Mean residual life cure models for right-censored data with and without length-biased sampling.

We propose a semiparametric mean residual life mixture cure model for right-censored survival data with a cured fraction. The model employs the proportional mean residual life model to describe the effects of covariates on the mean residual time of uncured subjects and the logistic regression model to describe the effects of covariates on the cure rate. We develop estimating equations to estimate the proposed cure model for the right-censored data with and without length-biased sampling, the latter is often found in prevalent cohort studies. In particular, we propose two estimating equations to estimate the effects of covariates in the cure rate and a method to combine them to improve the estimation efficiency. The consistency and asymptotic normality of the proposed estimates are established. The finite sample performance of the estimates is confirmed with simulations. The proposed estimation methods are applied to a clinical trial study on melanoma and a prevalent cohort study on early-onset type 2 diabetes mellitus.

Maximum likelihood estimation for length-biased and interval-censored data with a nonsusceptible fraction.

Left-truncated data are often encountered in epidemiological cohort studies, where individuals are recruited according to a certain cross-sectional sampling criterion. Length-biased data, a special case of left-truncated data, assume that the incidence of the initial event follows a homogeneous Poisson process. In this article, we consider an analysis of length-biased and interval-censored data with a nonsusceptible fraction. We first point out the importance of a well-defined target population, which depends on the prior knowledge for the support of the failure times of susceptible individuals. Given the target population, we proceed with a length-biased sampling and draw valid inferences from a length-biased sample. When there is no covariate, we show that it suffices to consider a discrete version of the survival function for the susceptible individuals with jump points at the left endpoints of the censoring intervals when maximizing the full likelihood function, and propose an EM algorithm to obtain the nonparametric maximum likelihood estimates of nonsusceptible rate and the survival function of the susceptible individuals. We also develop a novel graphical method for assessing the stationarity assumption. When covariates are present, we consider the Cox proportional hazards model for the survival time of the susceptible individuals and the logistic regression model for the probability of being susceptible. We construct the full likelihood function and obtain the nonparametric maximum likelihood estimates of the regression parameters by employing the EM algorithm. The large sample properties of the estimates are established. The performance of the method is assessed by simulations. The proposed model and method are applied to data from an early-onset diabetes mellitus study.

Household structure and concurrent stunting and overweight among young children in Indonesia.

OBJECTIVE: To examine the association of household type and household composition with concurrent stunting and overweight in young children from urban and rural Indonesia. DESIGN: This study is a secondary data analysis using a nationally representative cross-sectional survey. Household structure was analysed as household type, household size, number of working adults, number of dependent adults and children, and household head's gender. We defined 'concurrent stunting and overweight' as height-for-age Z-score <-2 and weight-for-height Z-score >+2 based on WHO growth standards. Multivariable logistic regression to test the aforementioned association was performed separately for urban and rural areas. SETTING: Data were from Indonesia Basic Heath Research 2013. PARTICIPANTS: Children aged 2-5 years (n 45 050). RESULTS: The prevalence of concurrent stunting and overweight children was 5·6 %. In rural areas, this prevalence differed significantly by household types and the highest prevalence was among children in nuclear two-parent households (6·8 %). In rural areas, children in extended households had lower odds of concurrent stunting and overweight than those from nuclear households (OR = 0·73, 95 % CI 0·59, 0·92). In urban areas, household size and number of working adults were significantly associated with the decreased odds of concurrent stunting and overweight in children. CONCLUSIONS: Household structure was associated with children's concurrent stunting and overweight in urban and rural regions of Indonesia. The patterns of the association might differ between urban and rural regions, but no significant interaction term was found.

Age, period and birth cohort effects on the prevalence of overweight and obesity among Taiwanese adolescents: a national population-based study.

BACKGROUND: The age-period-cohort effects on youth overweight and obesity among junior and senior high school students in Taiwan is not clear. METHODS: We utilized the 2006-14 nationally representative School Physical Fitness Dataset. Based on the International Obesity Task Force cut-off criteria, a log-linear age-period-cohort analysis was performed to determine the influence of age, period and cohort on the trend in being overweight, obese and severely obese for both sexes. RESULTS: The final dataset included 1073173 individuals (n = 520 382 boys and 552 791 girls). For girls, the prevalence of overweight and obesity declined with age, and the prevalence of overweight declined over time. For boys, the prevalence of overweight and obesity declined with age and over time from 2006 to 2014. The prevalence of severe obesity declined over time and increased with age for the boys. The younger birth cohorts had greater odds of being overweight, obese and severely obese than the older birth cohorts. CONCLUSIONS: After differentiating the age-period-cohort effects, the data suggested a decreasing temporal trend in overweight and obesity among adolescents in Taiwan from 2006 to 2014. Among the birth cohorts of the 1990s, the younger cohorts had greater odds of being overweight and obese than the older cohorts when they reached adolescence.

Gender differences and burden of chronic conditions: impact on quality of life among the elderly in Taiwan.

BACKGROUND: Multiple chronic conditions affect people's health-related quality of life (QoL) and the distributions of the conditions may differ between genders. Our goal was to examine gender differences in chronic conditions and QoL among community-living elderly in Taiwan and to examine whether differences in QoL between genders, if present, were attributable to the distribution of chronic conditions. METHODS: We used data from the Nutrition and Health Survey in Taiwan (NAHSIT, 2005-2008), which interviewed a representative sample of the Taiwanese population. The survey questions included the SF-36 questionnaire to assess participants' QoL and items for participants' medical history. We used multiple linear regressions to examine the difference in QoL between genders. RESULTS: We included 1179 elders for our analysis; men accounted for 52% (612/1179). The mean age was 73; women were slightly younger. The mean (standard deviation) of SF-36 physical and mental health component score (PCS and MCS) was 44.5 (11.1) and 55.6 (9.0), respectively, and women reported a significantly lower PCS than men (difference - 4.85, p < 0.001). Urinary incontinence, arthritis, stroke, and kidney disease were associated with a clinically meaningful decrease in PCS (≤ - 6.5 points). The difference in PCS between genders was not attenuated after we accounted for chronic conditions in regression analysis. CONCLUSIONS: Our findings suggest that women tend to report that their physical health-related QoL is poorer than that of men, and such a difference does not seem to be attributable to the distribution of chronic conditions. Elderly men and women may perceive health-related QoL differently.

NASA Mission X Program for Healthy Eating and Active Living among Taiwanese Elementary School Students.

PURPOSE: This study assessed the effects of an intervention program adapted from the NASA Mission X (MX) program on children's Healthy Eating Active Living (HEAL) knowledge and behaviors and anthropometry. METHODS: This clustered randomized control trial recruited 8 elementary schools in remote rural areas of Northern Taiwan. The intervention was the 8-week MX program. All the 3rd and 4th graders were invited to the study (n = 245). Children's weight, height, HEAL knowledge and behaviors were measured pre- and post-intervention. RESULTS: The intervention group had significantly more improvements than control group in physical activity knowledge score (+0.91 vs. +0.25, p = 0.002), diet knowledge score (+0.62 vs. +0.17, p = 0.044), and score of interests in NASA and space exploration (+0.34 vs. -0.07, p < 0.0001). BMI increased from 18.4 to 18.6 (p < 0.05) for the control group but did not change for the intervention group. The changes in BMI between groups did not differ significantly. CONCLUSION AND PRACTICE IMPLICATIONS: This randomized controlled trial showed that the NASA MX program was feasible and acceptable among children in Taiwan, and improved children's HEAL knowledge. (ClinicalTrials.gov registration: NCT03355131).

Employment status and temporal patterns of energy intake: Nutrition and Health Survey in Taiwan, 2005-2008.

OBJECTIVE: To (i) identify the major temporal patterns of energy intake among adults; (ii) examine the association between employment status and the patterns; and (iii) examine the association between dietary quality and the patterns. DESIGN: Secondary analysis based on the cross-sectional population-based nutrition survey in Taiwan, 2005-2008. Based on energy intake levels at six time intervals of a day derived from 24 h recall data, we applied cluster analysis to identify major temporal patterns of energy intake. Self-reported employment status was categorized into six groups: full-time, part-time, no job, student, homemaker and retired. Multinomial logistic regression models were fitted to test the association between temporal patterns of energy intake and employment groups. SETTING: Non-institutionalized community dwellers. SUBJECTS: Non-pregnant adults (≥19 years old) with total energy intake between 2092 and 20920 kJ/d (500 and 5000 kcal/d; n 4508). RESULTS: Five major patterns were identified, which can be seen as the traditional meal pattern and its variants. About 20 % of adults had the traditional pattern. The most prevalent pattern was the delayed morning meal pattern (33 %), which had lower Ca and P intakes than the traditional pattern. About 14 % of adults had the delayed lunchtime pattern, which had lower protein, PUFA, fibre, Ca, P, vitamin D and vitamin E intakes than the traditional. Adjusted prevalence of the delayed lunchtime pattern was highest among full-time students (34 %), followed by part-time workers (24 %), and was lower in retired (8 %), homemakers (11 %) and full-time employed adults (12 %). CONCLUSION: Adults' temporal patterns of energy intake, which varied with their employment status, affected their dietary quality.

Association between obesity with low muscle mass and dialysis mortality.

BACKGROUND/AIM: To examine the association between body composition and dialysis mortality. METHODS: Adult patients who underwent haemodialysis in Taoyuan General Hospital from 2012 to 2016 were enrolled. We reviewed their baseline characteristics and followed up their treatment over 5 years after dialysis. Patients with body mass index >25 kg/m2 were defined as obese. High or low muscle mass were classified by skeletal muscle mass index (SMMI) based on consensus from Chinese population. All age-matched subjects were classified into four groups: (A) optimal; (B) obesity; (C) low muscle mass; and (D) obesity with low muscle mass. Adjusted hazard ratios for mortality and cumulative survival curves were evaluated by Cox proportional hazard model and Kaplan-Meier method. The discriminative power of SMMI was calculated according to the area under the curve and the receiver operating characteristic curve. RESULTS: From a total of 176 age-matched patients, the incidence rates of mortality for different groups were 3.7, 7.8, 10.3 and 16.5 per 1000 person-months. After adjusting for continuous variables, SMMI was independently associated with mortality. The difference between groups A and D was more significant in women than in men after multivariate adjustment (adjusted hazard ratios: 7.465 vs 1.682) (P = 0.035 and 0.553). The discriminative power of SMMI to predict 5-year mortality was 0.700 for men and 0.750 for women, and the best cut-off values were 11.1 and 8.4 kg/m2 CONCLUSIONS: Low muscle mass was associated with dialysis mortality. Obesity with low muscle mass was a predictor for dialysis mortality in women.

The changing food outlet distributions and local contextual factors in the United States.

BACKGROUND: Little is known about the dynamics of the food outlet distributions associated with local contextual factors in the U.S. This study examines the changes in food stores/services at the 5-digit Zip Code Tabulated Area (ZCTA5) level in the U.S., and assesses contextual factors associated with the changes. METHODS: Data from 27,878 ZCTA5s in the contiguous United States without an extreme change in the number of 6 types of food stores/services (supermarkets, small-size grocery stores, convenience stores, fresh/specialty food markets, carry-out restaurants, and full-service restaurants) were used. ZCTA5s' contextual factors were from the 2000 Census. Numbers of food stores/services were derived from the Census Business Pattern databases. Linear regression models assessed contextual factors' influences (racial/ethnic compositions, poverty rate, urbanization level, and foreign-born population%) on 1-year changes in food stores/services during 2000-2001, adjusted for population size, total business change, and census regions. RESULTS: Small-size grocery stores and fresh/specialty food markets increased more and convenience stores decreased more in Hispanic-predominant than other areas. Among supermarket-free places, new supermarkets were less likely to be introduced into black-predominant than white-predominant areas (odds ratio (OR) = 0.52, 95% CI = 0.30-0.92). However, among areas without the following type of store at baseline, supermarket (OR = 0.48 (0.33-0.70)), small-size grocery stores (OR = 1.32 (1.08-1.62)), and fresh/specialty food markets (OR = 0.70 (0.53-0.92)) were less likely to be introduced into areas of low foreign-born population than into areas of high foreign-born population. Higher poverty rate was associated with a greater decrease in supermarket, a less decrease in small-size grocery stores, and a less increase in carry-out restaurants (all p for trends <0.001). Urban areas experienced more increases in full-service and carry-out restaurants than suburban areas. CONCLUSIONS: Local area characteristics affect 1-year changes in food environment in the U.S. Hispanic population was associated with more food stores/services capable of supplying fresh food items. Black-predominant and poverty-afflicted areas had a greater decrease in supermarkets. Full-service and carry-out restaurants increased more in urban than suburban areas. Foreign-born population density was associated with introduction of grocery stores and fresh/specialty food markets into the areas.

Examining social norm impacts on obesity and eating behaviors among US school children based on agent-based model.

BACKGROUND: Although the importance of social norms in affecting health behaviors is widely recognized, the current understanding of the social norm effects on obesity is limited due to data and methodology limitations. This study aims to use nontraditional innovative systems methods to examine: a) the effects of social norms on school children's BMI growth and fruit and vegetable (FV) consumption, and b) the effects of misperceptions of social norms on US children's BMI growth. METHODS: We built an agent-based model (ABM) in a utility maximization framework and parameterized the model based on empirical longitudinal data collected in a US nationally representative study, the Early Childhood Longitudinal Study - Kindergarten Cohort (ECLS-K), to test potential mechanisms of social norm affecting children's BMI growth and FV consumption. RESULTS: Intraclass correlation coefficients (ICC) for BMI were 0.064-0.065, suggesting that children's BMI were similar within each school. The correlation between observed and ABM-predicted BMI was 0.87, indicating the validity of our ABM. Our simulations suggested the follow-the-average social norm acts as an endogenous stabilizer, which automatically adjusts positive and negative deviance of an individual's BMI from the group mean of a social network. One unit of BMI below the social average may lead to 0.025 unit increase in BMI per year for each child; asymmetrically, one unit of BMI above the social average, may only cause 0.015 unit of BMI reduction. Gender difference was apparent. Social norms have less impact on weight reduction among girls, and a greater impact promoting weight increase among boys. Our simulation also showed misperception of the social norm would push up the mean BMI and cause the distribution to be more skewed to the left. Our simulation results did not provide strong support for the role of social norms on FV consumption. CONCLUSIONS: Social norm influences US children's BMI growth. High obesity prevalence will lead to a continuous increase in children's BMI due to increased socially acceptable mean BMI. Interventions promoting healthy body image and desirable socially acceptable BMI should be implemented to control childhood obesity epidemic.

Effect of recommendations of breakfast and late-evening snack habits on body composition and blood pressure: A pilot randomized trial.

Breakfast skipping and late-evening snack are prevalent in young adults. This randomized controlled intervention aimed to evaluate the influence of meal habit recommendations on young adults' body composition and blood pressure. Nonpregnant adults (≥20 y old) who were eligible for bioelectrical impedance analysis examination (neither pacemaker installed nor medications that would affect body composition, like diuretics or corticosteroids) were enrolled after they provided informed consent (n = 125). Subjects were randomized into three groups, every group receiving one of the following recommendations: (a) daily breakfast consumption (within 2 h after waking up), (b) avoidance of late-evening snacks (after 21:00h or within 4 h before sleep, with the exception of water), and (c) both recommendations. Body composition and blood pressure were measured before randomization at baseline and at the follow-up 1 y later. Intent-to-treat analysis showed that the recommendation of daily breakfast may contribute to a lower increment of diastolic blood pressure by 3.23 mmHg (95% CI: 0.17-6.28). Receiving the breakfast recommendation was associated with more reduction of total body fat percent by 2.99% (95% CI: 0.23-5.74) and percent trunk fat by 3.63% (95% CI: 0.40-6.86) in inactive youths. Recommendation of avoiding late-evening snack did not significantly affect the outcome measures (ClinicalTrials.gov Identifier: NCT03828812).

Influence of school beverage environment on the association of beverage consumption with physical education participation among US adolescents.

OBJECTIVES: We examined the association of adolescents' beverage consumption with physical activity and studied how their school beverage environment influences the association. METHODS: We used nationally representative data from the 2007 Early Childhood Longitudinal Study-Kindergarten Cohort (n = 8850). We examined nonlinear associations of eighth graders' self-report of beverage consumption (milk, 100% juices, soft drinks) with moderate to vigorous physical activity and physical education (PE) participation using piecewise linear regression models. RESULTS: We found a nonlinear association of participation in PE class with beverage consumption, especially in schools with vending machines and those selling soft drinks. For students participating in PE less than 3 days per week, beverage consumption was not significantly associated with participation in PE class frequency. For students participating in PE 3 to 5 days per week, 1 more day of participation in PE class was associated with 0.43 (SE = 0.14; P = .002) more times per week of soft drink consumption and 0.41 (SE = 0.17; P = .021) fewer glasses per week of milk consumption. CONCLUSIONS: The more soft drink and less milk consumption related to high participation in PE class might be prevented by improving the beverage environment in schools. Systematic environmental interventions are needed to prevent such potential unintended consequences of promoting physical activity.

Race, place, and obesity: the complex relationships among community racial/ethnic composition, individual race/ethnicity, and obesity in the United States.

OBJECTIVES: We explored the association between community racial/ethnic composition and obesity risk. METHODS: In this cross-sectional study, we used nationally representative data from the Medical Expenditure Panel Survey linked to geographic data from the US Decennial Census and Census Business Pattern data. RESULTS: Living in communities with a high Hispanic concentration (≥ 25%) was associated with a 0.55 and 0.42 increase in body mass index (BMI; defined as weight in kilograms divided by the square of height in meters) and 21% and 23% higher odds for obesity for Hispanics and non-Hispanic Whites, respectively. Living in a community with a high non-Hispanic Asian concentration (≥ 25%) was associated with a 0.68 decrease in BMI and 28% lower odds for obesity for non-Hispanic Whites. We controlled for individual- and community-level social, economic, and demographic variables. CONCLUSIONS: Community racial/ethnic composition is an important correlate of obesity risk, but the relationship differs greatly by individual race/ethnicity. To better understand the obesity epidemic and related racial/ethnic disparities, more must be learned about community-level risk factors, especially how built environment and social norms operate within communities and across racial/ethnic groups.

Common carotid end-diastolic velocity and intima-media thickness jointly predict ischemic stroke in Taiwan.

BACKGROUND AND PURPOSE: In Asian populations, few studies investigated the association between stroke and common carotid artery intima-media thickness (IMT). Our previous case-control studies showed that low end-diastolic velocity (EDV) in common carotid artery, a potential hemodynamic marker of intracranial resistance, was associated with ischemic stroke. Therefore, we investigated the relationship between both EDV and IMT and incident ischemic stroke in an Asian population. METHODS: Baseline data from 3175 adults (30 years or older) in the Cardiovascular Diseases Risk Factor Two-Township Study were linked to incidental ischemic stroke status derived from insurance claims and death certificate records. Hazard ratios for risk of ischemic stroke for high IMT and low EDV values measured in common carotid artery were calculated using Cox proportional hazard models. RESULTS: With 9.85 years (median) of follow-up, 184 persons had ischemic stroke develop. Compared with the first tertile of IMT, hazard ratios were 2.03 (95% confidence intervals, 1.27-3.25) for the second tertile and 3.87 (95% confidence intervals, 2.36-5.69) for the third tertile. Hazard ratios of EDV were 5.31 (95% confidence intervals, 3.52-7.99; first tertile) and 1.94 (95% confidence intervals, 1.21-3.09; second tertile) compared with the third tertile. The individuals with high IMT and low EDV had >2-fold ischemic stroke risk compared to those with low IMT and high EDV (2.10; 95% confidence intervals, 1.35-3.26) after adjusting for age, sex, and traditional cardiovascular risk. CONCLUSIONS: Common carotid IMT and EDV jointly and independently predicted future ischemic stroke in this Taiwanese population. More prospective studies are required in various ethnic groups to understand the significance and implication of the current findings, particularly with respect to EDV.

Adolescents' Physical Activity and the Association With Perceived Social Support of Parents and Peers in Indonesia.

This study examined the trends of adolescents' physical activity (PA) and its association with parental and peer support, based on the Indonesia Global School-Based Health Survey. Between 2007 and 2015, prevalence of PA in adolescents declined from 24.4% to 16.5%. Prevalence of active transportation (AT) decreased from 47.2% to 32.3%. Prevalence of sedentary leisure behavior (SLB) declined from 33.6% to 27.2%. Girls' SLB was inversely associated with parental supervision SLB in 2007 (odds ratio [OR] = 0.49; 95% CI = 0.30-0.80) and in 2015 (adjusted OR [AOR] = 0.55; 95% CI = 0.43-0.71), and so was boys' SLB in 2015 (OR = 0.75; 95% CI = 0.59-0.95). Boys' AT was inversely associated with peer support in 2015 (OR = 0.73; 95% CI = 0.59-0.91). Parental control was associated with PA in girls (OR = 1.71; 95% CI = 1.23-2.37), in boys (OR = 1.65; 95% CI = 1.07-2.54), and with SLB among girls in 2015 (OR = 1.28; 95% CI = 1.11-1.47). Hence, adolescents' PA was associated with perceived social support.

Dietary knowledge, preferences and behaviors in Ramadan among Muslim patients with type 2 diabetes.

AIMS: To explore the association between dietary knowledge, attitude, and practices during Ramadan among Muslim patients with type 2 diabetes. METHODS: Recruited after Ramadan from public clinics and a hospital in Banda Aceh, Indonesia, 401 outpatients recalled their food consumption frequencies of high-fiber food, deep-fried food, and high-sugar dessert, and relevant knowledge and attitudes. Multivariable logistic regression models were applied to examine the research questions. RESULTS: Vegetable consumption and preference were both high among the patients. However, only 4.5% knew that brown rice is rich in fiber, and 19% agreed that whole-grain foods were accessible. Deep-fried food consumption and its availability at home was common, even though the majority considered it should be avoided. Patients with a lower preference for deep-fried foods were less likely to consume deep-fried foods during Ramadan (OR = 0.239, 95% CI = 0.109-0.523, p = 0.001). Knowledge of the glycemic index's health implication was associated with more high-fiber foods consumption (OR = 2.733, 95% CI = 1.179-6.332, p = 0.019). Yet, knowing the potential risk of added sugar on blood glucose level was associated with high-sugar dessert consumption (OR = 2.997, 95% CI = 1.482-6.060, p = 0.002). CONCLUSION: The patients' low consumption of whole-grain food and common comsumption of deep-fried food during Ramadan would be the first priority to be improved. Along with dietary knowledge and attitude, food environment could be an important factor that influences patients' dietary behaviors.

Hepatic extravasation complicated by umbilical venous catheterization in neonates: A 5-year, single-center experience.

BACKGROUND: Care of newborns in the neonatal intensive care unit generally involves umbilical venous catheterization (UVC) for central vein access to enable medical needs. The study aimed to evaluate the sonographic appearance, risk factors, and outcomes of UVC-related hepatic extravasation (HE) in neonates. METHODS: A 5-year retrospective study where 33 neonates were enrolled with a diagnosis age ranging from 2 to 25 days. 78.8% of the subjects had UVC malpositioning shown on initial radiography. All neonates sonographically diagnosed with HE, and follow-up ultrasound (US) was performed. RESULTS: The main findings of HE on US were hyperechoic or heterogeneous lesions of a lobulated (51.7%) or wedge shape (48.3%), located mainly in the left lobe (72.7%). The mean time to resolution of HE was 2.25 months. Seven (21.2%) patients showed hepatic vascular thrombosis at follow-up. Two (6%) patients had abnormal liver function, which subsequently normalized. CONCLUSION: Malposition of the UV catheter was the predisposing factor for UVC-related HE in neonates. US facilitates detection of UVC malpositioning and diagnosis of HE, as well as delayed complications. A shorter duration of UVC placement is associated with favorable outcomes of UVC-related HE in neonates.

Secular trends and associated factors of age at natural menopause in Taiwanese women.

OBJECTIVE: Age at natural menopause (ANM) is considered an indicator for chronic disease and mortality risk in later life. Research suggests that ANM appears to vary across geographic regions and ethnicities. The aim of this study was to explore the secular trends and factors associated with ANM in Taiwanese women. METHODS: We used data from three cross-sectional phases of the Nutrition and Health Survey in Taiwan. In all, 4,111 women aged 35 years and over were included. Information on ANM and sociodemographics, lifestyle, and health factors were collected using household questionnaires. A Cox proportional-hazards model was used to determine the association of ANM with relevant factors, and a life table method was used to estimate median ANM. RESULTS: Life table method estimated the median ANM to be 50 years. ANM was getting later for women born in younger cohorts (hazard ratio [HR] 0.87 per 10-year difference, 95% confidence interval [CI] 0.81-0.95). ANM was also later among women who achieved higher educational levels (HR 0.91 per one-category difference, 95% CI 0.86-0.96) and who had been married (HR 0.64, 95% CI 0.42-0.96). ANM occurred later for parous than for nulliparous women. Multivariable analysis found no significant associations of ANM with age at menarche, smoking, or alcohol drinking. CONCLUSIONS: The results suggest that women in the younger cohorts, with higher educational levels, and who are parous and married may have later ANM. The trend effect of secular time and educational levels on ANM may reflect the influences of socioeconomic/nutritional status in their childhood or throughout their lifetime.

Is ischemic stroke risk related to folate status or other nutrients correlated with folate intake?

BACKGROUND AND PURPOSE: Folate status was inversely associated with plasma homocysteine concentration, a potential risk factor of cardiovascular disease. However, it is uncertain whether folate is causally associated with risk of ischemic stroke (IS). We aimed to examine the association between IS incidence and folate intake, biochemical folate status, and folate associated nutrients. METHODS: Information on baseline characteristics and food frequency questionnaire was collected in 1990 to 1993 and included for analyses data from 1772 adults over 40 years, who were free of stroke and cancer at baseline from the CardioVascular Disease risk FACtor Two-township Study. Multivariate Cox proportional hazard model was used to relate baseline nutrient status with IS event. RESULTS: Over an average of 10.6 years of follow-up, 132 incident IS events were documented. Low folate intake (1st and 2nd quartiles) was significantly and independently associated with increased IS risk (HR=1.61; 95% CI: 1.04 to 2.48 and HR=1.82; 95% CI: 1.20 to 2.76) compared with those in the 3rd and 4th quartile combined, whereas no association was observed for plasma folate concentration. On the other hand, several nutrients correlated with dietary folate: vitamin B2, potassium, iron, vitamin A of plant origin, calcium were also associated with IS risk in an inverse linear manner with HR ranging from 1.5 to 1.9 for the first quartile. CONCLUSIONS: The protective association of dietary folate on IS risk may be in part through that of other correlated nutrients or other dietary components.