Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) cohort: study protocol and results of the first 3 years of enrollment

Metabolic phenotyping with computed tomography deep learning for metabolic syndrome, osteoporosis and sarcopenia predicts mortality in adults

BACKGROUND

Computed tomography (CT) body compositions reflect age-related metabolic derangements. We aimed to develop a multi-outcome deep learning model using CT multi-level body composition parameters to detect metabolic syndrome (MS), osteoporosis and sarcopenia by identifying metabolic clusters simultaneously. We also investigated the prognostic value of metabolic phenotyping by CT model for long-term mortality.

METHODS

The derivation set (n = 516; 75% train set, 25% internal test set) was constructed using age- and sex-stratified random sampling from two community-based cohorts. Data from participants in the individual health assessment programme (n = 380) were used as the external test set 1. Semi-automatic quantification of body compositions at multiple levels of abdominal CT scans was performed to train a multi-layer perceptron (MLP)-based multi-label classification model. External test set 2 to test the prognostic value of the model output for mortality was built using data from individuals who underwent abdominal CT in a tertiary-level institution (n = 10 141).

RESULTS

The mean ages of the derivation and external sets were 62.8 and 59.7 years, respectively, without difference in sex distribution (women 50%) or body mass index (BMI; 23.9 kg/m2). Skeletal muscle density (SMD) and bone density (BD) showed a more linear decrement across age than skeletal muscle area. Alternatively, an increase in visceral fat area (VFA) was observed in both men and women. Hierarchical clustering based on multi-level CT body composition parameters revealed three distinctive phenotype clusters: normal, MS and osteosarcopenia clusters. The L3 CT-parameter-based model, with or without clinical variables (age, sex and BMI), outperformed clinical model predictions of all outcomes (area under the receiver operating characteristic curve: MS, 0.76 vs. 0.55; osteoporosis, 0.90 vs. 0.79; sarcopenia, 0.85 vs. 0.81 in external test set 1; P < 0.05 for all). VFA contributed the most to the MS predictions, whereas SMD, BD and subcutaneous fat area were features of high importance for detecting osteoporosis and sarcopenia. In external test set 2 (mean age 63.5 years, women 79%; median follow-up 4.9 years), a total of 907 individuals (8.9%) died during follow-up. Among model-predicted metabolic phenotypes, sarcopenia alone (adjusted hazard ratio [aHR] 1.55), MS + sarcopenia (aHR 1.65), osteoporosis + sarcopenia (aHR 1.83) and all three combined (aHR 1.87) remained robust predictors of mortality after adjustment for age, sex and comorbidities.

CONCLUSIONS

A CT body composition-based MLP model detected MS, osteoporosis and sarcopenia simultaneously in community-dwelling and hospitalized adults. Metabolic phenotypes predicted by the CT MLP model were associated with long-term mortality, independent of covariates.

Extracellular fluid excess linked to reduced choroidal vascularity index in patients with chronic kidney disease

Extracellular fluid (ECF) excess is common in patients with chronic kidney disease (CKD). This study (involving 284 patients with CKD) explored the association between choroidal vascularity index (CVI) and ECF excess. We categorised patients into three groups based on extracellular water/total body water: normal, mildly overhydrated, and severely overhydrated. The more severe ECF status was associated with a lower CVI after adjustment (B = - 0.902, p = 0.001). In non-diabetic patients, both vascular luminal (LA, p < 0.001) and stromal areas (SA, p = 0.003) were significantly reduced in patients with severe ECF excess compared to others, whereas diabetic patients showed no significant differences in LA (p = 0.96) and SA (p = 0.86) based on ECF excess status. These findings suggest that ECF status may influence CVI in patients with CKD, underscoring the need for further research to clarify its direct impact on choroidal changes.

A Prospective Sociocentric Study of 2 Entire Traditional Korean Villages: The Korean Social Life, Health, and Aging Project (KSHAP)

The Korean Social Life, Health, and Aging Project (KSHAP) was a multidisciplinary prospective study conducted in South Korea that measured various health biomarkers from blood, hair, and brain magnetic resonance imaging, and we examined their associations with sociocentric (global) social network data of older adults in 2 entire villages (or cohorts). Cohort K included participants aged 60 years or older, and cohort L included participants aged 65 years or older. We performed a baseline survey involving 814 of the 860 individuals (94.7% response rate) in cohort K in 2012 and 947 of the 1,043 individuals (90.8% response rate) in cohort L in 2017. We gathered longitudinal data for 5 waves in cohort K from 2011 to 2019 and 2 waves in cohort L from 2017 to 2022. Here, we describe for the first time the follow-up design of the KSHAP, the changes in social networks, and various biomarkers over a number of years. The data for cohort K are publicly available via the Korean Social Science Data Archive as well as the project website, and the data for cohort L will be shared soon.

Nocturnal systolic blood pressure dipping and progression of chronic kidney disease

The relationship between declining nocturnal blood pressure (BP) and adverse cardiovascular outcomes is well-recognized. However, the relationship between diurnal BP profile and the risk of chronic kidney disease (CKD) progression is unclear. Herein, we examined the association between nocturnal systolic SBP (SBP) dipping and CKD progression in 1061 participants at the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (CMERC-HI). The main exposure was diurnal systolic BP (SBP) profile and diurnal SBP difference ([nighttime SBP-daytime SBP] × 100/daytime SBP). The primary outcome was CKD progression, defined as a composite of ≥ a 50% decline in the estimated glomerular filtration rate from baseline or the initiation of kidney replacement therapy. During 4749 person-years of follow-up (median, 4.8 years), the composite outcome occurred in 380 (35.8%) participants. Compared to dippers, the hazard ratios (HRs) for the risk of adverse kidney outcomes were 1.02 (95% confidence interval [CI], 0.64-1.62), 1.30 (95% CI, 1.02-1.66), and 1.40 (95% CI, 1.03-1.90) for extreme dipper, non-dipper, and reverse dipper, respectively. In a continuous modeling, a 10% increase in diurnal SBP difference was associated with a 1.21-fold (95% CI, 1.07-1.37) higher risk of CKD progression. Thus, decreased nocturnal SBP decline was associated with adverse kidney outcomes in patients with CKD. Particularly, patients with non-dipping and reverse dipping patterns were at higher risk for CKD progression than those with a dipping pattern.

Cortical and Trabecular Bone Deficit in Middle-Aged Men Living with HIV

A significant increase in the risk of hip fracture was observed in middle-aged men living with human immunodeficiency virus (MLWH), almost a decade earlier than those without infection. Data regarding cortical and trabecular bone deficit of hip, an important determinant of bone strength, in MLWH are limited. Quantitative CT was performed in consecutive MLWH aged ≥30 years between November 2017 and October 2018 at Severance Hospital, Seoul, Korea. Volumetric bone mineral density (vBMD) and cortical bone mapping parameters of hip (cortical thickness [CTh], cortical bone vBMD [CBMD], cortical mass surface density [CMSD], endocortical trabecular density [ECTD]) were compared to age-matched and body mass index (BMI)-matched controls (1:2) using a community-based healthy adults cohort. Among 83 MLWH and 166 controls (mean age: 47.2 years; BMI: 23.6 kg/m2 ), MLWH had lower total hip vBMD (280 ± 41 versus 296 ± 41 mg/cm3 ), CMSD (155 versus 160 mg/cm2 ), and ECTD (158 versus 175 mg/cm3 ) than controls that remained robust after adjustment for covariates (adjusted β: total hip vBMD, -18.8; CMSD, -7.3; ECTD, -18.0; p < 0.05 for all). Cortical bone mapping revealed localized deficit of CTh, CBMD, and CMSD in the anterolateral trochanteric region and femoral neck in MLWH compared to controls, with a more extensive ECTD deficit. In MLWH, lower CD4 T-cell count (/100 cells/mm3 decrement) and protease inhibitor (PI)-based regimen (versus non-PI regimen) at the time of antiretroviral treatment initiation were associated with lower total hip vBMD (adjusted β -7.5 for lower CD4 count; -28.3 for PI-based regimen) and CMSD (adjusted β -2.6 for lower CD4 count; -12.7 for PI-based regimen; p < 0.05 for all) after adjustment for covariates including age, BMI, smoking, alcohol use, hepatitis C virus co-infection, tenofovir exposure, and CT scanner types. MLWH had lower hip bone density with cortical and trabecular bone deficit compared to community-dwelling controls. © 2023 American Society for Bone and Mineral Research (ASBMR).

Diet quality partially mediates the association between ultraprocessed food consumption and adiposity indicators

OBJECTIVE

This study evaluated the potential role of overall diet quality in the associations between ultraprocessed food (UPF) consumption and adiposity indicators among Korean adults.

METHODS

Baseline data of participants (n = 4331) of the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) cohort study were obtained. Dietary information was collected by a validated food frequency questionnaire. UPF was defined using the NOVA classification. Overall diet quality was assessed using the Korean Healthy Eating Index. Adiposity indicators included BMI, waist circumference, percentage body fat by bioimpedance, and visceral fat mass by whole-body dual-energy x-ray absorptiometry. Mediation analysis after adjustment for potential confounders was performed.

RESULTS

UPF intake was associated with higher adiposity indicators after adjustment for confounders. The mediating effect of the Korean Healthy Eating Index on the relationship between UPF consumption and each adiposity indicator was 35.6% (95% CI: 4.9% to 255.9%) for BMI, 38.3% (17.9% to 132.1%) for waist circumference, 40.2% (8.3% to 259.4%) for percentage body fat, and 60.7% (-396.4% to 662.7%) for visceral fat mass.

CONCLUSIONS

UPF consumption was positively associated with adiposity indicators, which were partially attributed to the overall diet quality. Further studies are needed to better understand the causal mechanisms of these associations.

Ultra-Processed Food Consumption and Obesity in Korean Adults

BACKGRUOUND

This study aimed to investigate the association between consumption of ultra-processed foods (UPF) and obesity in Korean adults.

METHODS

We included the Cardiovascular and Metabolic Diseases Etiology Research Center cohort study baseline data of adults aged 30 to 64 years who completed a validated food frequency questionnaire. UPF was defined using the NOVA food classification. Multivariable linear and logistic regression analyses were performed to assess the association of dietary energy contribution of UPF with obesity indicators (body mass index [BMI], obesity, waist circumference [WC], and abdominal obesity).

RESULTS

Consumption of UPF accounted for 17.9% of total energy intake and obesity and abdominal obesity prevalence was 35.4% and 30.2%, respectively. Compared with those in the lowest quartile of UPF consumption, adults in the highest quartile had greater BMI (β=0.36; 95% confidence interval [CI], 0.15 to 0.56), WC (β=1.03; 95% CI, 0.46 to 1.60), higher odds of having obesity (odds ratio [OR], 1.24; 95% CI, 1.07 to 1.45), and abdominal obesity (OR, 1.34; 95% CI, 1.14 to 1.57), after adjusting for sociodemographic characteristics, health-related behaviors, and family history of diseases. Dose-response associations between UPF consumption and obesity indicators were consistently found (all P trend <0.01). However, the strength of association was halved for all obesity indicators after further adjustments for total energy intake and overall diet quality score, and the trend toward association for obesity and WC disappeared.

CONCLUSION

Our finding supports the evidence that consumption of UPF is positively associated with obesity among Korean adults.

Short-term Blood Pressure Variability and Incident CKD in Patients With Hypertension: Findings From the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (CMERC-HI) Study

RATIONALE & OBJECTIVE

The association between short-term blood pressure variability (BPV) and kidney outcomes is poorly understood. This study evaluated the association between short-term BPV and kidney disease outcomes in people with hypertension.

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

1,173 hypertensive participants in the Cardiovascular and Metabolic Disease Etiology Research Center-High Risk (2013-2018) Study with estimated glomerular filtration rate (eGFR) ≥60mL/min/1.73m².

EXPOSURE

Short-term BPV assessed by average real variability (ARV).

OUTCOME

Composite kidney disease outcome (30% decline in eGFR from baseline, new occurrence of eGFR <60mL/min/1.73m², or onset of UACR >300mg/g).

ANALYTICAL APPROACH

Multivariable Cox regression analyses to evaluate the association between systolic and diastolic BP ARV (SBP-ARV and DBP-ARV) and outcomes.

RESULTS

During a median follow-up of 5.4 [4.1-6.5] years, 271 events of the composite kidney disease outcome occurred (46.5 per 1,000 person-years). Multivariable Cox analysis revealed that the highest SBP-ARV and DBP-ARV tertiles were associated with a higher risk of the composite kidney disease outcome than the lowest tertiles, independent of the 24-hour SBP or DBP levels (HR, 1.64 [95% CI, 1.16-2.33], and 1.60 [95% CI, 1.15-2.24] for SBP-ARV and DBP-ARV, respectively). These associations were consistent when SBP-ARV and DBP-ARV were treated as continuous variables (HR per 1.0-unit greater SBP-ARV, 1.03 [95% CI, 1.01-1.06]; HR per 1.0-unit greater DBP-ARV, 1.04 [95% CI, 1.01-1.08]). These associations were consistent, irrespective of subgroups (age, sex, 24-hour SBP or DBP, and moderate albuminuria). However, other measures of short-term BPV including SD, coefficient of variation, and dipping patterns were not associated with the composite kidney disease outcome.

LIMITATIONS

Observational study design, the use of single measurement of 24-hour BP, lack of information on changes in antihypertensive medication during the follow-up.

CONCLUSIONS

Short-term BPV is associated with the development of a composite kidney disease outcome in hypertensive patients.

Ideal cardiovascular health metrics and the risk of nonalcoholic fatty liver disease in Korean adults

BACKGROUND

The association between cardiovascular risk factors and nonalcoholic fatty liver disease (NAFLD) is well established, but whether cardiovascular health (CVH) metrics is associated with NAFLD had not been fully studied. Thus, we examined the association between CVH metrics and NAFLD in the middle-aged Korean population.

METHODS

We used data of 2,928 (851 men and 2,077 women) participants aged 30-64 years from the Cardiovascular and Metabolic Disease Etiology Research Center study. CVH metrics were measured using a modified version of Life's Simple 7 by the American Heart Association. NAFLD diagnosis was based on the fatty liver index or liver-to-spleen ratio on computed tomography. A multiple logistic regression model was used to investigate the cross-sectional and longitudinal associations between CVH metrics and NAFLD.

RESULTS

In the cross-sectional analysis, the odds ratio for NAFLD was lower in participants with ideal CVH (odds ratio [OR], 0.13; 95% confidence interval [CI], 0.08-0.18), while it was higher in individuals with poor CVH (OR, 2.87; 95% CI, 2.13-3.86). Similarly, the risk of new-onset NAFLD was lower in participants with ideal CVH (OR, 0.28; 95% CI, 0.11-0.74), and higher in individuals with poor CVH (OR, 2.20; 95% CI, 0.50-9.72) in the longitudinal analysis of a subgroup.

CONCLUSIONS

Ideal CVH was associated with a lower risk of NAFLD while poor CVH was associated with a higher risk of NAFLD. These findings suggest that making efforts to encourage people to manage their CVH to the ideal level may prevent and manage NAFLD.

Anti‐thymocyte globulin‐mediated immunosenescent alterations of T cells in kidney transplant patients

Objectives

Kidney transplant (KT) is the most effective treatment for end‐stage renal disease. The immunosuppressant anti‐thymocyte globulin (ATG) has been applied for induction therapy to reduce the risk of acute transplant rejection for patients at high immunological risk. Despite its putative role in replicative stress during immune reconstitution, the effects of ATG on T‐cell immunosenescent changes remain to be understood.

Methods

Phenotypic and functional features of senescent T cells were examined by flow cytometry in 116 healthy controls (HC) and 95 KT patients for comparative analysis according to ATG treatment and CMV reactivation. The TCR repertoire was analysed in peripheral blood mononuclear cells (PBMCs) of KT patients.

Results

T cells of KT patients treated with ATG (ATG⁺) show typical immunosenescent features, accumulation of CD28⁻, CD85j⁺ or CD57⁺ T cells, and imbalance of functional T‐cell subsets, compared with untreated KT patients (ATG⁻). Plasma IL‐15 and CMV‐IgG levels were higher in KT patients than in HCs, and the IL‐15 level positively correlated with the frequency of CD28⁻ T cells in KT patients. ATG⁺ patients had a higher prevalence of CMV reactivation, which is associated with an increased frequency of CD28⁻ T cells. As a result, ATG⁺ patients had expanded CMV‐specific T cells and decreased TCR diversity. However, proliferation, cytokine‐producing capacity and polyfunctionality of T cells were preserved in ATG⁺ patients.

Conclusion

Our findings suggest that ATG treatment contributes to the accumulation of senescent T cells, which may have lifelong clinical implications in KT patients. Thus, these patients require long‐term and comprehensive immune monitoring.

Physical and mental health characteristics related to trust in and intention to receive COVID-19 vaccination: results from a Korean community-based longitudinal study

OBJECTIVES

The aim of this study was to explore factors affecting attitudes toward coronavirus disease 2019 (COVID-19) vaccination, including socio-demographic characteristics and mental health status during the pandemic.

METHODS

This study analyzed responses from 1,768 participants who were originally included in a community cohort study and responded to 3 online surveys related to COVID-19 (March 2020 to March 2021). The k-means method was used to cluster trust in and intention to receive COVID-19 vaccination. Baseline (2013-2018) socio-demographic characteristics, physical health status, and depressive symptoms were analyzed as exposure variables, and current mental health status was included in the analyses.

RESULTS

Almost half of all participants were classified into the moderate trust and high intention cluster (n=838, 47.4%); those with high trust and high intention accounted only for 16.9%. They tended to be older, had high-income levels, and engaged in regular physical activity at baseline (p<0.05), and their sleep quality and psychological resilience were relatively high compared to other groups.

CONCLUSIONS

Our results suggest that more efforts are required to enhance the perceived need for and trust in COVID-19 vaccination.

Association between Metabolically Healthy Obesity and Subclinical Atherosclerosis in the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) Cohort

We aimed to investigate the association between a new definition of metabolic health (MH) and subclinical atherosclerosis in a cohort of patients without previous cardiovascular disease (CVD). In total, 7824 community-dwelling adults were categorized as normal weight, overweight, or obese. Metabolically healthy obesity (MHO) was defined as obesity accompanied by all of the following criteria: systolic blood pressure (BP) < 130 mmHg, no use of BP-lowering medication, waist-hip ratio <0.832 (women) and <0.887 (men), and no prevalent diabetes. Carotid atherosclerosis was defined as carotid plaque or mean carotid intima-media thickness ≥ 1.1 mm. The prevalence of carotid atherosclerosis was 8.3% and 1113 (14.2%) patients were classified as having MHO. All individuals classified as metabolically unhealthy were at an increased risk of carotid atherosclerosis independent of body mass index categories. Conversely, the risk of carotid atherosclerosis in individuals with MHO was not significantly increased compared to that in metabolically healthy normal weight participants (hazard ratio 1.20, 95% confidence interval 0.87−1.67). This new definition of MH was able to identify people with MHO without an increased risk of CVD in an Asian community cohort.

Association Between Social Network and Cognitive Function: A Cross-Sectional Assessment From the Cardiovascular and Metabolic Diseases Etiology Research Center Cohort (2013-2018)

BACKGROUND

This study aimed to investigate how social networks are associated with cognitive function in the middle-aged and elderly Korean population.

METHODS

A total of 7,704 individuals over the age of 50 were included from the baseline recruitment of the Cardiovascular and Metabolic Diseases Etiology Research Center cohort from the years 2013 to 2018. Egocentric social network characteristics including network size, intimacy, and frequency of face-to-face meetings were measured as exposures, and the Korean version of Mini-Mental State Examination (K-MMSE) score was measured to reflect general cognitive function as an outcome. We also stratified the analysis by income level into tertiles, with income caps of 42,000 thousand won and 72,000 thousand won. A general linear regression model was used, adjusting for age, gender, socioeconomic factors, lifestyle factors, depressive symptoms, and study settings.

RESULTS

Social network properties were positively associated with cognitive function in both men and women. However, the specific estimates varied according to gender and income level. In men, frequency was most significantly associated with cognitive function (standardized β = 0.093, p-value <0 .0001). In women, the strength of the association with cognitive function was found in size (standardized β = 0.055, p-value = 0.001). The effect modification of income level could be seen in the association between frequency and cognitive function. The strongest association between frequency and cognitive function was found in the middle income group in men (standardized β = 0.114, p-value = 0.0063), and the low income group in women (standardized β = 0.076, p-value = 0.0039).

CONCLUSION

There were positive associations between social network properties (i.e., size, intimacy, and frequency of face-to-face meetings) and cognitive function. The degree of association varied according to social network properties, gender, and income level. Overall, among social network properties, social network size was an important factor in the cognition of women, whereas frequency was important in the cognition of men.

Association between a family history of diabetes and carotid artery atherosclerosis in Korean adults

OBJECTIVES

Diabetes is a well-known risk factor for atherosclerosis, but the association between a family history of diabetes and atherosclerosis remains unknown. In this study, we assessed the association between a family history of diabetes and increased carotid intima-media thickness (IMT), a marker of subclinical atherosclerosis, in a middle-aged Korean population.

METHODS

This cross-sectional study included 3,974 community-dwelling adults (1,404 male and 2,570 female) aged 30-64 years from the Cardiovascular and Metabolic Diseases Etiology Research Center cohort. The presence of a family history of diabetes was assessed through face-to-face interviews using a standardized questionnaire. Carotid IMT was assessed using B-mode ultrasonography, and increased IMT was defined as a value in the top quartile of the IMT values of all participants. Multivariate logistic regression was used to evaluate independent associations between a family history of diabetes and increased IMT.

RESULTS

A family history of diabetes was significantly associated with increased carotid IMT (odds ratio, 1.23; 95% confidence interval, 1.03 to 1.48) after adjusting for sex; age; body mass index; systolic blood pressure; total cholesterol, triglyceride, and hemoglobin A1c levels; smoking; alcohol consumption; exercise; use of antidiabetic, antihypertensive, and antilipidemic drugs; and a family history of hypertension. The positive association remained significant after excluding participants with diabetes (odds ratio, 1.21; 95% confidence interval, 1.00 to 1.47).

CONCLUSIONS

A family history of diabetes was positively associated with increased carotid IMT, even in participants without diabetes. Therefore, information on a family history of diabetes may help identify individuals at high risk of atherosclerotic cardiovascular disease.

Impact of COVID-19 on mental health according to prior depression status: A mental health survey of community prospective cohort data

OBJECTIVE

We aimed to investigate the mental health impact of COVID-19 on a demographically well-characterized population cohort by gender and previous depression status.

METHODS

Among people who participated in a community cohort study between 2013 and 2018 with previous depression measurement, a total of 1928 people without quarantine experience (680 men and 1249 women) were included after responding to an online survey in March 2020. In the 2020 survey, people were queried about daily needs supply, social support, risk perception, change during the COVID-19 pandemic, as well as mental health indices measuring loneliness, anxiety symptoms, post-traumatic stress disorder (PTSD), and depression. Separate analyses by gender were conducted to assess the association between COVID-19-related experiences and each mental health index, using multivariable logistic regressions with additional adjustment and stratification with pre-existing depression status.

RESULTS

We could not observe significant gender differences for depression, anxiety, PTSD, and loneliness at 55 days after the start of the COVID-19 outbreak. Most external support, including daily needs supply and social support, protected men and women from experiencing severe anxiety (for life supply, OR = 0.92 (95%CI 0.88-0.97) (men) and OR = 0.95 (95% CI 0.91-0.99) (women); for social support, OR = 0.92(both for men and women, p < 0.01)). The results were similar for depression and PTSD. External support showed a larger reduction in the likelihoods for anxiety and depression during the COVID-19 pandemic among people with pre-existing depression compared to previously healthy people, and it was more prominent in men.

CONCLUSION

COVID-19 significantly affected the mental health of both men and women in the early period of the pandemic. Having enough supply of daily needs and social support seems important, especially for people with previous depression.

Association between psychological resilience and cognitive function in older adults: effect modification by inflammatory status

To examine the association between psychological resilience and cognitive function and investigate the role of acute inflammation as an effect modifier. Total 7535 people from the Cardiovascular and Metabolic Disease Etiology Research Center (CMERC), aged ≥ 50 years and residing in areas near Seoul, South Korea, were included in this cross-sectional analysis. Stressful life events in the past 6 months were gauged by the Life Experience Survey, and current depression symptoms were analyzed with the Beck Depression Inventory-II. Participants were categorized into the following four groups according to their past experience and depression status: reference, resilient, reactive depression, and vulnerable depression. Cognitive function was evaluated using the mini-mental state examination (MMSE). The level of high-sensitivity C-reactive protein (hsCRP) was measured from blood samples. A generalized linear model was used. Upon adjusting for socio-demographic factors, comorbidity, and lifestyle factors, the final model was stratified with the highest quartile of the hsCRP level by sex. Compared to the reference group, the resilient group showed higher MMSE, which was also significant in women (adj-β = 0.280, p-value < 0.001). Vulnerable depression group showed a significantly lower MMSE (adj-β =  − -0.997, p-value 0.002), especially in men. This pattern seemed to be limited to the low hsCRP subgroup. We provided evidence from the largest Korean population used to evaluate the association between psychological resilience and cognition, which was more prominent in low inflammatory status. Psychological resilience was associated with a lower likelihood of cognitive deficit in women. This pattern was modulated by inflammatory status.

Stressful life events and serum triglyceride levels: the Cardiovascular and Metabolic Diseases Etiology Research Center cohort in Korea

OBJECTIVES

Elevated serum triglyceride levels are a risk factor for developing cardiovascular disease. A number of studies have demonstrated a positive association between psychological stress and serum triglyceride levels. However, there is limited evidence regarding the impact of stressful life events (SLEs) on serum triglyceride levels in the healthy population. Therefore, we evaluated the independent association between SLEs and serum triglyceride levels in a middle-aged Korean population.

METHODS

We analyzed a sample of 2,963 people (aged 30-64 years; 36% men) using baseline data from the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) cohort study. The Korean version of the Life Experience Survey questionnaire was used to measure the presence and positive/negative impact of SLEs. Hypertriglyceridemia was defined as a fasting serum triglyceride level of ≥ 150 mg/dL.

RESULTS

Of the 2,963 participants, 33.1% reported at least 1 SLE over the past 6 months and 24.8% had hypertriglyceridemia. Even after adjusting for potential confounders, the serum triglyceride level was significantly associated with the total number of SLEs in men (3.333 mg/dL per event; p= 0.001), but not in women (0.451 mg/dL per event, p= 0.338). Hypertriglyceridemia was also associated with having 4 or more SLEs with positive effects (odds ratio [OR], 2.57; 95% CI, 1.02 to 6.46) and 4 or more SLEs with negative effects (OR, 1.99; 95% CI, 1.16 to 3.41) in men.

CONCLUSIONS

Our findings suggest that SLEs may increase the risk of hypertriglyceridemia in middle-aged men.

Soluble Urokinase-Type Plasminogen Activator Receptor, Changes of 24-Hour Blood Pressure, and Progression of Chronic Kidney Disease

Background

Soluble urokinase‐type plasminogen activator receptor (suPAR) is associated with cardiovascular risks and poor renal outcomes. However, whether elevated suPAR levels are associated with 24‐hour blood pressure patterns or kidney disease progression in patients with chronic kidney disease (CKD) is unclear.

Methods and Results

A total of 751 patients with CKD stage 1 to 5 were recruited from CMERC‐HI (Cardiovascular and Metabolic Disease Etiology Research Center–High Risk) cohort study (2013–2018). The relationship of serum suPAR levels to 24‐hour blood pressure parameters and CKD progression was analyzed. The median serum suPAR level was 1439.0 (interquartile range, 1026.2–2150.1) pg/mL, and the mean estimated glomerular filtration rate was 52.8±28.5 mL/min per 1.73 m² at baseline. Patients with higher suPAR levels had significantly higher levels of office, 24‐hour, daytime, and nighttime systolic blood pressure and nighttime diastolic blood pressure than those with lower suPAR levels. The highest suPAR tertile was associated with an increased risk of a reverse dipping pattern (odds ratio, 2.93; 95% CI, 1.27–6.76; P=0.01). During a follow‐up of 43.2 (interquartile range, 27.0–55.6) months, the CKD progression occurred in 271 (36.1%) patients. The highest suPAR tertile was significantly associated with higher risk of CKD progression than the lowest tertile (hazard ratio [HR], 2.09; 95% CI, 1.37–3.21; P=0.001). When the relationship was reevaluated with respect to each dipping pattern (dipper, extreme dipper, nondipper, and reverse dipper), this association was consistent only in reverse dippers in whom the risk of CKD progression increased (HR, 1.43; 95% CI, 1.02–2.01; P=0.03) with every 1‐unit increase in serum suPAR levels.

Conclusions

Elevated suPAR levels are independently associated with CKD progression, and this association is prominent in reverse dippers.

Effect of Smartphone-Based Lifestyle Coaching App on Community-Dwelling Population With Moderate Metabolic Abnormalities: Randomized Controlled Trial

Background

Metabolic disorders are established precursors to cardiovascular diseases, yet they can be readily prevented with sustained lifestyle modifications.

Objective

We assessed the effectiveness of a smartphone-based weight management app on metabolic parameters in adults at high-risk, yet without physician diagnosis nor pharmacological treatment for metabolic syndrome, in a community setting.

Methods

In this 3-arm parallel-group, single-blind, randomized controlled trial, we recruited participants aged 30 to 59 years with at least 2 conditions defined by the Third Report of the National Cholesterol Education Program expert panel (abdominal obesity, high blood pressure, high triglycerides, low high-density lipoprotein cholesterol, and high fasting glucose level). Participants were randomly assigned (1:1:1) by block randomization to either the nonuser group (control), the app-based diet and exercise self-logging group (app only), or the app-based self-logging and personalized coaching from professional dieticians and exercise coordinators group (app with personalized coaching). Assessments were performed at baseline, week 6, week 12, and week 24. The primary outcome was change in systolic blood pressure (between baseline and follow-up assessments). Secondary outcomes were changes in diastolic blood pressure, body weight, body fat mass, waist circumference, homeostatic model of assessment of insulin resistance, triglyceride level, and high-density lipoprotein cholesterol level between baseline and follow-up assessments. Analysis was performed using intention-to-treat.

Results

Between October 28, 2017 and May 28, 2018, 160 participants participated in the baseline screening examination. Participants (129/160, 80.6%) who satisfied the eligibility criteria were assigned to control (n=41), app only (n=45), or app with personalized coaching (n=43) group. In each group, systolic blood pressure showed decreasing trends from baseline (control: mean –10.95, SD 2.09 mmHg; app only: mean –7.29, SD 1.83 mmHg; app with personalized coaching: mean –7.19, SD 1.66 mmHg), yet without significant difference among the groups (app only: P=.19; app with personalized coaching: P=.16). Instead, those in the app with personalized coaching group had greater body weight reductions (control: mean –0.12, SD 0.30 kg; app only: mean –0.35, SD 0.36 kg, P=.67; app with personalized coaching: mean –0.96, SD 0.37 kg; P=.08), specifically by body fat mass reduction (control: mean –0.13, SD 0.34 kg; app only: mean –0.64, SD 0.38 kg, P=.22; app with personalized coaching: mean –0.79, SD 0.38 kg; P=.08).

Conclusions

Simultaneous diet and exercise self-logging and persistent lifestyle modification coaching were ineffective in lowering systolic blood pressure but effective in losing weight and reducing body fat mass. These results warrant future implementation studies of similar models of care on a broader scale in the context of primary prevention.

Trial Registration

ClinicalTrials.gov NCT03300271; http://clinicaltrials.gov/ct2/show/NCT03300271

Does serum vitamin D level affect the association between cardiovascular health and cognition? Results of the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) study

BACKGROUND AND PURPOSE

Few studies have assessed the role of vitamin D in the association between cardiovascular risk factors and cognitive function. Here, the aim was to investigate the association between cardiovascular health (CVH) and cognitive function according to vitamin D level in a middle-aged Korean population.

METHODS

This cross-sectional study included 840 men and 1811 women (mean age 57.2 years) from the Cardiovascular and Metabolic Diseases Etiology Research Center study baseline enrolment (2013-2018). Life's Simple 7 tools from the American Heart Association were used to assess CVH. Cognitive function was evaluated using the Mini-Mental State Estimation for Dementia Screening (MMSE-DS), and the serum 25-hydroxyvitamin D level was measured.

RESULTS

In the adjusted generalized linear regression models, no significant association between a high Life's Simple 7 score (4-7 metric at optimal level) and MMSE-DS score (β = 0.01, P = 0.93) was found. Amongst men with a high vitamin D level, the high Life's Simple 7 score group showed a significantly higher MMSE-DS score (β = 0.48, P = 0.03). However, amongst men in the low vitamin D group, the association was opposite with no statistical significance (β = -0.23, P = 0.08). In women, the results were similar, but both strata according to vitamin D level showed no statistical significance.

CONCLUSIONS

Our findings suggest that vitamin D is an effect modifier in the association between CVH and cognition, especially in men.

Comparison of Computed Tomography-based Abdominal Adiposity Indexes as Predictors of Non-alcoholic Fatty Liver Disease Among Middle-aged Korean Men and Women

Objectives:

We compared the associations of 3 computed tomography (CT)-based abdominal adiposity indexes with non-alcoholic fatty liver disease (NAFLD) among middle-aged Korean men and women.

Methods:

The participants were 1366 men and 2480 women community-dwellers aged 30-64 years. Three abdominal adiposity indexes—visceral fat area (VFA), subcutaneous fat area (SFA), and visceral-to-subcutaneous fat ratio (VSR)—were calculated from abdominal CT scans. NAFLD was determined by calculating the Liver Fat Score from comorbidities and blood tests. An NAFLD prediction model that included waist circumference (WC) as a measure of abdominal adiposity was designated as the base model, to which VFA, SFA, and VSR were added in turn. The area under the receiver operating characteristic curve (AUC), integrated discrimination improvement (IDI), and net reclassification improvement (NRI) were calculated to quantify the additional predictive value of VFA, SFA, and VSR relative to WC.

Results:

VFA and VSR were positively associated with NAFLD in both genders. SFA was not significantly associated with NAFLD in men, but it was negatively associated in women. When VFA, SFA, and VSR were added to the WC-based NAFLD prediction model, the AUC improved by 0.013 (p<0.001), 0.001 (p=0.434), and 0.009 (p=0.007) in men and by 0.044 (p<0.001), 0.017 (p<0.001), and 0.046 (p<0.001) in women, respectively. The IDI and NRI were increased the most by VFA in men and VSR in women.

Conclusions:

Using CT-based abdominal adiposity indexes in addition to WC may improve the detection of NAFLD. The best predictive indicators were VFA in men and VSR in women.

Depressive symptoms, its sub-factors, and augmentation index: the modifying effects according to inflammatory markers

Background This study aimed to investigate the association between depression and the augmentation index (AIx), and to further investigate whether there is a difference in this association according to the patients' inflammatory status. Methods This study included 458 men and 815 women (mean age: 49.35 years), a community-dwelling and middle-aged Korean population. The Korean version of the Beck Depression Inventory-II (BDI-II) was used to assess depressive symptoms. Arterial stiffness was evaluated via an AIx normalized to 75 beats/min. We confirmed two factors from BDI-II after conducting a factor analysis. Multiple regression models were used after adjusting for socio-demographic factors, lifestyle factors, systolic blood pressure, diabetes history, and body mass index. We further stratified the data according to inflammatory biomarkers with cutoffs of the 75^th percentile. Results There was a significant positive association between the BDI-II score and arterial stiffness (ß= 0.09, p-value=0.037). In women, the somatic-affective factor showed a stronger positive association (ß= 0.20, p-value=0.018) with arterial stiffness than the cognitive factor (ß= 0.12, p-value=0.148). There was no significant association in men (ß= -0.01, p-value=0.943). In subgroup analyses, women showed significant positive associations between the somatic affective factor of depressive symptoms on and arterial stiffness according to both inflammatory markers (IL-6: ß= 0.17, p-value=0.039; hs-CRP: ß= 0.17, p-value=0.094) Limitations The design of the cross-sectional study limits causal interpretation. Conclusion Depression and its somatic-affective factor were positively associated with arterial stiffness in women. Inflammatory status may be involved in modifying the association between depressive symptoms, its sub-factors, and AIx.

Association between the Thigh Muscle and Insulin Resistance According to Body Mass Index in Middle-Aged Korean Adults

BACKGROUND

We examined the associations between thigh muscle area (TMA) and insulin resistance (IR) according to body mass index (BMI) in middle-aged Korean general population.

METHODS

TMA was measured using quantitative computed tomography and corrected by body weight (TMA/Wt) in 1,263 men, 788 premenopausal women, and 1,476 postmenopausal women all aged 30 to 64 years. The tertiles of TMA/Wt were calculated separately for men and for premenopausal and postmenopausal women. Homeostatic model assessment for insulin resistance (HOMA-IR) was performed using fasting blood glucose and insulin levels, and increased IR was defined according to sex-specific, top quartiles of HOMA-IR. Associations between the TMA/Wt tertiles and increased IR according to the BMI categories (<25 and ≥25 kg/m²) were assessed using multivariable logistic regression analysis.

RESULTS

In men with higher BMIs, but not in those with lower BMIs, the presence of an increased IR had significantly higher odds ratios in the lower TMA/Wt tertiles, even after adjustment for visceral fat area. However, in premenopausal and postmenopausal women, there was no significant inverse association between TMA/Wt tertiles and increased IR, regardless of BMI category.

CONCLUSION

Our findings suggest that the thigh muscle is inversely associated with IR in men, particularly in those with higher BMIs.

Residential Radon Exposure and Cigarette Smoking in Association with Lung Cancer: A Matched Case-Control Study in Korea

Residential radon exposure and cigarette smoking are the two most important risk factors for lung cancer. The combined effects thereof were evaluated in a multi-center matched case-control study in South Korea. A total of 1038 participants were included, comprising 519 non-small cell lung cancer cases and 519 age- and sex- matched community-based controls. Residential radon levels were measured for all participants. Multivariate logistic regression was used to calculate odds ratios (OR) for lung cancer according to radon exposure (high ≥ 100 Bq/m3 vs. low < 100 Bq/m3), smoking status, and combinations of the two after adjusting for age, sex, indoor hours, and other housing information. The median age of the participants was 64 years, and 51.3% were women. The adjusted ORs (95% confidence intervals [CIs]) for high radon and cigarette smoking were 1.56 (1.03-2.37) and 2.53 (1.60-3.99), respectively. When stratified according to combinations of radon exposure and smoking status, the adjusted ORs (95% CIs) for lung cancer in high-radon non-smokers, low-radon smokers, and high-radon smokers were 1.40 (0.81-2.43), 2.42 (1.49-3.92), and 4.27 (2.14-8.52), respectively, with reference to low-radon non-smokers. Both residential radon and cigarette smoking were associated with increased odds for lung cancer, and the difference in ORs according to radon exposure was much greater in smokers than in non-smokers.

Effects of cigarette smoking on blood lipids in Korean men: Cardiovascular and Metabolic Diseases Etiology Research Center cohort

BACKGROUND/AIMS

Cigarette smoking and abnormal blood lipids are major risk factors for cardiovascular disease. The results of previous studies on the relationship between cigarette smoking and dyslipidemia are controversial. In the present study, we investigated the independent association between cigarette smoking and blood lipid levels in a male Korean population.

METHODS

A total of 1,932 men aged from 30 to 64 years old participated in the Cardiovascular and Metabolic Diseases Etiology Research Center cohort study. Smoking history was obtained by in-person interviews. In all regression models, measurements of triglyceride levels were log-transformed.

RESULTS

Triglyceride levels were higher in current smokers than in never-smokers (median: 149 mg/dL vs. 115 mg/dL, p < 0.001) even after adjusting age, body mass index, alcohol intake, systolic blood pressure, fasting glucose, physical activity, and nutrition intake (β = 0.14, p < 0.001). We further divided people into heavy and light smokers using 20 pack-years as the cut-off. Higher triglyceride were found in current heavy smokers (β = 0.18, p < 0.001), current light smokers (β = 0.13, p < 0.001), as well as in past heavy smokers (β = 0.08, p = 0.037), as compared to never-smokers. Moreover, significantly lower high-density lipoprotein cholesterol (HDL-C) were observed in current heavy smokers (β = -2.27 mg/dL, p = 0.009).

CONCLUSION

Cigarette smoking is associated with higher triglyceride in Korean men, with the most dramatic effect seen in current smokers with a smoking history of more than 20 pack-years. HDL-C were also lower in current smokers with more than 20 pack-years.

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.

Dose-Response Association between Smoking Cessation and Arterial Stiffness: The Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) Cohort

Background and Objectives

Cigarette smoking has been reported to be associated with arterial stiffness. However, the clinical relevance of smoking cessation on arterial stiffness is debatable. Thus, we evaluated whether smoking cessation is associated with arterial stiffness.

Methods

A total of 1,169 male participants aged 30–64 years with absence of cardiovascular diseases in 2013–2017 were selected from the Cardiovascular and Metabolic Disease Etiology Research Center cohort study. The subjects were classified into the following 5 groups based on self-reporting: non-smokers, former smokers (<1, 1 to <10, and ≥10, years after cessation), and current smokers. Arterial stiffness was assessed using the augmentation index (AIx). The radial artery AIx was obtained from the peripheral artery waveform. The association was explored cross-sectionally.

Results

The AIx of former smokers did not differ from that of non-smokers (p=0.089). However, after former smokers were stratified by duration of smoking cessation, we noted a linear trend according to the smoking status (p<0.001). Men who quit smoking <1 year ago showed an elevated AIx (β=3.94, standard error=1.54, p=0.011) as much as ones of current smokers (β=4.39, standard error=0.74, p<0.001), while those who quit more than a decade ago showed an AIx similar to that of non-smokers (β=0.35, standard error=0.82, p=0.670) after controlling covariates.

Conclusions

A dose-response association between smoking cessation and AIx was revealed, which implies the possibility of a reversible effect of smoking cessation on arterial stiffness. Therefore, our findings may motivate current smokers to modify their smoking habits to delay or reverse disease progression.

Cohort Profile: The Cardiovascular and Metabolic Diseases Etiology Research Center Cohort in Korea

Mortalities from cardiovascular disease in Korea have decreased markedly over the past three decades. The major cardiovascular and metabolic risk factors, however, remain prevalent, and their burden on health is large. The Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) planned a cohort study in order to identify novel risk factors and to develop evidence-based prevention strategies of cardiovascular and metabolic diseases. The CMERC deliberately designed two prospective cohorts, a community-based general population cohort (the CMERC cohort) and its sister cohort (a hospital-based high-risk patient cohort), covering a broad spectrum of cardiovascular and metabolic diseases. This paper describes the CMERC cohort study of community-dwelling adults aged 30 to 64 years. A total of 8097 adults completed baseline measurement between 2013 and 2018. Baseline measurements assessed socio-demographic factors, medical history, health-related behaviors, psychological health, social network and support, anthropometry, body composition, and resting blood pressure and comprised electrocardiography, carotid artery ultrasonography, fasting blood analysis, and urinalysis. Both active follow-up through an annual telephone survey and a 5-year on-site health examination survey and passive follow-up through secondary data linkage with national databases, such as national death records, have been applied. Researchers interested in collaborative research may contact the corresponding author.

Presence of Metabolic Syndrome Components Is Associated with Tooth Loss in Middle-Aged Adults

PURPOSE

In general, the prevalence of metabolic syndrome (MS) and tooth loss increases with age. We investigated the relationship between the presence of MS, its elements, and tooth loss in middle-aged Korean adults.

MATERIALS AND METHODS

This study included Korean adults between 30 and 64 years of age who resided in the capital area of Seoul. From January to June 2014, individuals interested in participating in the oral health survey among those who visited the university hospital's cardiovascular center and provided informed consent were selected. Among 748 subjects who responded to the oral health questionnaires, 30 were excluded due to unclear responses; therefore, a total of 718 were included in the final analysis.

RESULTS

The crude odds ratio (OR) of ≥one MS component affecting tooth loss was 1.45 [95% confidence interval (CI), 1.06-2.00]. After adjusting for sex, age, education, income level, occupation, smoking status, kidney disease, chronic obstructive pulmonary disease, and rheumatic disease, the adjusted OR was 1.47 (95% CI, 1.06-2.05), which was statistically significant (p<0.05). The OR for tooth loss was higher in the presence of ≥one component of MS (50-64 years of age) in females.

CONCLUSION

This study suggests that female aged 50-64 years may have higher likelihood of tooth loss upon the presence of at least one MS component. Prevention against MS among female of older age could contribute to maintenance of remaining teeth. Further well-designed studies are needed.

The Association of Adiponectin and Visceral Fat with Insulin Resistance and β-Cell Dysfunction

BACKGROUND

Obesity is a risk factor for metabolic abnormalities. We investigated the relationship of adiponectin levels and visceral adiposity with insulin resistance and β-cell dysfunction.

METHODS

This cross-sectional study enrolled 1,347 participants (501 men and 846 women aged 30-64 years) at the Cardiovascular and Metabolic Diseases Etiology Research Center. Serum adiponectin levels and visceral fat were measured using enzyme-linked immunosorbent assay kits and dual-energy X-ray absorptiometry, respectively. Insulin resistance was evaluated using the homeostatic model assessment of insulin resistance (HOMA-IR) and Matsuda insulin sensitivity index. β-cell dysfunction was evaluated using the homeostatic model assessment of β-cell function (HOMA-β), insulinogenic index, and disposition index.

RESULTS

Regarding insulin resistance, compared with individuals with the highest adiponectin levels and visceral fat mass < 75th percentile, the fully adjusted odds ratios (ORs) for HOMA-IR ≥ 2.5 and Matsuda index < 25th percentile were 13.79 (95% confidence interval, 7.65-24.83) and 8.34 (4.66-14.93), respectively, for individuals with the lowest adiponectin levels and visceral fat ≥ 75th percentile. Regarding β-cell dysfunction, the corresponding ORs for HOMA-β < 25th percentile, insulinogenic index < 25th percentile, and disposition index < 25th percentile were 1.20 (0.71-2.02), 1.01 (0.61-1.66), and 1.87 (1.15-3.04), respectively.

CONCLUSION

Low adiponectin levels and high visceral adiposity might affect insulin resistance and β-cell dysfunction.

Comparison of self-reported and accelerometer-assessed measurements of physical activity according to socio-demographic characteristics in Korean adults

OBJECTIVES

Previous studies have shown relatively low correlations between self-reported and accelerometer-assessed physical activity (PA). However, this association differs by socio-demographic factors, and this relationship has not been fully investigated in the general population. Thus, we investigated the correlation between self-reported and accelerometer-assessed PA and whether it differed by demographic and socioeconomic factors among the Korean general population.

METHODS

This cross-sectional study included 623 participants (203 men and 420 women) aged 30 to 64 years, who completed a PA questionnaire and wore a wrist-worn accelerometer on the non-dominant wrist for 7 days. We examined the agreement for metabolic equivalent task minutes per week (MET-min/wk) between the 2 measures and calculated Spearman correlation coefficients according to demographic and socioeconomic factors.

RESULTS

The kappa coefficient between tertiles of self-reported and accelerometer-assessed total MET-min/wk was 0.16 in the total population, suggesting overall poor agreement. The correlation coefficient between the 2 measurements was 0.26 (p<0.001) in the total population, and the correlation tended to decrease with increasing age (p for trend <0.001) and depression scores (p for trend <0.001).

CONCLUSIONS

We found a low correlation between self-reported and accelerometer-assessed PA among healthy Korean adults, and the correlation decreased with age and depression score. When studying PA using accelerometers and/or questionnaires, age and depression need to be considered, as should differences between self-reported and accelerometer-assessed PA.

Association of appendicular skeletal muscle mass with carotid intima-media thickness according to body mass index in Korean adults

OBJECTIVES

The combined effects of obesity and appendicular skeletal muscle (ASM) on atherosclerosis, especially in middleaged populations, remain poorly understood. This cross-sectional study investigated the effects of ASM on carotid intima-media thickness (IMT) according to body mass index (BMI) in middle-aged Korean adults.

METHODS

Herein, 595 men and 1,274 women aged 30-64 years completed questionnaires and underwent health examinations as part of the Cardiovascular and Metabolic Disease Etiology Research Center cohort. ASM was measured via bioelectrical impedance analysis and adjusted for weight (ASM/Wt). IMT was assessed using B-mode ultrasonography; highest quartile of IMT was defined as gender-specific top quartile of the IMT values. Higher BMIs was defined as a BMI over 25.0 kg/m2 .

RESULTS

Compared to the highest ASM/Wt quartile, the lowest ASM/Wt quartile was significantly associated with highest quartile of IMT in men with lower BMIs (adjusted odds ratio [aOR], 2.78; 95% confidence interval [CI], 1.09 to 7.13), but not in those with higher BMIs (aOR, 0.59; 95% CI, 0.24 to 1.91). In women, there was no significant association of low skeletal muscle mass with highest quartile of IMT, regardless of BMI.

CONCLUSIONS

Low appendicular skeletal muscle mass is associated with carotid arterial wall thickening in men with lower BMIs, but not in men with higher BMIs. Our findings suggest that the risk of atherosclerosis may be low in middle-aged Korean men with appropriate body weight and skeletal muscle mass maintenance.

Association between appendicular skeletal muscle mass and depressive symptoms: Review of the cardiovascular and metabolic diseases etiology research center cohort

BACKGROUND

The effects of skeletal muscle mass on depressive symptoms remain poorly understood, especially in the middle-aged population. We examined the relationship between skeletal muscle mass and depressive symptoms according to sex and menopausal status in the middle-aged Korean population.

METHODS

Herein, 1,151 men and 2,176 women aged 30-64 years completed questionnaires and underwent health examinations in the Cardiovascular and Metabolic Disease Etiology Research Center study. Appendicular skeletal muscle mass (ASM) was measured via bioelectrical impedance analysis and adjusted for height squared (ASM/Ht²). Both continuous values and tertile groups of ASM/Ht² were used for analysis. Depressive symptoms were assessed using the Beck Depressive Inventory-II (BDI), and the prevalence of depressive symptoms was determined as a BDI score ≥ 20.

RESULTS

Multiple logistic regression analysis using a fully adjusted model showed that depressive symptoms were more frequently observed among men in the lower ASM/Ht² tertile and middle ASM/Ht² tertile than among those in the higher ASM/Ht² tertile. Each 1-kg/m² decrease in ASM/Ht² was significantly associated with the presence of depressive symptoms in men. Such significant association was not observed among premenopausal and postmenopausal women.

LIMITATIONS

The cross-sectional nature of the study design, measurement of skeletal muscle mass and depressive symptoms only once, estimation of skeletal muscle mass using bioelectrical impedance analysis, assessing depressive symptoms by self-reported questionnaire, and potential unknown confounding variables constitute the limitations of our study.

CONCLUSIONS

The independent association between low skeletal muscle mass and depressive symptoms was observed in men but not in women.

Are Serum Vitamin D Levels Associated With Dry Eye Disease? Results From the Study Group for Environmental Eye Disease

Objectives

Dry eye disease (DED) is an increasingly important public health problem in Korea. Previous studies conducted in Korea have reported inconsistent results regarding the protective effects of vitamin D on DED, and these discrepancies may be related to the relatively simple questionnaire that has been used. Thus, we evaluated the association of serum vitamin D levels with DED using the ocular surface disease index (OSDI).

Methods

The present study evaluated data from participants in the Study Group for Environmental Eye Disease (2014-2015). This group included data from 752 participants, and data from 740 participants (253 men and 487 women) were analyzed in the present study. DED severity was evaluated using the OSDI.

Results

Higher serum vitamin D levels were associated with a non-significantly reduced risk of DED in the crude analysis (odds ratio [OR], 0.991; 95% confidence interval [CI], 0.971 to 1.011) and in the adjusted analysis (OR, 0.988; 95% CI, 0.966 to 1.010). In the crude analysis of no/mild DED vs. moderate/severe DED, men exhibited a decreased risk with increasing serum vitamin D levels (OR, 0.999; 95% CI, 0.950 to 1.051), while women exhibited an increased risk (OR, 1.003; 95% CI, 0.979 to 1.027). In these analyses, we found no significant associations.

Conclusions

The findings of the present study support previous reports that serum vitamin D levels are not associated with DED.

Association of Insulin Resistance with Lower Bone Volume and Strength Index of the Proximal Femur in Nondiabetic Postmenopausal Women

Background

Type 2 diabetes mellitus is associated with an increased risk of osteoporotic fracture despite relatively preserved bone mineral density (BMD). Although this paradox might be attributed to the influence of insulin resistance (IR) on bone structure and material properties, the association of IR with femur bone geometry and strength indices remains unclear.

Methods

Using data from the Cardiovascular and Metabolic Disease Etiology Research Center cohort study, we conducted a cross-sectional analysis among nondiabetic postmenopausal women. IR was estimated using the homeostasis model assessment of IR (HOMA-IR). Compartment-specific volumetric BMD (vBMD) and bone volume of proximal femur were measured using quantitative computed tomography. The compressive strength index (CSI), section modulus (Z), and buckling ratio of the femoral neck were calculated as bone strength indices.

Results

Among 1,008 subjects (mean age, 57.3 years; body mass index [BMI], 23.6 kg/m²), BMI, waist circumference, and vBMD of the femoral neck and total hip increased in a linear trend from the lowest (<1.37) to highest (≥2.27) HOMA-IR quartile (P<0.05 for all). The HOMA-IR showed an independent negative association with total bone volume (standardized β=−0.12), cortical volume (β=−0.05), CSI (β=−0.013), and Z (β=−0.017; P<0.05 for all) of the femoral neck after adjustment for age, weight, height, physical activity, and vitamin D and high-sensitivity C-reactive protein levels. However, the association between HOMA-IR and vBMD was attenuated in the adjusted model (femoral neck, β=0.94; P=0.548).

Conclusions

Elevated HOMA-IR was associated with lower cortical bone volume and bone strength indices in nondiabetic postmenopausal women, independent of age and body size.

Can persistent organic pollutants distinguish between two opposite metabolic phenotypes in lean Koreans?

AIMS

This study investigated the association of persistent organic pollutants (POPs), an emerging new risk factor for type 2 diabetes and the metabolic syndrome, with the presence of opposite phenotypes of glucose and lipid metabolism among normal-weight Koreans of similar body composition.

METHODS

Fifty subjects, randomly selected from an ongoing community-based cohort study, from two opposite phenotype groups - metabolically unhealthy normal weight (MUHNW) and metabolically healthy normal weight (MHNW) - were matched for waist circumference, visceral fat mass and demographic variables, then compared for serum concentrations of POPs.

RESULTS

Most POPs (10 out of 13 compounds) were present in higher serum concentrations in the MUHNW than in the MHNW. In particular, serum concentrations of all compounds of the organochlorine pesticide class were 2.2 to 4.7 times higher in cases than in controls. Compared with the lowest tertile of summary measures of POPs, Odds ratios (95% confidence interval) for the second and third tertiles were 7.4 (1.9-29.4) and 10.4 (2.6-41.2), respectively. Adjusting for possible confounders did not change the results.

CONCLUSION

Taken altogether, these findings from the present and previous studies suggest that increased serum POP concentrations may play an important role in the development of unhealthy metabolic phenotypes in lean people.