective Markers of Different Obesity Phenotypes in Korean Adults: A Cross-Sectional Analysis
  Sung Ryul Yu, Kyung-A Shin
  Diabetes, Metabolic Syndrome and Obesity.2023; Volume 16: 495.     CrossRef
• Metabolically healthy obesity is associated with higher risk of both hyperfiltration and mildly reduced estimated glomerular filtration rate: the role of serum uric acid in a cross-sectional study
  Hong Zhang, Rui Chen, Xiaohong Xu, Minxing Yang, Wenrong Xu, Shoukui Xiang, Long Wang, Xiaohong Jiang, Fei Hua, Xiaolin Huang
  Journal of Translational Medicine.2023;[Epub]     CrossRef
• Prevalence and associations of metabolic syndrome in patients with alcohol use disorder
  Anna Hernández-Rubio, Arantza Sanvisens, Ferran Bolao, Isabel Cachón-Suárez, Carme Garcia-Martín, Antoni Short, Ramón Bataller, Roberto Muga
  Scientific Reports.2022;[Epub]     CrossRef
• Effects of bariatric surgery on renal function and associated factors with bivariate analysis: a cohort study
  Juliana Amaro Borborema Bezerra, Eduardo Pachu Raia dos Santos, Carlos Teixeira Brandt
  F1000Research.2022; 11: 409.     CrossRef
• Metabolic obesity phenotypes and chronic kidney disease: a cross-sectional study from the RaNCD cohort study
  Samira Arbabi Jam, Behrooz Moloudpour, Farid Najafi, Mitra Darbandi, Yahya Pasdar
  BMC Nephrology.2022;[Epub]     CrossRef
• Abdominal obesity phenotypes and risk of kidney function decline: Tehran Lipid and Glucose Study
  Asharf Shahali, Erfan Tasdighi, Maryam Barzin, Maryam Mahdavi, Majid Valizadeh, Mahtab Niroomand, Fereidoun Azizi, Farhad Hosseinpanah
  Obesity Research & Clinical Practice.2020; 14(2): 168.     CrossRef
• Obese First degree relatives of hemodialysis patients are at Higher Risk for Developing Kidney Diseases: In a Cross-sectional Study
  Abozaid Mohammed Elemam
  Sudan Journal of Medical Sciences.2019;[Epub]     CrossRef