Hyo-Min Kim

The Relationship of Caffeine Intake with Depression, Anxiety, Stress, and Sleep in Korean Adolescents

Background In various studies in adults, caffeine may increase wakefulness and relieve pain, but caffeine overdose can cause many adverse serious effects on health. Caffeine intake has recently been increasing in adolescents. In spite of importance of caffeine effects on Korean adolescents, there are lack of scientific and systematic studies. The purpose of our study was to identify the relationship between caffeine consumption and effects on adolescents. Methods We performed study on 234 middle school students at one middle school in Daegu using a self-report questionnaire. We divided students to quartiles according to amount of caffeine intake. We used Beck Depression Inventory (BDI) to evaluate the degree of depression and Beck Anxiety Inventory (BAI) to evaluate the degree of anxiety. We also used Insomnia Severity Scale (ISI) to evaluate the degree of insomnia and Global Assessment of Recent Stress (GARS) to evaluate the stress in students. We used logistic regression analysis to identify the relationship between caffeine consumption and effects. Results Higher caffeine intake was associated with higher weight, height, lower academic achievement, and higher score in BDI, BAI, ISI, and GARS (P for trend <0.005). Higher caffeine intake quartile was associated with greater odds of having significant depression (BDI ≥10, P for trend=0.011), and insomnia (ISI ≥8, P for trend=0.015) after adjustment for factors that can affect the psychological status. Conclusion We found that caffeine intake is associated weight, height, academic achievement, and higher score in BDI, BAI, ISI, and GARS. Caffeine intake was positively associated with the severity of depression and the severity of insomnia among adolescents in Korean.

Beneficial Effects of Appropriate Sleep Duration on Depressive Symptoms and Perceived Stress Severity in a Healthy Population in Korea

Background Recently, several institutions, including the American Academy of Sleep Medicine, the Sleep Research Society, and the National Sleep Foundation, have made consensus recommendations concerning appropriate sleep duration for adults. Although numerous studies conducted in Western populations have provided evidence of the harmful effects of short or long sleep duration on mental health, it is still unclear whether these consensus recommendations are appropriate in Korean culture. Methods Data from 1,892 subjects with no history of medical or psychiatric diagnoses were selected from the Korea National Health and Nutrition Examination Survey of 2014. Subjects were divided into seven groups based on their sleep duration (≤4, 5, 6, 7, 8, 9, and ≥10 hours). Depressive symptoms were measured using the Patient Health Questionnaire-9 and perceived stress severity was evaluated using a Likert-type scale. Group differences in depressive symptoms and severity of stress were analyzed using an analysis of covariance. Results Depressive symptoms in subjects with sleep duration of ≤4 hours (5.7±5.9) or 5 hours (3.4±3.9) were higher than in subjects with a sleep duration of 7 (2.2±2.9) or 8 hours (2.2±2.9) (corrected P<0.05). Furthermore, subjects with a short sleep duration (5 hours or below) had greater perceived stress severity than subjects with a sleep duration of 7 or 8 hours (corrected P<0.05). Conclusion Our results suggest that maintaining an appropriate sleep duration as found in the recent consensus recommendation is important for mental health, even in healthy subjects without any medical or psychiatric illnesses, in Korea.

Associations between Body Mass Index and Chronic Atrophic Gastritis and Intestinal Metaplasia

Background/Aims Chronic atrophic gastritis (AG) and intestinal metaplasia (IM) of the stomach are premalignant lesions. The present study aimed to examine the associations between obesity and these lesions. Methods A total of 2,997 patients, who underwent gastroscopy, participated in this study, excluding those who had been diagnosed with gastric cancer. Participants were divided into four groups based on their body mass index (BMI). The risk of AG and IM with increasing BMI was analyzed in men and women, separately. Results The association between BMI and AG was not significant. After adjusting for age, smoking, alcohol, and AG, the odds ratios for IM in the overweight, obesity, and severe obesity groups were 2.25 (95% confidence interval [CI], 1.50-3.37), 2.32 (95% CI, 1.58-3.42), and 4.86 (95% CI, 2.04-11.5) in men, and 2.66 (95% CI, 1.29-5.47), 4.46 (95% CI, 2.28-8.75), and 9.57 (95% CI, 3.26-28.12) in women, compared with the normal BMI group. Conclusions Gastric IM was significantly associated with increased BMI.