Age at menarche and non-alcoholic fatty liver disease

Shift work and non-alcoholic fatty liver disease in young, healthy workers

Non-alcoholic fatty liver disease (NAFLD) is a relatively common disease, and preventing its occurrence is important for both individual health and reducing social costs. Shift work is reported to have several negative effects on health. An association has been observed between NAFLD and both sleep time and quality; however, this association remains unclear in night shift workers. We aimed to evaluate the relationship between shift work and the incidence of NAFLD. Overall, 45,149 Korean workers without NAFLD were included at baseline. NAFLD was defined as the presence of a fatty liver observed on ultrasonography without excessive alcohol use. incidence rate ratios for incident NAFLD were estimated using negative binomial regression according to age groups (20s, 30s, 40s, and 50s). In the 20s age group, shift work showed a significant incidence rate ratio (IRR) for NAFLD in all models. After adjusting for all variables, the IRR (95% confidence interval) was 1.24 (1.08-1.43) in the 20s age group. In their 20s, a significant association between shift work and incident NAFLD was consistently observed among women and workers with poor sleep quality. In this large-scale cohort study, shift work was significantly associated with the development of NAFLD among young workers in their 20s.

Impact of nonalcoholic fatty liver disease on the risk of gallbladder polyps in lean and non-obese individuals: A cohort study

BACKGROUND

The association between non-obese or lean nonalcoholic fatty liver disease (NAFLD) and gallbladder polyps (GBPs) has not yet been evaluated. We aimed to determine whether NAFLD is an independent risk factor for the development of GBPs, even in non-obese and lean individuals.

METHODS

We analyzed a cohort of 331 208 asymptomatic adults who underwent abdominal ultrasonography (US). The risk of GBP development was evaluated according to the obesity and NAFLD status.

RESULTS

The overall prevalence of NAFLD and GBPs ≥ 5 mm was 28.5% and 2.9%, respectively. The prevalence of NAFLD among 160 276 lean, 77 676 overweight and 93 256 obese participants was 8.2%, 31.2%, and 61.1%, respectively. Individuals with NAFLD had a significantly higher incidence of GBPs with a size of ≥ 5 mm [adjusted odds ratio (OR) = 1.18; 95% confidence interval (CI): 1.11-1.25]. A higher body mass index and its categories were also significantly associated with an increased risk of GBPs ≥ 5 mm. Moreover, risk of GBPs ≥ 5 mm was significantly increased even in NAFLD individuals who are not obese (lean: adjusted OR = 1.36, 95% CI: 1.19-1.54; overweight: adjusted OR = 1.14, 95% CI: 1.03-1.26, respectively).

CONCLUSIONS

Non-obese/lean NAFLD is an independent risk factor for GBP development, suggesting that NAFLD may play an important role in the pathogenesis of GBPs regardless of the obesity status. Therefore, a more thorough evaluation for GBPs may be necessary when hepatic steatosis is detected on abdominal US, even in non-obese or lean individuals.

17β-Estradiol (E2) Upregulates the ERα/SIRT1/PGC-1α Signaling Pathway and Protects Mitochondrial Function to Prevent Bilateral Oophorectomy (OVX)-Induced Nonalcoholic Fatty Liver Disease (NAFLD)

Premature menopause is associated with an increased prevalence of nonalcoholic fatty liver disease (NAFLD). Menopausal hormone therapy (MHT) has been widely used in clinical practice and has the potential to protect mitochondrial function and alleviate NAFLD. After bilateral oophorectomy (OVX), female rats without 17β-estradiol (E2) intervention developed NAFLD, whereas E2 supplementation was effective in preventing NAFLD in female rats. The altered pathways and cellular events from both comparison pairs, namely, the OVX vs. sham group and the OVX vs. E2 group, were assessed using transcriptomic analysis. KEGG pathways enriched by both transcriptomic and metabolomic analyses strongly suggest that oxidative phosphorylation is a vital pathway that changes during the development of NAFLD and remains unchanged when E2 is applied. Liver tissue from the OVX-induced NAFLD group exhibited increased lipid peroxidation, impaired mitochondria, and downregulated ERα/SIRT1/PGC-1α expression. An in vitro study indicated that the protective effect of E2 treatment on hepatic steatosis could be abolished when ERα or SIRT1 was selectively inhibited. This damage was accompanied by reduced mitochondrial complex activity and increased lipid peroxidation. The current research indicates that E2 upregulates the ERα/SIRT1/PGC-1α signaling pathway and protects mitochondrial function to prevent OVX-induced NAFLD.

Age at menarche and metabolic dysfunction-associated fatty liver disease: Evidence from a large population-based epidemiological study in Southwest China

BACKGROUND

The relationship between age at menarche and metabolic dysfunction-associated fatty liver disease remains largely not clear. The objective of this study was to examine the association between age at menarche (AAM) and metabolic dysfunction-associated fatty liver disease (MAFLD) in Chinese women and whether any observed associations were mediated by early adulthood adiposity.

METHODS

The cross-sectional study included 46,873 Chinese women, aged 30-79 from baseline data of the China Multi-Ethnic Cohort study. Logistic regression models were used to evaluate the association between AAM and MAFLD. Mediation analysis was adopted to examine whether early adulthood adiposity (around 25 years) mediated the association between AAM and MAFLD.

RESULTS

AAM was linearly and inversely associated with the risk of MAFLD (P for nonlinearity =0.743). In a multivariable-adjusted model, the odds ratios and 95% confidence interval (ORs (95% CI)) for MAFLD comparing menarche at <12, 12, 13, 15, 16, 17, ≥18 years to menarche at 14 years were 1.290 (1.082-1.537), 1.172 (1.068-1.285), 1.042 (0.960-1.131), 0.937 (0.861-1.020), 0.911(0.835-0.994), 0.868 (0.786-0.959), and 0.738 (0.670-0.814), respectively (P for trend <0.001). The 6.4% increased MAFLD risk was associated with each preceding year in AAM. The association between AAM and MAFLD was modified by age, ethnicity, and menopause. Early adulthood adiposity partially mediated this association.

CONCLUSION

The findings of this study suggest that obesity prevention strategies are needed from young adulthood in women who undergo early menarche to reduce the risk of MAFLD.

Prediabetes diagnosis is associated with the progression of coronary artery calcification: The Kangbuk Samsung Health Study

AIM

To investigate the associations between prediabetes defined by different diagnostic criteria and coronary artery calcification (CAC) and its progression over time.

MATERIALS AND METHODS

This cross-sectional study included 146 436 Korean adults without diabetes who underwent CAC estimation computed tomography (CT) during health examinations from 2011 to 2019. We used multinomial logistic regression models. The longitudinal study comprised 41 100 participants with at least one follow-up cardiac CT and annual CAC progression rates and ratios were estimated. Prediabetes was categorized into three groups: isolated glucose prediabetes (fasting blood glucose [FBG] 100-125 mg/dl, HbA1c < 5.7%), isolated HbA1c prediabetes (FBG < 100 mg/dl, HbA1c 5.7%-6.4%) and prediabetes meeting both FBG and HbA1c criteria (FBG 100-125 mg/dl, HbA1c 5.7%-6.4%).

RESULTS

After adjusting for covariates, the prevalence ratios (95% CI) for CAC scores of more than 100 comparing isolated glucose prediabetes, isolated HbA1c prediabetes and prediabetes fulfilling both criteria with those of normoglycaemia were 1.12 (0.99-1.26), 1.24 (1.11-1.39) and 1.31 (1.18-1.45), respectively. The multivariable-adjusted ratio (CIs) of annual CAC progression rates comparing the corresponding groups with the normoglycaemia group were 1.031 (1.023-1.039), 1.025 (1.019-1.032) and 1.054 (1.047-1.062), respectively.

CONCLUSIONS

CAC risk and CAC progression were consistently highest in individuals meeting both glucose and HbA1c criteria, while all three prediabetes types showed a significantly increased risk of CAC progression. Atherosclerosis risk reduction management is necessary for prediabetes, especially in patients meeting both criteria.

Non-alcoholic fatty liver disease through the female lifespan: the role of sex hormones

The prevalence of non-alcoholic fatty liver disease (NAFLD) differs between various stages of the female lifespan. The aim of this review is to summarize current evidence on the association of NAFLD and circulating sex hormones and to explore the pathogenesis of NAFLD within the context of (1) sex hormone changes during the reproductive, post-reproductive female life and beyond and (2) the in vitro and in vivo evidence on pharmacological modulation in women on menopausal hormone treatment (MHT) or endocrine therapy after breast cancer. The fluctuation in estrogen concentrations, the relative androgen excess, and the age-related reduction in sex hormone-binding globulin are related to increased NAFLD risk. Moreover, the peri-menopausal changes in body composition and insulin resistance might contribute to the increased NAFLD risk. Whether MHT prevents or improves NAFLD in this population remains an open question. Studies in women with breast cancer treated with tamoxifen or non-steroidal aromatase inhibitors point to their adverse effects on NAFLD development, although a more pronounced effect of tamoxifen is reported. Future studies focusing on the underlying pathogenesis should identify subgroups with the highest risk of NAFLD development and progression into more aggressive forms, as well as elucidate the role of hormone therapies, such as MHT.

Increased Risk of NAFLD in Adults with Glomerular Hyperfiltration: An 8-Year Cohort Study Based on 147,162 Koreans

This study evaluated whether glomerular hyperfiltration (GHF) could predict nonalcoholic fatty liver disease (NAFLD) and fibrosis. A longitudinal cohort study including 147,479 participants aged 20–65 years without NAFLD and kidney disease at baseline was performed. GHF cutoff values were defined as age- and sex-specific estimated glomerular filtration rate (eGFRs) above the 95th percentile, and eGFR values between the 50th and 65th percentiles were used as reference groups. NAFLD was diagnosed via abdominal ultrasonography, and the fibrosis status was evaluated using the NAFLD fibrosis score and Fibrosis-4. During 598,745 person years of follow-up (median, 4.6 years), subjects with GHF at baseline had the highest hazard ratio (HR) for the development of NAFLD (HR 1.21; 95% CI 1.14–1.29) and fibrosis progression (HR 1.42; 95% CI 1.11–1.82) after adjusting for confounding factors. A higher baseline eGFR percentile maintained a higher risk of NAFLD and fibrosis probability. The persistent GHF group during follow-up had the highest HR for NAFLD compared to the persistent non-GHF group (HR 1.31; 95% CI 1.14–1.51). These results were consistent in all subgroups and statistically more prominent in participants without diabetes. GHF was positively associated with increased risk of NAFLD and probability of liver fibrosis in healthy adults.

Factors early in life associated with hepatic steatosis

BACKGROUND

The rise in prevalence of non-alcoholic fatty liver disease (NAFLD) mirrors the obesity epidemic. NAFLD is insidious but may gradually progress from simple steatosis to steatohepatitis, fibrosis and cirrhosis and/or hepatocellular carcinoma. Intervention strategies to ameliorate developmental programming of NAFLD may be more efficacious during critical windows of developmental plasticity.

AIM

To review the early developmental factors associated with NAFLD.

METHODS

Databases MEDLINE via PubMed, and EMBASE and Reference Citation Analysis were searched and relevant publications up to April 30, 2021 were assessed. Original research studies that included risk factors associated with early development of NAFLD in human subjects were included. These factors include: Maternal factors, intrauterine and prenatal factors, post-natal factors, genetic and ethnic predisposition, childhood and adolescence environmental factors. Studies were excluded if they were review articles or animal studies, case reports or conference abstracts, or if NAFLD was not clearly defined and assessed radiologically.

RESULTS

Of 1530 citations identified by electronic search, 420 duplicates were removed. Of the 1110 citations screened from title and abstract, 80 articles were included in the final analysis. Genetic polymorphisms such as patatin-like phospholipase domain-containing protein 3 (PNPLA3) and membrane-bound O-acyltransferase domain-containing protein 7 (MBOAT7) were associated with increased risk of NAFLD. Familial factors such as maternal obesogenic environment and parental history of hepatic steatosis was associated with offspring NAFLD. Longer duration of exclusive breastfeeding in infancy was associated with a lower risk of developing NAFLD later in life while metabolic dysfunction and/or obesity in adolescence was associated with increased risk of NAFLD. Studies relating to socioeconomic factors and its association with NAFLD reported confounding results.

CONCLUSION

Maternal metabolic dysfunction during pregnancy, being exclusively breastfed for a longer time postnatally, diet and physical activity in childhood and adolescence are potential areas of intervention to decrease risk of NAFLD.

Could maternal thyroid function during pregnancy affect daughters' age at menarche through child growth? A mediation analysis

Early menarche is associated with adverse health outcomes during adolescence as well as breast and other reproductive cancers later in adulthood. However, the causes of early menarche and the pathways through which they operate are not fully understood. Though maternal thyroid function during pregnancy affects child growth, and rapid childhood growth is associated with a decreased age at menarche, the relationship between prenatal maternal thyroid function and daughters' age at menarche has not been examined. We conducted a mediation analysis in a historical cohort of 260 mother-child pairs to estimate the total and indirect effects of maternal prenatal thyroid function on daughters' age at menarche. No association was observed between thyroid stimulating hormone (TSH) or anti-thyroid peroxidase antibodies (ATPO) and daughters' age at menarche. Using a sample-specific, a-priori cutoff at the 10th percentile, low levels of maternal free thyroxine (FT4) were associated with earlier daughter age at menarche, with a hazard ratio (95 % CI) of 1.70 (1.02, 2.84) comparing the bottom 10th percentile with the top 90th percentile of exposure levels. Higher maternal FT4 was associated with rapid child weight gain from ages 5-9, and rapid child weight gain from ages 5-9 was associated with earlier age at menarche; the estimated indirect effect of this pathway was null. While maternal FT4 is associated with earlier age at menarche in daughters, this is not mediated by rapid weight gain in our study population, suggesting that maternal FT4 is operating through a different pathway.

Long working hours are associated with a higher risk of non-alcoholic fatty liver disease: A large population-based Korean cohort study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD), a common chronic liver disease, may progress to fibrosis, cirrhosis, hepatocellular carcinoma, and liver failure. But only a few cross-sectional studies have reported an association of NAFLD with working hours. This cohort study further examined the association between working hours and the development of NAFLD.

METHODS

We included 79,048 Korean adults without NAFLD at baseline who underwent a comprehensive health examination and categorized weekly working hours into 35-40, 41-52, 53-60, and >60 hours. NAFLD was defined as the presence of fatty liver, in the absence of excessive alcohol use, as observed by ultrasound.

RESULTS

During a median follow-up of 6.6 years, 15,095 participants developed new-onset NAFLD (incidence rate, 5.55 per 100 person-years). After adjustment for confounders, the hazard ratios (95% confidence interval) for the development of NAFLD in 41-52, 53-60, and >60 working hours compared with that in 35-40 working hours were 1.07 (1.02-1.13), 1.06 (1.00-1.13), and 1.13 (1.05-1.23), respectively. Furthermore, the association remained significant after confounders were treated as time-varying covariates.

CONCLUSION

In this large-scale cohort, long working hours, especially >60 working hours a week, were independently associated with incident NAFLD. Our findings indicate that long working hours are a risk factor for NAFLD.

Associations Between Reproductive and Hormone-Related Factors and Risk of Nonalcoholic Fatty Liver Disease in a Multiethnic Population

BACKGROUND & AIMS

Despite apparent differences between men and women in the prevalence and incidence of nonalcoholic fatty liver disease (NAFLD), there are limited epidemiologic data regarding the associations of reproductive and hormone-related factors with NAFLD. We examined the associations of these factors and exogenous hormone use with NAFLD risk in African American, Japanese American, Latino, Native Hawaiian, and white women.

METHODS

We conducted a nested case-control study (1861 cases and 17,664 controls) in the Multiethnic Cohort Study. NAFLD cases were identified using Medicare claims data; controls were selected among participants without liver disease and individually matched to cases by birth year, ethnicity, and length of Medicare enrollment. Reproductive and hormone-related factors and covariates were obtained from the baseline questionnaire. Multivariable logistic regression was used to calculate odds ratios (ORs) and 95% CIs.

RESULTS

Later age at menarche was associated inversely with NAFLD (P_trend = .01). Parity, regardless of number of children or age at first birth, was associated with increased risk of NAFLD (OR, 1.25; 95% CI, 1.05-1.48). Oral contraceptive use also was linked to increased risk of NAFLD (OR, 1.14; 95% CI, 1.01-1.29; duration of use P_trend = .04). Compared with women with natural menopause, those with oophorectomy (OR, 1.41; 95% CI, 1.18-1.68) or hysterectomy (OR, 1.33; 95% CI, 1.11-1.60) had an increased risk of NAFLD. A longer duration of menopause hormone therapy (only estrogen therapy) was linked with an increasing risk of NAFLD (OR per 5 years of use, 1.08, 95% CI, 1.01-1.15).

CONCLUSIONS

Findings from a large multiethnic study support the concept that menstrual and reproductive factors, as well as the use of exogenous hormones, are associated with the risk of NAFLD.

Early menarche is associated with insulin-resistance and non-alcoholic fatty liver disease in adolescents with obesity

OBJECTIVES

Recent evidence linked early menarche to a higher risk of insulin-resistance (IR) and nonalcoholic fatty liver disease (NAFLD) in adulthood. We aimed to evaluate the impact of early menarche on glucose derangements and NAFLD in a sample of Italian adolescents with obesity.

METHODS

Anthropometric and biochemical evaluations were conducted in all the enrolled 318 obese patients (mean age 12.31 ± 2.95 years). NAFLD was defined by the presence of ultrasound detected liver steatosis and/or alanine transaminase (ALT) levels >40 IU/L.

RESULTS

Patients with early menarche showed both higher homeostasis model assessment of insulin-resistance (HOMA-IR) (p=0.008) and ALT (p=0.02) values, an increased prevalence of NAFLD (p=0.001), and lower Matsuda and Insulinogenic Index (IGI) values than the other obese patients. The association between early menarche and both ALT and Matsuda Index remained significant in General Linear Models (GLMs) in which respectively body mass index standard deviation score (BMI-SDS) and Matsuda Index, and BMI-SDS were included as covariates. Patients with early menarche also showed a higher risk of both HOMA-IR>3 (OR 1.69, CI 1.05-2.70, p=0.02) and NAFLD (OR 1.10, CI 1.01-1.21, p=0.03).

CONCLUSIONS

Girls with obesity presenting early menarche showed higher HOMA-IR levels, lower Matsuda Index and IGI values, and higher risk of NAFLD compared to girls without early menarche.

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.

Influence of Gender and Reproductive Factors on Liver Fibrosis in Patients With Chronic Hepatitis B Infection

INTRODUCTION:

The role of reproductive factors in the development of chronic hepatitis B (CHB) remains unknown. We assessed the potential contributions of gender, menopausal status, and menarche age to liver fibrosis in CHB.

METHODS:

A cross-sectional prospective study included 716 women and 716 age-matched men with CHB who were not currently receiving antiviral therapy. Liver stiffness measurement using transient elastography was used to stage liver fibrosis as F0–F1 (<7.2 kPa), F ≥ 2 (7.2 kPa), F ≥ 3 (9.4 kPa), and F = 4 (12.2 kPa). Female patients were asked regarding their age at menarche and menopausal status using a questionnaire.

RESULTS:

Of the 716 women, 121 (16.9%) were postmenopausal, and 80 (11.2%) had advanced liver fibrosis. Multivariate logistic regression analysis showed that the postmenopausal status compared with the premenopausal status (odds ratio [OR] = 3.65–8.83; P < 0.05) and age at menarche of >14 years compared with <13 years (OR = 2.85–3.95; P < 0.05) were significantly associated with advanced fibrosis. Compared with premenopausal women, age-matched men had a higher OR for advanced fibrosis (P < 0.05). Compared with postmenopausal women, age-matched men did not show a significant difference in the degree of liver fibrosis (P > 0.05). Longitudinal data analysis showed that postmenopausal women (n = 31) were significantly less likely to undergo regression of liver fibrosis after antiviral treatment vs premenopausal women (n = 19) (26.3% vs 74.2%, respectively; P < 0.001).

DISCUSSION:

Menopause and late menarche aggravated liver fibrosis in untreated CHB, besides menopause delayed fibrosis regression under antiviral therapy. The protective effect of female gender against fibrosis was lost for postmenopausal women.

TRANSLATIONAL IMPACT:

It is important to consider menopausal status and age at menarche in establishing surveillance strategies among CHB females. Postmenopausal estrogen therapy may be considered for the prevention or treatment of liver fibrosis.

NAFLD in women: Unique pathways, biomarkers and therapeutic opportunities

Purpose of review

In this review article we evaluate sex differences in the natural history of NAFLD and highlight distinct risk profiles of women with NAFLD, as well as unique treatment considerations and research gaps.

Summary of findings

Reproductive factors, such as menopausal status should be considered when evaluating NAFLD risk in women, as well as additional reproductive risk factors such as age at menarche, presence of polycystic ovary syndrome, and gestational diabetes. Women do appear to have lower risk for hepatocellular carcinoma from NASH, as well as lower mortality from NASH cirrhosis than men, although among women, NASH is now the leading indication for liver transplant. Data on sex differences in biomarker development and clinical trials are lacking, and researchers should be encouraged to evaluate biomarker performance by sex, and specifically report clinical trial endpoints in women.

The association of physical activity and sleep duration with incident anxiety symptoms: A cohort study of 134,957 Korean adults

BACKGROUND

Maintaining adequate levels of sleep and physical activity (PA) as self-help for the prevention of new-onset anxiety symptoms is becoming more important.

METHODS

A cohort study was performed with 134,957 adults, free of anxiety symptoms at baseline who underwent at least two comprehensive health screening examinations between 2012 and 2017. At baseline, the amount of PA was measured using the International Physical Activity Questionnaire-Short Form and sleep duration per day was assessed using a self-report questionnaire. The study's end point was new-onset anxiety symptoms, defined as a Beck Anxiety Inventory score of ≥19.

RESULTS

During 361,969 person-years of follow-up, 5086 participants developed case-level anxiety. Compared with a reference (0-600 METs-min/wk), a U-shaped relationship was observed between PA and case-level anxiety. The most beneficial levels of PA for reducing incident anxiety symptoms were higher in men than women (men: 1800-3000 METs-min/wk HR, 0.88 [95% CI, 0.78-0.81], 3000-6000 METs-min/wk HR, 0.81 [95% CI, 0.70-0.93]; women: 600-1,200 METs-min/wk HR, 0.86 [95% CI, 0.76-0.98]). In comparison with a reference (<6 h), the relationship between sleep duration and case-level anxiety also had a U-shaped pattern. The optimal sleep duration for decreasing the onset of case-level anxiety was 7-8 h, regardless of sex (men: HR, 0.75 [95% CI, 0.63-0.90]; women; HR, 0.61 [95% CI, 0.54-0.70]).

LIMITATIONS

PA, sleep duration, and anxiety symptoms were measured using self-report questionnaires.

CONCLUSIONS

The results of this study revealed the appropriate levels of PA and total sleep time for reducing incident anxiety symptoms.

Age at onset of different pubertal signs in boys and girls and differential DNA methylation at age 10 and 18 years: an epigenome-wide follow-up study

STUDY QUESTION

Is the age of onset of pubertal markers related to subsequent changes in DNA methylation (DNAm)?

SUMMARY ANSWER

We identified 273 cytosine-phosphate-guanine (CpG) dinucleotides in girls and 67 CpGs in boys that were related to puberty and that were replicable in two other investigations.

WHAT IS KNOWN ALREADY

Previously, 457 CpGs (not gender-specific) and 347 (in girls) and 50 (in boys), respectively, were found to be associated with puberty, according to investigations of studies from Denmark (20 girls and 31 boys) and North America (30 girls and 25 boys).

STUDY DESIGN SIZE DURATION

The study was based on a birth cohort of 1456 participants born in 1989/90, with follow-up at age 10 and 18 years.

PARTICIPANTS/MATERIALS SETTING METHODS

The follow-up included 470 participants with information on DNAm and age of pubertal onset (244 girls and 226 boys). Age of pubertal onset was ascertained retrospectively at age 18 years. Using the Pubertal Development Scale, both genders were asked about ages of onset of growth spurt, body hair growth and skin changes. Ages at voice deepening and growth of facial hair were inquired from boys; ages at breast development and menarche from girls. Blood samples were collected at 10 and 18 years of age. DNA was extracted using a standard salting out procedure. The methylation level for each CpG site was assessed using one of two different platforms. DNAm was measured by a ratio of intensities denoted as β values for each CpG site. After quality control, 349 455 CpG sites were available for analysis. M values were calculated (log2(β/(1-β)) to approximate a normal distribution, and their levels were adjusted for blood cell proportions. Linear mixed models were applied to test the association between age of pubertal markers and repeated measurement of DNAm at 10 and 18 years.

MAIN RESULTS AND THE ROLE OF CHANCE

In girls, a total of 63 019 CpGs statistically significantly changed after occurrence of any of the five pubertal events and 13 487 were changed subsequent to all five events: the respective number is boys were 3072 and 301. To further exclude false-positive findings, we investigated which CpGs were replicable in prior studies from Denmark or North America, resulting in 273 replicable CpG in girls and 67 CpGs in boys (236 and 68 genes, respectively). Most identified genes are known to be related to biological processes of puberty; however, genetic polymorphisms of only four of these genes were previously linked to pubertal markers in humans.

LIMITATIONS REASONS FOR CAUTION

The relative age of pubertal onset to the age of DNAm measurements does not allow causal inference, since DNAm at an earlier age may have affected the pubertal age or pubertal age may have altered later DNAm. This investigation concentrates on autosomes. CpGs on X and Y chromosomes are not included in the current study.

WIDER IMPLICATIONS OF THE FINDINGS

Assessment of biological processes involved in pubertal transitions should include epigenetic information. Differential DNAm related to puberty needs to be investigated to determine whether it can act as an early marker for adult diseases known to be associated with puberty.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by NIH grants R03HD092776 (Epigenetic characterization of pubertal transitions) and R01AI121226. The 10-year follow-up of this study was funded by National Asthma Campaign, UK (Grant No 364), and the 18-year follow-up by a grant from the National Heart and Blood Institute (R01 HL082925). The authors have no conflicts to report.

Self-rated health and risk of incident non-alcoholic fatty liver disease: A cohort study

Although self-rated health (SRH), a subjective measure of overall health status, associates with metabolic abnormalities, studies on the relationship between SRH and non-alcoholic fatty liver disease (NAFLD), a hepatic manifestation of metabolic syndrome, are limited. In this study, we evaluated whether or not SRH predicts the risk of incident NAFLD. This cohort study was performed in a sample of 148,313 Korean adults free of ultrasound-diagnosed NAFLD at baseline with annual or biennial follow-up for a median of 3.7 years. SRH and NAFLD were measured at baseline and follow-up visits. NAFLD was determined based on the ultrasound-diagnosed fatty liver without excessive alcohol consumption or any other cause. Hazard ratios with 95% confidence intervals were estimated via a parametric proportional hazards model. During 522,696.1 person-years of follow-up, 23,855 individuals with new-onset NAFLD were identified (incidence rate, 45.6 per 1,000 person-years). After adjustments for possible confounders including total calorie intake, sleep duration, and depressive symptoms, the multivariate-adjusted hazard ratios (95% confidence intervals) for incident NAFLD comparing good, fair, and poor or very poor SRH to very good SRH were 1.06 (0.97-1.14), 1.18 (1.09-1.27), and 1.24 (1.13-1.37), respectively. This association of SRH with incident NAFLD remained significant after accounting for changes in SRH and confounders during follow-up and was similar across clinically relevant subgroups. In a large-scale cohort study of apparently healthy Korean adults, poor SRH was independently and positively associated with incident NAFLD risk, indicating a predictive role of SRH as a health measure in NAFLD.

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 5^th 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.

Alcoholic and Nonalcoholic Fatty Liver Disease and Incident Hospitalization for Liver and Cardiovascular Diseases

BACKGROUND & AIMS

We compared the associations of nonalcoholic fatty liver disease (NAFLD) and alcohol-associated fatty liver disease (AFLD) with risk of incident hospitalization for liver and cardiovascular diseases.

METHODS

We collected data from the Kangbuk Samsung Health Study on 218,030 men and women in Korea who underwent a health examination from 2011 through 2016. Fatty liver disease (FLD) was detected by ultrasound during the initial examination. The Fibrosis-4 index was used to identify individuals with liver fibrosis. Participants were followed up for as long as 5.9 years and data on hospitalizations for liver and cardiovascular diseases were collected.

RESULTS

The prevalence of NAFLD was 22.0% and the prevalence of AFLD was 6.4%. Over a median follow-up period of 4.2 years, we observed 51 and 1097 incident cases of liver disease- or cardiovascular disease-related hospitalizations, respectively. After adjustment for potential confounders, the multivariable-adjusted hazard ratios for liver disease-related hospitalization, comparing NAFLD and AFLD with the reference category (no excessive alcohol intake and no FLD), were 1.73 (95% CI, 0.76-3.96) and 5.00 (95% CI, 2.12-11.83), respectively. The corresponding hazard ratios for cardiovascular disease hospitalization were 1.20 (95% CI, 1.02-1.40) and 1.08 (95% CI, 0.86-1.34), respectively. Among participants with FLD, the risk of liver disease-related hospitalization increased with high Fibrosis-4 index scores, whereas the risk of incident cardiovascular disease did not.

CONCLUSIONS

In a large cohort study, we found an increased risk of liver disease-related hospitalizations for patients with NAFLD or AFLD, especially among those with Fibrosis-4 index scores. An increased risk of cardiovascular disease-associated hospitalization was observed in patients with NAFLD but not AFLD.

High-Risk Human Papillomavirus Infection and the Risk of Cardiovascular Disease in Korean Women

RATIONALE

Until now, no cohort studies have evaluated the relationship between high-risk human papillomavirus (HPV) infection and new-onset cardiovascular diseases (CVD).

OBJECTIVE

We investigated an association between high-risk HPV infection and the development of CVD.

METHODS AND RESULTS

We conducted a cohort study of 63 411 women aged 30 or older without CVD at baseline who underwent a high-risk HPV test and were followed annually or biennially from 2011 to 2016. CVD was ascertained through the linkage to the Health Insurance and Review Agency database. A Cox-proportional hazards regression model was used to estimate adjusted hazard ratios (HRs) with 95% CIs of incident CVD. The prevalence of high-risk HPV infection was 7.6%. During 261 598.9 person-years of follow-up, 1122 cases of new-onset CVD were identified (incidence rate of 4.3 per 10³ person-years). High-risk HPV infection was significantly associated with incident CVD. After adjustment for possible confounders, and high sensitivity C-reactive protein, a significant association between high-risk HPV infection and incident CVD was still observed, with a corresponding HR (95% CI) of 1.25 (1.03-1.52). This association was stronger among individuals with obesity and those with metabolic syndrome. Multivariable-adjusted HR (95% CI) for incident CVD comparing high-risk HPV-positive- to high-risk HPV-negative participants was 1.10 (0.87-1.39) in the nonobese, whereas corresponding HR (95% CI) was 1.73 (1.19-2.51) in those with obesity ( P for interaction by obesity=0.02). Similarly, multivariable-adjusted HR (95% CI) for incident CVD comparing high-risk HPV-positive- to high-risk HPV-negative participants was 1.09 (0.87-1.36) in those without metabolic syndrome and 1.99 (1.28-3.08) in those with MetS ( P for interaction=0.05).

CONCLUSION

In this large cohort, high-risk HPV infection was significantly associated with an increased risk of developing CVD, especially in obese individuals and those with MetS, indicating that high-risk HPV might affect CVD risk with possible effect modification by obesity and MetS.

Association Between Nonalcoholic Fatty Liver Disease and Future Deterioration of Metabolic Health: A Cohort Study

OBJECTIVE

It was hypothesized that the presence of nonalcoholic fatty liver disease (NAFLD) at baseline predicts future conversion from the metabolically healthy (MH) to the metabolically unhealthy (MU) phenotype according to body fat mass.

METHODS

A total of 22,551 Korean participants (13,601 men and 8,950 women) aged 18 to 78 years in the Kangbuk Samsung Health Study cohort were enrolled from 2007 to 2013.

RESULTS

During a median of 5.1 years of follow-up (interquartile range 2.1-9.8 years), 23.5% (n = 5,298) of MH individuals converted to the MU phenotype. NAFLD at baseline predicted conversion independent of age, sex, BMI, lifestyle factors, individual components of metabolic syndrome, and insulin resistance (HR, 1.29; 95% CI: 1.19-1.39; P < 0.0001). In participants with lower BMI and fat mass, NAFLD was strongly associated with conversion; however, as BMI and fat mass increased, the risk decreased, and there was no association in participants with higher BMI and fat mass (P < 0.0001 for trend).

CONCLUSIONS

NAFLD at baseline was independently associated with future conversion from the MH to the MU phenotype.

Solitary kidney and risk of chronic kidney disease

The renal outcome of solitary kidney remains controversial. We examined the longitudinal association of congenital or acquired solitary kidney with the development of chronic kidney disease (CKD). A cohort study was performed involving 271,171 Korean men and women free of CKD at baseline who underwent a health screening program and who were followed annually or biennially for an average of 5.4 years. Solitary kidney was determined based on ultrasonographic findings. CKD was defined as an estimated glomerular filtration rate of < 60 ml/min/1.73 m² and/or the presence of proteinuria in two or more consecutive visits. During 1,472,519.6 person-years of follow-up, 2989 participants developed CKD (incidence rate: 2.0 per 1000 person-years). After adjustment for potential confounders, the aHR (95% CIs) for incident CKD comparing solitary kidney to the control was 3.26 (1.63-6.54). In analyses of cause-specific solitary kidney, aHR (95% CIs) for CKD comparing unilateral nephrectomy and congenital solitary kidney to the control were 6.18 (2.31-16.49) and 2.22 (0.83-5.92), respectively. The association between solitary kidney and CKD was stronger in men. Having a solitary kidney was independently associated with an increased risk of CKD development. Therefore, preventive strategies for reducing the risk of CKD are required in individuals with a solitary kidney.

Metabolic syndrome and incident depressive symptoms in young and middle-aged adults: A cohort study

BACKGROUND

Recent studies on the prospective association between metabolic syndrome (MetS) and depression have reported conflicting findings.

METHODS

A cohort study was performed with 115,223 middle-aged adults, free of depression at baseline, who underwent at least 2 comprehensive exams between 2012 and 2015. MetS was assessed according to the National Cholesterol Education Program Adult Treatment Panel III. The study endpoint was new onset of depression, defined as a Center for Epidemiologic Studies-Depression Scale score ≥ 16.

RESULTS

Over 253,451.6 person-years, 6,833 participants developed depression. When the participants with 0 MetS components were set as a reference, the multivariable-adjusted hazard ratio (HR, 95% confidence interval [CI]) for incident depression formed a U-shaped curve with the number of MetS components (p for trend = 0.229): 1 (1.07 [1.02-1.15]); 2 (0.92 [0.82-1.06]); 3 (0.85 [0.78-1.07]); 4 (1.16 [1.06-1.32]); and 5 MetS components (1.25 [1.10-1.54]). The presence or absence of MetS was not significant in new-onset depression. In examining potential clustering and synergistic effects of the constituent parts, waist circumference was the major driving factor of incident depression, and its relative excess risk due to interaction increased with the number of combinations.

LIMITATIONS

We used a self-reported depression scale, and the follow-up period was relatively short.

CONCLUSIONS

Future studies investigating the risk for incident depression should place more focus on the number of MetS abnormalities and specific MetS factors, such as waist circumference, than the presence or absence of MetS.

Obesity and Weight Gain Are Associated With Progression of Fibrosis in Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

The effects of weight change on the progression of liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD) in the general population are unclear. We evaluated the association of weight change and baseline body mass index (BMI) with fibrosis progression, determined by non-invasive measurement of a marker, in young and middle-aged adults with NAFLD.

METHODS

We performed a prospective cohort study of 40,700 adults with NAFLD in Korea who received regular health screening examinations and were followed for a median 6.0 years. Weight change was defined as the difference between weights measured at baseline and at a subsequent follow-up visit. The progression from a low to an intermediate or high probability of advanced fibrosis was assessed using the aspartate aminotransferase to platelet ratio index (APRI).

RESULTS

During 275,421.5 person-years of follow-up, 5454 subjects with a low APRI progressed to an intermediate or high APRI. Multivariable-adjusted hazard ratios for APRI progression, determined by comparing the first and second weight change quintiles (the weight-loss group) and the fourth and fifth quintiles (weight-gain group) with the third quintile (weight-stable group, reference), were 0.68 (95% CI, 0.62-0.74), 0.86 (95% CI, 0.78-0.94), 1.17 (95% CI, 1.07-1.28), and 1.71 (95% CI, 1.58-1.85), respectively. The multivariable-adjusted hazard ratios for APRI progression were determined by comparing subjects with BMIs of 23-24.9, 25-29.9, and ≥30 with subjects with BMIs of 18.5-22.9 kg/m² (reference); these ratios were 1.13 (95% CI, 1.02-1.26), 1.41 (95% CI, 1.28-1.55), and 2.09 (95% CI, 1.86-2.36), respectively.

CONCLUSIONS

In a prospective cohort study of 40,700 adults with NAFLD, we found obesity and weight gain to be independently associated with increased risk of fibrosis progression, based on APRI. Maintaining a normal healthy weight and preventing weight gain may help reduce fibrosis progression in individuals with NAFLD.

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.

Prolonged sitting increases the risk of gallstone disease regardless of physical activity: a cohort study

OBJECTIVES

We aimed to examine the relationship between sitting time and the development of ultrasonography-diagnosed gallstone disease (GSD) in young and middle-aged Korean men and women.

MATERIAL AND METHODS

We conducted a cohort study of 147,237 participants without GSD at baseline who underwent a health checkup examination between 2011 and 2015 and were followed annually or biennially until December 2016. Sitting time and physical activity were measured using the validated Korean version of the international physical activity questionnaire short form. GSD was defined as either having had a cholecystectomy or having gallstones based on ultrasound.

RESULTS

During 486,376 person-years of follow-up, 2382 incident GSD cases were identified. Both prolonged sitting time and inactive physical activity had a significant independent association with the increased risk of GSD. The multivariate-adjusted hazard ratios (95% confidence interval for GSD comparing sitting times of 5-9 and ≥10 h/day with the sitting time of <5 h/day were 1.08 (0.97-1.21) and 1.15 (1.02-1.29), respectively (p for trend = .023). The multivariate-adjusted hazard ratios (95% CIs) for GSD in both the inactive and the minimally active groups compared with HEPA group were 1.22 (1.08-1.38) and 1.13 (0.99-1.28, respectively (p for trend = .001).

CONCLUSION

This study demonstrated that sitting time may be associated with GSD risk regardless of physical activity. The findings of this study suggest that both increasing participation in physical activity and reducing sitting time may be independently important in reducing the risk of GSD.

Nonalcoholic Fatty Liver Disease Associates With Increased Overall Mortality and Death From Cancer, Cardiovascular Disease, and Liver Disease in Women but Not Men

BACKGROUND & AIMS

It is not clear whether women vs men have increased mortality from nonalcoholic fatty liver disease (NAFLD). We investigated whether NAFLD is associated with increased overall and cause-specific deaths in a Korean population using a large health study database.

METHODS

We collected data on 318,224 subjects in Korea (165,131 men and 153,093 women) age 20 to 94 years (mean age, 39.3 y), enrolled in the Kangbuk Samsung Health Study cohort. All subjects underwent a comprehensive annual or biennial health examination in Seoul or Suwon, South Korea, from 2002 through 2012. The presence of NAFLD was ascertained by ultrasonography in the absence of other known liver diseases. Mortality (from 2002 through 2012) was determined by the nationwide death certificate data from the Korea National Statistical Office.

RESULTS

During a median 5.7-year follow-up period, cumulative overall mortality was 0.51% (1613 deaths)-cancer was the leading cause of death. In men, NAFLD was not associated with increased mortality from any cause, except lower rate of death from cancer (hazard ratio, 0.79; 95% CI, 0.66-0.93; P = .005), after adjusting for age, body mass index, smoking status, daily alcohol consumption, and physical activity. In women, NAFLD was independently associated with death from all causes (hazard ratio, 1.79; 95% CI, 1.50-2.14; P < .0001), death from cancer (hazard ratio, 1.83; 95% CI, 1.42-2.35; P < .0001), death from cardiovascular disease (hazard ratio, 1.63; 95% CI, 1.00-2.66; P = .0498), and death from liver disease (hazard ratio, 5.58; 95% CI, 1.79-17.39; P = .003). In obese men, NAFLD was associated with a reduced risk of death from cancer. However, NAFLD was associated with increased risk of death from cardiovascular disease in nonobese men. In obese women, NAFLD did not increase risk of death compared with obesity alone. However, NAFLD was associated with increased overall risk of death and risk of death from cancer in nonobese women.

CONCLUSIONS

Associations between NAFLD and mortality differ between men and women in Koreans. NAFLD was associated with increased overall mortality and death from cancer, cardiovascular disease, and liver disease in women, but these associations were not observed in men.

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.

Early menarche is associated with non-alcoholic fatty liver disease in adulthood

BACKGROUND

The aim of this study was to examine the association between early menarche (<12 years) and non-alcoholic fatty liver disease (NAFLD) in premenopausal women and to explore whether it is mediated by adult obesity and insulin resistance.

METHODS

We analyzed data of premenopausal women, aged ≥15 years, from the Korea National Health and Nutrition Examination Survey (2007-2009). We divided the women into three groups: early menarche, reference (12.00-15.99 years), and late menarche. The presence of NAFLD was determined using hepatic steatosis index >36.0.

RESULTS

Of the 4,387 women evaluated, 673 (15.4%) met the criteria for NAFLD. The prevalence of NAFLD was higher in both women with early and late menarche compared with the reference (early, 23.4%; reference, 14.0%; late, 19.9%, P < 0.001). After adjustment of confounders including age, the OR for NAFLD in early menarche compared with the reference was 3.04 (95%CI: 1.99-4.65). Further adjustment of mediators, such as central obesity or insulin resistance, attenuated the association to 1.91-2.17. There was no association, however, between late menarche and NAFLD after adjustment of confounders.

CONCLUSIONS

Early menarche was associated with an increased risk of NAFLD in young and middle-aged premenopausal Korean women.

Nonalcoholic Fatty Liver Disease Is Associated with Increased Risk of Reflux Esophagitis

BACKGROUND

Reflux esophagitis is associated with obesity and metabolic syndrome; however, the relationship between nonalcoholic fatty liver disease (NAFLD) and reflux esophagitis is unclear.

AIM

We examined the association between NAFLD and the development of reflux esophagitis.

METHODS

Our cohort consisted of 117,377 Korean adults without reflux esophagitis at baseline who underwent a health checkup program including upper endoscopy between 2002 and 2014 and were followed annually or biennially until December 2014. NAFLD was defined as hepatic steatosis on ultrasonography in the absence of excessive alcohol use or any other identifiable cause.

RESULTS

Over 520,843.2 person-years of follow-up, 22,500 participants developed reflux esophagitis (incidence density, 43.2 per 1000 person-years). In models adjusted for age and sex, the adjusted hazard ratio (aHR) (95% confidence interval [CI]) for incident reflux esophagitis in subjects with NAFLD compared to those without was 1.16 (1.13-1.20). After further adjustment for confounders of center, year of visit, smoking status, alcohol intake, regular exercise, education level, and body mass index, the association between NAFLD and incident reflux esophagitis was attenuated, but remained significant (aHR 1.06; 95% CI 1.02-1.10).

CONCLUSIONS

In this large cohort of Korean men and women, participants with NAFLD exhibited increased incidence of reflux esophagitis independent of possible confounders, suggesting that NAFLD contributes to the development of reflux esophagitis.

Non-alcoholic fatty liver disease and the development of nephrolithiasis: A cohort study

Background

Non-alcoholic fatty liver disease (NAFLD), a hepatic manifestation or precursor of metabolic syndrome, may increase nephrolithiasis, a renal manifestation of insulin resistance, but the prospective association between NAFLD and incident nephrolithiasis has not been evaluated. We examined the association of NAFLD with the development of nephrolithiasis in a large cohort of Korean men and women.

Methods

We performed a cohort study of 208,578 Korean adults who underwent a health checkup examination between January 2002 and December 2014 and were followed-up annually or biennially through December 2014. NAFLD was defined as the presence of fatty liver in the absence of excessive alcohol use or other identifiable causes. Fatty liver and nephrolithiasis were determined based on ultrasonographic findings. We used a parametric Cox model to estimate the adjusted hazard ratios (HRs) of nephrolithiasis according to the presence of NAFLD.

Results

During 1,054,887.6 person-year of follow-up, 16,442 participants developed nephrolithiasis. After adjusting for age, center, year of screening exam, smoking status, alcohol intake, physical activity, education level, body mass index, history of hypertension and diabetes, HOMA-IR, uric acid and C-reactive protein, male participants with NAFLD had a significantly increased risk of nephrolithiasis than those without NAFLD (adjusted HR 1.17, 95% CI 1.06–1.30). However, no association between NAFLD and nephrolithiasis was observed in women (adjusted HR 0.97, 95% CI 0.81–1.16).

Conclusions

In this large cohort study of young and middle-aged Koreans, NAFLD was significantly associated with an increased incidence of nephrolithiasis in men but not in women.

NAFLD as a Sexual Dimorphic Disease: Role of Gender and Reproductive Status in the Development and Progression of Nonalcoholic Fatty Liver Disease and Inherent Cardiovascular Risk

Nonalcoholic fatty liver disease (NAFLD) spans steatosis through nonalcoholic steatohepatis, cirrhosis, and hepatocellular carcinoma (HCC) associated with striking systemic features and excess cardiovascular and liver-related mortality. The pathogenesis of NAFLD is complex and multifactorial. Endocrine derangements are closely linked with dysmetabolic traits. For example, in animal and human studies, female sex is protected from dysmetabolism thanks to young individuals’ ability to partition fatty acids towards ketone body production rather than very low density lipoprotein (VLDL)-triacylglycerol, and to sex-specific browning of white adipose tissue. Ovarian senescence facilitates both the development of massive hepatic steatosis and the fibrotic progression of liver disease in an experimental overfed zebrafish model. Consistently, estrogen deficiency, by potentiating hepatic inflammatory changes, hastens the progression of disease in a dietary model of nonalcoholic steatohepatitis (NASH) developing in ovariectomized mice fed a high-fat diet. In humans, NAFLD more often affects men; and premenopausal women are equally protected from developing NAFLD as they are from cardiovascular disease. It would be expected that early menarche, definitely associated with estrogen activation, would produce protection against the risk of NAFLD. Nevertheless, it has been suggested that early menarche may confer an increased risk of NAFLD in adulthood, excess adiposity being the primary culprit of this association. Fertile age may be associated with more severe hepatocyte injury and inflammation, but also with a decreased risk of liver fibrosis compared to men and postmenopausal status. Later in life, ovarian senescence is strongly associated with severe steatosis and fibrosing NASH, which may occur in postmenopausal women. Estrogen deficiency is deemed to be responsible for these findings via the development of postmenopausal metabolic syndrome. Estrogen supplementation may at least theoretically protect from NAFLD development and progression, as suggested by some studies exploring the effect of hormonal replacement therapy on postmenopausal women, but the variable impact of different sex hormones in NAFLD (i.e., the pro-inflammatory effect of progesterone) should be carefully considered.

Development of Nephrolithiasis in Asymptomatic Hyperuricemia: A Cohort Study

BACKGROUND

Although the association between gout and nephrolithiasis is well known, the relationship between asymptomatic hyperuricemia and the development of nephrolithiasis is largely unknown.

STUDY DESIGN

Cohort study.

SETTING & PARTICIPANTS

239,331 Korean adults who underwent a health checkup examination during January 2002 to December 2014 and were followed up annually or biennially through December 2014.

PREDICTOR

Baseline serum uric acid levels of participants.

OUTCOME

The development of nephrolithiasis during follow-up.

MEASUREMENTS

Nephrolithiasis is determined based on ultrasonographic findings. A parametric Cox model was used to estimate the adjusted HRs of nephrolithiasis according to serum uric acid level.

RESULTS

During 1,184,653.8 person-years of follow-up, 18,777 participants developed nephrolithiasis (incidence rate, 1.6/100 person-years). Elevated uric acid level was significantly associated with increased risk for nephrolithiasis in a dose-response manner (P for trend < 0.001) in men. This dose-response association was not observed in women. In male participants, multivariable-adjusted HRs for incident nephrolithiasis comparing uric acid levels of 6.0 to 6.9, 7.0 to 7.9, 8.0 to 8.9, 9.0 to 9.9, and ≥10.0mg/dL with uric acid levels < 6.0mg/dL were 1.06 (95% CI, 1.02-1.11), 1.11 (95% CI, 1.05-1.16), 1.21 (95% CI, 1.13-1.29), 1.31 (95% CI, 1.17-1.46), and 1.72 (95% CI, 1.44-2.06), respectively. This association was observed in all clinically relevant subgroups and persisted even after adjustment for homeostasis model assessment of insulin resistance and high-sensitivity C-reactive protein level.

LIMITATIONS

Dietary information and computed tomographic diagnosis of nephrolithiasis were unavailable.

CONCLUSIONS

In this large cohort study, increased serum uric acid level was modestly and independently associated with increased risk for the development of nephrolithiasis in a dose-response manner in apparently healthy men.

Dietary sodium and potassium intake in relation to non-alcoholic fatty liver disease

A few epidemiological data are available assessing the associations of intakes of sodium (Na) and potassium (K) with non-alcoholic fatty liver disease (NAFLD). We aimed to examine the associations of dietary intake of Na and K with the prevalence of ultrasound-diagnosed NAFLD. We performed a cross-sectional study of 100 177 participants (46 596 men and 53 581 women) who underwent a health screening examination and completed a FFQ at the Kangbuk Samsung Hospital Total Healthcare Centers, South Korea, between 2011 and 2013. NAFLD was defined by ultrasonographic detection of fatty liver in the absence of excessive alcohol intake or other known causes of liver disease. The proportion of NAFLD was 35·6 % for men and 9·8 % for women. Increasing prevalence of NAFLD was observed with increasing Na intake. The multivariable-adjusted prevalence ratios (PR) of NAFLD comparing the highest with the lowest quintile of energy-adjusted Na intake were 1·25 (95 % CI 1·18, 1·32; P trend<0·001) in men and 1·32 (95 % CI 1·18, 1·47; P trend <0·001) in women. However, when we additionally adjusted for body fat percentage, the association became attenuated; the corresponding PR of NAFLD were 1·15 (95 % CI 1·09, 1·21) in men and 1·06 (95 % CI 0·95, 1·17) in women. No inverse association was observed for energy-adjusted K intake. Our findings suggest that higher Na intake is associated with a greater prevalence of NAFLD in young and middle-aged asymptomatic adults, which might be partly mediated by adiposity.

Duration of reproductive lifespan and age at menarche in relation to metabolic syndrome in postmenopausal Chinese women

AIM

This study aimed to assess the associations between menstrual characteristics and the prevalence of metabolic syndrome (MetS) and non-alcoholic fatty liver disease.

METHODS

A cross-sectional study was conducted with a sample of 1625 postmenopausal women in China. Subjects were classified into three groups according to the tertiles of some variables related to the reproductive life. We assessed associations in multivariable-adjusted analyses, using logistic regressions.

RESULTS

After adjustments for confounding factors, the odds ratios (OR) for predicting the presence of MetS increased gradually: as the years of menstruation increased (18-34 years vs 35-37 years vs 38-46 years: OR [95% confidence interval (CI)] = 1 vs 1.231 [0.942-1.610] vs 1.309 [0.985-1.740], respectively); as age at menopause increased (31-48 years vs 49-51 years vs 52-59 years: OR [95%CI] = 1 vs 1.115 [0.846-1.469] vs 1.315 [0.986-1.753], respectively); and as age at menarche decrease (11-13 years vs 14-15 years vs 16-20 years: OR [95%CI] = 1 vs 0.950 [0.728-1.240] vs 0.862 [0.610-1.119], respectively). Among the components of MetS, the highest tertile of years of menstruation was significantly associated with elevated waist circumference (OR =1.401 [95%CI = 1.092-1.798]), and elevated triglyceride (OR =1.220 [95%CI = 0.934-1.593]). Nevertheless, the association between these reproductive factors and non-alcoholic fatty liver disease was not significant.

CONCLUSION

Longer duration of menstruation and earlier age at menarche were significantly associated with a higher risk of central obesity and MetS in postmenopausal Chinese women.

Metabolically healthy obesity is associated with an increased risk of diabetes independently of nonalcoholic fatty liver disease

OBJECTIVE

This study examined whether the metabolically healthy obesity (MHO) phenotype was associated with an increased risk of diabetes in a large cohort of metabolically healthy individuals and whether that association differed by presence of nonalcoholic fatty liver disease (NAFLD).

METHODS

The cohort consisted of 74,509 Korean adults who were metabolically healthy at baseline, defined as not having any metabolic syndrome component except large waist circumference and having homeostasis model assessment of insulin resistance <2.5. NAFLD was defined as hepatic steatosis on ultrasonography in the absence of excessive alcohol use or any other identifiable cause.

RESULTS

Over 304,852.6 person-years of follow-up, 472 participants developed diabetes (incidence density, 1.5 per 1,000 person-years). The multivariable-adjusted hazard ratios (95% confidence intervals) for incident diabetes in subjects with overweight and obesity compared with subjects with normal weight were 1.29 (1.00-2.16) and 1.57 (1.14-2.16), respectively, for subjects without NAFLD and 1.90 (0.95-3.80) and 2.57 (1.32-5.02), respectively, for those with NAFLD (P for interaction =0.57).

CONCLUSIONS

In this metabolically healthy population, individuals with overweight and obesity exhibited an increased incidence of diabetes, regardless of the presence of NAFLD. This finding suggests that the obese phenotype per se, independent of the presence of NAFLD, can increase the development of diabetes.

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.

Age at Menarche and Gallstone Disease in Middle-Aged Women

The goal of this study was to explore the association between age at menarche and gallstone disease (GSD) in Korean women and to determine whether any of the observed associations were mediated by adult adiposity. A cross-sectional study was performed on 83 275 Korean women, aged 30 years or older, who underwent a health checkup examination between March 2011 and April 2013. Information regarding age at menarche was collected using standardized, self-administered questionnaires. Gallstone disease was defined as either having gallstones or having had a cholecystectomy based on ultrasound. Logistic regression models were used to evaluate the association between age at menarche and GSD. Of the 83 275 women evaluated in this study, 3341 had GSD. Age at menarche was negatively associated with the prevalence of GSD. In a multivariable-adjusted model adjusting for potential confounders including reproductive factors and body weight at age 20, the odds ratios (95% confidence intervals) for GSD comparing menarche at <12, 12, 14, 15, and 16 to 18 years to menarche at 13 years were 1.46 (1.23-1.75), 1.19 (1.04-1.35), 0.97 (0.87-1.09), 0.92 (0.82-1.03), and 0.89 (0.78-1.02), respectively (P for trend <.001). Adjusting for adult body mass index or percentage fat mass (%) partially reduced these associations; however, they remained statistically significant. Early menarche was associated with increasing prevalence of GSD in a large sample of middle-aged women. The findings of this study extend the range of adverse health outcomes associated with early menarche and suggest that obesity prevention strategies could be useful for reducing the risk of GSD in women who experience early menarche.

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.