Differences in prevalence of hypertension subtypes according to the 2018 Korean Society of Hypertension and 2017 American College of Cardiology/American Heart Association guidelines: The Korean National Health and Nutrition Examination Survey, 2007-2017 (KNHANES IV-VII)

Background: The significance of high systolic and diastolic blood pressure remains controversial. We assessed the differences in prevalence of hypertension and its subtypes according to the different hypertension diagnostic criteria embodied by the 2017 American College of Cardiology/American Heart Association (2017 ACC/AHA) and 2018 Korean Society of Hypertension (2018 KSH) guidelines. Methods: We used the 2007-2017 Korea National Health and Nutrition Examination Survey (KNHANES) data to calculate guideline-specific hypertension prevalence among untreated, adult participants. By the 2017 ACC/AHA guideline, a mean SBP ≥130 mmHg, DBP ≥80 mmHg, or currently using antihypertensive medications were considered to have hypertension. Isolated diastolic hypertension (IDH) was defined as DBP ≥80 mmHg and SBP <130 mmHg, isolated systolic hypertension (ISH) as SBP ≥130 mmHg and DBP <80 mmHg, and systolic diastolic hypertension (SDH) as SBP ≥130 mmHg and DBP ≥80 mmHg. In a similar manner, by the 2018 KSH guideline, all hypertension and its subtype prevalence were calculated using the 140/90 mmHg cutoff. The two versions of all hypertension and its corresponding subtype prevalence were calculated among all study participants and separately by sex and age then compared via analysis of variance. Results: The prevalence of all hypertension increased from 25.9% (95% confidence interval (CI) 25.4-26.5) defined by the 2018 KSH guideline to 46.3% (95% CI 45.6-46.9) classified by the 2017 ACC/AHA guideline. Such increase was primarily manifested through substantial increase in IDH prevalence, from 5.2% (95% CI 4.9-5.4) defined by the 2018 KSH guideline to 17.9% (95% CI 17.4-18.3) defined by the 2017 ACC/AHA guideline, and was most notably observed in young age groups, 30-49 years. ISH prevalence showed minimal differences. SDH prevalence moderately increased from 3.5% (95% CI 3.3-3.7) defined by the 2018 KSH guideline to 11.1% (95% CI 10.7-11.4) defined by the 2017 ACC/AHA guideline, achieved primarily among participants aged 50 years or above. Conclusions: Changes in each subtype prevalence made differential contribution to additionally classified hypertension cases by the 2017 ACC/AHA guideline. Future studies should investigate the diastolic-associated cardiovascular risks and benefits of its long-term primary prevention in the young population.ope

Self-reported diet management, dietary quality, and blood pressure control in Korean adults with hypertension

Objectives: Hypertension control is a major public health concern. Daily preventive practices of the affected individual are essential for controlling blood pressure (BP). We investigated the association of diet management practice, dietary quality, and BP control among Korean adults with known hypertension. Methods: We included 4107 participants aged 40-79 years who reported physician-diagnosed hypertension in the Korea National Health and Nutrition Examination Survey 2013-2016. Dietary management practice was defined by self-report, and dietary intakes were assessed by a 24-h dietary recall. Dietary quality and adherence were evaluated based on the Korean Healthy Eating Index (KHEI) using food and nutrient intakes assessed by a 24-h dietary recall. BP control was defined as systolic/diastolic BP < 140/90 mmHg. Results: While the prevalence of dietary management was higher in women than men, BP control rate was not different by sex. Dietary management practice had no significant association with BP control in both men and women. Only in men, dietary quality was positively associated with BP control (OR: 1.10 per KHEI 10 score increase, 95% CI: 1.00-1.20, p-value = 0.04). Men who had a highly adherent diet seemed to have a higher possibility of BP control, but there was no statistical significance (OR: 1.54, 95% CI: 0.84-2.81, p-value = 0.16). Conclusions: A high-quality diet was positively associated with BP control in Korean men aware of their hypertension. Our findings highlight the beneficial impact of dietary management as a means for achieving blood pressure control.ope

Association between estimated glomerular filtration rate (eGFR) and asymmetric dimethylarginine (ADMA) concentrations among the elderly in a rural community: a cross-sectional study

BACKGROUND: Reduced glomerular filtration rate and increased asymmetric dimethylarginine (ADMA) are prevalent in elderly people. However, most of the studies that have examined the association between the two conditions were performed in patients with renal dysfunction, but not in the general elderly population. Thus, we investigated an association between estimated glomerular filtration rate (eGFR) and ADMA concentration among community-dwelling older Koreans. METHODS: A cross-sectional study was conducted on 269 men and 382 women (mean age, 71.6 years) enrolled in the Korean Social Life, Health, and Aging Project (KSHAP), a population-based cohort study of health determinants in elderly Koreans. We calculated eGFR using chronic kidney disease- Epidemiology Collaboration Group (CKD-EPI) equation. ADMA concentration was measured by an enzyme-linked immunosorbent assay. The association between eGFR and ADMA concentrations was analyzed by multiple linear regression models. RESULTS: The mean ADMA was significantly higher in people with eGFR< 60 mL/min/1.73m2 (0.691 μmol/L) than in those with eGFR≥60 mL/min/1.73m2 (0.667 μmol/L, p = 0.013). The negative correlations between eGFR level and ADMA concentrations were significant in men and women after adjusted age. After adjusting for potential confounders which were sex, age, body surface, blood pressure, total and HDL cholesterol, diabetes, smoking, and drinking, eGFR levels were inversely associated with ADMA concentrations both in men (β = - 0.0015, p = 0.005) and women (β = - 0.001, p = 0.039). CONCLUSION: Our findings suggest that an inverse association exists between eGFR and ADMA concentrations among the Korean elderly in a rural community.ope

2018 Korean society of hypertension guidelines for the management of hypertension: part III-hypertension in special situations

Treatment of hypertension improves cardiovascular, renal, and cerebrovascular outcomes. However, the benefit of treatment may be different according to the patients' characteristics. Additionally, the target blood pressure or initial drug choice should be customized according to the special conditions of the hypertensive patients. In this part III, we reviewed previous data and presented recommendations for some special populations such as diabetes mellitus, chronic kidney disease, elderly people, and cardio-cerebrovascular disease.ope

Perceived Discrimination, Depression, and the Role of Perceived Social Support as an Effect Modifier in Korean Young Adults

OBJECTIVES: The relationships among discrimination, social support, and mental health have mostly been studied in minorities, and relevant studies in the general population are lacking. We aimed to investigate associations between discrimination and depressive symptoms in Korean non-minority young adults, considering the role of social support. METHODS: In total, 372 participants who completed the psychological examinations conducted in the third wave of the Jangseong High School Cohort study were included. We used the Everyday Discrimination Scale to evaluate perceived discrimination and the Beck Depression Inventory-II to measure depressive symptoms. Social support was measured by the Multidimensional Scale of Perceived Social Support. Multivariate linear regression was conducted to investigate associations between discrimination and depression, along with the effect modification of social support. We stratified the population by gender to investigate gender differences. RESULTS: Perceived discrimination was significantly associated with depressive symptoms (β=0.736, p&lt;0.001), and social support was negatively associated with depression (β=-0.245, p&lt;0.001). In men, support from friends was the most influential factor (β=-0.631, p=0.011), but no significant effect modification was found. In women, support from family was the most influential factor (β=-0.440, p=0.010), and women with higher familial support showed a significantly diminished association between discrimination and depression, unlike those with lower family support. CONCLUSIONS: Discrimination perceived by individuals can lead to depressive symptoms in Korean young adults, and this relationship can may differ by gender and social support status.ope

Association of social network size and composition with physical activity in Korean middle-aged adults

Objectives: Physical activity (PA) is an established protective factor for many chronic diseases. Numerous studies have established positive relationships between social networks and PA. Accordingly, this study examined the relationship between social network structures (specifically the network size and the number and proportion of same-sex alters) and self-reported PA in Korean middle-age adults, where the term "alter" refers to a respondent's social network members. Methods: We analyzed 8,092 participants of the Cardiovascular and Metabolic Diseases Etiology Research Center cohort. We assessed the association between each network structure variable and PA level using a linear regression model. Then, we employed logistic regression to evaluate associations between social network structure and adherence to guideline-recommended exercise levels. Socio-demographic factors and health status measures were used as covariates. Results: In both sexes, the social network size and proportion of same-sex network members showed positive relationships with total and moderate-to-vigorous PA. Notably, female participants with a greater number of kin were more likely to satisfy the recommended amount of total PA. Conclusions: These findings suggest that large scale, same-sex intervention programs can help to achieve recommended PA regimens.ope

Associations between age and dyslipidemia are differed by education level: The Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) cohort

BACKGROUND: Dyslipidemia is a multifactorial disorder, which arises from complex interactions among genetic and environmental risk factors. Previous studies have established the deteriorating effect of aging on lipid profiles. However, little is known about the role of education level, a stable marker of socioeconomic status, which reflect modifiability of lifestyle risk factors. Therefore, we examined the association between age and individual dyslipidemia parameter across education level among healthy, middle-aged Korean women. METHODS: From 2049 middle-aged women, education attainment was classified into completion of elementary school or below, middle school, high school, college or above. Dyslipidemia was assessed in adherence to the 2018 Korean Dyslipidemia Treatment Guideline. Multivariable logistic regression and generalized linear model tested for associations between age and dyslipidemia parameter across education level and other known risk factors, including menopause, obesity, and current drinking and smoking. RESULTS: In this cross-sectional analysis, the prevalence of each dyslipidemia parameter was significantly different by age and education level. The odds ratio (OR) for dyslipidemia was higher among participants who were older and had received higher education (OR = 2.31, p for interaction = 0.008) than younger and low education counterpart. The interaction between age and education level remained significant for hypercholesterolemia (p for interaction = 0.003) and hyper-LDL-cholesterolemia (p for interaction = 0.002). CONCLUSIONS: Separate examination of individual dyslipidemia parameter indicated varying degree of interaction with age and education level. Such results imply that each type of lipid abnormality may arise from and be exacerbated by heterogeneous composition of biological and lifestyle risk factors, which may be reflected by education level.ope

Serum HBV surface antigen positivity is associated with low prevalence of metabolic syndrome in Korean adult men

BACKGROUND: Metabolic syndrome has clinical implications for chronic liver disease, but the relationship between chronic hepatitis B and metabolic syndrome remains unclear. The aim of this study was to determine whether hepatitis B surface antigen (HBsAg) positivity is associated with metabolic syndrome. METHODS: Data were obtained from the Third Korean National Health and Nutrition Examination Survey (KNHANES). Participant sera were tested for HBsAg. Metabolic syndrome was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III guidelines for Koreans. RESULTS: Of the 5108 participants, 209 (4.1%) tested positive for HBsAg, and 1364 (26.7%) were diagnosed with metabolic syndrome. The prevalence of metabolic syndrome was 23.4% in HBsAg-positive men, 31.5% in HBsAg-negative men, 18.6% in HBsAg-positive women, and 23.7% in HBsAg-negative women. After adjusting for multiple factors, male participants who tested positive for serum HBsAg had an odds ratio of 0.612 (95% confidence interval [CI] 0.375-0.998) for metabolic syndrome and an odds ratio of 0.631 (95% CI 0.404-0.986) for elevated triglycerides. Women who tested positive for serum HBsAg had an odds ratio of 0.343 (95% CI 0.170-0.693) for elevated triglycerides. CONCLUSIONS: Positive results for serum HBsAg are inversely associated with metabolic syndrome in men and with elevated triglycerides in men and women. This suggests that elevated triglycerides may contribute to the inverse association between HBsAg and metabolic syndrome.ope

Low-Dose Persistent Organic Pollutants Impair Insulin Secretory Function of Pancreatic β-Cells: Human and In Vitro Evidence

Low-dose persistent organic pollutants (POPs), especially organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), have emerged as a new risk factor for type 2 diabetes. We evaluated whether chronic exposure to low-dose POPs affects insulin secretory function of β-cells in humans and in vitro cells. Serum concentrations of OCPs and PCBs were measured in 200 adults without diabetes. Mathematical model-based insulin secretion indices were estimated by using a 2-h seven-sample oral glucose tolerance test. Insulin secretion by INS-1E β-cells was measured after 48 h of treatment with three OCPs or one PCB mixture. Static second-phase insulin secretion significantly decreased with increasing serum concentrations of OCPs. Adjusted means were 63.2, 39.3, 44.1, 39.3, 39.7, and 22.3 across six categories of a summary measure of OCPs (Ptrend = 0.02). Dynamic first-phase insulin secretion remarkably decreased with increasing concentrations of OCPs among only insulin-sensitive individuals (Ptrend = 0.02); the insulin levels among individuals with high OCPs were ∼30% of those with low OCPs. Compared with OCPs, PCBs showed weaker associations. The decreased insulin secretion by INS-1E β-cells was observed for even 1 pmol/L OCP. The data from human and in vitro cell experiments suggest that chronic exposure to low-dose POPs, especially OCPs, can induce pancreatic β-cell dysfunction.ope

Relationship between serum aminotransferase level and mortality from all causes and liver diseases in middle-aged men

Dept. of Public Health/박사[한글] 전세계적으로 만성 B형 간염과 C형 간염 유병률은 각각 6%와 3% 정도로 추정되며, 이들은 간경변 및 간암으로 진행되어 많은 사망의 원인이 되기도 한다. 특히, 아프리카와 아시아 지역은 간질환 유병률 및 사망률이 높은 지역으로 알려져 있으며, 우리 나라에서도 간질환은 단일 장기에 의한 사망으로 1위를 차지하고 있는 중요한 질환이다. 혈청 아미노산전환효소 (AST 및 ALT) 검사는 간질환의 진단과 조기검진에 가장 널리 사용되는 생화학 검사이다. 헌재 혈청 AST 및 ALT 농도의 정상 상한값으로는 40 IU/L를 가장 많이 사용되고 있다. 하지만, 혈청 AST 및 ALT 농도에 따른 간질환 발생 또는 사망에 대한 전향적 연구 결과는 거의 없는 실정이며, 현재 사용되는 정상 상한값을 간질환 환자의 조기 발견에 이용할 경우 민감도가 낮아서 이를 고쳐야 한다는 주장도 제기되고 있다. 따라서 본 연구는 일반 성인 남성 인구에서 혈청 아미노산전환효소 농도와 간질환 및 전체 사망률과의 관계를 밝히고, 현재 사용되고 있는정상 범위의 적절성을 평가하기 위하여 시행하기 위하여 시행되었다. 본 연구는 의료보험관리공단 (Korea Medical Insurance Corporation, KIMC) 코호트 자료를 이용하였다. 연구 대상은 1990년과 1992년 두 차례의 건강검진에 모두 참여한 35-59세 남성이었으며, 1992년 당시에 이미 질병을 가지고 있다고 응답한 사람은 대상에서 제외되었다. 연구 대상자들은 1993년부터 2000년까지 8년 동안 사망여부와 사망 원인에 대하여 추적관찰 되었다. 독립변수인 혈청 아미노산 전환효소 농도와 종속변수인 사망률과의 관계는 콕스의 비례위험 회귀모형을 통하여 분석하였으며, 연령, 체질량지수(body mass index), 혈압, 흡연, 음주, 혈청 포도당 및 콜레스테롤 농도, 간질환 가족력 등의 변수는 통계적 방법으로 보정하였다. 연구 대상자 95,459명 가운데 추적기간 동안 3,370명의 사망이 관찰되었으며 이 가운데 19%는 간암 또는 간질환이 사망 원인이었다. 다른 변수의 영향을 보정한 상태에서 혈청 AST 및 ALT 농도는 전체 사망 및 간질환으로 인한 사망과 통계적으로 유의한 양의 상관관계를 보였다. 매우 낮은 수준(<20 IU/L)의 혈청 효소 농도와 비교하면, 20-39 IU/L 범위의 효소 농도에서 통계적으로 의미 있게 사망 위험이 증가하였다. 혈청 AST 농도 20-29 IU/L 와 30-39 IU/L의 전체 사망에 대한 비교위험도(95% 신뢰구간)는 각각 1.3 (1.2-1.4)과 1.8 (1.6-2.0)이었으며, 혈청 ALT 농도에서는 비교위험도가 각각 1.2 (1.1-1.3)와 1.7 (1.5-2.9)이었다. 간질환으로 인한 사망 위험은 더 크게 증가하여, 혈청 AST의 비교위험도는 2.6 (1.8-3.9)과 7.9 (5.3-11.8), ALT의 비교위험도는 2.4 (1.8-3.3)와 7.7 (5.8-10.4)이었다. 혈청 AST 및 ALT 검사를 이용하여 향후 8년간 간질환 사망을 예측하는데 최적의 기준치를 ROC 곡선(receiver-operating characteristic curves)을 이용하여 추정한 결과, AST는 31 IU/L 그리고 ALT 는 30 IU/L으로 계산되었다. 기존의 정상 상한값 대신 이 값을 사용할 경우 검사의 민감도가 AST는 52%에서 70%로 ALT는 44%에서 66%로 크게 향상된 반면, 특이도는 각각 94%에서 82%, 91%에서 79%로 감소하였다. 이 결과는 현재 사용되고 있는 정상 상한값이 간질환의 조기 발견적절하지 않음을 보여주며, 정상범위를 재설정하여야 할 필요성을 제기하는 것이다. [영문] Chronic liver diseases constitute an enormous global burden. Worldwide about 350 million people are chronic carriers of the hepatitis B virus (HBV), and 170million people are affected by hepatitis C virus (HCV). These infections are responsible for a large proportion of mortality from end-stage liver disease and liver cancer. Morbidity and mortality from liver diseases are especially high in some African and Asian countries including Korea. Serum aspartate and alanine aminotransferase (AST and ALT) levels are most commonly measured to screen acute and chronic liver disease. However, the widely used normal limits (40 IU/L for men) sometimes fail to identify people with chronic liver disease. And little is known about the serum aminotransferase level in relation with mortality. This study was performed to investigate the relationship between serum aminotransferase level and mortality in general population. This is a prospective study using the KMIC (Korea Medical Insurance Corporation) Study cohort. The study population consisted of 95,459 men who were aged 35 to 59 years at baseline, had participated both health examinations in 1990 and 1992, and answered that they had no known disease. Primary outcomes were deaths from all causes and deaths from liver diseases during the follow-up period between 1993 and 2000. Independent association between serum aminotransferase level and mortality was assessed after adjusting for age, body mass index, blood pressure, smoking, alcohol consumption, serum glucose and cholesterol level, and family history of liver disease using Cox proportional hazard regression models. During the follow-up period, 3,370 deaths were reported, and liver diseases accounted for 19% of all mortality. There was significant positive relationship between serum aminotransferase level and mortality from all causes and liver diseases. When compared to the lowest level (<20 IU/L), enzyme levels of 20 to 39 IU/L were also related to increased risk of mortality. Adjusted risk ratio (95% CI) for all-cause mortality of serum AST of 20-29 IU/L and 30-39 IU/L were 1.3 (1.2-1.4) and 1.8 (1.6-2.0), respectively. Corresponding risk ratio (95% CI) of serum ALT of 20-29 IU/L and 30-39 IU/L were 1.2 (1.1-1.3) and 1.7 (1.5-2.9), respectively. Relationship between liver disease mortality and serum aminotransferase level was more prominent; corresponding risk ratio (95% CI) were 2.6 (1.8-3.9) and 7.9 (5.3-11.8) for AST, and 2.4 (1.8-3.3) and 7.7 (5.8-10.4) for ALT, respectively. The best cutoff values of AST and ALT tests in identifying men at high risk for liver disease mortality were estimated to 31 IU/L and 30 IU/L, respectively using receiver-operating characteristic curves. If this new cutoff values were used instead of current normal limits (40 IU/L), the sensitivity could be increased from 52% to 70% for AST and from 44% to 66% for ALT. The related tradeoff in specificity was acceptable (AST, 92% to 82%; ALT, 91% to 79%). These results suggest the need to revise the current normal limits for serum aminotransferase levels.ope