Association between liver function markers and menstrual cycle irregularity in Korean female population

Alteration of menstrual cycle by individual lifestyles and unfavorable habits may cause menstrual irregularity. We aimed to investigate the relationship between lifestyle factors and menstrual irregularity in Korean women using data from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES) 2010-2012. This cross-sectional study included 3779 nondiabetic Korean women aged 19-49 years who did not take any oral contraceptives or sex hormonal compounds. We examined the association of menstrual irregularity with age, body mass index (BMI), drinking experience, and smoking habits. Age, Asian BMI, marriage status, age at menarche, and smoking habits were significantly associated with menstrual cycle irregularity (p < 0.01). The prevalence of menstrual irregularity was significantly increased at younger ages: 18.4%, 10.3%, and 10.5% at 19-29, 30-39, and 40-49 years, respectively. Moreover, obesity groups, defined as per Asian BMI using modified WHO criteria, were strongly associated with menstrual irregularity. BMI 25.0-29.9 [obesity class I] (adjusted odds ratios [OR], 1.94; 95% confidence intervals [CI], 1.37-2.74) and ≥30.0 [obesity class II] (adjusted OR, 2.18; 95% CI, 1.22-3.91) presented significantly higher risk of menstrual irregularity compared with BMI 18.5-22.9 [normal weight]. Multivariable analysis revealed that high BMI in younger women aged 19-29 years (p < 0.001) and smoking habits in middle-aged women aged 30-39 years (p < 0.005) significantly predicted menstrual irregularity. This study substantiated that menstrual irregularity was closely associated with higher BMI and smoking habits in nondiabetic Korean women. Weight loss and smoking cessation should be recommended to promote women's reproductive health.

The aim of this study was to identify the relationship between awareness of nutrition labeling and menstrual cycle irregularity in women from a nationally representative sample of the Korean population. A cross-sectional analysis was performed using hierarchical multivariable logistic regression analysis models. A total of 4,324 women aged 19~54 years from the 2010~2012 Korean National Health and Nutrition Examination Survey participated in the study. The participants were classified into three groups based on self-report responses to a questionnaire about their awareness of nutrition labels: Reading, Not-Reading, and Not-Knowing Groups. The Reading, Not-Reading, and Not-Knowing Groups comprised 46.4%, 44.9%, and 8.7% of the participants, respectively, and 53.6% of the participants had never used nutrition labels. In the Not-Knowing Group, irregular menstrual cycles for more than 3 months were significantly more common than women with irregular menstrual cycles for up to 3 months and women with regular menstrual cycles. Women in the Not-Knowing Group were more likely to exhibit menstrual cycle irregularity (adjusted odds ratio: 1.63, 95% confidence interval: 1.10~2.41) compared to women in the Reading Group after adjusting for age, body mass index, smoking status, alcohol intake, exercise regularity, stress, depression, suicidal ideation, metabolic syndrome, age at menarche, parity, and use of oral contraceptives. No awareness of nutrition labeling appears to be associated with a higher prevalence of menstrual cycle irregularity in a nationally representative group of Korean women.

This study was performed to assess the relationship between menstrual irregularity and dental pain or chewing discomfort in women before menopause, using nationally representative data. This study analyzed 4595 participants who were ≥19 years or older, and did not have missing values for outcome variables from the Korean National Health and Nutrition Examination Survey. Tooth pain was considered present if the participant felt throbbing discomfort, pain, or sensitivity when eating hot or cold food or drinking hot or cold beverages. Self-reported oral chewing discomfort was obtained. Adjusted odds ratios and their 95% confidence intervals for tooth pain in the individuals with menstrual cycle irregularity were 1.30 (1.05, 1.62) after adjustment for age, body mass index, drinking, smoking, income, exercise, stress, metabolic syndrome, and the frequency of tooth brushing. Adjusted odds ratios and their 95% confidence intervals for chewing discomfort in the individuals with menstrual cycle irregularity were 1.33 (1.03, 1.72) after adjustment. The association between menstrual irregularity and dental pain or chewing discomfort in women before menopause was proven—after adjusting for confounding factors—by multiple logistic regression analyses. Menstrual cycle irregularity may be considered a potential risk indicator for dental pain or chewing discomfort in Korean women before menopause.

Validated non-invasive measures of fatty liver are needed that can be applied across populations and over time. A fatty liver index (FLI) including body mass index, waist circumference, triglycerides and gamma glutamyltransferase (GGT) activity was developed in an Italian municipality, but has not been validated widely or examined in a multiethnic population. We evaluated this FLI in the multiethnic U.S. National Health and Nutrition Examination Survey (NHANES) and also to explore whether an improved index for the U.S. population (US FLI) could be derived. The US FLI would then used to examine U.S. time trends in fatty liver prevalence. We studied 5869 fasted, viral hepatitis negative adult participants with abdominal ultrasound data on fatty liver in the 1988-1994 NHANES. Time trend analyses included 21712 NHANES 1988-1994 and 1999-2012 participants. The prevalence of fatty liver was 20%. For the FLI, the area under the receiver operating characteristic curve [AUC; 95% confidence interval (CI)] was 0.78 (0.74-0.81). The US FLI included age, race-ethnicity, waist circumference, GGT activity, fasting insulin and fasting glucose and had an AUC (95% CI) of 0.80 (0.77-0.83). Defining fatty liver as a US FLI ≥ 30, the prevalence increased from 18% in 1988-1991 to 29% in 1999-2000 to 31% in 2011-2012. For predicting fatty liver, the US FLI was a modest improvement over the FLI in the multiethnic U.S. population. Using this measure, the fatty liver prevalence in the U.S. population increased substantially over two decades.

Numerous anecdotal accounts and qualitative research studies have reported on post-vaccination menstrual irregularities in women of reproductive age. However, none have quantified the impact. This is the first systematic review and meta-analysis to quantify and characterize the menstrual irregularities associated with vaccination for women of reproductive age. A search on July 20, 2022, retrieved articles published between December 1, 2019, and July 1, 2022, from MEDLINE, Embase, and Web of Science. The included articles were studies with full texts written in English that reported on menstrual irregularities for vaccinated vs. unvaccinated women of reproductive age. The quality of the studies was evaluated using the Study Quality Assessment Tool for Observation Cohort and Cross-Sectional Studies. Four observational studies were included. Review Manager was used to generating a forest plot with odds ratios (ORs) at the 95% confidence interval (CI), finding statistically significant associations between vaccination and menstrual irregularities for 25,054 women of reproductive age (OR = 1.91, CI: 1.76–2.07) with a significant overall effect of the mean (Z = 16.01, p < 0.0001). The studies were heterogeneous with significant dispersion of values (χ2 = 195.10 at df = 3, p < 0.00001, I2 = 98%). The findings of this systematic review and meta-analysis are limited by the availability of quantitative data. The results have implications for treating women of reproductive age with menstrual irregularities and informing them about the potential side effects of vaccinations.

Menstrual irregularity is a common reproductive endocrine disorder among women of reproductive age, serving both as an early indicator of various gynecological diseases and a potential marker of underlying metabolic disturbances. Low-density lipoprotein cholesterol (LDL-C), a key indicator of lipid metabolism, lacks robust epidemiological evidence regarding its association with menstrual irregularity. This study utilized data from the 2013 to 2014 cycle of the National Health and Nutrition Examination Survey, which included (n = 623) women aged 15 to 49 years, to train a logistic regression model for assessing the association between LDL-C levels and menstrual irregularity. The model was externally validated using data from the 2009 to 2010 cycle (n = 799). Model performance was evaluated using the area under the receiver operating characteristic curve (area under the curve [AUC]), calibration plots, and confusion matrices. A nomogram was constructed to enhance clinical interpretability. The analysis indicated that LDL-C levels and age were significant predictors of menstrual irregularity. The AUCs of the model were 0.754 in the training set and 0.765 in the validation set, demonstrating good predictive performance and robustness. Residual analysis and collinearity diagnostics further supported the good fit of the model. The nomogram based on the final model enables visualized assessment of individual risk, aiding clinical risk stratification and decision-making. Elevated LDL-C levels are significantly associated with menstrual irregularity in women of reproductive age, suggesting its potential role as a metabolic biomarker of reproductive health. Longitudinal studies are recommended to clarify the causal relationship and to explore the potential of lipid-lowering interventions in menstrual regulation.

The presence of fatty liver (FL) has been suggested to influence the incidence of colorectal cancer (CRC). This study aimed to evaluate the predictive utility of six alternative indices of FL-namely, liver fat percentage (PLF), lipid accumulation product (LAP), hepatic steatosis index (HSI), United States fatty liver index (USFLI), fatty liver index (FLI), and Zhejiang University index (ZJU)-in assessing the risk of CRC. We aimed to determine their effectiveness in predicting CRC risk by comparing these surrogate indices. Data for this study were derived from the National Health and Nutrition Examination Survey (NHANES) conducted between 2003 and 2018, focusing on adults over 20 years old. The six FLIs were calculated using established methodologies outlined in prior research. To identify key variables, the Boruta algorithm was employed. The relationships between FLIs and CRC risk were assessed using multivariable logistic regression, generalized linear models (GLMs), and restricted cubic spline (RCS) models. Additionally, subgroup analyses were performed to investigate the effects of potential confounders. Among the 16,250 individuals surveyed, 96 were diagnosed with CRC. Those with CRC exhibited significantly higher levels of PLF (4.65 vs. 3.31, P=0.004), LAP (55.63 vs. 42.34, P=0.04), USFLI (23.22 vs. 17.83, P<0.001), and FLI (58.16 vs. 50.86, P=0.048) compared to individuals without CRC. Multivariate logistic regression and RCS analyses indicated that, of the six indices, only USFLI was significantly associated with an increased risk of CRC. Notably, further stratification of USFLI revealed that this association was consistently stronger in individuals aged over 65 years [odds ratio (OR) =1.023; 95% confidence interval (CI): 1.005-1.041; P=0.01] and among non-smokers (OR =1.018; 95% CI: 1.003-1.033; P=0.02) after adjusting for multiple confounders. The USFLI index demonstrated a more significant association with the risk of CRC compared to the other five alternative FLIs, highlighting its potential utility in predicting CRC risk in clinical settings.

Thyroid Function and Risk of Non-Alcoholic Fatty Liver Disease in Euthyroid Subjects

Non-alcoholic fatty liver disease and sarcopenia is associated with the risk of albuminuria independent of insulin resistance, and obesity

The authors examined prospectively between 1986 and 1997 the relation of irregular menstrual cycles and irregular menstrual bleeding duration earlier in life with risk of hip fracture in 33,434 postmenopausal Iowa women. Over the 318,522 person-years of follow-up, 523 hip fractures were reported. Adjusted for age, smoking, body mass index, waist/hip ratio, and estrogen use, the relative risk of hip fracture in women who reported always having irregular menstrual cycles, compared with women who never had irregular cycles, was 1.36 (95% confidence interval (CI): 1.03, 1.78). Women who reported having irregular menstrual bleeding duration had a 1.40-fold (95% CI: 1.10, 1.78) increased risk of hip fracture compared with women with regular bleeding duration. In addition, women who reported having both irregular menstrual cycles and irregular menstrual bleeding had a 1.82-fold (95% CI: 1.55, 2.15) higher risk of hip fracture than did women who reported neither irregularity. Women who reported only one menstrual disturbance did not have a risk of hip fracture that was significantly different from women who reported no menstrual disturbances. The authors conclude that women with menstrual irregularities are at increased risk of hip fracture, probably because they are estrogen or progesterone deficient.

Background and Aims: Nonalcoholic fatty liver disease (NAFLD) is a global health problem, and dietary intervention is still considered one of the primary interventions. This study aimed to examine cross-sectional associations between dietary and serum levels of folate and NAFLD. Methods: We conducted a study of 7543 adults who participated in the National Health and Nutrition Examination Survey, 2009-2018. NAFLD status was determined by a fatty liver index (FLI) value ≥60. Multivariable logistic regression models were used to estimate associations between folate and NAFLD. Results: Almost half (45%) of the patients were classified as having NAFLD based on the FLI. In the fully adjusted model, participants in the highest quartile of dietary total folate and food folate were found to have a lower prevalence of NAFLD than those in the lowest quartile [odds ratio (OR)quartile 4 versus 1 = 0.582; 95% confidence interval (CI) = 0.350-0.968; and ORquartile 4 versus 1 = 0.737; 95% CI = 0.611-0.888, respectively], and the fourth quartile values of serum total folate and 5-methyl-tetrahydrofolate were significantly negatively associated with NAFLD prevalence (ORquartile 4 versus 1 = 0.664; 95% CI = 0.495-0.891; and ORquartile 4 versus 1 = 0.712; 95% CI = 0.532-0.954, respectively). Subgroup analyses revealed that this beneficial association was more significant in women (ORquartile 4 versus 1 = 0.526; 95% CI = 0.329-0.843; pinteraction < 0.001) than in men (ORquartile 4 versus 1 = 0.805; 95% CI = 0.546-1.186). Conclusions: Higher dietary folate intake and serum folate levels are associated with a lower NAFLD prevalence among U.S. adults and the trend is more pronounced among women, indicating opportunities for dietary NAFLD interventions.

Primary Sjögren's syndrome (pSS) is a progressive systemic autoimmune disorder with a strong female predominance. Hormonal influences are thought to play a role in the development of pSS. However, no studies have specifically evaluated the association between irregular menstrual cycles and pSS. Therefore, using a health claims database, this study investigated the risk of pSS in women with irregular menstrual cycles. We conducted a case-control study using the Taiwan's National Health Insurance Research Database. A total of 360 patients diagnosed with pSS (International Classification of Diseases, ninth revision, clinical modification, ICD-9-CM code 710.2) between 2001 and 2012 were identified. Controls were frequency-matched at a rate of 5:1 to the cases by five-year age interval and index year. Both cases and controls were retrospectively traced back until 2001 for the diagnosis of irregular menstrual cycles (ICD-9-CM code 626.4). The risk of pSS was assessed using multivariate logistic regression analyses. Irregular menstrual cycles were significantly associated with pSS [adjusted odds ratio, (AOR) = 1.38, p = 0.027], after adjusted for insured amount, urbanization level, and thyroid disorder. In addition, when the data were stratified by three age categories, only the patients in the age category of 45-55 years showed significant association between irregular menstrual cycles and pSS (AOR = 1.74, p = 0.005). In this nationwide, population-based case-control study, we found a significant increased risk of pSS in female patients with irregular menstrual cycles, particularly those in their mid-forties to mid-fifties.

The fatty liver index (FLI) predicts fatty liver by using BMI, waist circumference, γ-glutamyltransferase and triglycerides. We investigated the association between the FLI and the risk of type 2 diabetes and evaluated to what extent single FLI components contribute to the diabetes risk. We analysed a case-cohort study (random sub-cohort: 1922; incident cases: 563) nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study. The proportion of exposure effect (PEE) explained by single FLI components was evaluated and effect decomposition using inverse probability weighting (IPW) was applied. Women and men with a FLI ≥60 compared to those with a FLI <30 had a multivariable-adjusted Hazard Ratio (HR) of 17.6; 95% confidence interval (CI) 11.1-28.0 and HR: 10.9; 95% CI 6.22-19.2, respectively. Adjustment for BMI or waist circumference attenuated this association in men [PEEBMI (95% CI) = 53.8% (43.9%-65.8%); PEEwaist (95% CI) = 54.8% (44.2%-68.8%)]. In women, adjustment for waist circumference attenuated the association to a lesser degree than in men [PEEwaist (95% CI) = 31.1%; (21.9%-43.1%)] while BMI had no appreciable effect [PEEBMI (95% CI) = 11.0% (2.68%-21.0%)]. γ-glutamyltransferase and triglycerides showed only a small attenuation in women [PEEGGT(95% CI) = 3.11% (-0.72%-4.48%); PEETG (95% CI) = 6.36% (3.81%-9.92%)] and in men [PEEGGT = 0%; PEETG (95% CI) = 6.23% (2.03%-11.8%)]. In women, the total effect was decomposed into a direct effect and 4 indirect effects (HRBMI = 1.10; HRwaist = 1.28; HRGGT = 0.97 and HRTG = 1.03). In men, the 4 indirect effects were HRBMI = 1.25; HRwaist = 1.29; HRGGT = 0.97 and HRTG = 0.99. These data suggest that the FLI, as a proxy for fatty liver, is associated with risk of type 2 diabetes. This association is only partly explained by standard estimates of overall and abdominal body fatness, particularly among women.

To determine whether high heart rate is associated with low bone mineral density (BMD) in older women with hypertension. Retrospective cohort study. Population-based study conducted in Korea (Korea National Health and Nutritional Examination Survey 2009-10). Postmenopausal women aged 60 and older with hypertension (N=981) divided into 2 groups according to resting heart rate, with a cut-off value of 80 bpm, which has been found to be associated with osteoporosis. BMD profiles and clinical and laboratory data were collected. Osteoporosis was defined as a T-score of -2.5 or less, according to World Health Organization criteria. BMD was significantly lower in participants with a high heart rate, even after adjustment for age, diabetes mellitus, white blood cell count, and fasting glucose and triglyceride levels. The prevalence of osteoporosis was also significantly higher in those participants. In multivariate logistic regression analysis, the group with high heart rate was 1.7 times as likely (95% confidence interval=1.2-2.3) to have osteoporosis as those with a lower heart rate, independent of age, body mass index, comorbidities, and laboratory findings. High heart rate is independently associated with lower BMD in older women with hypertension; proactive surveillance of BMD could be helpful when managing older women with hypertension and a high heart rate.

Atrial fibrillation (AF) is the most diagnosed arrhythmia in clinical settings. The fatty liver index (FLI) is a marker of liver steatosis with potential cardiovascular implications. This study investigated whether FLI could predict the risk of AF.Methods and Results: We used data from the Suita Study, a Japanese population-based prospective cohort study. A total of 2,346 men and 3,543 women, aged 30-84 years, without prevalent AF were included and followed up. The diagnosis of AF was established during follow-up using electrocardiograms, hospital records, and death certificates. FLI was assessed during a baseline health checkup. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated for incident AF per FLI quintile and log-transformed FLI. Within a median 14.5 years of follow-up, 142 men and 105 women developed AF. Compared with women in the third (middle) FLI quintile, women in the first (lowest), fourth, and fifth (highest) quintiles showed a higher risk of AF, with multivariable-adjusted HRs of 2.37 (95% CI 1.06-5.31), 2.60 (95% CI 1.30-5.17), and 2.04 (95% CI 1.00-4.18), respectively. No corresponding associations were observed in men. The change in log-transformed FLI was not associated with the risk of AF in either sex. A U-shaped association between FLI and AF risk was detected in Japanese women. FLI could be a screening tool to detect women at high risk of developing AF.