Persistence or regression of prediabetes and coronary artery calcification among adults without diabetes.

OBJECTIVE: The effect of changes in glycemic status on subclinical atherosclerosis is uncertain. We assessed the association of persistence, regression, or progression of prediabetes with coronary artery calcium score (CACS) as a measure of subclinical atherosclerosis. DESIGN: A cross-sectional study, comprising 126 765 adults, and longitudinal sub-study, comprising 40 622 adults (with baseline and at least 1 follow-up computed tomography scan to assess changes in CACS), were undertaken. METHODS: Changes in glycemic status over 1.5 years (interquartile range, 1.0-2.0) before the first CACS assessment were categorized according to 6 groups: persistent normoglycemia (reference), normoglycemia to prediabetes, normoglycemia to diabetes, prediabetes to normoglycemia, persistent prediabetes, and prediabetes to diabetes. Logistic regression was used to calculate the odds ratios (ORs) and 95% CIs for prevalent coronary artery calcification (CAC). Mixed models with random intercepts and random slopes were used to estimate 5-year CAC progression rates. RESULTS: Mean (SD) age was 41.3 (7.0) years (74.7% male) (n = 126 765). Multivariable-adjusted OR for prevalent CAC was 1.13 (95% CI, 1.08-1.18) for persistent prediabetes, 1.05 (0.98-1.12) for regression to normoglycemia, and 1.46 (95% CI, 1.27-1.67) for progression from prediabetes to diabetes, compared with persistent normoglycemia. Coronary artery calcification progression increased significantly in all prediabetes groups. Multivariable-adjusted ratio of 5-year CAC progression rates was 1.19 (95% CI, 1.16-1.22) (persistent prediabetes), 1.11 (1.07-1.14) (regression to normoglycemia), and 1.63 (95% CI, 1.26-2.10) (progression from prediabetes to diabetes). CONCLUSIONS: Unfavorable changes in glycemic status, including persistence of prediabetes or progression to diabetes from prediabetes, were associated with increased risk of CAC.

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.

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.

Effect of Intermittent Hypoxia on Metabolic Syndrome and Insulin Resistance in the General Male Population.

Background and objectives: Obstructive sleep apnea (OSA) is closely associated with insulin resistance (IR) and is an independent risk factor for incident type 2 diabetes mellitus (T2DM). Most studies evaluate the correlation between OSA and IR in only obese or T2DM patients. Therefore, we tried to investigate the effect of OSA on metabolic syndrome and IR in the general healthy male population. Materials and Methods: 184 subjects who visited a preventive health examination program were recruited for this study. All subjects received overnight polysomnography by a portable device (Watch-PAT 200). We examined several metabolic parameters and a homeostasis model of assessment for insulin resistance index (HOMA-IR). The subjects were divided into three groups by AHI (Apnea-hyponea index): normal group (AHI < 5), mild OSA group (5 ≤ AHI < 15), and moderate-severe OSA group (AHI ≥ 15). They were also divided into two groups according to minimum oxygen saturation: low group, Min-SpO2 < 88%; and high group, Min-SpO2 ≥ 88%. Results: Parameters of metabolic syndrome, including waist circumference, systolic and diastolic blood pressure, triglyceride, and high-density lipoprotein cholesterol showed significant differences among the AHI groups. Furthermore, HOMA-IR showed significant differences among the AHI groups. Those parameters, including metabolic syndrome and HOMA-IR, also showed differences between Min-SpO2 groups. Conclusions: In summary, this study helps confirm that AHI is associated with HOMA-IR in the general male population. Furthermore, the severity of AHI correlated with the parameters of metabolic syndrome. Therefore, AHI might be an indicator for evaluating both T2DM and metabolic syndrome, even in the general male population.

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.

Bidirectional Association between Nonalcoholic Fatty Liver Disease and Gallstone Disease: A Cohort Study.

Nonalcoholic fatty liver disease (NAFLD) and gallstone disease (GD) are often found to coexist but the sequential relationship of NAFLD and GD to each other remains controversial. We prospectively evaluated the bidirectional relationship of NAFLD with GD. A cohort study was performed on Korean adults who underwent a health checkup and were followed annually or biennially for a mean of 6.0 years. Fatty liver and gallstones were diagnosed by ultrasound. NAFLD was defined as hepatic steatosis on ultrasonography in the absence of excessive alcohol use or other identifiable causes. The NAFLD severity was determined by non-invasive fibrosis markers. Among 283,446 participants without either gallstones or cholecystectomy at baseline, 6440 participants developed gallstones. Among 219,641 participants without NAFLD at baseline, 49,301 participants developed NAFLD. The multivariable-adjusted hazard ratio (95% confidence interval) for incident gallstone comparing the NAFLD group vs. the non-NAFLD group was 1.26 (1.17⁻1.35). Increased non-invasive fibrosis markers of NAFLD were positively associated with an increased incidence of gallstones in a graded and dose-responsive manner (p-trend < 0.01). The multivariable-adjusted hazard ratios (95% confidence intervals) for incident NAFLD comparing gallstone and cholecystectomy to no GD were 1.14 (1.07⁻1.22) and 1.17 (1.03⁻1.33), respectively. This large-scale cohort study of young and middle-aged individuals demonstrated a bidirectional association between NAFLD and GD. NAFLD and its severity were independently associated with an increased incidence of gallstones, while GD and cholecystectomy were also associated with incident NAFLD. Our findings indicate that the conditions may affect each other, requiring further studies to elucidate the potential mechanisms underlying this association.

Physical activity and impaired left ventricular relaxation in middle aged adults.

The aim of this study was to examine the relationship between physical activity level and impaired left ventricular (LV) relaxation in a large sample of apparently healthy men and women. We conducted a cross-sectional study in 57,449 adults who underwent echocardiography as part of a comprehensive health examination between March 2011 and December 2014. Physical activity level was assessed using the Korean version of the International Physical Activity Questionnaire Short Form. The presence of impaired LV relaxation was determined based on echocardiographic findings. Physical activity levels were inversely associated with the prevalence of impaired LV relaxation. The multivariable-adjusted odds ratios (95% confidence interval) for impaired LV relaxation comparing minimally active and health-enhancing physically active groups to the inactive group were 0.84 (0.77-0.91) and 0.64 (0.58-0.72), respectively (P for trend < 0.001). These associations were modified by sex (p for interaction <0.001), with the inverse association observed in men, but not in women. This study demonstrated an inverse linear association between physical activity level and impaired LV relaxation in a large sample of middle-aged Koreans independent of potential confounders. Our findings suggest that increasing physical activity may be independently important in reducing the risk of impaired LV relaxation.

Changes in sleep duration and subsequent risk of hypertension in healthy adults.

Study Objectives: It is unknown whether changes in sleep duration are associated with hypertension risk. The aim of this study was to investigate whether changes in sleep duration were associated with subsequent risk of developing hypertension in young and middle-aged women and men. Methods: We analyzed data from 106385 participants who were free of hypertension and cardiovascular disease during the exposure period and who underwent a health checkup exam, including repeated measures of sleep duration. Results: Over 250907.5 person-years, we documented 4750 incident cases of hypertension. Both a decrease in sleep duration and persistently short sleep were associated with an elevated risk of hypertension during the subsequent 2.4 years. In analyses for relevant covariates during the exposure period, a decrease of ≥2 hours of sleep and an increase of ≥2 hours of sleep compared with no change in sleep duration were associated with a higher risk of incident hypertension in women (hazard ratio [HR]: 1.46; 95% confidence interval [CI] 1.08-1.98) and men (HR: 1.31; 95% CI 1.10-1.56). Women with persistently shorter sleep durations compared with those who maintained 7 hours of sleep, were at greater risk of developing hypertension during the subsequent follow-up period. Conclusion: In this large study of young and middle-aged women and men, we found that individuals with either considerable changes in sleep duration or persistently short sleep were at an increased risk of incident hypertension, underscoring the importance of maintaining moderate sleep duration to prevent hypertension.

Low relative muscle mass and left ventricular diastolic dysfunction in middle-aged adults.

OBJECTIVES: The association between low skeletal muscle mass and left ventricular diastolic dysfunction (LVDD), a predictor of future heart failure, is largely unexplored. We investigated the relationship between relative muscle mass and LVDD. METHODS: We conducted a cross-sectional study in 67,106 Koreans who underwent an echocardiography as part of a comprehensive health examination between January 2012 and December 2014. Skeletal muscle mass index (SMI) [SMI (%)=total skeletal muscle mass (kg)/body weight (kg)×100] was estimated using a bioelectrical impedance analyzer. The presence of LVDD was determined using echocardiographic findings. RESULTS: In 67,106 participants, 19,232 subjects (28.7%) and 1553 subjects (2.3%) had LVDD and left ventricular (LV) hypertrophy, respectively. SMI was positively associated with E/A ratio and septal E', whereas E/E' ratio and LV mass index were negatively associated with SMI. Lower SMI was associated with increased presence of LVDD. In a multivariable-adjusted model controlling for potential confounders including physical activity, insulin resistance, and LV mass, the odds ratios for LVDD in SMI quartiles 1, 2, and 3 compared with quartile 4 were 2.11 (1.97-2.25), 1.79 (1.68-1.90), and 1.45 (1.36-1.55), respectively (P for trend<0.001). CONCLUSIONS: In a large sample of young and middle-aged Korean adults, low relative muscle mass was independently associated with increased risk of LVDD, indicating an independent role of skeletal muscle mass in the pathogenesis of LVDD.

Coexistence of Colorectal Adenomas and Coronary Calcification in Asymptomatic Men and Women.

GOALS: Because of shared risk factors between clinically manifest cardiovascular disease and colorectal cancer, we hypothesized the coexistence of subclinical atherosclerosis measured by coronary artery calcium (CAC) and colorectal adenoma (CRA) and that these 2 processes would also share common risk factors. BACKGROUND: No study has directly compared the risk factors associated with subclinical coronary atherosclerosis and CRA. STUDY: This was a cross-sectional study using multinomial logistic regression analysis of 4859 adults who participated in a health screening examination (2010 to 2011; analysis 2014 to 2015). CAC scores were categorized as 0, 1 to 100, or >100. Colonoscopy results were categorized as absent, low-risk, or high-risk CRA. RESULTS: The prevalence of CAC>0, CAC 1 to 100 and >100 was 13.0%, 11.0%, and 2.0%, respectively. The prevalence of any CRA, low-risk CRA, and high-risk CRA was 15.1%, 13.0%, and 2.1%, respectively. The adjusted odds ratios (95% confidence interval) for CAC>0 comparing participants with low-risk and high-risk CRA with those without any CRA were 1.35 (1.06-1.71) and 2.09 (1.29-3.39), respectively. Similarly, the adjusted odds ratios (95% confidence interval) for any CRA comparing participants with CAC 1 to 100 and CAC>100 with those with no CAC were 1.26 (1.00-1.6) and 2.07 (1.31-3.26), respectively. Age, smoking, diabetes, and family history of CRC were significantly associated with both conditions. CONCLUSIONS: We observed a graded association between CAC and CRA in apparently healthy individuals. The coexistence of both conditions further emphasizes the need for more evidence of comprehensive approaches to screening and the need to consider the impact of the high risk of coexisting disease in individuals with CAC or CRA, instead of piecemeal approaches restricted to the detection of each disease independently.

Association of Age at Menarche With Left Ventricular Diastolic Dysfunction in Middle-Aged Women.

BACKGROUND: There is sparse research on whether if early menarche is related to left ventricular (LV) diastolic dysfunction. The present study examined this relationship in Korean women.Methods and Results:In a cross-sectional study we analyzed the records of 18,910 Korean women (≥30 years) who underwent echocardiography as part of a comprehensive health examination. Age at menarche was assessed using standardized, self-administered questionnaires. Presence of LV diastolic dysfunction was determined from the echocardiographic findings. Of the 18,910 women, 3,449 had LV diastolic dysfunction. Age at menarche was inversely associated with prevalence of LV diastolic dysfunction. In a multivariable-adjusted model, odds ratios (95% confidence interval) for LV diastolic dysfunction comparing menarche age to menarche at 15-18 years were 1.77 (1.38-2.27) for <12 years, 1.31 (1.11-1.54) for 12 years, 1.26 (1.11-1.43) for 13 years, and 1.03 (0.91-1.15) for 14 years (P for trend <0.001). Adjusting for body mass index or percent fat mass partially reduced these associations. CONCLUSIONS: This large study found an inverse relationship between menarche age and LV diastolic dysfunction. Future prospective studies are needed to investigate potential causal relationships.

Sleep duration and quality in relation to chronic kidney disease and glomerular hyperfiltration in healthy men and women.

BACKGROUND: It is unclear whether sleep duration and quality are associated with chronic kidney disease (CKD) and glomerular hyperfiltration. The aim of this study was to examine the association of sleep duration and quality with CKD and glomerular hyperfiltration in young and middle-aged adults. METHODS: We conducted a cross-sectional study of men and women who underwent a health checkup examination, including assessment of sleep duration and quality (n = 241,607). Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m2, and glomerular hyperfiltration was defined as eGFR above the age-/sex-specific 95th percentile. RESULTS: In a multinomial logistic regression analysis adjusting for relevant confounders, the adjusted prevalence ratios for CKD (95% confidence interval) comparing sleep durations of ≤ 5, 6, 8, and 9 hours with 7 hours were 1.22 (0.95-1.55), 0.93 (0.75-1.14), 0.97 (0.75-1.26), and 1.56 (1.06-2.30) in men and 0.98 (0.68-1.43), 1.03 (0.72-1.46), 1.39 (0.97-2.00), and 1.31 (0.78-2.22) in women, respectively. The corresponding prevalence ratios (95% confidence interval) for glomerular hyperfiltration were 1.00 (0.93-1.08), 0.97 (0.91-1.03), 1.03 (0.94-1.13), and 1.39 (1.13-1.72) in men and 1.04 (0.95-1.14), 0.96 (0.90-1.04), 1.11 (1.02-1.20), and 1.28 (1.14-1.45) in women, respectively. Poor subjective sleep quality was associated with glomerular hyperfiltration in men and women. CONCLUSION: In this large study of young and middle-aged adults, we found that long sleep duration was associated with CKD and glomerular hyperfiltration. Additionally, poor subjective sleep quality was associated with increased prevalence of glomerular hyperfiltration, suggesting the importance of adequate quantity and quality of sleep for kidney function.

Relationship Between γ-Glutamyltransferase Levels and Left Ventricular Diastolic Dysfunction.

BACKGROUND: The goal of this study was to examine the association of serum γ-glutamyltransferase (GGT) levels with left ventricular (LV) diastolic dysfunction and LV hypertrophy.Methods and Results:A cross-sectional study of 79,459 Korean men and women who underwent an echocardiography as part of a comprehensive health examination between March 2011 and December 2014. The presence of LV diastolic dysfunction and LV hypertrophy was determined using echocardiography. Of the subjects, 5,447 had LV diastolic dysfunction and 2,070 had LV hypertrophy. Both LV diastolic dysfunction and LV hypertrophy were associated with higher levels of serum GGT. Multivariable-adjusted odds ratios (95% confidence interval) for LV diastolic dysfunction comparing serum GGT quartiles 2-4 with quartile 1 were 1.25 (1.08-1.44), 1.65 (1.43-1.91) and 2.23 (1.92-2.58), respectively (P for trend <0.001). Multivariable-adjusted odds ratios (95% CI) for LV hypertrophy comparing serum GGT quartiles 2-4 with quartile 1 were 1.13 (0.94-1.36), 1.14 (0.93-1.40) and 1.33 (1.07-1.65), respectively (P for trend 0.01). These associations of serum GGT levels with LV diastolic dysfunction and LV hypertrophy were modified by age (P for interaction <0.05). CONCLUSIONS: This study demonstrated a positive association between serum GGT levels and LV diastolic dysfunction and LV hypertrophy in a large cohort of middle-aged men and women independent of potential confounders.

Waist Gain Is Associated with a Higher Incidence of Nonalcoholic Fatty Liver Disease in Korean Adults: A Cohort Study.

BACKGROUND: We examined the relationship between changes in waist circumference (WC) and the incidence of nonalcoholic fatty liver disease (NAFLD). METHODS: A cohort study of 37,130 men and women were followed-up annually or biennially. Differences in WC between baseline and subsequent measurements were categorized in quartiles: first (WC loss), second (no change in WC as the reference), third and highest quartiles (WC gain). The presence of fatty liver was determined using ultrasound. Parametric Cox modeling was used to estimate the adjusted hazard ratios (aHR) and 95% confidence intervals (CIs) of the incidence of NAFLD. RESULTS: During 127,324.4 person-years of follow-up, 6249 participants developed NAFLD. Despite adjusting for possible confounders, the risk of development of NAFLD increased with increasing quartiles of WC change in a dose-response manner (p for trend < 0.001). Compared with the reference, WC loss was associated with a lower risk of NAFLD (men: aHR 0.79 [95% CI: 0.73-0.87]; women: 0.72 [0.63-0.81]), and the highest quartile (WC gain) was associated with a higher risk of NAFLD (men: 1.30 [1.19-1.42]; women: 1.48 [1.31-1.67]). CONCLUSION: Waist gain appears to increase the risk of developing NAFLD, independently of the baseline body mass index and WC.

Metabolically Healthy Obesity and the Development of Nonalcoholic Fatty Liver Disease.

OBJECTIVES: The risk of nonalcoholic fatty liver disease (NAFLD) among obese individuals without obesity-related metabolic abnormalities, a condition referred to as metabolically healthy obese (MHO), is largely unexplored. Therefore, we examined the association between body mass index (BMI) categories and the development of NAFLD in a large cohort of metabolically healthy men and women. METHODS: A cohort study was conducted in 77,425 men and women free of NAFLD and metabolic abnormalities at baseline, who were followed-up annually or biennially for an average of 4.5 years. Being metabolically healthy was defined as not having any metabolic syndrome component and having a homeostasis model assessment of insulin resistance <2.5. The presence of fatty liver was determined using ultrasound. RESULTS: During 348,193.5 person-years of follow-up, 10,340 participants developed NAFLD (incidence rate, 29.7 per 1,000 person-years). The multivariable adjusted hazard ratios (95% confidence intervals) for incident NAFLD comparing overweight and obese with normal-weight participants were 2.15 (2.06-2.26) and 3.55 (3.37-3.74), respectively. In detailed dose-response analyses, increasing baseline BMI showed a strong and approximately linear relationship with the incidence of NAFLD, with no threshold at no risk. This association was present in both men and women, although it was stronger in women (P for interaction <0.001), and it was evident in all clinically relevant subgroups evaluated, including participants with low inflammation status. CONCLUSIONS: In a large cohort of strictly defined metabolically healthy men and women, overweight and obesity were strongly and progressively associated with an increased incidence of NAFLD, suggesting that the obese phenotype per se, regardless of metabolic abnormalities, can increase the risk of NAFLD.

Relationship Between Low Relative Muscle Mass and Coronary Artery Calcification in Healthy Adults.

OBJECTIVE: Sarcopenia or low muscle mass is related to cardiovascular risk factors; however, the association between low muscle mass and subclinical atherosclerosis has been largely unexplored. We investigated whether muscle mass is related to coronary artery calcification (CAC) in a large sample of middle-aged asymptomatic adults. APPROACH AND RESULTS: We performed a cross-sectional study of 31 108 asymptomatic adults without cancer, diabetes mellitus, or known cardiovascular disease who underwent a health checkup examination including cardiac tomography estimation of CAC scores between 2012 and 2013. Skeletal muscle mass index (SMI) [SMI (%)=total skeletal muscle mass (kg)/body weight (kg)×100] was estimated using a bioelectrical impedance analyzer. We assessed the relationship between SMI and CAC scores using both multivariate-adjusted Tobit models and multinomial logistic regression models. Of the 31 108 subjects, 3374 subjects (10.9%) had a CAC score 1 to 100, and 628 subjects (2.0%) had a CAC score >100. SMI was inversely associated with CAC score ratios. Specifically, in a multivariable-adjusted model adjusting for potential confounders, CAC score ratios (95% confidence intervals) of SMI for quartiles 1, 2, and 3 compared with quartile 4 were 2.27 (1.70-3.05), 1.46 (1.15-1.85), and 1.24 (0.98-1.55), respectively (P for trend <0.001). Adjusting for insulin resistance reduced the magnitude of the associations, but they remained statistically significant. CONCLUSIONS: Relative muscle mass was negatively associated with the prevalence of coronary calcification, supporting low muscle mass as an independent risk factor of coronary heart disease.

Sleep Duration, Sleep Quality, and Markers of Subclinical Arterial Disease in Healthy Men and Women.

OBJECTIVE: Short and long sleep duration are associated with increased risk of clinical cardiovascular events, but the association between sleep duration and subclinical cardiovascular disease is not well established. We examined the association between sleep duration and sleep quality with coronary artery calcification (CAC) and with brachial-ankle pulse wave velocity (PWV) in a large sample of young and middle-aged asymptomatic adults. APPROACH AND RESULTS: We conducted a cross-sectional study of adult men and women who underwent a health checkup examination, including assessment of sleep duration and quality and coupled with either CAC (n=29 203) or brachial-ankle PWV (n=18 106). The multivariate-adjusted CAC score ratios (95% confidence interval) comparing sleep durations of ≤5, 6, 8, and ≥9 hours with 7 hours of sleep were 1.50 (1.17-1.93), 1.34 (1.10-1.63), 1.37 (0.99-1.89), and 1.72 (0.90-3.28), respectively (P for quadratic trend=0.002). The corresponding average differences in brachial-ankle PWV were 6.7 (0.75-12.6), 2.9 (-1.7 to 7.4), 10.5 (4.5-16.5), and 9.6 (-0.7 to 19.8) cm/s, respectively (P for quadratic trend=0.019). Poor subjective sleep quality was associated with CAC in women but not in men, whereas the association between poor subjective sleep quality and brachial-ankle PWV was stronger in men than in women. CONCLUSIONS: In this large study of apparently healthy men and women, extreme sleep duration and poor subjective sleep quality were associated with increased prevalence of CAC and higher PWV. Our results underscore the importance of an adequate quantity and quality of sleep to maintain cardiovascular health.

Relationship of sitting time and physical activity with non-alcoholic fatty liver disease.

BACKGROUND & AIMS: The goal of this study was to examine the association of sitting time and physical activity level with non-alcoholic fatty liver disease (NAFLD) in Korean men and women and to explore whether any observed associations were mediated by adiposity. METHODS: A cross-sectional study was performed on 139,056 Koreans, who underwent a health examination between March 2011 and December 2013. Physical activity level and sitting time were assessed using the validated Korean version of the international Physical Activity Questionnaire Short Form. The presence of fatty liver was determined using ultrasonographic findings. Poisson regression models with robust variance were used to evaluate the association of sitting time and physical activity level with NAFLD. RESULTS: Of the 139,056 subjects, 39,257 had NAFLD. In a multivariable-adjusted model, both prolonged sitting time and decreased physical activity level were independently associated with increasing prevalence of NAFLD. The prevalence ratios (95% CIs) for NAFLD comparing 5-9 and ⩾10 h/day sitting time to <5h/day were 1.04 (1.02-1.07) and 1.09 (1.06-1.11), respectively (p for trend <0.001). These associations were still observed in subjects with BMI <23 kg/m(2). The prevalence ratios (95% CIs) for NAFLD comparing minimally active and health-enhancing physically active groups to the inactive group were 0.94 (0.92-0.95) and 0.80 (0.78-0.82), respectively (p for trend <0.001). CONCLUSIONS: Prolonged sitting time and decreased physical activity level were positively associated with the prevalence of NAFLD in a large sample of middle-aged Koreans, supporting the importance of reducing time spent sitting in addition to promoting physical activity.

Metabolic syndrome, insulin resistance, and mammographic density in pre- and postmenopausal women.

Little is known about the association of metabolic syndrome (MetS) or insulin resistance (IR) with mammographic density, a strong risk factor for breast cancer. The goal of this study was to evaluate these associations in pre- and postmenopausal women. A cross-sectional study was performed in 73,974 adult women who underwent a comprehensive health screening examination that included a mammogram between 2011 and 2013 (mean age 42.6 years). MetS was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III. IR was assessed with the homeostasis model assessment-insulin resistance (HOMA-IR). Adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for dense breast were estimated using logistic regression models after adjustment for potential confounders. In premenopausal women, MetS and all its components except waist circumference were associated with dense breast. After adjustment for potential confounders, the OR (95% CI) for dense breast in women with MetS compared with those without MetS was 1.22 (1.06-1.39). In postmenopausal women, however, there was positive but non-significant association between MetS and dense breast. In both pre- and postmenopausal women, high blood glucose and IR were positively associated with dense breast. The OR (95% CI) for dense breast between the highest and lowest quartiles of HOMA-IR was 1.29 (1.20-1.39) for premenopausal women and 1.44 (1.05-1.97) for postmenopausal women. In a large sample of Korean women, MetS and IR were associated with mammographic dense breast, demonstrating that IR, a potentially modifiable risk factor, may increase breast cancer risk, possibly through high mammographic density.

Relation of Dietary Glycemic Index and Glycemic Load to Coronary Artery Calcium in Asymptomatic Korean Adults.

The relation between glycemic index, glycemic load, and subclinical coronary atherosclerosis is unknown. The aim of the study was to evaluate the associations between energy-adjusted glycemic index, glycemic load, and coronary artery calcium (CAC). This study was cross-sectional analysis of 28,429 asymptomatic Korean men and women (mean age 41.4 years) without a history of diabetes or cardiovascular disease. All participants underwent a health screening examination between March 2011 and April 2013, and dietary intake over the preceding year was estimated using a validated food frequency questionnaire. Cardiac computed tomography was used for CAC scoring. The prevalence of detectable CAC (CAC score >0) was 12.4%. In multivariable-adjusted models, the CAC score ratios (95% confidence intervals) comparing the highest to the lowest quintile of glycemic index and glycemic load were 1.74 (1.08 to 2.81; p trend = 0.03) and 3.04 (1.43 to 6.46; p trend = 0.005), respectively. These associations did not differ by clinical subgroups, including the participants at low cardiovascular risk. In conclusion, these findings suggest that high dietary glycemic index and glycemic load were associated with a greater prevalence and degree of CAC, with glycemic load having a stronger association.