Association between body fat and bone mineral density in Korean adults: a cohort study.

Although obesity was once considered protective against osteoporosis, various factors influence the relationship between fat and bone mineral density (BMD). To establish the importance of healthy body composition in decelerating declines in BMD, we conducted a study to compare the association between body fat composition and BMD in Korean adults. Using data collected from the Kangbuk Samsung Health Study from 2012 to 2019, this cohort study compared the incidence of decreased BMD among the following four groups: normal BMI and normal adiposity (NBMI-NA), normal BMI and high adiposity (NBMI-HA), overweight, and obesity. Decreased BMD was defined as a Z-score ≤ - 2.0 in premenopausal women and men < 50 years of age or a T-score < - 1.0 in postmenopausal women and men ≥ 50 years of age. Individuals who were diagnosed with osteoporosis or compression fracture after their second visit were categorized as having decreased BMD. The incidence rate of decreased BMD in the NBMI-NA group was 3.37, and that in the NBMI-HA group was 4.81, which was the highest among all groups. After adjusting for confounding factors, NBMI-HA led to a significantly greater risk of decreased BMD compared to NBMI-NA (HR 1.47; 95% CI 1.09-1.99). Even with a normal BMI, a high BFP was associated with an increased risk of decreased BMD. Therefore, healthy body composition management, not simply BMI, is important in preventing decreased BMD.

The association between cotinine-measured smoking intensity and sleep quality.

INTRODUCTION: Cigarette smoking is suggested to be associated with sleep problems. This study evaluated the quantitative association between urinary cotinine-verified smoking intensity and sleep quality assessed by the Pittsburgh Sleep Quality Index (PSQI). METHODS: This was a cross-sectional study of 189970 participants from the Kangbuk Samsung Health Study recruited between 2016 and 2018. Logistic regression analysis adjusted for covariates was performed to estimate the association between urinary cotinine levels assessed by quartiles and poor sleep quality, defined as global PSQI score >5. RESULTS: The odds ratios (OR) and 95% confidence intervals (CI) for poor sleep quality comparing the highest urinary cotinine quartile to non-smokers were: 1.23 (95% CI: 1.16-1.30) for overall, 1.19 (95% CI: 1.12-1.26) for males, and 1.55 (95% CI: 1.29-1.87) for females. Among self-reported never smokers, cotinineverified smokers had higher odds for decreased sleep quality compared to cotinineverified never smokers with OR of 1.26 (95% CI: 1.08-1.46). CONCLUSIONS: Elevated urinary cotinine levels were associated with poor sleep quality in relatively young and middle-aged South Korean adults. Higher odds for poor sleep quality among cotinine-verified smokers who self-reported as never smokers also demonstrate the value of quantitative measurement of urinary cotinine. Prospective studies are warranted to clarify the cause-effect relationship between smoking and sleep quality.

Fasting ketonuria is inversely associated with coronary artery calcification in non-diabetic individuals.

BACKGROUND AND AIMS: Increased levels of ketone bodies, an alternative fuel when glucose availability is low, may exert beneficial effects on cardiovascular disease (CVD) risk factors. Whether increased ketone bodies are associated with coronary artery calcium (CAC), a recognized and strong cardiovascular risk factor, remains unknown. We investigated the association of fasting ketonuria with CAC and its progression. METHODS: Cross-sectional and longitudinal studies were conducted in adults without diabetes or CVD. Subjects underwent routine health examinations including cardiac computed tomography estimations of CAC scores. Logistic regression models were performed to compute the odds ratios (ORs), 95% confidence intervals (CIs), for prevalent CAC scores >0 according to fasting ketonuria categories (0, 1, and ≥2). Linear mixed models with random intercepts and random slopes were used to estimate CAC progression. RESULTS: Of 144,346 subjects, 12.3% had CAC scores >0 at baseline. Overall, higher fasting ketonuria was associated with decreased prevalence of coronary calcification than no ketonuria. Multivariable-adjusted ORs (95% CIs) for prevalent CAC by comparing ketonuria categories 1 and ≥2 with no ketonuria, were 0.94 (0.84-1.06) and 0.82 (0.71-0.95), respectively. The associations did not differ according to clinically relevant subgroups. Ketonuria was associated with lower CAC progression over time; the multivariable adjusted ratio of progression rates comparing ketonuria ≥2 versus no ketonuria was 0.976 (0.965-0.995). CONCLUSIONS: We found an inverse association between fasting ketonuria and subclinical coronary atherosclerosis, in both prevalence and progression. The potentially protective role of increased ketone body formation in CVD requires further investigation.

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.

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.

Association Between Frailty-Related Factors and Depression among Older Adults.

OBJECTIVES: We analyzed the association between individual frailty-related factors and depression in older adults. METHODS: A total of 796 older adults who underwent geriatric assessments were included in this cross-sectional study. The frailty-related factors studied were grip strength, physical activity, walking speed, weight loss, and recurrent falls. Depression was based on the Geriatric Depression Scale. RESULTS: After adjustment for covariates, recurrent falls were associated with depression in males (OR 3.84, 95% CI 1.30-11.35). Among females, weakest grip strength, slow walking speed, and weight loss were associated with depression (OR 2.61, 95% CI 1.52-4.49; OR 1.78, 95% CI 1.02-3.11; and OR 2.52, 95% CI 1.17-5.44, respectively). Having more frailty-related factors was also associated with higher odds of depression. CONCLUSIONS: The associations between individual frailty-related factors and depression differed among males and females. Further prospective studies on depression and individual frailty-related factors by sex may help elucidate specific targets to be prioritized for clinical assessment and intervention. CLINICAL IMPLICATIONS: Older adults affected by depression and frailty may present different clinical manifestations based on sex, and require different treatment approaches. Clinicians should assess both physical and psychological needs for integrated care in frail older adults.

Depression and increased risk of non-alcoholic fatty liver disease in individuals with obesity.

Abstract. AIMS: The longitudinal relationship between depression and the risk of non-alcoholic fatty liver disease is uncertain. We examined: (a) the association between depressive symptoms and incident hepatic steatosis (HS), both with and without liver fibrosis; and (b) the influence of obesity on this association. METHODS: A cohort of 142 005 Korean adults with neither HS nor excessive alcohol consumption at baseline were followed for up to 8.9 years. The validated Center for Epidemiologic Studies-Depression score (CES-D) was assessed at baseline, and subjects were categorised as non-depressed (a CES-D < 8, reference) or depression (CES-D ⩾ 16). HS was diagnosed by ultrasonography. Liver fibrosis was assessed by the fibrosis-4 index (FIB-4). Parametric proportional hazards models were used to estimate the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). RESULTS: During a median follow-up of 4.0 years, 27 810 people with incident HS and 134 with incident HS plus high FIB-4 were identified. Compared with the non-depressed category, the aHR (95% CIs) for incident HS was 1.24 (1.15-1.34) for CES-D ⩾ 16 among obese individuals, and 1.00 (0.95-1.05) for CES-D ⩾ 16 among non-obese individuals (p for interaction with obesity <0.001). The aHR (95% CIs) for developing HS plus high FIB-4 was 3.41 (1.33-8.74) for CES-D ⩾ 16 among obese individuals, and 1.22 (0.60-2.47) for CES-D ⩾ 16 among non-obese individuals (p for interaction = 0.201). CONCLUSIONS: Depression was associated with an increased risk of incident HS and HS plus high probability of advanced fibrosis, especially among obese individuals.

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.

'You gotta have something to chew on': perceptions of stress-induced eating and weight gain among office workers in South Korea.

OBJECTIVE: Job-related chronic stress has been discussed as a risk factor for weight change and metabolic disorders. The current study was conducted to understand the situations in which stress-induced eating occurs among office workers and how workers perceive stress to influence their daily eating practices and weight change. DESIGN: In-depth, one-on-one interviews were conducted with office workers. SETTING: Metropolitan areas in South Korea. PARTICIPANTS: Twenty-two office workers from thirteen companies participated in the study. RESULTS: Most participants mentioned that they often felt work-related stress and reported various levels of perceived stress, as measured with open-ended questions. The main sources of work stress were (i) the nature of job characteristics, (ii) performance evaluations and (iii) relationships within the organisation. Participants linked stress with increased food consumption and cravings for sweet, savoury and greasy foods. Many participants emphasised the links between multiple health behaviours and stress. Not only dietary choices but also alcohol consumption, sleeping difficulty and insufficient physical activity were related to coping with work stress and demands. Finally, most participants who perceived work stress believed that their weight gain in adulthood was triggered by work stress. CONCLUSIONS: It is necessary to consider promoting behavioural modifications to support weight management and providing a means for stress management and the minimisation of stress-inducing working environments for workers to maintain or achieve a healthy weight and to prevent chronic disease incidence.

Depressive symptoms and risk of liver-related mortality in individuals with hepatitis B virus infection: a cohort study.

The impact of depression on the risk of liver-related mortality in individuals with hepatitis B virus (HBV) infection remains unclear. We examined the association between depression, HBV infection, and liver-related mortality. A total of 342,998 Korean adults who underwent health examinations were followed for up to 7.8 years. Depressive symptoms were defined as a Center for Epidemiologic Studies-Depression score ≥ 16. Cox proportional hazard models were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). During 1,836,508 person-years of follow-up, 74 liver-related deaths and 54 liver cancer deaths were identified (liver-related mortality rate of 4.0 per 105 person-years and liver cancer mortality rate of 2.9 per 105 person-years). Subjects with depressive symptoms had an increased risk of liver-related mortality with a corresponding multivariable aHR of 2.00 (95% CI 1.10-3.63) compared to those without depressive symptoms. This association was more evident in HBsAg-positive participants with a corresponding multivariable aHR of 4.22 (95% CI 1.81-9.88) than HBsAg-negative participants (P for interaction by HBsAg positivity = 0.036). A similar pattern was observed in relation to liver cancer mortality. In this large cohort, depressive symptoms were associated with an increased risk of liver-related mortality, with a stronger association in HBsAg-positive individuals.

Glycemic Status, Insulin Resistance, and the Risk of Nephrolithiasis: A Cohort Study.

RATIONALE & OBJECTIVE: The effect of glycemic status on nephrolithiasis risk remains controversial. This study sought to examine the association of glycemic status and insulin resistance with incident nephrolithiasis. STUDY DESIGN: A retrospective cohort study. SETTING & PARTICIPANTS: 278,628 Korean adults without nephrolithiasis who underwent a comprehensive health examination between 2011 and 2017. EXPOSURES: Glucose level, glycated hemoglobin level, and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR). OUTCOME: Nephrolithiasis ascertained using abdominal ultrasound. ANALYTICAL APPROACH: A parametric proportional hazard model was used to estimate adjusted HRs and 95% CIs. We explored prespecified potential sex differences in the association of glycemic status and incident nephrolithiasis. RESULTS: During a median follow-up of 4.2 years, 6,904 participants developed nephrolithiasis. Associations between levels of glycemic status and incident nephrolithiasis were examined separately in men and women (P for interaction = 0.003). Among men, multivariable-adjusted HRs for incident nephrolithiasis comparing glucose levels of 90-99, 100-125, and ≥ 126 mg/dL were 1.10 (95% CI, 1.01-1.19), 1.11 (95% CI, 1.02-1.21), and 1.27 (95% CI, 1.10-1.46), respectively, while HRs for incident nephrolithiasis comparing glycated hemoglobin levels of 5.7%-5.9%, 6.0%-6.4%, and 6.5%-<5.7% were 1.03 (95% CI, 0.96-1.10), 1.18 (95% CI, 1.07-1.31), and 1.20 (95% CI, 1.06-1.37), respectively. The HR for incident nephrolithiasis comparing the highest HOMA-IR quintile to the lowest quintile was 1.18 (95% CI, 1.06-1.31). Among women, no apparent association was found between glycemic status and nephrolithiasis risk. LIMITATIONS: Glucose tolerance testing and computed tomography assessment for nephrolithiasis were not available. CONCLUSIONS: Higher glycemic values, even within the normoglycemic range, and HOMA-IR were positively associated with increased risk for nephrolithiasis, associations that were only observed among men. Insulin resistance and hyperglycemia may contribute to the development of nephrolithiasis, particularly among men.

Efficacy and Safety of Sinetrol-XPur on Weight and Body Fat Reduction in Overweight or Obese Adults: A 12-Week, Randomized, Double-Blind, Parallel, Placebo-Controlled Trial.

This study investigated the effect of Sinetrol-XPur on weight and body fat reduction in overweight or obese Korean participants. Among 100 overweight or obese participants enrolled in a 12-week randomized, double-blinded, controlled study, 86 participants completed the trial. Participants took either two Sinetrol-XPur tablets (450 mg per tablet) or two placebo tablets once a day. Bodyweight, body fat percentage, body mass index (BMI), body fat mass, waist circumference, and various safety parameters were measured. After the 12-week intervention, a significant reduction was observed in the body fat mass (P = .030) by dual-energy X-ray absorptiometry (DEXA), body weight (P = .002), and BMI (P = .002) compared to the placebo. Body fat percentage (P = .007) by DEXA showed a significant reduction in the Sinetrol-XPur group, but no difference compared to the control group. Abdominal metabolic risks by computed tomography and blood biochemistry analysis were significantly decreased in the Sinetrol-XPur group, but there were no differences between the Sinetrol-XPur and placebo groups. Safety profiles were not different between the two groups. These results suggested that Sinetrol-XPur significantly reduced body weight, body fat mass, and BMI in obese Korean subjects, which confirms the antiobesity effect of Sinetrol-XPur in the Korean population.

Association of change in alcohol consumption on fasting serum glucose, insulin resistance, and beta cell function among Korean men.

We aimed to determine the association between alcohol consumption change on fasting serum glucose, insulin resistance, and beta cell function. The study population consisted of 55,858 men from the Kangbuk Samsung Health Study. Participants were divided into non-, light, moderate, and heavy drinkers for each of the first and second health examinations based on a self-reported questionnaire on alcohol consumption. The adjusted mean values for change in fasting serum glucose (FSG), homeostatic model assessment of insulin resistance (HOMA-IR), and beta cell function (HOMA-ß) levels were determined according to alcohol consumption change by linear regression. Compared to sustained initial drinkers, those who increased alcohol intake to moderate (p < 0.001) and heavy (p < 0.001) levels had increased FSG levels. In contrast, reduction in alcohol intake to light levels among initial heavy drinkers was associated with reduced change in FSG levels (p = 0.007) compared to sustained heavy drinkers. No significant associations were observed between changes in alcohol intake with HOMA-IR levels. Compared to sustained light drinkers, those who increased alcohol intake to moderate (p < 0.001) and heavy (p = 0.009) levels had lower increases in HOMA-ß levels. Finally, compared to sustained heavy drinkers, those who reduced alcohol consumption to light levels had greater increases in HOMA-ß levels (p = 0.002). Increases in alcohol consumption were associated with higher blood glucose levels and worsened beta cell function. Heavy drinkers who reduce alcohol intake could benefit from improved blood glucose control via improved beta cell function.

Perceived stress and non-alcoholic fatty liver disease in apparently healthy men and women.

Psychological stress may have adverse metabolic effects and induce unhealthy behaviors, but the role of stress in the development of non-alcoholic fatty liver disease (NAFLD) is largely unexplored. We investigated the association between perceived stress and the prevalence of NAFLD in a large sample of apparently healthy men and women. We performed a cross-sectional study of 171,321 adults who underwent health screening examination between 2011 and 2013 in one health screening center. Perceived stress was assessed using the short version of the Perceived Stress Inventory (PSI). NAFLD was assessed using ultrasonography in the absence of excessive alcohol use or any other identifiable cause of liver disease. The prevalence of NAFLD was 27.8%. In fully-adjusted multivariable models, the odds ratio (95% confidence intervals) for NAFLD comparing participants in the 5th quintile of PSI score (≥23) with those in the lowest quintile (<12) was 1.17 (1.11, 1.22), with a moderately increased prevalence of NALFD across quintiles of PSI score. The positive association between PSI score and NAFLD was observed in all subgroups analyzed, although the association was stronger in men compared to women (p interaction <0.001), and in obese compared to non-obese (p interaction 0.005). In this large study of apparently healthy men and women, higher perceived stress was independently associated with an increased prevalence of NAFLD, supporting a possible relationship between perceived stress and NAFLD. Prospective study is needed to elucidate mediating mechanisms to warrant stress management to reduce NAFLD.

Low Levels of Alcohol Consumption, Obesity, and Development of Fatty Liver With and Without Evidence of Advanced Fibrosis.

BACKGROUND AND AIMS: The effects of low-level alcohol consumption on fatty liver disease and the potential for effect modification by obesity is uncertain. We investigated associations among low-level alcohol consumption, obesity status, and the development of incident hepatic steatosis (HS), either with or without an increase in noninvasive liver fibrosis score category (from low to intermediate or high category). APPROACH AND RESULTS: A total of 190,048 adults without HS and a low probability of fibrosis with alcohol consumption less than 30 g/day (men) and less than 20 g/day (women) were followed for up to 15.7 years. Alcohol categories of no, light, and moderate consumption were defined as 0, 1-9.9, and 10-29.9 g/day (10-19.9 g/day for women), respectively. HS was diagnosed by ultrasonography, and the probability of fibrosis was estimated using the fibrosis-4 index (FIB-4). Parametric proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). A total of 43,466 participants developed HS, 2,983 of whom developed HS with an increase in FIB-4 index (to intermediate or high scores). Comparing light drinkers and moderate drinkers with nondrinkers, multivariable-adjusted HRs (95% CI) for incident HS were 0.93 (0.90-0.95) and 0.90 (0.87-0.92), respectively. In contrast, comparing light drinkers and moderate drinkers with nondrinkers, multivariable-adjusted HRs (95% CI) for developing HS plus intermediate/high FIB-4 were 1.15 (1.04-1.27) and 1.49 (1.33-1.66), respectively. The association between alcohol consumption categories and incident HS plus intermediate/high FIB-4 was observed in both nonobese and obese individuals, although the association was stronger in nonobese individuals (P for interaction by obesity = 0.017). CONCLUSIONS: Light/moderate alcohol consumption has differential effects on the development of different stages of fatty liver disease, which is modified by the presence of obesity.

Smoking and the Risk of Non-Alcoholic Fatty Liver Disease: A Cohort Study.

OBJECTIVES: The role of smoking in the development of non-alcoholic fatty liver disease (NAFLD) remains controversial. We assessed the risk of incident NAFLD according to smoking status and urinary cotinine levels. METHODS: We performed a cohort study of 199,468 Korean adults without NAFLD at baseline who were followed annually or biennially for a median of 4.1 years. The presence of fatty liver was determined using ultrasound. NAFLD severity was assessed using NAFLD fibrosis score (NFS), a non-invasive fibrosis marker. RESULTS: During 1,070,991 person-years of follow-up, 45,409 participants developed NAFLD. Self-reported current smoking, pack-years, and urinary cotinine level were significantly associated with increased risk for NAFLD. For men, the multivariable-adjusted hazard ratios (aHR) (95% confidence intervals (CI)) for incident NAFLD comparing 10-19.9, and ≥20 pack-years to 0 pack-years were 1.25 (1.21- 1.29), and 1.36 (1.30-1.42), respectively; for women, aHR (95% CI) for NAFLD comparing 5-9.9, and ≥10 pack-years to 0 pack-years were 1.25 (1.04-1.50), and 1.46 (1.17-1.81), respectively. Smoking pack-years were also associated with increased risk for NAFLD plus intermediate or high fibrosis score. For men, the aHR (95% CI) for NAFLD plus intermediate or high NFS comparing ≥20 pack-years to 0 pack-years was 1.29 (1.18-1.42); for women, the aHR (95% CI) comparing ≥10 pack-years to 0 pack-years was 1.75 (1.12-2.73). CONCLUSIONS: In a large cohort of young and middle-aged men and women, current smoking, pack-years, and urinary cotinine levels were positively associated with the risk of incident NAFLD, suggesting that smoking contributes to the development of NAFLD.

Alcoholic and non-alcoholic fatty liver disease and associations with coronary artery calcification: evidence from the Kangbuk Samsung Health Study.

OBJECTIVE: Recent evidence suggests that alcoholic fatty liver disease (AFLD) and non-alcoholic fatty liver disease (NAFLD) may differentially affect risk of cardiovascular mortality. To investigate whether early liver disease due to AFLD or NAFLD have similar or dissimilar effects on risk of early coronary artery atherosclerosis, we have investigated the associations between AFLD and NAFLD and coronary artery calcium (CAC). DESIGN: A cross-sectional study was performed in 105 328 Korean adults who attended a health check-up programme. CAC score was assessed using CT, daily alcohol intake was recorded as grams/day and liver fat by ultrasound. Logistic regression model was used to calculate ORs with 95% CIs for prevalent CAC. RESULTS: Both NAFLD and AFLD were positively associated with CAC score. After adjusting for potential confounders, multivariable-adjusted OR (95% CIs) for CAC >0 comparing NAFLD and AFLD to the reference (absence of both excessive alcohol use and fatty liver disease) were 1.10 (95% CI 1.05 to 1.16) and 1.20 (95% CI 1.11 to 1.30), respectively. In post hoc analysis, OR (95% CI) for detectable CAC comparing AFLD to NAFLD was 1.09 (95% CI 1.01 to 1.17). Associations of NAFLD and AFLD with CAC scores were similar in both non-obese and obese individuals without significant interaction by obesity (p for interaction=0.088). After adjusting for homeostasis model assessment of insulin resistance and high-sensitivity C reactive protein, the associations between fatty liver disease and CAC scores remained statistically significant. CONCLUSION: In this large sample of young and middle-aged individuals, early liver disease due to NAFLD and AFLD were both significantly associated with the presence of coronary artery calcification.

Nonheavy Drinking and Worsening of Noninvasive Fibrosis Markers in Nonalcoholic Fatty Liver Disease: A Cohort Study.

The effect of modest alcohol consumption on fibrosis progression in the general population with nonalcoholic fatty liver disease (NAFLD) remains unclear. We examined the association of nonheavy alcohol consumption with worsening of noninvasive fibrosis indices in a large-scale, low-risk population with NAFLD. A cohort study was performed in 58,927 Korean adults with NAFLD and low fibrosis scores who were followed for a median of 4.9 years. Non-, light, and moderate drinkers were defined as 0 g/day, 1-9.9 g/day, and 10-29.9 g/day (10-19.9 g/day for women), respectively. Progression from low to intermediate or high probability of advanced fibrosis was assessed using noninvasive indices including NAFLD fibrosis score (NFS) and Fibrosis-4 Index (FIB-4). A parametric proportional hazards model was used to estimate the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). During 347,925.4 person-years of follow-up, 5,630 subjects with low FIB-4 progressed to intermediate or high FIB-4. The multivariable-adjusted HRs (95% CI) for worsening of FIB-4 comparing light and moderate drinkers with nondrinkers were 1.06 (0.98-1.16) and 1.29 (1.18-1.40), respectively. Similarly, using NFS, corresponding HRs (95% CI) comparing light and moderate drinkers with nondrinkers were 1.09 (1.02-1.16) and 1.31 (1.23-1.40), respectively. Furthermore, the association of moderate drinkers with worsening of either FIB-4 or NFS remained significant after introducing alcohol use and confounders treated as time-varying covariates. Conclusion: In this large-scale cohort of young and middle-aged individuals with NAFLD, nonheavy alcohol consumption, especially moderate alcohol consumption, was significantly and independently associated with worsening of noninvasive markers of fibrosis, indicating that even moderate alcohol consumption might be harmful.

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.