Myung Ki

Physical activity and sedentary behaviour at different life stages and adult blood pressure in the 1958 British cohort

Objectives: To investigate whether physical activity or sedentary behaviour at different life stages is associated with blood pressure (BP) in mid-adulthood; activity levels have accumulative associations with BP; and adult body mass index (BMI) mediates associations. Methods: Information on activity and television-viewing was available at several ages (23, 33, 42, 45 years) and BP at 45 years for the 1958 British birth cohort (n = 9927). Associations were examined with and without adjustment for covariates. Results: Active adults, generally, had lower mean systolic and diastolic BP and risk of hypertension than nonactive, although varying by age. After adjustment for covariates, systolic and diastolic BP for active men at 23 years or at 45 years were 1–2 mmHg lower; similar associations were seen for women active at 33 years. Some but not all associations attenuated with further adjustment for BMI: odds ratio (OR) for hypertension associated with 23 years activity changed from 0.82 [95% confidence interval (CI) 0.74, 0.91] to 0.79 (0.70, 0.90) after BMI adjustment. Independent associations of activity at more than one age were found, such that prevalence of hypertension was higher in men active at 23 years but not at 45 years, than men sustaining activity (39 vs. 31%). Sitting at work was unrelated to BP, but there was a trend of higher BP with greater television-viewing: for example risk of hypertension was higher by 10–12% per h/day television-viewing at 45 years after adjustment for covariates, attenuating after allowance for BMI. Conclusion: Our study suggests that there are benefits to BP of becoming and sustaining active lifestyles and minimizing television-viewing over many years of adulthood, with a mediating role for BMI.

Health selection operating between classes and across employment statuses

Backgrounds The debate on health selection which describes the influence of health on subsequent social mobility is highly contested. The authors set out to examine the effect of health selection by looking at the effect of previous health status on changes in socio-economic position (SEP) over two time periods. Method Data were pooled from 13 waves (1991–2003) of the British Household Panel Survey (BHPS). Using a multilevel multinomial approach, the presence of health selection between classes and into/out of employment was concurrently tested and compared. Results In the descriptive analysis, poor health was consistently associated with moving downward, while the outcome was inverse for upward movement. After accounting for the data structure using multilevel analysis, health was a predictor for social mobility when leaving and entering employment, but the effect was minimal for transitions between classes for both men and women. Conclusion The non-significant impact of health on mobility inside employment may reflect the presence of the significant impact of health on mobility between employment and non-employment. This implies that the effect of health was not evenly spread over all social mobility, but rather tends to concentrate on some types of mobility. The effect of each predictor on social mobility is more concentrated among specific transitions, and health and age were likely to be substantial in moving into/out of the labour force, whereas education was a relevant predictor for mobility into/out of upper classes, in particular, classes I/II.

Age-related differences in diabetes care outcomes in Korea: a retrospective cohort study

BackgroundAge-related differences in diabetes outcomes are important both for clinical and policy considerations. To clarify the basis of such differences, we investigated patterns of associations for age in relation to hospitalization and glycemic control and examined the role of other factors.Methods4471 patients with diabetes aged 40–79 years were drawn from a retrospectively retrieved National Health Insurance Cohort. Using logistic regression, risk factors measured over the two years (2007–2008) were examined for their associations with hospitalization and poor glycemic control during the last year (2009) of follow-up.ResultsCompared to the middle-aged patients, older patients were more likely to have been hospitalized (Adjusted odds ratio (ORadjusted) = 1.97(95% CI = 1.28, 3.04) for the oldest group (ages 70–79) vs youngest group (ages 40–49)) but less likely to have poor glycemic control (ORadjusted = 0.45 (95% CI = 0.37, 0.56) for the oldest group vs youngest group). Older patients were also less likely to be obese but had more complications, longer duration of diabetes, lower continuity of care, and higher blood pressure and total cholesterol level. The pattern of associations for hospitalization and glycemic control was not uniform across the risk factors, sharing only a few common factors such as the duration of diabetes and blood pressure. In general, poor glycemic control was affected predominantly by metabolic management, while hospitalization was strongly related to functional status (i.e., number of complications) and care quality measures (i.e., continuity of care).ConclusionHospitalization was higher among the older diabetic patients, despite better glycemic control. Factors were differently associated with the two diabetes-related outcomes, providing more comprehensive risk profiles for hospitalization. The co-existence of improved glycemic control and increased hospitalization among older diabetic patients suggests an extension of a geriatric evaluation to wider functional and comorbidity status.

Delays in depression treatment among Korean population

Delays in mental health service utilization for patients with depression have been observed globally. To elucidate some aspects of delays, age‐related associations with a series of variables representing different stages of mental health service use were studied concurrently.

Socioeconomic inequalities in health in the context of multimorbidity: A Korean panel study

Socioeconomic inequalities in health are commonly known to decrease at late age. Yet, it remains unclear whether socioeconomic inequalities in health at late age appear in relation to multimorbidity, particularly in Korea where social support remains unsatisfactory for older people. Using three waves of Korea Health Panel, data of 19,942 observations with repeated measure were constructed to ensure a temporal sequence between three socioeconomic measures (i.e., poverty, employment status, and education) and multimorbidity with a t to t+1 year transition. A multilevel multinomial model was applied to quantify the socioeconomic impact across different age, diseases and disease groups, both separately and in combination. There were associations between socioeconomic position (SEP) and multimorbidity, and increasing trends of socioeconomic inequalities not only with greater number of morbidity but also with age. The latter result was only observed with employment status through mid-to-early old age; i.e., between the 40s (odds ratio (OR) = 2.45, 95% confidence interval (CI):1.08–5.57) and 70s (OR = 3.48, 95%CI: 1.24–9.74). The patterns of socioeconomic inequalities in multimorbidity varied for particular pairs of diseases and were stronger in the disease pairs co-occurring with mental and cardiovascular diseases but weaker in the disease pairs co-occurring with cancer. Accumulation of adversity tended to intensify with increase in number of diseases and older age, though this finding was not consistently supported. The labour market should be encouraged to actively participate in actions to promote healthy aging needs to be complemented by the provision of more generous and universal income support to the elderly in Korea.

Risk factors for feelings of sadness and suicide attempts among cancer survivors in South Korea: findings from nationwide cross-sectional study (KNHANES IV–VI)

Introduction As the number of cancer survivors is rapidly increasing with the increased incidence of the disease and improved survival of patients, the prevalence of, and risk factors for, mental health problems and suicidality among cancer survivors should be examined. Methods and analysis Using data obtained from the Korean National Health and Nutrition Examination Survey (2007–2013), we examined 1285 and 33 772 participants who had been and never been diagnosed with cancer, respectively. We investigated the risks of feelings of sadness and suicide attempts among cancer survivors and general population and examined differences in the risks of cancer survivors among subgroups according to cancer-related characteristics. Results The median age of survivors at the time of the survey and at diagnosis was 63 and 54 years, respectively. After adjusting for sex, level of education, household income, occupation, marital status, cancer type, current status of treatment, age at diagnosis and years since diagnosis, the risk of suicide attempts was significantly higher in participants diagnosed with cancer before 45 years of age compared with those diagnosed at 45–64 years (adjusted OR=3.81, 95% CI 1.07 to 13.60, P=0.039), and the higher risk of suicide attempts with borderline significance was found in those for whom more than 10 years had passed since diagnosis compared with those for whom the diagnosis was made only 2–10 years ago (adjusted OR=3.38, 95% CI 0.98 to 11.70, P=0.055). However, feelings of sadness were not significantly associated with any cancer-related characteristic. Conclusion Our results reveal an increased risk of suicide attempts among cancer survivors diagnosed early in life and in those for whom more than 10 years has passed since the diagnosis, suggesting the need for intensive monitoring and support for mental health problems and suicidal risks in this population.

ASSOCIATIONS BETWEEN SEDENTARY BEHAVIOUR AND CARDIOVASCULAR, HAEMOSTATIC AND DIABETIC MARKERS IN MID-ADULT LIFE (45 YEARS)

Background Recent studies show TV-viewing time being related to mortality independent to physical activity (PA). However, the mechanism behind this association is unclear. Aim We investigate cross-sectional associations between sedentary behaviour and preclinical variations in markers for cardiovascular disease (CVD) and diabetes. Methods Using data from the 1958 British birth cohort, we analysed associations between (1) television (TV)-viewing and (2) sitting at work with blood pressure (BP), total cholesterol, triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL), glycated haemoglobin (HbA1c), C-reactive protein (CRP), fibrinogen, tissue plasminogen activator (tPA), D-dimer and von Willebrand factor (vWF) at 45 years. TV-viewing was measured in six categorises from none to >4 h /day. Sitting at work was measured as a continuous variable. Analysis adjusted for confounding factors (birth-weight, long-term illness, smoking, drinking, diet, social class and concurrent moderate/vigorous leisure-time PA). We assessed whether associations were mediated by body mass index (BMI). Inverse probability weights were used to account for attrition. Analysis was separate for males (n=4632) and females (n=4665). Results Men had higher total cholesterol, LDL, triglycerides, BP, HbA1c, tPA and vWF compared to women. Both genders had similar TV-viewing patterns, but men spent more time sitting at work. Preliminary analysis suggests that TV-viewing was consistently associated with adverse biomarker levels, usually with a stronger trend in women than men. For example increasing by a category of TV-viewing was linked to an unadjusted 11.0% (95% CI: 6.9% to 15.1%) increase in CRP in men and a 22.3% (95% CI: 18.0% to 26.6%) increase in women. Adjustment attenuated the relationships slightly to a 5.5% (95% CI: 1.3% to 9.8%) increase in men and a 18.1% (95% CI: 13.6% to 22.6%) increase in women. Associations with sitting were less consistent. After adjustment, sitting at work for 1–2, 2–3 and >3 h/day compared to <1 h/day, was linked to CRP increasing by -3.1% (95% CI: −19.7% to 13.6%), −6.8% (−22.9% to 9.3%) and 5.5% (95% CI: −6.3% to 17.3%) respectively for men and by −20.7% (95% CI: −40.4% to −1.0%), 1.3% (−16.7% to 19.3%) and 7.9% (−8.1% to 23.8%) respectively for women. Results, particularly for TV-viewing in women, were not wholly mediated by BMI. Conclusions Two indicators of sedentary behaviour show inconsistent associations with CVD biomarkers: TV-viewing shows strong trends, whereas trends for sitting at work are less consistent. The contrast between the two markers of sedentary behaviour brings into question the role of sedentary behaviour and its measurement in relation to CVD risk.

The Epidemiological Influence of Climatic Factors on Shigellosis Incidence Rates in Korea

Research has shown the effects of climatic factors on shigellosis; however, no previous study has evaluated climatic effects in regions with a winter seasonality of shigellosis incidence. We examined the effects of temperature and precipitation on shigellosis incidence in Korea from 2002–2010. The incidence of shigellosis was calculated based on data from the Korean Center for Disease Control and Prevention (KCDC, Cheongju, Korea), and a generalized additive model (GAM) was used to analyze the associations between the incidence and climatic factors. The annual incidence rate of shigellosis was 7.9 cases/million persons from 2002–2010. During 2007–2010, high incidence rates and winter seasonality were observed among those aged ≥65 years, but not among lower age groups. Based on the GAM model, the incidence of shigellosis is expected to increase by 13.6% and 2.9% with a temperature increase of 1 °C and a lag of two weeks and with a mean precipitation increase of 1 mm and a lag of five weeks after adjustment for seasonality, respectively. This study suggests that the incidence of shigellosis will increase with global climate change despite the winter seasonality of shigellosis in Korea. Public health action is needed to prevent the increase of shigellosis incidence associated with climate variations.

Age, Period, and Cohort Effects on Suicide Mortality in South Korea, 1992–2015

Although the effects of age, period, and cohort (APC) on suicide are important, previous work in this area may have been invalid because of an identification problem. We analyzed these effects under three different scenarios to identify vulnerable groups and thus overcame the identification problem. We extracted the annual numbers of suicides from the National Death Register of Korea (1992–2015) and estimated the APC effects. The annual average suicide rates in 1992–2015 were 31.5 and 14.7 per 100,000 males and females, respectively. The APC effects on suicide were similar in both sexes. The age effect was clearly higher in older subjects, in contrast to the minimal changes apparent during earlier adulthood. The birth cohort effect showed an inverted U shape; a higher cohort effect was evident in females born in the early 1980s when period drift was larger than 3.7%/year. Period effect increased sharply during the early 1990s and 2000s. We found that elderly and young females may be at a particularly high risk of suicide in Korea.

Differentiation of direct and indirect socioeconomic effects on suicide attempts in South Korea

Abstract Despite the wide recognition of the inverse association between socioeconomic position (SEP) and suicidal behaviors, its underlying process and potential mediators are little known. This study investigated the pathway from SEP to suicide attempts with attention to potential mediators. From the Korean Health and Nutrition Examination Survey 2007–2013, which is a nationwide cross-sectional survey of the health and nutritional status, a total of 34,565 participants (≥30 years) were included in the analysis. To unfold the pathways linking SEP to suicide attempts, the direct and indirect effects of 3 SEP measures (educational attainment, household income, and occupational group) and 3 mediators (physical illness, mental health problems, and problematic drinking) were differentiated using structured equation model (SEM). Most of direct and indirect effects of educational attainment, household income, and occupational group on suicide attempts were significant; Nonemployment status had the largest total (&bgr; = 0.291, P < .01) and direct effects (&bgr; = 0.212, P < .01), while educational attainment had the largest indirect effect (&bgr; = −0.124, P < .01). Educational attainment was mainly mediated by physical illness and problem drinking, whereas household income and occupational group were mainly mediated by anxious or depressed mood and problem drinking. Physical illness played a major role in explaining suicide attempts, compared to mental health problem and problem drinking. Overall, experience of socioeconomic disadvantage increased suicide attempts independently of mental and physical problems. An extension of suicide prevention program is required for comprehensively targeting people with general problems such as physical illness and low SEP, complemented to narrowly targeting high risk group with, such as mental health problem.