Evaluation of the Effects of Differences in Metal Artifact Type and Location on Image Quality in Computed Tomography Scans.

Artifacts in computed tomography scans distort anatomical information and prevent an accurate diagnosis. Therefore, this study aims to determine the most effective method for reducing metal-induced artifacts by evaluating the effects of the metal artifact type and location, and the tube voltage on the image quality. Fe and Cu wires were inserted into a Virtual Water™ phantom at 6.5 and 11 cm distances from the center point (DPs). The contrast-to-noise ratios (CNRs) and signal-to-noise ratios (SNRs) were calculated to compare the images. The results reveal higher CNRs and SNRs when using standard and Smart metal artifact reduction (Smart MAR) algorithms for Cu and Fe insertions, respectively. The standard algorithm leads to a higher CNR and SNR for Fe and Cu at DPs of 6.5 and 11 cm, respectively. The Smart MAR algorithm provides effective outcomes at voltages of 100 and 120 kVp for wires located at 11 and 6.5 cm DP, respectively. The most effective imaging conditions for MAR is generated by the Smart MAR algorithm with a tube voltage for 100 kVp for Fe located at a DP of 11 cm. MAR can be improved by setting suitable tube voltage conditions according to the type and location of inserted metal.

Bidirectional association between blood pressure and depressive symptoms in young and middle-age adults: A cohort study.

AIMS: To evaluate the bidirectional relationship between blood pressure (BP) and depressive symptoms using a large prospective cohort study. METHODS: Prospective cohort study was performed in 276 244 adults who participated in a regular health check-up and were followed annually or biennially for up to 5.9 years. BP levels were categorised according to the 2017 American College of Cardiology and American Heart Association hypertension guidelines. Depressive symptoms were assessed using Centre for Epidemiologic Studies-Depression (CESD) questionnaire and a cut-off score of ≥25 was regarded as case-level depressive symptoms. RESULTS: During 672 603.3 person-years of follow-up, 5222 participants developed case-level depressive symptoms. The multivariable-adjusted hazard ratios (HRs) [95% confidence interval (CI)] for incident case-level depressive symptoms comparing hypotension, elevated BP, hypertension stage 1 and hypertension stage 2 to normal BP were 1.07 (0.99-1.16), 0.93 (0.82-1.05), 0.89 (0.81-0.97) and 0.81 (0.62-1.06), respectively (p for trend <0.001). During 583 615.3 person-years of follow-up, 27 787 participants developed hypertension. The multivariable-adjusted HRs (95% CI) for incident hypertension comparing CESD 16-24 and ⩾25 to CESD < 16 were 1.05 (1.01-1.11) and 1.12 (1.03-1.20), respectively (p for trend <0.001) and in the time-dependent models, corresponding HRs (95% CI) were 1.12 (1.02-1.24) and 1.29 (1.10-1.50), respectively (p for trend <0.001). CONCLUSIONS: In this large cohort study of young and middle-aged individuals, higher BP levels were independently associated with a decreased risk for developing case-level depressive symptoms and depressive symptoms were also associated with incident hypertension. Further studies are required to elucidate the mechanisms underlying the bidirectional association between BP levels and incident depression.

Metabolic syndrome and incident depressive symptoms in young and middle-aged adults: A cohort study.

BACKGROUND: Recent studies on the prospective association between metabolic syndrome (MetS) and depression have reported conflicting findings. METHODS: A cohort study was performed with 115,223 middle-aged adults, free of depression at baseline, who underwent at least 2 comprehensive exams between 2012 and 2015. MetS was assessed according to the National Cholesterol Education Program Adult Treatment Panel III. The study endpoint was new onset of depression, defined as a Center for Epidemiologic Studies-Depression Scale score ≥ 16. RESULTS: Over 253,451.6 person-years, 6,833 participants developed depression. When the participants with 0 MetS components were set as a reference, the multivariable-adjusted hazard ratio (HR, 95% confidence interval [CI]) for incident depression formed a U-shaped curve with the number of MetS components (p for trend = 0.229): 1 (1.07 [1.02-1.15]); 2 (0.92 [0.82-1.06]); 3 (0.85 [0.78-1.07]); 4 (1.16 [1.06-1.32]); and 5 MetS components (1.25 [1.10-1.54]). The presence or absence of MetS was not significant in new-onset depression. In examining potential clustering and synergistic effects of the constituent parts, waist circumference was the major driving factor of incident depression, and its relative excess risk due to interaction increased with the number of combinations. LIMITATIONS: We used a self-reported depression scale, and the follow-up period was relatively short. CONCLUSIONS: Future studies investigating the risk for incident depression should place more focus on the number of MetS abnormalities and specific MetS factors, such as waist circumference, than the presence or absence of MetS.

The Relationship between Plasma Oxytocin Levels and Social Anxiety Symptoms.

OBJECTIVE: The pathophysiology of social anxiety disorder (SAD) is not yet well understood, but previous research has suggested that oxytocin is associated with social behavior and may play a role in human anxiety states and anxiety-related traits. The aim of this study was to investigate the possible relationship between social anxiety symptoms and plasma oxytocin levels. METHODS: Twenty-three male patients with SAD and 28 healthy male controls participated in this study. All participants were assessed using the Mini International Neuropsychiatric Interview (MINI) and the Liebowitz Social Anxiety Scale (LSAS). Multivariate regression analysis was performed to identify associations between plasma oxytocin levels and SAD. RESULTS: In multiple regression models, after controlling for age and years of education, we found that higher oxytocin levels were significantly associated with higher total LSAS scores (R2 =0.157, coefficient=0.145, 95% CI=-0.0005-0.291, p=0.051) and fear subscale scores (R2 =0.134, coefficient=0.083, 95% CI=0.007-0.159, p=0.034) in the SAD group. CONCLUSION: In this study, increased plasma oxytocin levels were associated with higher social anxiety symptoms among SAD patients, but not among controls. This might be because among SAD patients, higher oxytocin (OT) secretion is an insufficient compensatory attempt to reduce social anxiety symptoms.

Association between physical activity and depressive symptoms in general adult populations: An analysis of the dose-response relationship.

This study investigated the dose-response relationship between physical activity and depression. We collected data from 99,846 participants who had no medical contraindications to exercise. Using the short-form Korean version of the International Physical Activity Questionnaire, total physical activity was computed in metabolic equivalents (METs). We used the Center for Epidemiologic Studies Rating Scale for Depression to assess depressive symptoms and set a cut off score of 21. Logistic regression analyses were used to determine any relationships. To assess the effect of sex difference on the association between physical activity and depression, we stratified our data by sex. Compared with the sedentary group (0-600 METs-min/week), 1-15 times the recommended minimum physical activity was associated with a significantly lower risk of depression in all adults. The optimal range for a lower risk of depression was 2-3 times the recommended minimum. After stratifying our data by sex, we found that optimal ranges were 10-15 times the recommended minimum physical activity in men and 3-5 times in women. This study established a U-shaped dose-response relationship between physical activity and depression. The optimal range and upper threshold for anti-depression effect of physical activity were higher in men than in women.

Impaired facial expression recognition in patients with social anxiety disorder: a case-control study.

INTRODUCTION: The aim of this study was to investigate whether social anxiety disorder (SAD) patients have low emotion recognition accuracy, take longer for emotion recognition and tended to interpret a stimulus more negatively than controls. METHODS: Fifty-six SAD patients and 56 healthy controls were participated in this study. We evaluated facial emotion recognition using a computer program in which participants chose one of seven emotions as displayed in each of 55 photographs of faces. We compared the accuracy and reaction times of the patients and controls. We further analysed which emotions were selected in the incorrect answers. RESULTS: SAD patients showed delayed reaction times for all emotions except anger and lower accuracy for fear, surprise, neutrality and happiness compared to controls. After applying Bonferroni correction, only delayed reaction time for surprise and happiness were remain significant. Neutrality was not mistaken for a negative emotion at a higher rate by SAD patients than by controls. CONCLUSION: This result suggests that the alterations of reaction time and accuracy of emotion recognition of SAD patients, especially in emotions with positive valence, play a more important role than negative bias in the cognitive aspects of SAD.

Korean Guidelines for the Pharmacological Treatment of Social Anxiety Disorder: Initial Treatment Strategies.

OBJECTIVE: The aim of the present study was to provide clinical consensus and evidence regarding initial treatment strategies for the pharmacological treatment of social anxiety disorder (SAD) in Korea. METHODS: We prepared a questionnaire to derive a consensus from clinicians regarding their preference for the pharmacological treatment of SAD in Korea. Data regarding medication regimens and psychotropic drugs used during initial treatment, the doses used, and the pharmacological treatment duration were obtained. Responses were obtained from 66 SAD experts, and their opinions were classified into three categories (first-line, second-line, third-line) using a chi-square analysis. RESULTS: Clinicians agreed upon first-line regimens for SAD involving monotherapy with selective serotonin reuptake inhibitors (SSRIs) or the serotonin-norepinephrine reuptake inhibitor (SNRI) venlafaxine, or combined therapy using antidepressants with betablockers or benzodiazepines on a standing or as-needed basis. First-line psychotropic drug choices for initial treatment included the following: escitalopram, paroxetine, sertraline, venlafaxine, and propranolol. The medication dosage used by domestic clinicians was found to be comparable with foreign guidelines. Domestic clinicians tended to make treatment decisions in a shorter amount of time and preferred a similar duration of maintenance treatment for SAD when compared with foreign clinicians. CONCLUSION: This study may provide significant information for developing SAD pharmacotherapy guidelines in Korea, especially in the early stage of treatment.

Gender Differences of Occupational Stress Associated with Suicidal Ideation among South Korean Employees: The Kangbuk Samsung Health Study.

OBJECTIVE: In this study, the relationship between occupational stress and suicidal ideation was investigated, focusing on gender differences among Korean employees. METHODS: Cross-sectional data for 53,969 workers were collected at Kangbuk Samsung Hospital health screening centers. Risk of suicidal ideation was assessed using a self-reported questionnaire examining suicidal ideation during the past year. Occupational stress was measured using 24 items of the Korean Occupational Stress Scale-Short Form (KOSS-SF). Logistic regression analysis was employed to estimate the odds ratios and 95% confidence intervals of the relationships between suicidal ideation and components of occupational stress. RESULTS: In multivariable-adjusted models, all job stress contributed to increased risk of suicidal ideation in males. Most subscales, except insufficient job control and organizational system, were risk factors of suicidal ideation in females. Further adjustments for depression markedly attenuated this relationship. However, the effects of insufficient job control and lack of reward on suicidal ideation remained significant in males, and interpersonal conflict remained significant in females. CONCLUSION: The results suggest that occupational stress plays a significant role in increasing risk of suicidal ideation through elevation of depressive symptoms. Gender differences in components of occupational stress associated with suicidal ideation were also observed.

Subclinical Hypothyroidism and Incident Depression in Young and Middle-Age Adults.

Background: The role of subclinical hypothyroidism in the development of depression remains controversial. We examined the prospective association between subclinical hypothyroidism and incident depressive symptoms. Methods: We conducted a prospective cohort study of 220,545 middle-age adults without depression who had undergone at least two comprehensive health examinations between 1 January 2011 and 31 December 2014. Thyroid-stimulating hormone, free triiodothyronine (FT3), and free thyroxine (FT4) levels were measured using an electrochemiluminescent immunoassay. The study outcome was incident depressive symptoms, defined as a Center for Epidemiologic Studies-Depression score >16. Results: During a median follow-up period of 2 years, incident depressive symptoms occurred in 7323 participants. The multivariable-adjusted hazard ratio for incident depressive symptoms comparing subclinical hypothyroid and euthyroid participants was 0.97 (95% confidence interval, 0.87 to 1.09). Similarly, among euthyroid participants (n = 87,822), no apparent association was found between thyroid hormone levels and an increased risk of incident depressive symptoms. Conclusions: No apparent association was found between subclinical hypothyroidism and incident depressive symptoms in a large prospective cohort of middle-age men and women.

Early menarche is associated with non-alcoholic fatty liver disease in adulthood.

BACKGROUND: The aim of this study was to examine the association between early menarche (<12 years) and non-alcoholic fatty liver disease (NAFLD) in premenopausal women and to explore whether it is mediated by adult obesity and insulin resistance. METHODS: We analyzed data of premenopausal women, aged ≥15 years, from the Korea National Health and Nutrition Examination Survey (2007-2009). We divided the women into three groups: early menarche, reference (12.00-15.99 years), and late menarche. The presence of NAFLD was determined using hepatic steatosis index >36.0. RESULTS: Of the 4,387 women evaluated, 673 (15.4%) met the criteria for NAFLD. The prevalence of NAFLD was higher in both women with early and late menarche compared with the reference (early, 23.4%; reference, 14.0%; late, 19.9%, P < 0.001). After adjustment of confounders including age, the OR for NAFLD in early menarche compared with the reference was 3.04 (95%CI: 1.99-4.65). Further adjustment of mediators, such as central obesity or insulin resistance, attenuated the association to 1.91-2.17. There was no association, however, between late menarche and NAFLD after adjustment of confounders. CONCLUSIONS: Early menarche was associated with an increased risk of NAFLD in young and middle-aged premenopausal Korean women.

What Kind of Stress Is Associated with Depression, Anxiety and Suicidal Ideation in Korean Employees?

Various types of stress affect mental health in the form of mood disorders, anxiety disorders, and suicidal ideation. Recently, the increasing suicide rate in the working-age population has become a major mental health concern in Korea. Thus, we investigated what kind of stress influence depression, anxiety, and suicidal ideation in Korean employees. The study participants were 189,965 employees who attended health screenings and responded to the Center for Epidemiologic Study-Depression Scale, the Beck Anxiety Inventory, and a questionnaire on the major causes of stress and suicidal ideation. We investigated the major causes of stress by gender and age categories and used binary logistic regression to determine the impact of the causes of stress on depression, anxiety and suicidal ideation. Of several stress causes, work-related stress was the most prevalent, regardless of age category and gender, followed by interpersonal relationships. However, interpersonal relationships and financial problems were the predominant causes of stress related to depression or suicidal ideation. This research suggests that despite the fact that work is the most common cause of stress for Korean employees, stress related to life problems other than work has a greater influence on the mental health of Korean employees.

Binge eating is associated with trait anxiety in Korean adolescent girls: a cross sectional study.

BACKGROUND: Binge eating occurs more frequently in women than in men, and is known to be related to psychological factors such as stress, depression, and anxiety. This study examined the relationship between binge eating and depression, trait anxiety, and perceived stress in Korean adolescents. METHODS: Four hundred girls (aged 17-18 years) from two high schools located in Seoul completed self-report questionnaires. In total, 327 participants returned reliable responses, and were included in the final study. Binge eating was measured using the Bulimic Inventory Test Edinburgh. The questionnaire also included the Perceived Stress Scale (PSS), Trait Anxiety (TA) of State-Trait Anxiety Inventory, Anxiety Sensitivity Inventory (ASI), and Beck Depression Inventory (BDI). RESULTS: The binge-eating group had higher BMI than the control group. The binge-eating group showed higher scores than control on the PSS, BDI, ASI, and TA. The TA was most highly correlated with binge eating. From logistic regression analysis, TA was revealed to be the only factor that raised the risk of binge eating, whereas PSS, BDI, and ASI showed no statistical significance. CONCLUSION: Although binge eating was correlated with perceived stress, depression, and trait anxiety, when their influences were controlled, only binge eating appeared to be associated with trait anxiety.

The associations among vitamin D deficiency, C-reactive protein, and depressive symptoms.

OBJECTIVE: Vitamin D deficiency has been reported to be associated with depression, but the underlying mechanisms aren't well understood. Our study aims to investigate the associations among serum vitamin D, C-reactive protein (CRP) level, and depressive symptoms. METHODS: Serum levels of Vitamin D and CRP were measured from 52,228 participants. Depressive symptoms were assessed using a Korean version of the CES-D scale. We used logistic regression to calculate the odds ratio (ORs) of depressive symptoms according to vitamin D and CRP levels. The regressions were adjusted for covariates, and each model was adjusted mutually for vitamin D and CRP levels. RESULTS: A significant difference was found in vitamin D status between depressed and non-depressed participants, but CRP status was not significantly different. The OR for the presence of depressive symptoms was significantly increased in participants with vitamin D deficiency after adjusting for potentially confounding factors (Adjusted OR=1.158, 95% CI=1.003-1.336, p=0.046). The OR of depressive symptoms was not significantly increased in individuals with high (3.01-10mg/L) CRP level compared to individuals with low (≤3mg/L) CRP level (Adjusted OR=1.004, 95% CI=0.821-1.227, p=0.97). There was no significant association between vitamin D and CRP level. Additional adjustment for serum CRP level did not weaken the resulting association between vitamin D deficiency and the presence of depressive symptoms. CONCLUSION: Vitamin D deficiency was associated with depressive symptoms, but elevated serum CRP level was not. The results indicate that CRP level does not account for the association between vitamin D deficiency and the presence of depressive symptoms.

Pharmacotherapy and group cognitive behavioral therapy enhance follow-up treatment duration in gambling disorder patients.

BACKGROUND: Longer treatment duration is important for the successful treatment of gambling disorder (GD). This retrospective study investigated the factors and interventions that might enhance treatment duration in GD patients in South Korea. METHODS: A total of 758 outpatients with a primary diagnosis of GD, who were treated in a clinical practice from 2002 to 2011, were assessed by retrospective chart review. We compared the treatment duration according to pharmacotherapy and group cognitive behavioral therapy (CBT). RESULTS: Pharmacotherapy contributed to a longer duration of treatment maintenance, despite the patients' gambling severity (p < 0.001). Participation in group CBT (p < 0.001) and antidepressants (p = 0.009) were associated with a longer treatment duration after adjusting for age, depression, and gambling severity. The treatment maintenance duration was the longest in those receiving combined antidepressant pharmacotherapy and group CBT (F = 35.79, p < 0.001). CONCLUSIONS: Group CBT and antidepressants seem to enhance treatment follow-up duration in GD patients. Additional studies are needed to advance GD prevention and treatment strategies.

Ferritin level is associated with metabolic syndrome and elevated alanine aminotransferase in children and adolescents.

BACKGROUND: The aim of the study was to investigate the association among elevated serum ferritin, metabolic syndrome (MetS) and 'elevated alanine aminotransferase (ALT) levels beyond healthy-range limits' in children and adolescents. METHODS: We analyzed data from 4855 subjects (2579 male) aged 10-19 who participated in the Korea National Health and Nutrition Examination Survey (KNHANES) (2007-2012). RESULTS: The prevalence of MetS and 'elevated ALT' tended to increase with an increase in the serum ferritin quartile (p-value for trend: all <0.05). The odds ratios (ORs) for MetS in serum ferritin quartile-Q4 compared to ferritin quartile-Q1 was 1.59 (1.01, 2.55) in females after adjusting for age, body mass index (BMI), and insulin resistance. The ORs for 'elevated ALT' in ferritin quartile-Q4 compared to ferritin quartile-Q1 were 4.45 (2.18, 9.10) in male and 3.10 (1.70, 5.66) in female subjects after adjusting for other covariates. CONCLUSIONS: The independent association between elevated serum ferritin and MetS (or 'elevated ALT') begins in children and adolescents.

Early Improvement in One Week Predicts the Treatment Response to Escitalopram in Patients with Social Anxiety Disorder: A Preliminary Study.

OBJECTIVE: Social anxiety disorder (SAD) shows relatively delayed responses to pharmacotherapy when compared to other anxiety disorders. Therefore, more effective early therapeutic decisions can be made if the therapeutic response is predictable as early as possible. We studied whether the therapeutic response at 12 weeks is predictable based on the early improvement with escitalopram at 1 week. METHODS: The subjects were 28 outpatients diagnosed with SAD. The subjects took 10-20 mg/day of escitalopram. The results of the Liebowitz social anxiety scale (LSAS), Hamilton anxiety rating scale, and Montgomery-Asberg depression rating scale were evaluated at 0, 1, 4, 8, and 12 weeks of treatment. Early improvement was defined as a ≥10% reduction in the LSAS total at 1 week of treatment, and endpoint response was defined as a ≥35% reduction in the LSAS total score. The correlation between clinical characteristics and therapeutic responses was analyzed by simple linear regression. The correlation between early improvement responses and endpoint responses was analyzed by multivariate logistic regression analysis and receiver operating characteristic curves. RESULTS: When we adjusted the influence of a ≥35% reduction in the LSAS total endpoint score on a ≥10% reduction of the LSAS total score at 1 week of treatment for the patients' age, the early improvement group at 1 week of treatment was expected to show stronger endpoint responses compared to the group with no early improvement. CONCLUSION: The results suggest that a ≥10% reduction in the LSAS total score in a week can predict endpoint treatment response.

The Efficacy and Safety of Clonazepam in Patients with Anxiety Disorder Taking Newer Antidepressants: A Multicenter Naturalistic Study.

OBJECTIVE: This study compared the efficacy and tolerability of clonazepam with other benzodiazepines in patients with anxiety disorders. METHODS: Inclusion criteria were as follows: age >20 years, diagnosis of anxiety disorder according to the Diagnostic and Statistical Manual of Mental Disorders 4th edition, text revision (DSM-IV-TR) criteria, taking only one type of antidepressant, and prescribed one of three oral benzodiazepines (alprazolam, clonazepam, or lorazepam). At baseline and week 6, clinical benefit was evaluated using the Clinical Global Impression-Severity Scale (CGI-S), Clinical Global Impression-Anxiety Scale (CGI-anxiety), and Clinical Global Impression-Sleep Scale (CGI-sleep). RESULTS: Among 180 patients, no differences in demographic characteristics among the three benzodiazepine groups were noted. After six weeks of treatment, all benzodiazepine groups showed significant improvements in CGI-S, CGI-anxiety, and CGI-sleep scores (p<0.001). There were no differences in mean changes in CGI-S, CGI-anxiety and CGI-sleep among the three benzodiazepine groups. The incidence of side effects was significantly lower in the clonazepam group than with the other benzodiazepines. The incidences of adverse events for the clonazepam, alprazolam, and lorazepam groups were 26.7% (n=20), 48.4% (n=31), and 43.9% (n=18), respectively. CONCLUSION: The present study suggests that clonazepam is as efficacious as other benzodiazepines for the treatment of various anxiety disorders. Furthermore, the safety profile of clonazepam was superior to the other benzodiazepines in this study.

Efficacy of pamidronate in pediatric osteosarcoma patients with low bone mineral density.

PURPOSE: Most surviving pediatric osteosarcoma patients experience osteoporosis, bone pain, and pathologic fracture during and after therapy. The aim of this study was to evaluate the efficacy and side effects of pamidronate therapy in these patients. METHODS: Nine osteosarcoma patients (12.8±1.6 years of age; 5 boys and 4 girls) who had a history of nontraumatic fracture or severe pain after completing chemotherapy were included. Intravenous pamidronate (1.5 mg/kg) was given every 6 weeks for 4 to 6 cycles. Bone mineral density (BMD) of the lumbar spine was measured by dual-energy x-ray absorptiometry. Clinical outcomes including acute side effects were also evaluated. RESULTS: After pamidronate treatments, all patients experienced decreased pain. Seven of 9 patients could walk without a crutch. The BMD of lumbar spine was increased by 0.108±0.062 mg/cm(2) after 8.4±1.0 months (n=8, P=0.017) and the mean z-score improved from -2.14±0.94 to -1.76±0.95 (P=0.161). Six patients (67%) had an acute-phase reaction, and 2 patients had symptomatic hypocalcemia. CONCLUSION: Pamidronate appears to be safe and effective for the treatment of osteosarcoma in children with low BMD and bone pain.

Early menarche is associated with metabolic syndrome and insulin resistance in premenopausal Korean women.

In pediatrics, identifying risk factors is important in planning the prevention of cardiovascular disease. The aim of this study was to determine whether there is an independent association between early menarche (<12 years) and metabolic syndrome (MetS) in Korean women. We analyzed data from 4463 premenopausal women from the Fourth Korea National Health and Nutrition Examination Survey-IV (2007-2009). MetS was defined by the International Diabetes Federation for Asians and insulin resistance (IR) was defined as HOMA-IR more than 3.05. The prevalence of MetS and IR was 7.9 and 15.0%. Women (55.6%) with MetS also showed IR. The prevalence of MetS was higher in both women with early menarche and late menarche (≥16 years) compared with the reference group (early, 12.8%; reference, 7.0%; late, 11.0%, both P = 0.002). However, the odds ratio for MetS was 3.54 (95% confidence interval (CI), 2.14-5.87) and for IR was 2.98 (95% CI, 1.99-4.47) after adjusting for age and other confounders such as lifestyle variables, reproductive variables and sociodemographic variables only in women with early menarche CONCLUSION: Early menarche was associated with an increased risk of MetS and IR in premenopausal Korean women. WHAT IS KNOWN: Early menarche is associated with higher risk of CVD-related death and all-cause mortality in Western studies. Early menarche is associated with higher risk of diabetes in Korean premenopausal women. WHAT IS NEW: Early menarche (<12 years) is associated with metabolic syndrome and insulin resistance in nationally representative Korean premenopausal women. However, late menarche (>16 years) is not associated with metabolic syndrome after controlling for age and other confounders.

Association between the CLOCK gene 3111 T > C polymorphism and an irregular menstrual cycle in Korean adolescents.

The menstrual cycle is an example of a human infradian rhythm, but an altered sleep-wake cycle or a disrupted circadian rhythm can change the regularity of the menstrual cycle. In this study, we investigated whether an irregular menstrual cycle is associated with polymorphisms in the CLOCK (3111T > C) and/or PER3 (variable number tandem repeat, VNTR) genes, which are known to have an impact on the circadian rhythm. One hundred ninety-seven postmenarchal, adolescent girls from two girls' high schools in Seoul, Korea, were studied. All participants were requested to complete the Perceived Stress Scale (PSS), the State-Trait Anxiety Inventory (STAI), and the Beck Depression Inventory (BDI) to assess the emotional distress that might cause menstrual irregularity. Every participant donated a blood sample from which DNA was extracted and genotyped for the CLOCK 3111T > C and PER3 VNTR polymorphisms. A significant association was found between the CLOCK 3111T > C genotype and irregular menstrual cycles. Subjects with the 3111T > C genotype had a high risk of an irregular menstrual cycle compared with 3111T/T homozygous subjects (odds ratio [OR] = 2.88; 95% confidence interval [CI]: 1.26-6.55). When multivariate logistic regression analysis was performed to adjust for age, PSS, STAI, BDI and BMI, subjects with the 3111T > C polymorphism showed a significantly increased OR for irregular menstrual cycles (OR = 3.09; 95% CI: 1.32-7.21). There was no significant association between the PER3 VNTR polymorphism and the irregularity of the menstrual cycle (p > 0.05). The results of this study suggest that the CLOCK 3111T > C polymorphism could be an independent risk factor for irregular menstrual cycles, irrespective of psychological distress and endocrine or metabolic conditions, and could be used as a molecular marker for gynecological studies on this aspect.