Su-Min Jeong

Association of Hemoglobin Concentration and Its Change With Cardiovascular and All‐Cause Mortality

Background Anemia is thought to increase mortality risks, but the effects of high hemoglobin concentration on survival are unclear. The effect of change in hemoglobin concentrations on survival in the general population is also unknown. This study aimed to examine the effect of hemoglobin concentrations and their changes on cardiovascular and all‐cause mortality risks. Methods and Results We retrospectively analyzed a cohort from the NHIS‐HEALS (National Health Insurance Service–National Health Screening Cohort) database, including 170 078 men and 122 116 women without cardiovascular diseases, aged >40 years at baseline, with hemoglobin concentrations available for both first and second health examinations. We assessed 2 independent variables: “One‐time” hemoglobin concentrations and changes in hemoglobin from first to second examination. Participants were followed up for a median of 8 years to determine mortality related to myocardial infarction, stroke, all cardiovascular diseases, and all causes. Hemoglobin concentrations showed a U‐ or J‐shaped association with cardiovascular and all‐cause mortality after adjusting for cardiovascular risk factors. When anemic men achieved normal hemoglobin concentrations, the all‐cause mortality risk decreased, with an adjusted hazard ratio of 0.67 (95% confidence interval, 0.59–0.77), in comparison with those whose anemia persisted. Both increases and decreases of hemoglobin concentration outside the normal range elevated all‐cause mortality risk (adjusted hazard ratio: 1.39 [95% confidence interval, 1.28–1.49] and 1.10 [95% confidence interval, 1.01–1.20], respectively), compared with persistent normal hemoglobin concentrations. The trend was similar in women but was less significant. Conclusions Low or high hemoglobin concentrations were associated with elevated cardiovascular and all‐cause mortality. Reaching and maintaining hemoglobin concentrations within the normal range correlated with decreased all‐cause mortality.

Association Between Timed Up and Go Test and Future Dementia Onset

Background This study evaluated whether baseline results of the Timed Up and Go (TUG) test is associated with future dementia occurrence. Methods Using the Korean National Health Insurance Service-National Health Screening Cohort database, we identified 49,283 subjects without a dementia diagnosis who participated in the National Screening Program for Transitional Ages at 66 years of age during 2007-2012. Gait impairment was defined as taking longer than 10 seconds to perform the TUG test. Dementia occurrence was defined by the first prescription for acetylcholinesterase inhibitors or N-Methyl-D-Aspartate receptor antagonist with an International Classification of Diseases 10th Revision (ICD-10) code for dementia (F00, F01, F02, F03, G30, F051, or G311) during 2007-2013. Cox proportional hazard regression models were used to assess the hazard ratios for dementia occurrence according to baseline TUG test results. Results Mean follow-up period was 3.8 years. Incidence rates of dementia were 4.6 and 6.8 cases per 1,000 person-years in the normal and impaired TUG groups, respectively. The impaired TUG group showed a higher risk of total dementia incidence (adjusted hazard ratio [aHR], 1.34; 95% confidence interval [95% CI], 1.14-1.57). Subtype analysis showed that the impaired TUG group had a higher risk of Alzheimers disease (aHR, 1.26; 95% CI, 1.06-1.51) and vascular dementia (aHR, 1.65; 95% CI, 1.19-2.30). Conclusions The TUG test result was associated with future dementia occurrence. More vigilant follow-up and early intervention to prevent dementia would benefit elderly people with impaired TUG test result.

High neutrophil to lymphocyte ratios predict intracranial atherosclerosis in a healthy population

BACKGROUND AND AIMS Although atherosclerosis has been shown to be an inflammatory disease, intracranial atherosclerosis (ICAS) has not been well addressed. The purpose of this study was to evaluate the relationship between the neutrophil to lymphocyte ratio (NLR) and the presence of ICAS lesions in a generally healthy population. METHODS A consecutive series of subjects, who voluntarily visited for health check-ups between January 2006 and December 2013, were selected. Brain magnetic resonance imaging, brain magnetic angiography (MRA), and blood cell count data were assessed. ICAS was defined as an occlusion or more than 50% stenosis of intracranial vessels, as observed on brain MRA images. NLR was calculated based on absolute neutrophil and lymphocyte counts. RESULTS A total of 2842 subjects were evaluated, and 76 ICAS cases were found. The median NLR was 1.52 [1.17-2.01]. In multivariate analysis, NLR remained an independent predictor of ICAS [adjusted OR (aOR) = 1.72, 95% confidence interval (CI) = 1.01-2.95, p = 0.048]. Age (aOR = 1.08, 95% CI = 1.05-1.11, p < 0.001) and hypertension (aOR = 1.81, 95% CI = 1.11-2.94, p = 0.017) were also significant factors for ICAS independent of NLR. Regarding ICAS burdens, NLR was significantly higher when the number of ICAS lesions (p = 0.017) or occlusive ICAS lesions (p = 0.005) was increased in a dose-response manner. CONCLUSIONS A high NLR was associated with both prevalence and burdens of ICAS in a healthy population.

Association between cognitive impairment and poor antihypertensive medication adherence in elderly hypertensive patients without dementia

Adherence to antihypertensive medication is a critical factor to control blood pressure and prevent complications. However, cognitive impairment can negatively affect medication adherence. In this study, we investigated the association between cognitive function and antihypertensive medication adherence among elderly hypertensive patients using the Korean National Health Insurance Service National Sample Cohort Data of the Elderly Cohort. The study included 20,071 elderly hypertensive patients and the prevalence of poor medication adherence to antihypertensive medications was 16.4%. A multivariate logistic regression analysis showed that lower cognitive function was associated with poor medication adherence (adjusted odds ratio 0.980, 95% confidence interval 0.961–0.999). Additionally, high income levels, living in metropolitan areas, and comorbidities (such as stroke, coronary heart disease, diabetes, and dyslipidemia) were positively associated with medication adherence, while patients diagnosed with cancers showed poor medication adherence. Our study demonstrated that cognitive impairment is a possible risk factor for poor antihypertensive medication adherence, even in patients without dementia. Thus, clinicians involved with geriatric care should monitor patients’ cognitive function and medication adherence. And if a patient shows cognitive impairment, clinicians need to educate patients and caregivers about the importance of proper adherence, and consider proper interventions to optimize the cognitive function of elderly patients.

Association of change in total cholesterol level with mortality: A population-based study

Background Hypercholesterolemia is a well-established risk factor for coronary heart disease, but the association between cholesterol level change and mortality is not fully understood. We aimed to investigate the association of 2 year (2002–2003 to 2004–2005) change in cholesterol with all-cause and cause-specific mortality in a population-based cohort study. Methods and findings The study population consisted of 269,391 participants aged more than 40 years who were free of myocardial infarction, stroke and cancer using the Korean National Health Insurance Service—National Health Screening Cohort. Cholesterol levels were classified into 1st, 2nd and 3rd tertiles during each of the first and second health examinations, respectively. The participants were followed-up for all-cause and cause-specific mortality from 1 January 2006 to 31 December 2013. Compared to participants who stayed within the 2nd tertile group for cholesterol during both the first and second examinations, participants who became or maintained cholesterol levels to the 1st tertile during the second examination had increased risk of all-cause mortality [adjusted hazard ratio (aHR) with 95% confidence interval (95% CI) = 1.28 (1.18–1.38) in 1st/1st, 1.16 (1.07–1.26) in 2nd/1st and 1.47 (1.32–1.64) in 3rd/1st tertile levels, respectively]. In addition, increased or persistent high cholesterol levels to the 3rd tertile was associated with elevated risk for all-cause mortality [aHR (95% CI) = 1.10 (1.01–1.20) in 1st/2nd, 1.16(1.03–1.31) in 1st/3rd and 1.15(1.05–1.25) in 3rd/3rd tertile levels]. Conclusions Changes in cholesterol levels in either direction to low cholesterol or persistently low cholesterol levels were associated with higher risk of mortality. Particularly, spontaneous decline in cholesterol levels may be a marker for worsening health conditions.

Effect of Change in Total Cholesterol Levels on Cardiovascular Disease Among Young Adults

Background Although high serum cholesterol in young adults is known to be a predictor for cardiovascular events, there is not enough evidence for the association of cholesterol level change with cardiovascular disease (CVD). This study aimed to evaluate whether the change in cholesterol is associated with incidence of CVD among young adults. Methods and Results We examined 2 682 045 young adults (aged 20–39 years) who had undergone 2 consecutive national health check‐ups provided by Korean National Health Insurance Service between 2002 and 2005. Cholesterol levels were classified into low (<180 mg/dL), middle (180–240 mg/dL) and high (≥240 mg/dL). CVD events were defined as ≥2 days hospitalization attributable to CVD for 10 years follow‐up. Increased cholesterol levels were significantly associated with elevated ischemic heart disease risk (adjusted hazard ration [aHR]=1.21; 95% confidence interval [CI]=1.03–1.42 in low‐high group and aHR=1.21; 95% CI=1.15–1.27 in middle‐high group) and cerebrovascular disease (CEVD) risk (aHR=1.24; 95% CI=1.05–1.47 in low‐high group and aHR=1.09; 95% CI=1.02–1.16 in middle‐high group). Decreased cholesterol levels were associated with reduced ischemic heart disease risk (aHR=0.91; 95% CI=0.88–0.95 in middle‐low group, aHR=0.65; 95% CI=0.56–0.75 in high‐low group and aHR=0.68; 95% CI=0.65–0.73 in high‐middle group). Furthermore, lower cerebrovascular disease risk (aHR=0.76; 95% CI=0.62–0.92) was observed in the high‐low group compared with patients with sustained high cholesterol. Conclusions The findings of our study indicate that increased cholesterol levels were associated with high CVD risk in young adults. Furthermore, young adults with decreased cholesterol levels had reduced risk for CVD.

Association of Obesity or Weight Change With Coronary Heart Disease Among Young Adults in South Korea

Importance Previous studies have shown a U- or J-shaped association of body mass index (BMI) or change in BMI with coronary heart disease (CHD) among middle-aged and elderly adults. However, whether a similar association exists among young adults is unclear. Objective To determine whether an association exists between BMI or BMI change with CHD among young adults. Design, Setting, and Participants This population-based longitudinal study used data obtained by the Korean National Health Insurance Service from 2002 to 2015. The study population comprised 2 611 450 men and women aged between 20 and 39 years who underwent 2 health examinations, the first between 2002 and 2003 and the second between 2004 and 2005. Exposures World Health Organization Western Pacific Region guideline BMI categories of underweight, normal weight, overweight, obese grade 1, and obese grade 2 derived during the first health examination and change in BMI calculated during the second health examination. Main Outcomes and Measures Body mass index (calculated as weight in kilograms divided by height in meters squared). Absolute risks (ARs), adjusted hazard ratios (aHRs), and 95% CIs for acute myocardial infarction or CHD during follow-up from 2006 to 2015. Results Data from 1 802 408 men with a mean (SD) age of 35.1 (4.8) years and 809 042 women with a mean (SD) age of 32.5 (6.3) years were included. The mean (SD) BMI was 23.2 (3.2) for the total population, 24.0 (3.0) for men, and 21.4 (2.9) for women. Compared with normal weight men, overweight (AR, 1.38%; aHR, 1.18 [95% CI, 1.14-1.22]), obese grade 1 (AR, 1.86%; aHR, 1.45 [95% CI, 1.41-1.50]), and obese grade 2 (AR, 2.69%; aHR, 1.97 [95% CI, 1.86-2.08]) men had an increased risk of CHD (P < .001 for trend). Similarly, compared with normal weight women, overweight (AR, 0.77%; aHR, 1.34 [95% CI, 1.24-1.46]), obese grade 1 (AR, 0.95%; aHR, 1.52 [95% CI, 1.39-1.66]), and obese grade 2 (AR, 1.01%; aHR, 1.64 [95% CI, 1.34-2.01]) women had an increased risk of CHD (P < .001 for trend). Compared with participants who maintained their weight at normal levels, those who became obese had elevated CHD risk among men (0.35% increase in AR; aHR, 1.35 [95% CI, 1.17-1.55]) and women (0.13% increase in AR; aHR, 1.31 [95% CI, 0.95-1.82]). Weight loss to normal levels among obese participants was associated with reduced CHD risk for men (0.58% decrease in AR; aHR, 0.77 [95% CI, 0.64-0.94]) and women (0.57% decrease in AR; aHR, 0.66 [95% CI, 0.45-0.98]). Conclusions and Relevance Obesity and weight gain were associated with elevated risk of CHD among young adults in this study. Studies that prospectively determine the association between weight change and CHD risk are needed to validate these findings.

Increased Risk of Osteoporosis in Gastric Cancer Survivors Compared to General Population Control: A Study with Representative Korean Population

Purpose Although several studies have suggested that osteoporosis is common in survivors of gastric cancer (GC), no study to date has directly assessed the risk for osteoporosis in GC survivors compared to matched controls. Thus, we aimed to investigate the relative risk for osteoporosis in survivors of GC compared to general population. Materials and Methods We used the Korea National Health and Nutrition Examination Survey data (2008-2011). Patients with a history of GC (n=94) were defined as case among 8,142 individuals over 50 years old who were evaluated by dual-energy X-ray absorptiometry. Controls (n=470) were matched to cases by age and sex in a 1:5 ratio. Osteopenia (–2.5 < T-score < –1.0) and osteoporosis (T-score ≤ –2.5) were defined. Results The prevalence of osteoporosis in GC survivors was 30.2%, which was significantly greater than that of controls (19.7%). In total, GC survivors had a 3.7-fold increased risk for osteoporosis compared to controls (p=0.021). In addition, the risk for osteoporosis of the total proximal femur total (TF) and femur neck (FN) was significantly increased among GC survivors compared to controls (adjusted relative risk, 4.64; 95% confidence interval, 1.16 to 18.6 in TF and adjusted relative risk, 3.58; 95% confidence interval, 1.19 to 10.8 in FN). Furthermore, we found sub-optimal daily calcium intake and mean serum levels of 25-hydroxy-vitamin D in both groups. Conclusion GC survivors are at significantly increased risk for osteoporosis, especially in the femur. Clinically, our finding supports the importance of screening bone health and adequate nutrient supplementation in survivors of GC.

Regional variations in frequency of glycosylated hemoglobin (HbA1c) monitoring in Korea: A multilevel analysis of nationwide data

PURPOSE Suboptimal frequency of glycosylated hemoglobin (HbA1c) monitoring is associated with poor diabetes control. We aimed to analyze compliance to HbA1c testing guidelines and explore associated individual and area-level determinants, focusing on regional variation. METHODS This cross-sectional study between the period of 2012-2013 was conducted by using the Korean National Health Insurance Research Database, and included 45,634 patients diagnosed with diabetes mellitus, who were prescribed any anti-diabetic medications, including insulin. We calculated the proportion of each HbA1c testing frequency (≥1, ≥2, or ≥4 times per year) stratified by 17 administrative regions. Multilevel and multivariate logistic analyses were performed with regional (proportion of farmer population) and individual characteristics (age, sex, income level, duration of diabetes, and most visited medical institution). RESULTS Overall, 67.3% of the patients received≥1 HbA1c test per year; 37.8% and 6.1% received ≥2 and ≥4 tests per year, respectively. Those managed in secondary-level hospitals or clinics and those living in rural areas were less likely to receive HbA1c testing. Even after adjusting for individual and regional level characteristics, significant area level variation was observed (variance participant coefficients were 7.91%, 9.58%, and 14.43% for testing frequencies of ≥1, ≥2, and ≥4 times a year, respectively). CONCLUSIONS The frequency of HbA1c monitoring is suboptimal in Korea, especially in rural areas. Moreover, significant regional variation was observed, implying a contextual effect. This suggests the need for developing policy actions to improve HbA1c monitoring. In particular, access to HbA1c testing in rural primary care clinics must be improved.