Min-Jung Kwon

Sleep duration and quality in relation to non-alcoholic fatty liver disease in middle-aged workers and their spouses

BACKGROUND & AIMSnAlthough accumulated evidence implies that short sleep duration and poor sleep quality may lead to an altered metabolic milieu, potentially triggering the development of non-alcoholic fatty liver disease (NAFLD), no studies have explored this association. This study sought to examine whether short sleep duration or poor sleep quality is associated with NAFLD in the general population.nnnMETHODSnWe assessed sleep duration and quality using the Pittsburgh Sleep Quality Index in 69,463 middle-aged workers and their spouses and carried out biochemical and anthropometric measurements. The presence of fatty liver was determined using ultrasonographic findings. Logistic regression models were used to evaluate the association of sleep duration and quality with NAFLD, after adjusting for potential confounders.nnnRESULTSnAfter controlling for the relevant confounding factors (age, alcohol intake, smoking, physical activity, systolic blood pressure, education level, marital status, presence of job, sleep apnea, and loud snoring), the adjusted odds ratio (95% confidence interval) for NAFLD comparing sleep duration ≤5 h to the reference (>7h) was 1.28 (1.13-1.44) in men and 1.71 (1.38-2.13) in women. After further adjustments for BMI, this association was not significant in men (OR: 1.03, 95% CI: 0.90-1.19) but remained significant in women (OR: 1.59, 95% CI: 1.23-2.05). The multivariate-adjusted odds ratio comparing participants with poor sleep quality vs. participants with good sleep quality was 1.10 (95% CI 1.02-1.19) and 1.36 (95% CI 1.17-1.59) in men and women, respectively.nnnCONCLUSIONSnIn the middle-aged, general population, short sleep duration, and poor sleep quality were significantly associated with an increased risk of NAFLD. Prospective studies are required to confirm this association.

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

BACKGROUND & AIMSnThe 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.nnnMETHODSnA 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.nnnRESULTSnOf 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).nnnCONCLUSIONSnProlonged 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.

A1C and Coronary Artery Calcification in Nondiabetic Men and Women

Objective—This study aimed to examine the association between glycohemoglobin (A1C) and coronary artery calcification (CAC) in nondiabetic men and women without overt cardiovascular disease or diabetes mellitus after accounting for fasting glucose and traditional cardiovascular disease risk factors. Approach and Results—A cross-sectional study was performed in 25u2009564 Korean adults (41.4±7.0 years) with no diabetes mellitus (fasting glucose, ≥7.0 mmol/L or a history of diabetes mellitus) and no clinically evident cardiovascular disease, who underwent a health checkup, including a cardiac computed tomography estimation of CAC scores and measurements of cardiovascular risk factors. The presence of CAC was defined as a CAC score >0; CAC was observed in 12.0% of men and 4.9% of women. Age-adjusted odds ratios (95% confidence interval) for CAC comparing A1C of 5.5% to 5.6%, 5.7% to 5.9%, and 6.0% to 6.4% with A1C <5.5% were 1.12 (0.99–1.28), 1.44 (1.27–1.63), and 1.63 (1.39–1.90) in men and 1.76 (0.96–3.25), 1.86 (1.05–3.29), and 3.09 (1.68–5.70) in women, respectively. After adjusting for potential confounders, the odds ratios (95% confidence interval) comparing A1C of 5.5% to 5.6%, 5.7% to 5.9%, and 6.0% to 6.4% with A1C of <5.5% were 1.04 (0.91–1.19), 1.21 (1.07–1.38), and 1.25 (1.05–1.48) in men and 1.75 (0.94–3.29), 1.59 (0.88–2.87), and 2.48 (1.29–4.74) in women, respectively. These associations persisted in subjects without any metabolic abnormalities, including fasting glucose ≥100 mg/dL. Conclusions—A higher A1C level was found to have a modest and independent association with the subclinical coronary atherosclerosis, even in metabolically healthy individuals.

Age at menarche and non-alcoholic fatty liver disease

BACKGROUND & AIMSnThe goal of this study was to examine the association between age at menarche and non-alcoholic fatty liver disease (NAFLD) in Korean women and to explore whether any observed associations were mediated by adult adiposity.nnnMETHODSnA cross-sectional study was performed for 95,183 Korean women, aged 30 or older, who underwent a regular health screening examination between March 2011 and April 2013. Information regarding age at menarche was collected using standardized, self-administered questionnaires. The presence of fatty liver was determined using ultrasonographic findings. Poisson regression models with robust variance were used to evaluate the association between age at menarche and NAFLD.nnnRESULTSnOf the 76,415 women evaluated in this study, 9601 had NAFLD. Age at menarche was inversely associated with the prevalence of NAFLD. In a multivariable-adjusted model, the prevalence ratios (95% CIs) for NAFLD comparing menarche at <12, 12, 14, 15, and 16-18 years to menarche at 13 years were 1.31 (1.18-1.45), 1.05 (0.97-1.13), 0.93 (0.87-0.99), 0.87 (0.82-0.93), and 0.78 (0.73-0.84), respectively (p for trend <0.001). Adjusting for adult BMI or percent fat mass (%) substantially reduced these associations; however, they remained statistically significant. The association between age at menarche and NAFLD was modified by age.nnnCONCLUSIONSnWe identified an inverse association between age at menarche and NAFLD in a large sample of middle-aged women. This association was partially mediated by adiposity. The findings of this study suggest that obesity prevention strategies are needed in women who undergo early menarche to reduce the risk of NAFLD.

Menopausal stages and non-alcoholic fatty liver disease in middle-aged women

OBJECTIVESnThere is no established evidence regarding the influence of the menopausal transition period on non-alcoholic fatty liver disease (NAFLD). The goal of this study was to examine the association between menopausal stages and the prevalence of NAFLD in middle-aged Korean women.nnnMETHODSnThis study was a cross-sectional analysis of 1559 women aged 44-56 years, who underwent a comprehensive health screening examination in the Kangbuk Samsung Hospital Total Healthcare Centers during 2012 and 2013. Information regarding menopause status was collected using a standardized, self-administered questionnaire. The presence of fatty liver was determined using ultrasonography. Menopausal stages were defined according to the criteria of the Stages of Reproductive Aging Workshop (STRAW+10) as follows: early menopausal transition was defined as a persistent difference in consecutive menstrual cycle length of seven or more days; late menopausal transition was defined as having an interval of amenorrhea of 60 days or more; post-menopause was defined as the absence of menstrual periods for 12 or more months since the last period; pre-menopause was defined as having a regular menstrual cycle and not meeting the above criteria. Odds ratios and 95% confidence intervals for NAFLD were estimated by menopausal stages.nnnRESULTSnOf the 1559 women, 334 had NAFLD. A higher prevalence of NAFLD was observed across menopausal stages (p for trend <0.05). After adjusting for age, center, BMI, smoking status, alcohol intake, physical activity, educational level, parity and age at menarche, the odds ratios (95% CIs) for NAFLD comparing early transition, late transition, and post-menopause to pre-menopause were 1.07 (0.68-1.67), 1.87 (1.23-2.85), and 1.67 (1.01-2.78), respectively.nnnCONCLUSIONSnThis study performed in middle-aged Korean women suggests that there is an increased prevalence of NAFLD in the late menopausal transition as well as post-menopausal stages, independent of a variety of potential confounders. The findings of this study suggest that early intervention strategies implemented before women begin to experience the menopausal transition are needed to reduce the risk of NAFLD.

Weight change as a predictor of incidence and remission of insulin resistance.

Objective The objective of this study was to assess the longitudinal relationship of weight change on incidence and remission of insulin resistance (IR). Methods We performed a cohort study in apparently healthy Korean men, 30 to 59 years of age, who underwent a health checkup and were followed annually or biennially between 2002 and 2009. The computer model of homeostasis model assessment, HOMA2-IR, was obtained at each visit, and IR was defined as HOMA2-IR ≥75th percentile. Results For IR development, 1,755 of the 6,612 IR-free participants at baseline developed IR (rate 5.1 per 100 person-years) during 34,294.8 person-years of follow-up. The hazard ratios (95% confidence intervals) for incident IR with weight changes of <−0.9 kg, 0.6–2.1 kg and ≥2.2 kg from visit 1 to visit 2 (average 1.8 years) compared to weight change of −0.9–0.5 kg (reference) were 0.78 (0.68–0.90), 1.19 (1.04–1.35) and 1.26 (1.11–1.44), respectively. This association persisted in normal-weight individuals or those without any metabolic syndrome traits and remained significant after introducing weight categories and confounders as time-dependent exposures (P-trend <0.001). For IR remission, 903 of 1,696 IR participants had no IR (remission rate 10.3 per 100 person-years) during 8,777.4 person-years of follow-up. IR remission decreased with increasing quartiles of weight change (P-trend <0.001) and this association persisted in normal-weight individuals. Conclusions Weight gain was associated with increased IR development and decreased IR remission regardless of baseline BMI status. Preventing weight gain, even in healthy and normal-weight individuals, is an important strategy for reducing IR and its associated consequences.

Menopausal stages and serum lipid and lipoprotein abnormalities in middle-aged women

OBJECTIVESnWhether menopausal stage is associated with abnormalities in serum lipid and lipoprotein profiles remains unclear; studies have been conducted mostly in Western populations. This study aimed to examine the prevalence of lipid and lipoprotein abnormalities by recently updated menopausal stages in middle-aged women.nnnSTUDY DESIGNnThis study was cross-sectional analysis of 1553 women aged 44-56 years, who underwent a comprehensive health screening examination in the Kangbuk Samsung Hospital Total Healthcare Centers, Korea, during 2012-2013. Lipid and lipoprotein profiles including total cholesterol (TC), triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), lipoprotein (a) (Lp(a)), apolipoprotein A1 (Apo A1), apolipoprotein B (Apo B) were assessed. Prevalence ratios and 95% confidence intervals for lipid and lipoprotein abnormalities were estimated by menopausal stages as defined by the 2011 Stages of Reproductive Aging Workshop+10 criteria.nnnRESULTSnIncreased prevalence of lipid and lipoprotein abnormalities were observed across menopausal stages. The increased prevalence of high non-HDL-C was associated with the late menopausal transition and post-menopausal stages and was more pronounced in women with body mass index (BMI) <23 kg/m(2) than in those with BMI ≥23 kg/m(2) (P for interaction=0.006). Similarly, there was an interaction between BMI and menopausal stages in relation to high Apo B (P for interaction=0.05) and high Apo B/Apo A1 ratio (P for interaction=0.06).nnnCONCLUSIONSnOur findings extend previous results and suggest that the increased prevalence of lipid and lipoprotein abnormalities was associated not only with the post-menopausal stage but also late menopausal transition period.

γ-Glutamyl Transferase Is Associated with Mortality Outcomes Independently of Fatty Liver

BACKGROUNDnHigh serum enzyme activity levels of γ-glutamyl transferase (GGT) are associated with increased risk of mortality, but whether this is mediated by fatty liver, as a common cause of high GGT levels, is uncertain. Our aim was to test whether GGT levels are associated with all-cause, cancer, and cardiovascular (CVD) mortality, independently of fatty liver.nnnMETHODSnIn an occupational cohort (n = 278 419), causes of death (International Statistical Classification of Diseases and Related Health Problems, 10th revision) were recorded over 7 years. Liver function tests and liver fat [measured by ultrasonographic standard criteria or fatty liver index (FLI)] were assessed at baseline. We used Cox proportional hazards models to estimate adjusted hazard ratios (HRs) and 95% CIs of all-cause, cancer, and CVD mortality for GGT quartiles (with lowest GGT quartile as reference).nnnRESULTSnThere were 136, 167, 265, and 342 deaths across increasing GGT quartiles. After adjusting for liver fat (by ultrasound diagnosis) in the fully adjusted model, all-cause and cancer mortality were increased in the highest GGT quartile [HR 1.50 (95% CI 1.15-1.96) and 1.57 (1.05-2.35), respectively]. For CVD mortality, the hazard was attenuated: HR 1.35 (95% CI 0.72-2.56). After adjusting for FLI in the fully adjusted model, HRs for all-cause, cancer, and CVD mortality were 1.46 (0.72-2.56), 2.03 (1.02-4.03), and 1.16 (0.41,3.24), respectively.nnnCONCLUSIONSnThere were similar hazards for all-cause and cancer mortality and attenuated hazards for CVD mortality for people in the highest GGT quartile, adjusting for fatty liver assessed by either ultrasound or FLI.

Intraocular pressure and coronary artery calcification in asymptomatic men and women

Objective We evaluated the relationship between intraocular pressure (IOP) and the risk of coronary artery calcification as a predictable marker of cardiovascular disease (CVD) in a large study of asymptomatic men and women. Methods A cross-sectional study was performed in 10 732 asymptomatic men and women without diagnosed CVD or glaucoma. Coronary artery calcium (CAC) was measured by cardiac CT. The IOPs of all participants were measured by experienced nurses with a non-contact tonometer and automatic air puff control. Logistic regression was used to estimate the OR (95% CI) for the presence of CAC (score >0) with IOP quartiles. Results The prevalence of detectable CAC was 13.7% in men and 4.3% in women. Increasing levels of right IOP were significantly associated with an increased prevalence of CAC. After adjusting for age, sex, smoking, alcohol intake, physical activity, body mass index, educational level, centre, family history of CVD, use of dyslipidaemia medication, diabetes, hypertension, total cholesterol, high density lipoprotein cholesterol and triglycerides, the ORs for CAC score >0, comparing 2–4 quartiles of the right IOP to the lowest quartiles, were 1.32 (95% CI 1.09 to 1.59), 1.20 (95% CI 0.98 to 1.46), and 1.28 (95% CI 1.05 to 1.56), respectively. These associations did not differ by clinically relevant subgroups. Conclusions A higher IOP is significantly associated with the presence of CAC regardless of conventional cardiovascular risk factors. The present study provides more insight into understanding the process of subclinical atherosclerosis in CVD and the relationship with a higher IOP as a common pathophysiology.

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

AbstractnLittle 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 42.6xa0years). 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 95xa0% 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 (95xa0% 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 (95xa0% 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.