Colonoscopic Screening and Risk of All-Cause and Colorectal Cancer Mortality in Young and Older Individuals

PURPOSE

The incidence of early-onset colorectal cancer (CRC) and associated mortality have been increasing. However, the potential benefits of CRC screening are largely unknown in young individuals. We aimed to evaluate the effect of CRC screening with colonoscopy on all-cause and CRC mortality among young (aged < 45 years) and older (aged ≥ 45 years) individuals.

Materials and Methods

This cohort study included 528,046 Korean adults free of cancer at baseline who underwent a comprehensive health examination. The colonoscopic screening group was defined as those who reported undergoing colonoscopy for CRC screening. Mortality follow-up until December 31, 2019 was ascertained based on nationwide death certificate data from the Korea National Statistical Office.

RESULTS

Colonoscopic screening was associated with a lower risk of all-cause mortality in both young and older individuals. Multivariable-adjusted time-dependent hazard ratios (95% confidence intervals) for all-cause mortality comparing ever- to never-screening were 0.86 (0.75-0.99) for young individuals and 0.71 (0.65-0.78) for older individuals. Colonoscopic screenings were also associated with a reduced risk of CRC mortality without significant interaction by age, although this association was significant only among participants aged ≥ 45 years, with corresponding time-dependent hazard ratios of 0.47 (0.15-1.44) for young individuals and 0.52 (0.31-0.87) for those aged ≥ 45 years.

CONCLUSION

Colonoscopic CRC screening decreased all-cause mortality among both young and older individuals, while significantly decreased CRC mortality was observed only in those aged ≥ 45 years. Screening initiation at an earlier age warrants more rigorous confirmatory studies.

Coronary artery calcium and risk of chronic kidney disease in young and middle-aged adults

Background

The role of coronary artery calcium score (CACS) in incident chronic kidney disease (CKD) in asymptomatic young populations remains unclear. The aim of this study was to evaluate the association between CACS and CKD development in adults.

Methods

A cohort study of 113 171 Korean adults (mean age, 40.6 years) without CKD and proteinuria at baseline, who underwent a cardiac tomography estimation of CACS during health screening examinations, was performed (median follow-up: 4.2 years). The outcome was CKD, defined as an estimated glomerular filtration rate (eGFR) &lt;60 ml/min/1.73 m2 and/or the presence of proteinuria. Hazard ratios (HRs) and 95% confidence intervals (CIs) for CKD were estimated using Cox proportional hazards regression analyses.

Results

A higher CACS was moderately associated with an increased risk of CKD in a dose-dependent manner. The multivariable-adjusted HRs (95% CIs) for CKD comparing CACS 1–100, 101–300, and &gt; 300 with CACS = 0 were 1.15 (1.05–1.25), 1.37 (1.13–1.66), and 1.71 (1.32–2.22), respectively (P for trend &lt; 0.001). When CKD was defined using low eGFR and proteinuria separately, corresponding HRs (95% CIs) for low eGFR were 1.31 (1.05–1.62), 1.41 (0.95–2.11), and 1.86 (1.16–3.00), respectively (P for trend = 0.003), while HR (95% CIs) for proteinuria were 1.11 (1.02–1.21), 1.32 (1.07–1.64), and 1.57 (1.16–2.12), respectively.

Conclusions

A higher CACS was progressively associated with an increased risk of CKD, even at low levels of CACS. Individuals with CACS &gt; 0 appear to have an increased risk of CKD and may benefit from preventive measures to reduce CKD risk.

High low-density lipoprotein cholesterol level is associated with an increased risk of incident early-onset vasomotor symptoms

We investigated the associations between serum lipid profiles and risk of early-onset vasomotor symptoms (VMSs) in premenopausal women. This cohort study comprised 2,540 premenopausal women aged 42-52 years without VMSs at baseline (median follow-up: 4.4 years). VMSs, including hot flashes and night sweats, were assessed using the Menopause-Specific Quality of Life questionnaire (Korean version). Early-onset VMSs were defined as VMSs that occurred premenopause; moderate/severe VMSs were defined as a score of ≥ 3 points (range: 0 to 6, 6 being most bothersome). Cox proportional hazard regression models were used to estimate hazard ratios with 95% confidence intervals (CI) for the development of VMSs across the lipid levels. Higher low-density lipoprotein (LDL) cholesterol levels were positively associated with increased risk of early-onset VMSs. Compared to the < 100 mg/dL LDL group, the multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for incident VMSs were 1.19 (1.03-1.37) and 1.20 (1.03-1.40) in participants with LDL cholesterol levels of 100-129 mg/dL and ≥ 130 mg/dL, respectively (P for trend = 0.027). The multivariable-adjusted HR for incident moderate/severe VMSs was 1.37 (95% CI: 1.08-1.73) in participants with LDL ≥ 130 mg/dL, compared to those with LDL < 100 mg/dL. Meanwhile, triglycerides and total and high-density lipoprotein cholesterol levels were not significantly associated with early-onset VMSs risk in premenopausal women. Premenopausal women with high serum LDL cholesterol concentrations had a higher risk of incident early-onset VMSs. Further studies should confirm our findings and examine whether LDL-lowering interventions reduce the risk of early-onset VMSs among women during menopause transition.

Ideal Cardiovascular Health Metrics and Risk of Incident Early-Onset Vasomotor Symptoms Among Premenopausal Women

CONTEXT

The relationship of ideal cardiovascular health (CVH) behaviors with preventing early-onset vasomotor symptoms (VMSs) is unknown.

OBJECTIVE

We investigated the association between CVH metrics and the development of early-onset VMSs in premenopausal women.

METHODS

This cohort study included 2541 premenopausal women aged 42 to 52 years without VMSs at baseline. CVH metrics were defined according to the American Heart Association Life Simple 7 metrics. Owing to limited availability of dietary information, CVH metrics were scored from 0 (unhealthy) to 6 (healthy) and classified into 3 groups: poor (0-2), intermediate (3-4), and ideal (5-6) CVH. VMSs, including hot flashes and night sweats, were assessed using the Menopause-Specific Quality of Life questionnaire. Moderate/severe VMSs was defined as a score of 3 or more points (range, 0 to 6; 6 being most bothersome).

RESULTS

During a median follow-up of 4.5 years, 1241 women developed VMSs before menopause. After adjustment for age, parity, education level, and alcohol consumption, the hazard ratio (HR) (95% CI) for developing early-onset VMSs comparing poor CVH group to the ideal group was 1.41 (1.07-1.86). CVH scores were also inversely associated with moderate/severe VMSs in a dose-response manner (P for trend = .004); specifically, multivariable-adjusted HRs comparing intermediate and poor CVH groups to the ideal group were 1.20 (95% CI, 1.02-1.43) and 1.57 (95% CI, 1.08-2.29), respectively.

CONCLUSION

Unfavorable CVH metrics were significantly associated with an increased risk of early-onset VMSs and its more severe forms among premenopausal women.

A multi-layer functional genomic analysis to understand noncoding genetic variation in lipids

A major challenge of genome-wide association studies (GWASs) is to translate phenotypic associations into biological insights. Here, we integrate a large GWAS on blood lipids involving 1.6 million individuals from five ancestries with a wide array of functional genomic datasets to discover regulatory mechanisms underlying lipid associations. We first prioritize lipid-associated genes with expression quantitative trait locus (eQTL) colocalizations and then add chromatin interaction data to narrow the search for functional genes. Polygenic enrichment analysis across 697 annotations from a host of tissues and cell types confirms the central role of the liver in lipid levels and highlights the selective enrichment of adipose-specific chromatin marks in high-density lipoprotein cholesterol and triglycerides. Overlapping transcription factor (TF) binding sites with lipid-associated loci identifies TFs relevant in lipid biology. In addition, we present an integrative framework to prioritize causal variants at GWAS loci, producing a comprehensive list of candidate causal genes and variants with multiple layers of functional evidence. We highlight two of the prioritized genes, CREBRF and RRBP1, which show convergent evidence across functional datasets supporting their roles in lipid biology.

Resolution of, and Risk of Incident Non-alcoholic Fatty Liver Disease With Changes in Serum 25-hydroxy Vitamin D Status

CONTEXT

A protective or causative role of vitamin D status on the risk of nonalcoholic fatty liver disease (NAFLD) remains inconclusive.

OBJECTIVE

To evaluate the association between changes in serum 25-hydroxyvitamin D [25(OH)D] status during follow-up and the risk of incident NAFLD and resolution of preexisting NAFLD.

DESIGN

A retrospective cohort study.

SETTING

Kangbuk Samsung Health Study based on routine health screening examinations.

PARTICIPANTS

Korean adults (mean age, 36.8 years; range, 18-96 years) who underwent comprehensive health examinations including assessment of serum 25(OH)D levels.

MAIN OUTCOME MEASURES

The main outcomes were (1) incidence and (2) resolution of NAFLD assessed by liver ultrasound. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% CIs for outcomes according to serum 25(OH)D levels.

RESULTS

Among 139 599 participants without NAFLD at baseline, 27 531 developed NAFLD during follow-up. Serum 25(OH)D levels were significantly and inversely associated with NAFLD development. Among 48 702 participants with NAFLD at baseline, 13 449 showed NAFLD resolution. Multivariable-adjusted HR (95% CI) for NAFLD resolution comparing 25(OH)D 10 to <20, 20 to <30, and ≥30 ng/mL to <10 ng/mL were 1.09 (1.03-1.15), 1.13 (1.06-1.21), and 1.21 (1.09-1.35), respectively. Additionally, an increase in 25(OH)D levels between baseline and the subsequent visit (median, 1.8 years) was associated with decreased NAFLD incidence, while persistently adequate 25(OH)D levels over time was associated with decreased incidence and increased resolution of NAFLD.

CONCLUSIONS

Maintaining adequate serum 25(OH)D concentrations may be beneficial for both prevention as well as resolution of NAFLD.

Low anti-Müllerian hormone levels are associated with an increased risk of incident early-onset vasomotor symptoms among premenopausal women

The role of anti-Müllerian hormone (AMH) levels in incident vasomotor symptoms (VMS) is largely unknown. This study aimed to investigate the relationship between AMH levels and the development of early-onset VMS among premenopausal women. Our cohort study comprised 2041 premenopausal women aged 42-52 years free of VMS at baseline whose AMH levels were measured. VMS, including hot flushes and night sweats, were assessed using the Korean version of the Menopause-specific Quality of Life questionnaire. Early-onset VMS was defined as the occurrence of VMS prior to menopause. Parametric proportional hazards models were used to estimate adjusted hazard ratios (HRs) and 95% CI. During a median follow-up of 4.4 years, 708 premenopausal women developed early-onset VMS (incidence rate, 8.0 per 100 person-years). Lower AMH levels were statistically significantly associated with an increased risk of early-onset VMS. After adjusting for age and other confounders, multivariable-adjusted HRs (95% CI) for incident VMS comparing AMH quintiles 4-1 to the highest quintile were 1.02 (0.78-1.33), 1.37 (1.06-1.76), 1.36 (1.04-1.76), and 2.38 (1.84-3.08), respectively (P for trend < 0.001). Our results support an independent role of serum AMH levels in predicting incident early-onset VMS among premenopausal women in the late reproductive stage.

Nonalcoholic Fatty Liver Disease and Risk of Early-Onset Vasomotor Symptoms in Lean and Overweight Premenopausal Women

The role of nonalcoholic fatty liver disease (NAFLD) in vasomotor symptom (VMS) risk in premenopausal women is unknown. We examined the prevalence of early-onset VMSs according to NAFLD status in lean and overweight premenopausal women. This cross-sectional study included 4242 premenopausal Korean women (mean age 45.4 years). VMSs (hot flashes and night sweats) were assessed using the Korean version of the Menopause-Specific Quality of Life questionnaire. Hepatic steatosis was determined using liver ultrasound; lean was defined as a body mass index of <23 kg/m2. Participants were categorized into four groups: NAFLD-free lean (reference), NAFLD-free overweight, lean NAFLD, and overweight NAFLD. Compared with the reference, the multivariable-adjusted prevalence ratios (PRs) (95% confidence intervals (CIs)) for VMSs in NAFLD-free overweight, lean NAFLD, and overweight NAFLD were 1.22 (1.06−1.41), 1.38 (1.06−1.79), and 1.49 (1.28−1.73), respectively. For moderate-to-severe VMSs, the multivariable-adjusted PRs (95% CIs) comparing NAFLD-free overweight, lean NAFLD, and overweight NAFLD to the reference were 1.38 (1.10−1.74), 1.73 (1.16−2.57), and 1.74 (1.37−2.21), respectively. NAFLD, even lean NAFLD, was significantly associated with an increased risk of prevalent early-onset VMSs and their severe forms among premenopausal women. Further studies are needed to determine the longitudinal association between NAFLD and VMS risk.

Consecutive gain and loss in body weight and waist circumference with risk of subsequent breast cancer in Korean women

BACKGROUND

This study investigated the association between longitudinal changes in weight and waist circumference and breast cancer risk according to menopausal status.

METHODS

This retrospective cohort study used data from the population-based Korean National Health Insurance Service (NHI) database. The study population included women aged ≥40 years who consecutively underwent three biennial breast cancer screenings between 2009-2014 and were followed up until 2020. The percentage changes in weight and waist circumference during the three screenings were calculated and categorized into five groups based on the level of increase or decrease in these two factors. Hazard ratios (HRs) and 95% confidence intervals (95% CI) for breast cancer risk were calculated and adjusted for other factors.

RESULTS

Of 691,253 premenopausal and 1,519,211 postmenopausal women, 9485 and 12,553 breast cancer cases were identified, respectively, during a median 6.9 follow-up years. Postmenopausal women with two consecutive weight gains had an increased risk of breast cancer risk (HR = 1.11, 95% CI = 1.01 to 1.22); meanwhile, consecutive weight loss was associated with a decreased risk (HR = 0.84, 95% CI = 0.76 to 0.93). Single time and continuous decreases in waist circumference were associated with a decreased risk (HR = 0.91, 95% CI = 0.85 to 0.98, and HR = 0.84, 95% CI = 0.76-0.93), while single time and continuous increases were associated with an increased risk (HR = 1.08, 95% CI = 1.01 to 1.15, and HR = 1.13, 95% CI = 1.04 to 1.22). Single weight gain was associated with the increased breast cancer risk in premenopausal women (HR = 1.07, 95% CI = 1.01 1.13).

CONCLUSIONS

Our findings suggest a dose-response relationship between weight, waist circumference change, and the risk of future breast cancer.

The Prevalence of Thyroid Dysfunction in Korean Women Undergoing Routine Health Screening: A Cross-Sectional Study

Background: Women are more likely to experience thyroid diseases than men. However, thyroid dysfunction risk in women undergoing the menopausal transition remains largely unknown. We explored the prevalence of thyroid dysfunction across menopausal stages. Methods: We conducted a cross-sectional study of 53,230 women aged 40 years or older who underwent health screening between 2014 and 2018. Menopausal stages were categorized into 4 based on the Stages of Reproductive Aging Workshop +10 criteria. A multinomial logistic regression model was used to estimate the prevalence ratios (PRs) with confidence intervals [CIs] for thyroid dysfunction in menopausal stages compared with that in premenopause. Results: The prevalence of overt hypothyroidism was significantly increased during late transition and postmenopause; it remained significant after further adjustments for potential confounders (age, center, year of examination, age at menarche, parity, education level, smoking status, alcohol consumption, physical activity, and body mass index) with corresponding multivariable-adjusted PRs [CI] of 1.61 [1.12-2.30] and 1.66 [1.16-2.37] in the late transition and postmenopausal stages, respectively. A significant increase in the prevalence of subclinical hypothyroidism was also observed in the late transition and postmenopausal stage with multivariable-adjusted PRs [CI] of 1.22 [1.06-1.40] and 1.24 [1.07-1.44], respectively. In contrast, subclinical and overt hyperthyroidism were not significantly associated with menopausal stages. Conclusions: In this study of pre- and perimenopausal Korean women, the prevalence of overt and subclinical hypothyroidism was significantly elevated in the late menopausal transition. Future prospective studies are warranted to investigate the clinical and prognostic significance of thyroid dysfunction in women during menopausal transition.

Risk of liver fibrosis in patients with prediabetes and diabetes mellitus

The aim of this study was to assess the risk of liver fibrosis in those with no glucose intolerance, prediabetes, or diabetes. A cross-sectional study was conducted based on a cohort from a health examination program which included a magnetic resonance elastography (MRE). Participants were classified into three groups according to glucose tolerance: no glucose intolerance, prediabetes, and diabetes mellitus. Liver fibrosis was evaluated by liver stiffness measurement (LSM) value using two-dimensional real-time MRE. The risk of significant liver fibrosis was compared among three groups. A total of 2,090 subjects were included: no glucose intolerance (n = 889); prediabetes (n = 985); and diabetes (n = 216). Mean values of LSM in those with no glucose intolerance, prediabetes, and diabetes were 2.37 ± 0.43 kPa, 2.41 ± 0.34 kPa, and 2.65 ± 0.70 kPa, respectively (p<0.001). Proportions of significant fibrosis (LSM ≥2.97 kPa) in no glucose intolerance, prediabetes, and diabetes groups were 3.1%, 4.4%, and 16.7%, respectively (p<0.001). Compared with those with no glucose intolerance, those with diabetes had higher risk of significant fibrosis (adjusted odds ratio [aOR]: 3.02, 95% confidence interval [CI]: 1.57–5.81, p<0.001). However, there was no difference between prediabetes and no glucose intolerance (aOR: 1.05, 95% CI: 0.59–1.86, p = 0.876). A subgroup analysis also showed that prediabetes, unlike diabetes, was not associated with significant fibrosis in subjects with or without liver disease. Diabetes, but not prediabetes, is a risk factor for significant liver fibrosis. This finding is consistent regarldess of the pressence of liver disease.

Robust artificial intelligence-powered imaging biomarker based on mammography for risk prediction of breast cancer

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Background: Accurate risk assessment allows the precise personalized screening of breast cancer. Conventional statistical risk models have been used that estimate the probability of breast cancer incidence with patient demographics, detailed personal and family history. The purpose of this study was to investigate the feasibility of the AI-powered Imaging Biomarker in mammography (IBM) which was developed to predict the risk of future breast cancer beyond the mammographic breast density. Methods: We trained and developed the deep learning risk model, the AI-powered IBM, using a total of 36,955 examinations from 21,438 patients, who underwent at least one mammogram using Hologic or Siemens machines and pathology-confirmed breast cancer outcomes. To discover the feasibility of the AI-powered IBM, mammograms and various clinical information including pathology-confirmed breast cancer outcomes were collected, which were only used for external validation. C-indices and receiver operating characteristic (ROC) curves for 1- to 5-year outcomes were obtained. We compared 5-year ROC area under the curves (AUCs) of our AI-powered IBM and statistical risk models including the Tyrer-Cuzick model and the Gail model, which were most commonly used and widely known, using DeLong’s test. Results: A total of 16,894 mammograms were collected for external validation, of which 4,002 were followed by a cancer diagnosis within 5 years. Our AI-powered IBM obtained C-index of 0.758, and the model demonstrated the risk of breast cancer with AUC of 0.895 (95% CI: 0.880, 0.909) at 1-year, 0.839 (0.824, 0.852) at 2-year, 0.807 (0.794, 0.819) at 3-year, 0.783 (0.7947, 0.819) at 4-year. The 5-year AUC of our AI-powered IBM was 0.808 (0.792, 0.822). Our AI-powered IBM showed significantly higher 5-year AUC than the Gail model (AUC: 0.572, P< 0.001) and the Tyrer-Cuzick model (0.569, P< 0.001). Conclusions: A deep learning AI-powered IBM using mammograms has a substantial potential to advance toward the robust risk prediction of breast cancer over conventional risk models. This approach for risk stratification of breast cancer might be feasible to improve personalized screening programs.

Alcohol Consumption Patterns and Risk of Early-Onset Vasomotor Symptoms in Premenopausal Women

The role of alcohol consumption in the risk of vasomotor symptoms (VMS), the most cardinal climacteric symptoms, is not well established. We examined their relationship with early-onset VMS among premenopausal women. Moderately-to-severely bothersome VMS, the primary outcome, was assessed using the Korean version of the Menopause-Specific Quality of Life questionnaire. The alcohol consumption categories included lifetime abstainer, former drinker, or current drinker, categorized as light, moderate, heavy, and very heavy. Compared with the lifetime-abstinence (reference), the multivariable-adjusted odds ratio (95% CIs) for prevalent VMS in alcohol consumption of <10, 10−19, 20−39, and ≥40 g/day were 1.42 (1.02−1.99), 1.99 (1.27−3.12), 2.06 (1.19−3.57), and 3.52 (1.72−7.20), respectively (p trend <0.01). Compared with the lifetime-abstinence, the multivariable-adjusted hazard ratios (95% CIs) for incident bothersome VMS among average alcohol consumption of <10, 10−19, 20−39, and ≥40 g/day were 1.10 (0.85−1.41), 1.03 (0.70−1.51), 1.72 (1.06−2.78), and 2.22 (1.16−4.23), respectively (p trend = 0.02). Increased alcohol consumption positively and consistently showed a relationship with increased risk of both prevalent and incident early-onset VMS. Refraining from alcohol consumption may help prevent bothersome VMS in premenopausal women.

Metabolically healthy and unhealthy obesity and risk of vasomotor symptoms in premenopausal women: cross-sectional and cohort studies

Objective

To examine the relationship between metabolically healthy and unhealthy obesity phenotypes and risk of vasomotor symptoms (VMS) in premenopausal women.

Design

Prospective cohort study.

Setting

Middle‐aged women in a cohort based on regular health screening examinations.

Population

Premenopausal Korean women aged 42–52 years were recruited and were followed up for a median of 4.2 years. The cross‐sectional and cohort studies comprised 4672 women and 2590 women without VMS at baseline, respectively.

Methods

Adiposity measures included body mass index (BMI), waist circumference and percentage body fat. Being metabolically healthy was defined as not having any metabolic syndrome components or a homeostasis model assessment of insulin resistance of 2.5 or more.

Main outcomes measures

VMS (hot flushes and night sweats) assessed using the questionnaire.

Results

All adiposity measures were positively associated with an increased risk of VMS in both cross‐sectional and longitudinal studies. The multivariable‐adjusted prevalence ratio (95% confidence interval [CI]) for VMS comparing percentage body fat of 35% or more with the reference was 1.47 (95% CI 1.14–1.90) in metabolically healthy women, and the corresponding prevalence ratio was 2.32 (95% CI 1.42–3.78) in metabolically unhealthy women (P_interaction = 0.334). The multivariable‐adjusted hazard ratio for incident VMS comparing percentage body fat of 35% or more with the reference was 1.34 (95% CI 1.00–1.79) in metabolically healthy women, whereas the corresponding hazard ratio was 3.61 (95% CI 1.81–7.20) in metabolically unhealthy women (P_interaction = 0.036). The association between BMI, waist circumference and VMS did not significantly differ by metabolic health status.

Conclusions

Maintaining normal weight and being metabolically healthy may help to prevent VMS in premenopausal women.

Tweetable abstract

Avoiding obesity and a metabolically unhealthy status may help reduce vasomotor symptoms in premenopausal women.

Avoiding obesity and a metabolically unhealthy status may help reduce vasomotor symptoms in premenopausal women.

Long or Irregular Menstrual Cycles and Risk of Prevalent and Incident Nonalcoholic Fatty Liver Disease

CONTEXT

The association of menstrual cycle length and irregularity with the risk of non-alcoholic fatty liver disease (NAFLD) is unknown.

OBJECTIVE

We examined this association in large cross-sectional and cohort studies.

METHODS

The cross-sectional study included 72 092 women younger than 40 years who underwent routine health examinations; the longitudinal analysis included the subset of 51 118 women without NAFLD at baseline. Long or irregular cycles were defined as menstrual cycles of 40 days or longer or too irregular to estimate. Abdominal ultrasonography was performed to identify NAFLD. Multivariable Cox proportional hazard regression analyses were performed to estimate hazard ratios (HRs) and 95% CIs for incident NAFLD according to menstrual cycle regularity and length, with 26- to 30-day cycles as the reference.

RESULTS

At baseline, 27.7% had long or irregular menstrual cycles and 7.1% had prevalent NAFLD. Long or irregular menstrual cycles were positively associated with prevalent NAFLD. During a median follow-up of 4.4 years, incident NAFLD occurred in 8.9% of women. After adjustment for age, body mass index, insulin resistance, and other confounders, the multivariable-adjusted HR for NAFLD comparing long or irregular menstrual cycles to the reference group was 1.22 (95% CI, 1.14-1.31); this association strengthened in the time-dependent analysis with an HR of 1.49 (95% CI, 1.38-1.60).

CONCLUSION

Long or irregular menstrual cycles were associated with increased risk of both prevalent and incident NAFLD in young, premenopausal women. Women with long or irregular menstrual cycles may benefit from lifestyle modification advice to reduce the risk of NAFLD and associated cardiometabolic diseases.

Mammographic Breast Density, Benign Breast Disease, and Subsequent Breast Cancer Risk in 3.9 Million Korean Women

Background Mammographic breast density and benign breast disease are strong risk factors for breast cancer. Accordingly, women with both risk factors may have a markedly high risk for developing breast cancer. Purpose To investigate the risk of breast cancer associated with the combination of mammographic density and benign breast disease in Korean women, where population-based mammographic breast cancer screening is provided for all women aged at least 40 years. Materials and Methods This is a retrospective analysis of data from a nationwide breast cancer screening program linked with the national cancer registry. The study included Korean women between 40-74 years of age screened for breast cancer between January 2009 and December 2010 and observed up to December 2020 (median follow-up of 10.6 years). Benign breast disease and breast density were extracted from mammography screening results. Cox proportional hazard regression analysis was used to calculate adjusted hazard ratios (HRs) for breast cancer risk. Results In this study, 3 911 348 women (mean age, 53 years ± 9 [SD]) were analyzed. During follow-up (median, 10.6 years), 58 321 women developed breast cancer. At screening, 10 729 (18.4%) cases of benign breast disease were detected among women who developed breast cancer. Women with extremely dense breasts (Breast Imaging Reporting and Data System [BI-RADS] density category D) and benign breast disease had a greater risk of breast cancer when compared with women presenting with fatty breast (BI-RADS density category A) and those without benign breast disease (HR, 2.75; 95% CI: 2.63, 2.88; P < .001). Women with benign breast disease and fatty breasts (HR, 1.49; 95% CI: 1.40, 1.58; P < .001) and women with extremely dense breasts and without benign breast disease (HR, 2.28; 95% CI: 2.20, 2.35; P < .001) also had an elevated breast cancer risk compared with women with fatty breast tissue. Conclusion Women with dense breasts and benign breast disease at screening mammography had an elevated risk of future breast cancer. © RSNA, 2022 Online supplemental material is available for this article.

Skeletal muscle mass to visceral fat area ratio as a predictor of NAFLD in lean and overweight men and women with effect modification by sex

The effect of sarcopenic visceral obesity on the risk of nonalcoholic fatty liver disease (NAFLD) is uncertain. We investigated (a) whether the skeletal muscle mass to visceral fat area ratio (SV ratio), as a measure of sarcopenic visceral obesity, is a risk factor for NAFLD; and (b) whether the SV ratio adds to conventional adiposity measures to improve prediction of incident NAFLD. Adults without NAFLD (n = 151,017) were followed up for a median of 3.7 years. Hepatic steatosis was measured using ultrasonography, and liver fibrosis scores were estimated using the Fibrosis‐4 index (FIB‐4) and the NAFLD Fibrosis Score (NFS). Cox proportional hazards models were used to determine sex‐specific adjusted hazard ratios (aHRs) (95% confidence intervals [CIs]). The incremental predictive performance was assessed using the area under the receiver operating characteristic curve, net reclassification improvement, and integrated discrimination improvement. Multivariable aHRs (95% CIs) for incident NAFLD comparing the lowest versus the highest quintile of SV ratio were 3.77 (3.56–3.99) for men and 11.69 (10.46–13.06) for women (p–interaction by sex < 0.001). For incident NAFLD with intermediate/high FIB‐4, aHRs were 2.83 (2.19–3.64) for men and 7.96 (3.85–16.44) for women (similar results were obtained for NFS). Associations remained significant even after adjustment for body mass index, waist circumference, and time‐varying covariates. These associations were also more pronounced in nonobese than obese participants (p–interaction < 0.001). The addition of SV ratio to conventional adiposity measures modestly improved risk prediction for incident NAFLD. SV ratio was inversely associated with risk of developing NAFLD, with effect modification by sex and obesity. Conclusion: Low SV ratio is a complementary index to conventional adiposity measures in the evaluation of NAFLD risk.

Liver Fibrosis in Asians With Metabolic Dysfunction-Associated Fatty Liver Disease

BACKGROUND & AIMS

This study aimed to evaluate risk factors associated with liver fibrosis in metabolic dysfunction-associated fatty liver disease (MAFLD).

METHODS

A cross-sectional study of 967 Korean patients with MAFLD involved a cohort from a health screening program during the years 2015-2018. The patients were classified into 4 MAFLD subgroups: group 1 (overweight). group 2 (obese), group 3 (lean/normal weight with metabolic abnormalities), and group 4 (diabetes). Liver fibrosis was assessed based on liver stiffness measurement (LSM) value using 2-dimensional real-time magnetic resonance elastography. We investigated differences in liver fibrosis according to MAFLD subgroup classification and determined the risk factors for significant fibrosis.

RESULTS

The mean age was 50.8 years, and 869 (90%) patients were male. The mean value of LSM in magnetic resonance elastography was 2.48 ± 0.47 kPa. Significant fibrosis (LSM ≥2.97 kPa) was observed in 66 (6.8%) of 967 patients. The proportion of significant fibrosis in MAFLD group 1, group 2, group 3, and group 4 was 1.3%, 5.5%, 6.4%, and 18.9%, respectively (P < .001). Multivariable analysis indicated that the risk factors for significant fibrosis were serum ferritin ≥300 ng/mL (odds ratio [OR], 1.96; 95% confidence interval [CI], 1.10-3.49; P = .023), Fibrosis-4 ≥1.3 (OR, 2.97; 95% CI, 1.68-5.24; P < .001), homeostatic model assessment of insulin resistance ≥2.0 (OR, 2.60; 95% CI, 1.25-5.43; P = .011), metabolic syndrome (OR, 2.53; 95% CI, 1.31-4.88; P = .006), and MAFLD group 4 (OR, 6.93; 95% CI, 1.96-24.51; P = .003). However, the etiology of liver disease was not statistically associated with liver fibrosis.

CONCLUSION

Liver fibrosis in patients with MAFLD varies according to subgroup classification based on diabetes, body mass index, and metabolic risk factors.

Ten-Second Heart Rate Variability, Its Changes Over Time, and the Development of Hypertension

BACKGROUND

The role of ultrashort-term heart rate variability (HRV) and its temporal changes in incident hypertension are unknown. We aimed to investigate the association between 10-second HRV, its changes, and incident hypertension in adults aged <40 years and older.

METHODS

This cohort study included 232 587 Koreans (mean age 37.6 years) without hypertension. Hypertension was defined according to the 2017 American College of Cardiology and American Heart Association hypertension guidelines. HRV, including the root mean square of successive RR interval differences and the SD of normal-to-normal RR intervals, was estimated using standard 12-lead, 10-second electrocardiography.

RESULTS

During a median follow-up of 3.8 years, 40 268 hypertension cases were identified (incidence rates: 36.1 and 67.9 per 1000 person-years for young and older participants, respectively). An inverse association was observed between HRV and hypertension risk, in a dose-dependent manner. The multivariable-adjusted hazard ratios (95% CIs) for hypertension comparing the first to the fifth quintiles of root mean square of successive RR interval difference and SD of normal-to-normal RR interval were 1.58 (1.52-1.63) and 1.35 (1.30-1.39), respectively. These associations were stronger in young adults than in older adults. In a subsample of 150 301 participants, compared with stable HRV, an increase in HRV over time was also inversely associated with incident hypertension.

CONCLUSIONS

A higher HRV and its increase over time on a 10-second electrocardiography were associated with a lower risk of hypertension. Our findings indicate that autonomic function, estimated using 10-second standard electrocardiography, plays a role in predicting hypertension, with a stronger effect in young adults.

Gut microbiota and the prevalence and incidence of renal stones

The role of the gut microbiome in the development of renal stone diseases has not been well characterized. This study focused on the taxonomic and functional profiles of gut microbiomes according to the prevalence and incidence of nephrolithiasis. Stool samples from 915 Korean adults were collected at baseline. Participants were followed for a median of 4.0 years. We evaluated the biodiversity of the gut microbiota and taxonomic profiles associated with nephrolithiasis status, using 16S rRNA gene sequencing. Nephrolithiasis status was categorized into three groups: control (no-stone at both baseline and follow-up visits), incidental nephrolithiasis, and prevalent nephrolithiasis. Compared to the control and incidental nephrolithiasis, the prevalent nephrolithiasis showed a reduced evenness in alpha diversity. Nephrolithiasis was associated with a reduced abundance of some key taxa involved in short-chain fatty acid production. Moreover, the abundance of Bifidobacterium, which possess oxalate-degrading ability, was higher in the control. Conversely, there was no significant difference in the bacterial composition between the incidental and prevalent nephrolithiasis. In our study with repeated nephrolithiasis measurements, prevalent renal stones were associated with an altered gut microbiota composition compared to the control. Besides the known oxalate degradation pathway, other functional pathways inferred in this study require further investigation.

Serum 25-hydroxy vitamin D and the risk of low muscle mass in young and middle-aged Korean adults

OBJECTIVE

Despite the known benefit of vitamin D in reducing sarcopenia risk in older adults, its effect against muscle loss in the young population is unknown. We aimed to examine the association of serum 25-hydroxy vitamin D [25(OH)D] level and its changes over time with the risk of incident low muscle mass (LMM) in young and middle-aged adults.

DESIGN

This study is a cohort study.

METHODS

The study included Korean adults (median age: 36.9 years) without LMM at baseline followed up for a median of 3.9 years (maximum: 7.3 years). LMM was defined as the appendicular skeletal muscle (ASM) mass by body weight (ASM/weight) of 1 s.d. below the sex-specific mean for the young reference group. Cox proportional hazard models were used to estimate hazard ratios (HRs) with 95% CIs.

RESULTS

Of the 192,908 individuals without LMM at baseline, 19,526 developed LMM. After adjusting for potential confounders, the multivariable-adjusted HRs (95% CIs) for incident LMM comparing 25(OH)D levels of 25-<50, 50-<75, and ≥75 nmol/L to 25(OH)D <25 nmol/L were 0.93 (0.90-0.97), 0.85 (0.81-0.89), and 0.77 (0.71-0.83), respectively. The inverse association of 25(OH)D with incident LMM was consistently observed in young (aged <40 years) and older individuals (aged ≥40 years). Individuals with increased 25(OH)D levels (<50-≥50 nmol/L) or persistently adequate 25(OH)D levels (≥50 nmol/L) between baseline and follow-up visit had a lower risk of incident LMM than those with persistently low 25(OH)D levels.

CONCLUSIONS

Maintaining sufficient serum 25(OH)D could prevent unfavourable changes in muscle mass in both young and middle-aged Korean adults.

Weight Change and the Development of Nonalcoholic Fatty Liver Disease in Metabolically Healthy Overweight Individuals

INTRODUCTION

The study sought to investigate the effect of weight change on hepatic steatosis (HS) incidence with or without liver fibrosis in metabolically healthy overweight or obese individuals.

METHODS

A cohort of 14,779 metabolically healthy men and women who were overweight or obese (body mass index ≥23 kg/m²) and free from HS and an intermediate or high probability of fibrosis at baseline were followed for a median of 5.2 years. Metabolic health was defined as freedom from the components of metabolic syndrome and a homeostatic model assessment of insulin resistance <2.5. Weight changes were calculated as differences from baseline at the next subsequent visit. The outcome was HS incidence, with or without liver fibrosis, as assessed by liver ultrasound and 2 noninvasive fibrosis scores.

RESULTS

During 76,794.6 person-years of follow-up, 3539 cases of HS incidence were identified. The multivariable adjusted hazard ratios (95% confidence intervals) for HS incidence by weight change group, <-5.0%, -5.0%-1.0%, 1.0%-5.0%, and >5.0%, relative to the no weight change group (-0.9% to 0.9%) were 0.52 (0.44-0.60), 0.83 (0.75-0.92), 1.21 (1.10-1.33), and 1.51 (1.36-1.69), respectively. Clinically relevant weight loss of >5% was also associated with a lowered risk of HS with intermediate or high probability of advanced fibrosis. In mediation analyses, associations remained significant, although adjustment for metabolic risk factors was attenuating.

DISCUSSION

Clinically relevant weight loss was associated with a reduced risk of developing nonalcoholic fatty liver disease with or without intermediate or high probability of advanced fibrosis in metabolically healthy overweight or obese individuals.

Caloric restriction in humans reveals immunometabolic regulators of health span

The extension of life span driven by 40% caloric restriction (CR) in rodents causes trade-offs in growth, reproduction, and immune defense that make it difficult to identify therapeutically relevant CR-mimetic targets. We report that about 14% CR for 2 years in healthy humans improved thymopoiesis and was correlated with mobilization of intrathymic ectopic lipid. CR-induced transcriptional reprogramming in adipose tissue implicated pathways regulating mitochondrial bioenergetics, anti-inflammatory responses, and longevity. Expression of the gene Pla2g7 encoding platelet activating factor acetyl hydrolase (PLA2G7) is inhibited in humans undergoing CR. Deletion of Pla2g7 in mice showed decreased thymic lipoatrophy, protection against age-related inflammation, lowered NLRP3 inflammasome activation, and improved metabolic health. Therefore, the reduction of PLA2G7 may mediate the immunometabolic effects of CR and could potentially be harnessed to lower inflammation and extend the health span.

Decrease in Sleep Duration and Poor Sleep Quality over Time Is Associated with an Increased Risk of Incident Non-Alcoholic Fatty Liver Disease

The impact of changes in sleep duration and sleep quality over time on the risk of non-alcoholic fatty liver disease (NAFLD) is not known. We investigated whether changes in sleep duration and in sleep quality between baseline and follow-up are associated with the risk of developing incident NAFLD. The cohort study included 86,530 Korean adults without NAFLD and with a low fibrosis score at baseline. The median follow-up was 3.6 years. Sleep duration and quality were assessed using the Pittsburgh Sleep Quality Index. Hepatic steatosis (HS) and liver fibrosis were assessed using ultrasonography and the fibrosis-4 index (FIB-4). Cox proportional hazard models were used to determine hazard ratios (HRs) and 95% confidence intervals (Cis). A total of 12,127 subjects with incident HS and 559 with incident HS plus intermediate/high FIB-4 was identified. Comparing the decrease in sleep duration of >1 h, with stable sleep duration, the multivariate-adjusted HR (95% CIs) for incident HS was 1.24 (1.15–1.35). The corresponding HRs for incident HS plus intermediate/high FIB-4 was 1.58 (1.10–2.29). Comparing persistently poor sleep quality with persistently good sleep quality, the multivariate-adjusted HR for incident HS was 1.13 (95% CI, 1.05–1.20). A decrease in sleep duration or poor sleep quality over time was associated with an increased risk of incident NAFLD, underscoring an important potential role for good sleep in preventing NAFLD risk.

Risk factors for hemorrhoidal disease among healthy young and middle-aged Korean adults

Hemorrhoidal disease is a highly prevalent anorectal condition causing substantial discomfort, disability, and decreased quality of life. Evidence on preventable risk factors for hemorrhoidal disease is limited. We conducted a cross-sectional study of 194,620 healthy men and women who completed a health screening exam including colonoscopy in 2011–2017. We evaluated potential risk factors of hemorrhoidal disease, including lifestyle factors, medical history, birth history, gastrointestinal symptoms, and anthropometric measurements. The prevalence of hemorrhoidal disease was 16.6%, and it was higher in females than in males (17.2 vs. 16.3%; P < 0.001). Compared to men, the prevalence of hemorrhoidal disease was higher in parous women (adjusted odds ratio [OR] 1.06; 95% confidence interval [CI] 1.02–1.10), and lower in nulliparous women (adjusted OR 0.92; 95% CI 0.86–0.98). In the adjusted analyses, older age, female sex, smoking, overweight, and being hypertensive were independently associated with the presence of hemorrhoidal disease. The prevalence of hemorrhoidal disease was positively associated with body mass index and waist circumference in parous women. The prevalence of hemorrhoidal disease was higher in older age, females, ever-smokers, and hypertensive participants. The association of excess adiposity with the prevalence of hemorrhoidal disease differed by sex and parity.

Liver fibrosis scores and risk of liver-related mortality in young adults with chronic hepatitis B: A cohort study

The predictive role of noninvasive liver fibrosis scores on liver-related mortality in patients with chronic hepatitis B below 40 years of age remains unclarified. We examined the association of liver fibrosis scores with liver-related mortality in young (<40 years) and older adults with hepatitis B virus (HBV) infection. A cohort study was performed in 21,360 HBsAg-positive Korean adults without liver cirrhosis or liver cancer at baseline who were followed up for up to 18 years. The liver fibrosis scores were determined using the fibrosis-4 score (FIB-4) and aspartate transaminase to platelet ratio index (APRI). Patients' vital status and cause of death were ascertained through the National Death Records. During a median follow-up of 10.2 years, 283 liver-related deaths were identified (liver-related mortality, 127.4/10⁵ person-years). The liver fibrosis scores were significantly associated with increased risks of liver-related mortality; this association did not differ by age group (<40 vs. ≥40 years). The multivariable-adjusted hazard ratios with 95% confidence intervals for liver-related mortality comparing intermediate and high to low FIB-4 scores were 4.23 (1.99-9.00), and 15.16 (5.18-44.38), respectively, among individuals under 40, and 4.46 (3.03-6.56) and 22.47 (15.11-33.41), respectively, among older individuals. These associations were similar in analyses using APRI. In this cohort of HBsAg-positive individuals, the liver fibrosis scores were associated with increased risks of liver-related mortality in young and older adults. The liver fibrosis scores have a role in predicting liver mortality, even in young adults with HBV.

The power of genetic diversity in genome-wide association studies of lipids

Increased blood lipid levels are heritable risk factors of cardiovascular disease with varied prevalence worldwide owing to different dietary patterns and medication use1. Despite advances in prevention and treatment, in particular through reducing low-density lipoprotein cholesterol levels2, heart disease remains the leading cause of death worldwide3. Genome-wideassociation studies (GWAS) of blood lipid levels have led to important biological and clinical insights, as well as new drug targets, for cardiovascular disease. However, most previous GWAS4-23 have been conducted in European ancestry populations and may have missed genetic variants that contribute to lipid-level variation in other ancestry groups. These include differences in allele frequencies, effect sizes and linkage-disequilibrium patterns24. Here we conduct a multi-ancestry, genome-wide genetic discovery meta-analysis of lipid levels in approximately 1.65 million individuals, including 350,000 of non-European ancestries. We quantify the gain in studying non-European ancestries and provide evidence to support the expansion of recruitment of additional ancestries, even with relatively small sample sizes. We find that increasing diversity rather than studying additional individuals of European ancestry results in substantial improvements in fine-mapping functional variants and portability of polygenic prediction (evaluated in approximately 295,000 individuals from 7 ancestry groupings). Modest gains in the number of discovered loci and ancestry-specific variants were also achieved. As GWAS expand emphasis beyond the identification of genes and fundamental biology towards the use of genetic variants for preventive and precision medicine25, we anticipate that increased diversity of participants will lead to more accurate and equitable26 application of polygenic scores in clinical practice.

Correlation between Gut Microbiota and Six Facets of Neuroticism in Korean Adults

A person high in neuroticism is more likely to experience anxiety, stress, worry, fear, anger, and depression. Previous studies have shown that the gut microbiota can influence personality and mental disorders, including stress, anxiety, and depression, through the gut-brain axis. Here, we investigated the correlations between the sub-facet of neuroticism and gut microbiota using the Revised NEO Personality Inventory and the 16S rRNA gene sequencing data 784 adults. We found that the high anxiety and vulnerability group showed significantly lower richness in microbial diversity than a group with low anxiety and vulnerability. In beta diversity, there was a significant difference between the low and high groups of anxiety, self-consciousness, impulsiveness, and vulnerability. In taxonomic compositions, Haemophilus belonging to Gammaproteobacteria was correlated with the Neuroticism domain as well as N1 anxiety and N6 vulnerability facets. The high N1 anxiety and N6 vulnerability group was correlated with a low abundance of Christensenellaceae belonging to Firmicutes Clostridia. High N4 self-consciousness was correlated with a low abundance of Alistipes and Sudoligranulum. N5 impulsiveness was correlated with a low abundance of Oscillospirales. Our findings will contribute to uncovering the potential link between the gut microbiota and neuroticism, and the elucidation of the correlations of the microbiome-gut-brain axis with behavioral changes and psychiatric cases in the general population.

Sleep Duration, Sleep Quality, and the Development of Nonalcoholic Fatty Liver Disease: A Cohort Study

INTRODUCTION

The longitudinal relationship between sleep duration, sleep quality, and the risk of nonalcoholic fatty liver disease (NAFLD) is unknown. We aimed to examine the association between sleep duration, sleep quality, and NAFLD development.

METHODS

Using the Pittsburgh Sleep Quality Index, sleep duration and quality were evaluated for 143,306 NAFLD-free Korean adults with a mean age of 36.6 years, who were followed for an average of 4.0 years. Hepatic steatosis (HS) was assessed using ultrasonography and liver fibrosis by the fibrosis-4 index (FIB-4) or the NAFLD fibrosis score. Flexible parametric proportional hazard models were used to determine the hazard ratios (HRs) and 95% confidence intervals.

RESULTS

There were 27,817 subjects with incident HS, of whom 1,471 had incident HS plus intermediate/high FIB-4. Multivariable-adjusted HRs (95% confidence intervals) for incident HS comparing sleep durations of ≤5, 6, 8, and ≥ 9 hours with 7 hours were 1.19 (1.14-1.23), 1.07 (1.04-1.10), 0.98 (0.94-1.02), and 0.95 (0.87-1.03), respectively. The corresponding HRs for incident HS plus intermediate/high FIB-4 were 1.30 (1.11-1.54), 1.14 (1.01-1.29), 1.11 (0.93-1.33), and 1.08 (0.71-1.63). The association between sleep duration and HS plus intermediate/high FIB-4 was inverse in individuals with good sleep quality but tended to be U-shaped in those with poor sleep quality. The results were similar if FIB-4 was replaced by the NAFLD fibrosis score.

DISCUSSION

In young adults, short sleep duration was independently associated with an increased risk of incident NAFLD with or without intermediate/high fibrosis score, suggesting a role for inadequate sleep quantity in NAFLD risk and severity.

Evaluation of the transient hypofrontality theory in the context of exercise: A systematic review with meta-analysis

Accumulating research suggests that, as a result of reduced neural activity in the prefrontal cortex (PFC), higher-order cognitive function may be compromised while engaging in high-intensity acute exercise, with this phenomenon referred to as the transient hypofrontality effect. However, findings in this field remain unclear and lack a thorough synthesis of the evidence. Therefore, the purpose of this meta-analysis was to evaluate the effects of in-task acute exercise on cognitive function, and further, to examine whether this effect is moderated by the specific type of cognition (i.e., PFC-dependent vs. non-PFC-dependent). Studies were identified by electronic databases in accordance with the PRISMA guidelines. In total, 22 studies met our inclusion criteria and intercept only meta-regression models with robust variance estimation were used to calculate the weighted average effect sizes across studies. Acute exercise at all intensities did not influence cognitive function (β = -0.16, 95% CI = [-0.58, 0.27], p = .45) when exercise occurred during the cognitive task, and no significant moderation effects emerged. However, there was evidence that cognitive task type (PFC-dependent vs. non-PFC-dependent) moderated the effect of high-intensity acute exercise on a concomitant cognitive performance (β = -0.81, 95% CI = [-1.60, -0.02], p = .04). Specifically, our findings suggest that PFC-dependent cognition is impaired while engaging in an acute bout of high-intensity exercise, providing support for the transient hypofrontality theory. We discuss these findings in the context of reticular-activating and cognitive-energetic perspectives.

Physical activity and the progression of coronary artery calcification

BACKGROUND

The association of physical activity with the development and progression of coronary artery calcium (CAC) scores has not been studied. This study aimed to evaluate the prospective association between physical activity and CAC scores in apparently healthy adults.

METHODS

Prospective cohort study of men and women free of overt cardiovascular disease who underwent comprehensive health screening examinations between 1 March 2011 and 31 December 2017. Baseline physical activity was measured using the International Physical Activity Questionnaire Short Form (IPAQ-SF) and categorised into three groups (inactive, moderately active and health-enhancing physically active (HEPA)). The primary outcome was the difference in the 5-year change in CAC scores by physical activity category at baseline.

RESULTS

We analysed 25 485 participants with at least two CAC score measurements. The proportions of participants who were inactive, moderately active and HEPA were 46.8%, 38.0% and 15.2%, respectively. The estimated adjusted average baseline CAC scores (95% confidence intervals) in participants who were inactive, moderately active and HEPA were 9.45 (8.76, 10.14), 10.20 (9.40, 11.00) and 12.04 (10.81, 13.26). Compared with participants who were inactive, the estimated adjusted 5-year average increases in CAC in moderately active and HEPA participants were 3.20 (0.72, 5.69) and 8.16 (4.80, 11.53). Higher physical activity was association with faster progression of CAC scores both in participants with CAC=0 at baseline and in those with prevalent CAC.

CONCLUSION

We found a positive, graded association between physical activity and the prevalence and the progression of CAC, regardless of baseline CAC scores.

Fatty liver disease and changes in dense breasts in pre- and postmenopausal women: the Kangbuk Samsung Health Study

PURPOSE

While increased breast density is a risk factor for breast cancer, the effect of fatty liver disease on breast density is unknown. We investigated whether fatty liver is a risk factor for changes in breast density over ~ 4 years of follow-up in pre- and postmenopausal women.

METHODS

This study included 74,781 middle-aged Korean women with mammographically determined dense breasts at baseline. Changes in dense breasts were identified by more screening mammograms during follow-up. Hepatic steatosis (HS) was measured using ultrasonography. Flexible parametric proportional hazards models were used to determine the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs), and a Weibull accelerated failure time model (AFT) was used to determine the time ratios (TRs) and 95% CIs.

RESULTS

During a median follow-up of 4.1 years, 4022 women experienced resolution of the dense breasts. The association between HS and dense breast resolution differed by the menopause status (P for interaction < 0.001). After adjusting for body mass index and other covariates, the aHRs (95% CI) for dense breast resolution comparing HS to non-HS were 0.81 (0.70-0.93) in postmenopausal women, while the association was converse in premenopausal women with the corresponding HRs of 1.30 (1.18-1.43). As an alternative approach, the multivariable-adjusted TR (95% CI) for dense breast survival comparing HS to non-HS were 0.81 (0.75-0.87) and 1.19 (1.06-1.33) in premenopausal and postmenopausal women, respectively.

CONCLUSION

The association between HS and changes in dense breasts differed with the menopause status. HS increased persistent dense breast survival in postmenopausal women but decreased it in premenopausal women.

The Relationship Between Breast Density Change During Menopause and the Risk of Breast Cancer in Korean Women

BACKGROUND

The aim of this study was to investigate the relationship between changes in breast density during menopause and breast cancer risk.

METHODS

This study was a retrospective, longitudinal cohort study for women over 30 years of age who had undergone breast mammography serially at baseline and postmenopause during regular health checkups at Samsung Medical Center. None of the participants had been diagnosed with breast cancer at baseline. Mammographic breast density was measured using the American College of Radiology Breast Imaging Reporting and Data System.

RESULTS

During 18,615 person-years of follow-up (median follow-up 4.8 years; interquartile range 2.8-7.5 years), 45 participants were diagnosed with breast cancer. The prevalence of dense breasts was higher in those who were younger, underweight, had low parity or using contraceptives. The cumulative incidence of breast cancer increased 4 years after menopause in participants, and the consistently extremely dense group had a significantly higher cumulative incidence (CI) of breast cancer compared with other groups [CI of extremely dense vs. others (incidence rate per 100,000 person-years): 375 vs. 203, P < 0.01].

CONCLUSION

Korean women whose breast density was extremely dense before menopause and who maintained this density after menopause were at two-fold greater risk of breast cancer.

PREVENTION RELEVANCE

Extremely dense breast density that is maintained persistently from premenopause to postmenopause increases risk of breast cancer two fold in Korean women. Therefore, women having risk factors should receive mammography frequently and if persistently extremely dense breast had been detected, additional modalities of BC screening could be considered.

Cigarette smoking and risk of infection-related mortality: A cohort study

BACKGROUND

Cigarette smoking is a leading cause of death worldwide and is associated with various diseases. However, studies addressing its impact on infection-related deaths are limited. This study examined the relationship between smoking and infection-related mortality.

METHODS

A cohort of 583,034 South Korean adults who underwent annual or biennial health examinations were followed-up for infection-related deaths using national records. Cox proportional hazards regression assessed hazard ratios (HRs) and 95% confidence intervals (CIs) for infection-related mortality.

RESULTS

The median follow-up was 9.1 years (maximum 18 years), and 335 infection-related deaths were identified. Current smoking, but not former smoking, was positively associated with an increased risk of infection-related mortality. After adjusting for possible confounders, the multivariable-adjusted HRs ( 95% CIs) for infection-related mortality comparing former and current smokers with never smokers were 0.94 (0.68-1.30) and 1.45 (1.05-2.02), respectively; and those for infection-related mortality by number of pack-years comparing 10-19.9 and ≥20 pack-years to <10 pack-years were 1.26 (0.81-1.96) and 1.47 (1.03-2.09), respectively, while those comparing 10-19 and ≥20 cigarettes/day to <10 cigarettes/day were 1.35 (0.86-2.11) and 1.54 (1.13-2.11), respectively (p for trend <0.05). Individuals with ≥20 pack-years had a 2.06 times greater risk of infection-related mortality when changes in smoking status and confounders during follow-up were updated in the analysis as time-varying covariates.

CONCLUSION

Current smoking status, intensity and pack-years were associated with an increased risk of infection-related death, with the highest risk of infection-related mortality found consistently in individuals with ≥20 pack-years.

IMPLICATIONS

In this large-scale cohort study of relatively young and middle-aged South Korean adults, current smoking, smoking intensity, and pack-years were associated with an increased risk of death due to infections; in particular, a significantly increased risk of infection-related mortality was consistently found in individuals with ≥20 pack-years. When appropriate, infection-related mortality should be included in smoking-attributable mortality burdens, and effective smoking control measures should be considered to improve infection-related mortality.

Administrative Coding in Electronic Health Care Record-Based Research of NAFLD: An Expert Panel Consensus Statement

BACKGROUND AND AIMS

Electronic health record (EHR)-based research allows the capture of large amounts of data, which is necessary in NAFLD, where the risk of clinical liver outcomes is generally low. The lack of consensus on which International Classification of Diseases (ICD) codes should be used as exposures and outcomes limits comparability and generalizability of results across studies. We aimed to establish consensus among a panel of experts on ICD codes that could become the reference standard and provide guidance around common methodological issues.

APPROACH AND RESULTS

Researchers with an interest in EHR-based NAFLD research were invited to collectively define which administrative codes are most appropriate for documenting exposures and outcomes. We used a modified Delphi approach to reach consensus on several commonly encountered methodological challenges in the field. After two rounds of revision, a high level of agreement (>67%) was reached on all items considered. Full consensus was achieved on a comprehensive list of administrative codes to be considered for inclusion and exclusion criteria in defining exposures and outcomes in EHR-based NAFLD research. We also provide suggestions on how to approach commonly encountered methodological issues and identify areas for future research.

CONCLUSIONS

This expert panel consensus statement can help harmonize and improve generalizability of EHR-based NAFLD research.

Self-reported and cotinine-verified smoking and increased risk of incident hearing loss

We examined the associations of smoking status and urinary cotinine levels, an objective measure of smoking, with the development of new-onset HL. This cohort study was performed in 293,991 Korean adults free of HL who underwent a comprehensive screening examination and were followed for up to 8.8 years. HL was defined as a pure-tone average of thresholds at 0.5, 1.0, and 2.0 kHz ≥ 25 dB in both ears. During a median follow-up of 4.9 years, 2286 participants developed new-onset bilateral HL. Self-reported smoking status was associated with an increased risk of new-onset bilateral HL. Multivariable-adjusted HRs (95% CIs) for incident HL comparing former smokers and current smokers to never-smokers were 1.14 (1.004-1.30) and 1.40 (1.21-1.61), respectively. Number of cigarettes, pack-years, and urinary cotinine levels were consistently associated with incident HL. These associations were similarly observed when introducing changes in smoking status, urinary cotinine, and other confounders during follow-up as time-varying covariates. In this large cohort of young and middle-aged men and women, smoking status based on both self-report and urinary cotinine level were independently associated with an increased incidence of bilateral HL. Our findings indicate smoking is an independent risk factor for HL.

Stages of menopause and abnormal lung function: a cross-sectional study of middle-aged women

OBJECTIVE

Whether hormonal changes during menopausal transition postmenopause stages influence pulmonary function is not clearly understood. We evaluated the association between each stage of menopause and the prevalence of abnormal lung function in healthy middle-aged women. We hypothesized that the prevalence of abnormal lung function would increase from the late menopausal transition stage during menopausal transition postmenopause stages.

METHODS

The study population included women 40 to 65 years of age who underwent comprehensive health screening examination at the Kangbuk Samsung Hospital Total Healthcare Centers from January 2015 to December 2017. Stages of menopause (premenopausal, early menopausal transition, late menopausal transition, and postmenopausal) were defined using the 2011 Stages of Reproductive Aging Workshop (STRAW + 10) criteria. Abnormal lung function was defined based on spirometry as forced expiratory volume in 1 second/forced vital capacity less than70% or forced vital capacity less than 80% predicted. Prevalence ratios (PRs) for abnormal lung function by stages of menopause were estimated from logistic regression models adjusted for age, anthropometric measurements, lifestyle factors, medical history, lipid and inflammatory biomarkers, and reproductive factors.

RESULTS

Among 43,822 participants, there were 4,615 participants (10.5%) with restrictive ventilatory disorder and 653 participants (1.5%) with obstructive ventilatory disorder. The fully adjusted PRs (95% confidence interval) for abnormal ventilatory disorder comparing early menopausal transition, late menopausal transition, and postmenopausal stage to premenopausal stage were 1.01 (0.94-1.08), 1.13 (1.03-1.22), and 1.10 (0.98-1.22), respectively. The fully adjusted PRs for restrictive ventilatory disorder comparing early menopausal transition, late menopausal transition, and postmenopausal stages to premenopausal stage were 1.02 (0.94-1.11), 1.18 (1.06-1.30), and 1.15 (1.00-1.31), respectively. There was, however, no clear association between stages of menopause and obstructive ventilatory disorder.

CONCLUSIONS

In this large study of middle-aged women, the fully adjusted prevalence of abnormal lung function, particularly that of restrictive ventilatory disorder, was higher in women in late menopausal transition and menopausal stages compared to women in premenopausal stage.

Blood eosinophil counts and the development of obstructive lung disease: the Kangbuk Samsung Health Study

The impact of blood eosinophil counts on the development of chronic obstructive lung disease (COPD) is unknown. We investigated whether a higher blood eosinophil counts was associated with the risk of developing obstructive lung disease (OLD) in a large cohort of men and women free lung disease at baseline.Cohort study of 359 456 Korean adults without a history of asthma and without OLD at baseline who participated in health screening exams including spirometry. OLD was defined as pre-bronchodilator FEV₁/FVC<0.7 and FEV₁<80% predicted.After a median follow-up of 5.6 years (interquartile range, 2.9-9.2), 5008 participants developed incident OLD (incidence rate, 2.1 per 1000 person-years; 95% CI, 2.1-2.2). In the fully-adjusted model, the HR (95% CI) for incident OLD comparing eosinophil counts of 100-<200, 200-<300, 300-<500 and ≥500 cells·μL^-1 to <100 cells·μL^-1 were 1.07 (1.00-1.15), 1.30 (1.20-1.42), 1.46 (1.33-1.60) and 1.72 (1.51-1.95) (p for trend <0.001). These associations were consistent in clinically relevant subgroups, including never, former, and current smokers.In this large longitudinal cohort study, blood eosinophil counts were positively associated with the risk of developing of OLD. Our findings indicate a potential role of eosinophil count as an independent risk factor for developing COPD.

The prospective relationship between low muscle mass and thyroid hormones among 198 069 euthyroid men and women; comparing different definitions of low muscle mass

OBJECTIVE

The impact of thyroid hormones within normal range on muscle mass remains unknown. We examined the association between new onset of low muscle mass (LMM) and thyroid hormones among euthyroid men and women with three different definitions of LMM in prospective cohort study.

METHODS

We performed a cohort study of 198 069 Korean adults (mean age of 39.2 years), free of LMM at baseline, who participated in a repeated screening examination and were followed up annually or biennially for up to 6.3 years. Thyroid-stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxin (FT4) levels were measured by an electrochemiluminescent immunoassay. Muscle mass was assessed using a bioelectrical impedance analyser. LMM was defined as the appendicular skeletal muscle mass (ASM) by body weight (ASM/weight, LMM-W), height squared (ASM/height² , LMM-H) and BMI (ASM/BMI, LMM-B) of one standard deviation below the sex-specific mean for young reference group.

RESULTS

During a median follow-up of 3.1 years (interquartile range, 2.0-4.1 years), new-onset LMM-W, LMM-H and LMM-B occurred in 17 856 (incident rate, 27.8 per 1000 person-years), 8307 (incident rate, 13.4 per 1000 person-years) and 13 990 participants (incident rate, 24.5 per 1000 person-years) in each. In euthyroid men, FT4 was inversely and FT3 positively associated with incident LMM-W in a dose-response manner. TSH and FT4 had inverse dose-response relationship with incident LMM-B. Incident LMM-H of euthyroid men has no apparent associations with any thyroid hormones. Euthyroid women had no dose-response relationship between thyroid hormones and any definition of LMM.

CONCLUSIONS

Among euthyroid men, FT4 had inverse dose-response association with new onset of LMM defined with weight (LMM-W) and BMI (LMM-B). Height squared LMM (LMM-H) had no apparent relationship with any thyroid hormones. Euthyroid women had no dose-responsive association between thyroid hormones and incident LMM.

Low-level alcohol consumption and cancer mortality

The effect of light-to-moderate alcohol consumption on cancer risk remains controversial. We examined the association between low-level alcohol consumption and cancer mortality. A cohort study included 331,984 Korean adults free of cancer at baseline who underwent a comprehensive health checkup examination. Participants were categorized into never drinkers, former drinkers, and current drinkers who were further divided into light, moderate, heavy, and very heavy drinkers. Vital status and cancer-related deaths were ascertained through links to national death records. During 1,633,906 person-years of follow-up (median 5.3 years interquartile range 3.8–6.2), 374 cancer-related deaths were identified (cancer-cause mortality rate of 23 per 10⁵ person-years). When former and never drinkers were classified as non-drinkers, the light drinkers had a lowest risk of cancer mortality compared with non-drinkers and other current drinkers (J-shaped); however, with consideration of lifetime abstinence history, current drinking was positively associated with cancer mortality in a dose-dependent manner. When changes in alcohol drinking status and confounders during follow-up were updated as time-varying covariates and never drinkers were used as the reference, the multivariable-adjusted hazard ratios (HRs) (95% confidence intervals, CIs) for cancer mortality among current light, moderate, heavy, and very heavy drinkers were 1.58 (1.03–2.43), 2.28 (1.41–3.70), 2.34 (1.42–3.85), and 2.97 (1.80–4.90), respectively, and the highest risk of cancer mortality was observed in former drinkers, who had an HR (95% CI) of 3.86 (2.38–6.28). Alcohol consumption was significantly and positively associated with an increased risk of cancer mortality in a dose-dependent manner, beginning with light drinkers.

Visual acuity and risk of overall, injury-related, and cardiovascular mortality: the Kangbuk Samsung Health Study

AIMS 

The associations of visual impairment (VI) with cardio-metabolic risk factors have been reported but its association with cardiovascular mortality remains uncertain. Therefore, we evaluated the association of visual acuity (VA) with overall, injury-related, and cardiovascular mortality.

METHODS AND RESULTS

A cohort study was performed in 580 746 Korean adults (average age, 39.7 years) who were followed for a median of 8.1 years (maximum, 16 years). Presenting VA was measured by the Early Treatment Diabetic Retinopathy Study (ETDRS) chart. Visual acuity in the better vision eye was categorized as normal vision (≥0.8), lowered vision (0.5-0.8), mild visual impairment (VI) (0.3-0.5), or moderate to severe VI (<0.3). Vital status and cause of death were ascertained through linkage to national death records. During 4 632 892.2 person-years of follow-up, 6585 overall deaths, 974 cardiovascular deaths, and 1163 injury-related deaths were identified. After adjustment for possible confounders, the multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for overall mortality among participants with lowered vision, minimal VI, and moderate to severe VI were 1.21 (1.13-1.29), 1.26 (1.15-1.37), and 1.54 (1.40-1.68), respectively, compared with those with normal vision. The corresponding HRs (95% CIs) for injury-related mortality were 1.12 (0.96-1.32), 0.98 (0.76-1.26), and 1.36 (1.04-1.79), respectively, and the corresponding HRs (95% CIs) for cardiovascular mortality were 1.32 (1.12-1.57), 1.43 (1.15-1.77), and 2.41 (1.94-2.99).

CONCLUSION 

In this large cohort of young and middle-aged individuals, VI was associated with increased risk of mortality especially due to cardiovascular disease.

High-sensitivity C-reactive Protein and Regression of Low-grade Squamous Intraepithelial Lesion: The Role of Low-grade Inflammation in Cervical Carcinogenesis

Background

Inflammation is emerging as a potential mechanism of cervical carcinogenesis. However, few studies have investigated the association between host inflammatory status and the natural course of cervical precursor lesion. The aim of this study was to assess the probability of LSIL regression, associated with an inflammatory biomarker, high-sensitivity C-reactive protein (hs-CRP).

Methods

In a longitudinal cohort study, female participants were examined annually or biannually using cervical cytology between 2006 and 2015. Incident LSIL cases were included in the analysis, with regression defined as at least one consecutive normal cytologic result. A total of 520 women aged 22–64 years were followed up for LSIL regression. The multivariable-adjusted hazard ratios (HRs) for LSIL regression were estimated using a parametric proportional hazards model.

Results

During 827.5 person-years of follow-up, 486 out of 520 subjects (93.5%) showed LSIL regression. After adjusting several important potential confounders, a higher quartile of hs-CRP levels was significantly associated with a lower rate of regression (for quartile 4 vs quartile 1, inverse HR 1.33; 95% CI, 1.04–1.69; P for trend = 0.028).

Conclusions

The low rate of spontaneous regression recorded in women with higher hs-CRP lends support to the role of the perturbated host inflammatory status in cervical carcinogenesis, and suggests that hs-CRP level could help monitor LSIL.

Smoking, urinary cotinine levels and incidence of visual impairment

The longitudinal relationship between smoking status and risk of developing visual impairment (VI) remains unclear. We examined the relationship of smoking status and urinary cotinine level, an objective measure of smoking, with incidence of VI. This cohort study included 279,069 individuals free of VI who were followed for up to 8.8 years (median 4.8 years). VI was defined as when bilateral visual acuity was worse than 0.5 (cutoffs of 0.3 Logarithm of the Minimum Angle of Resolution). During 1,324,429.8 person-years of follow-up, 7852 participants developed new-onset bilateral VI. Self-reported current smoking status was associated with increased risk of developing VI in both men and women, with a stronger association in women (P for interaction = 0.01). Multivariable adjusted hazard ratios (95% confidence intervals) for incident VI comparing current smokers to never-smokers were 1.14 (1.04–1.25) in men and 1.52 (1.28–1.80) in women. Urinary cotinine levels of ≥ 100 ng/ml were significantly associated with increased risk of incident VI, and these associations remained when introducing changes in urinary cotinine and other confounders during follow-up as time-varying covariates. Cigarette smoking assessed based on self-report and urinary cotinine level was associated with increased incidence of VI. Our findings identify smoking as an independent risk factor for VI.

Discordance Between Apolipoprotein B and Low-Density Lipoprotein Cholesterol and Progression of Coronary Artery Calcification in Middle Age

BACKGROUND

A high level of apolipoprotein B (apoB) is associated with incident coronary artery disease (CAD) when low-density lipoprotein cholesterol (LDL-C) level is discordantly low or concordantly high. However, data on the relationship of apoB with subclinical measure of CAD are limited.Methods and Results:A total of 14,205 men (mean age 41.0 years) who were free of cardiovascular disease at baseline and who underwent a health checkup exam, including measurement of coronary artery calcium (CAC), were studied. Of the study group, 2,773 participants (19.5%) had CAC at baseline, and CAC progression was observed in 2,550 (18.0%). The multivariate-adjusted CAC score ratios (95% confidence interval) comparing discordantly high apoB/low LDL-C and concordantly high apoB/high LDL-C with concordantly low apoB/low LDL-C were 1.51 (0.98-2.32) and 2.70 (2.19-3.33), respectively. The corresponding relative risks for CAC progression were 1.26 (1.02-1.56) and 1.49 (1.34-1.66), respectively. These associations did not change appreciably after adjustment for insulin resistance and subclinical inflammation.

CONCLUSIONS

Discordant analysis showed that a high apoB level was strongly associated with prevalence and progression of CAC independent of LDL-C in a large cohort of healthy adults. The present study results highlighted the importance of an apoB measure as a potential target for primary prevention of coronary atherosclerosis in healthy adults.

Author Correction: Perceived stress and non-alcoholic fatty liver disease in apparently healthy men and women

An amendment to this paper has been published and can be accessed via a link at the top of the paper.