Buyun Liu

• MD, PhD
• PostDoc Position at University of Iowa

Importance Polybrominated diphenyl ethers (PBDEs) are an important group of persistent organic pollutants with endocrine-disrupting properties. However, prospective cohort studies regarding the association of PBDE exposure with long-term health outcomes, particularly mortality, are lacking. Objective To examine the association of environmental exp...

Objective: Oleic acid, a subtype of monounsaturated fatty acid (MUFA), is present in abundance in certain edible oils, particularly olive oils. Epidemiological evidence concerning dietary oleic acid intake and the long-term risk of mortality is lacking. This study aimed to evaluate the associations of the dietary intake of oleic acid and other spec...

Few studies have investigated the potential combined effects of multiple PCB congeners on diabetes. To address this gap, we used data from 1244 adults in the National Health and Nutrition Examination Survey (NHANES) 2003–2004. We used (1) classification trees to identify serum PCB congeners and their thresholds associated with diabetes; and (2) log...

Objective Coronavirus Disease-19 (COVID-19) has become a global pandemic, and mental health of children and parents are affected by confinement in home. Since the outbreak of COVID-19 is still global pandemic currently, it is important to examine how the changes of children’s behaviors and parent–child relationship affect parental anxiety during th...

Background: Procyanidins have antioxidative properties that may protect against age-related brain oxidative stress. Previous studies indicated that procyanidin-rich foods could improve cognitive function and prevent neurodegenerative diseases. This study hypothesized that grape seed procyanidins extract (GSPE) would have a favorable effect on cogn...

Background To evaluate the association between the dietary inflammatory index (DII ® ) and incident cardiovascular disease (CVD) in Hispanic women from the Women’s Health Initiative (WHI), and to determine if body mass index (BMI) interacted with the DII scores. Methods Secondary analysis of baseline dietary data and long-term CVD outcomes among 3...

Background Adding salt at the table is a prevalent eating habit, but its long-term relationship with cardiovascular disease (CVD) and all-cause mortality remains unclear. We evaluated the associations of adding salt at the table with the risk of incident CVD and all-cause mortality. Methods Among 413,109 middle- and old-aged adults without cancer...

Pregnancy represents a critical window for both maternal and child health. Previous studies have shown that consumption of an organic diet during pregnancy can reduce pesticide exposure compared to consumption of a conventional diet. It is plausible that this could, in turn, improve pregnancy outcomes, because maternal pesticide exposure during pre...

Background: Chocolate contains both potentially harmful components (ie, stearic acid and added sugar) and beneficial components (ie, phenolics and flavonoids). Despite its popularity, the long-term health effects of chocolate consumption remain unclear. Objective: The aim of this study was to examine the association of chocolate consumption with...

Background: Previous attempts to identify low-carbohydrate diets (LCDs) in epidemiological studies relied on the LCD Score, which is unable to identify ketogenic dieters. Ketogenic ratios of macronutrients are clinical equations proposed to predict ketogenic diets; however, their utility in epidemiological studies is unknown. Objective: To deter...

Background: Vitamin D plays an essential role in immune responses to infections. However, the association between serum 25(OH)D concentrations and respiratory infection remains unclear. Objectives: The current study aimed to examine the association between serum 25(OH)D concentrations and respiratory infection among the United States adults. Me...

Background: Previous experimental studies showed that limiting methionine in the diet of animals or in cell culture media suppresses mammary cancer cell proliferation or metastasis. However, no previous study has investigated the associations of changes in methionine intake with survival among breast cancer survivors. We aimed to examine the assoc...

Background Previous dietary studies and current dietary guidelines have mainly focused on dietary intake and food patterns. Little is known about the association between eating behaviors such as meal frequency, skipping and intervals, and mortality. Objective The objective was to examine the associations of meal frequency, skipping and intervals w...

Background Current cholesterol guidelines have recommended very low low‐density lipoprotein cholesterol (LDL‐C) treatment targets for people at high risk of cardiovascular disease (CVD). However, recent observational studies indicated that very low LDL‐C levels may be associated with increased mortality and other adverse outcomes. The association b...

This cross-sectional study estimates the prevalence of autism spectrum disorder in children and adolescents aged 3 to 17 years in the US in 2019 and 2020.

Background Hypoalbuminemia is common among individuals with obesity who qualify for bariatric surgery, but its relevance to clinical outcomes after bariatric surgery remains to be established. Objectives To examine the association of pre-operative serum albumin with 30-day post-operative outcomes. Setting Data from the 2015-2019 Metabolic and Bar...

Background Multiple sclerosis (MS) has been associated with increased mortality ratios, but few studies have investigated the independent association of MS with mortality. Objective To examine the prospective association of MS with risk of mortality in a nationally representative sample of U.S. adults. Methods This prospective study included 23,0...

Background: n-3 and n-6 PUFAs have physiologic roles in sleep processes, but little is known regarding circulating n-3 and n-6 PUFA and sleep parameters. Objectives: We sought to assess associations between biomarkers of n-3 and n-6 PUFA intake with self-reported sleep duration and difficulty falling sleeping in the Fatty Acids and Outcome Resea...

Background: Previous studies have predominately examined associations of respiratory allergy and skin allergy with ADHD, but little is known about the association between food allergy and ADHD. Methods: We included 192,573 children aged 4-17 years from the National Health Interview Survey (NHIS), a leading health survey in a nationally represent...

Importance Some prior evidence suggests that adverse pregnancy outcomes (APOs) may be associated with heart failure (HF). Identifying unique factors associated with the risk of HF and studying HF subtypes are important next steps. Objective To investigate the association of APOs with incident HF overall and stratified by HF subtype (preserved vs r...

Laboratory studies have shown that nickel exposure may adversely affect glucose metabolism. However, studies about the effects of environmental nickel exposure on diabetes pathogenesis in humans are sparse. We aimed to evaluate the association of urinary nickel concentrations, as a biomarker of environmental nickel exposure, and diabetes in a natio...

Importance Although seafood is known to contain heart-healthy omega-3 fatty acids, many people choose to limit their seafood consumption because of fear of mercury exposure from seafood. It is imperative to clarify the potential health effects of current mercury exposure in contemporary populations. Objective To examine the association of seafood...

Importance Maternal infection has been implicated in the pathogenesis of preterm birth through intrauterine inflammatory response. Chlamydia, gonorrhea, and syphilis are among the most common sexually transmitted infections worldwide, but studies on their association with preterm birth are sparse. Objective To examine the association between mater...

Objective: The study aimed to examine how the phonological loop influences reading ability and processing in Chinese children with developmental dyslexia (DD). Methods: This study included 30 children with DD and 37 children without DD. Two types of articles (i.e., scenery prose and narrative story) and two conditions (under the conditions of artic...

Background and Objectives The mortality from Parkinson's disease (PD) and its long-term trends in the United States remains unknow. This study aimed to describe the trends in PD mortality in the United States from 1999 to 2019. Methods We used data from the National Vital Statistics System, a nationwide, population-based, death registry, to determ...

Context Accelerating evidence of endocrine-related morbidity has raised alarm about the ubiquitous use of phthalates in the human environment, but studies have not directly evaluated mortality in relation to these exposures. Objectives To evaluate associations of phthalate exposure with mortality, and quantify attributable mortality and lost econo...

Toxicological and epidemiological studies implicate exposure to dithiocarbamate (DTC) fungicides in adverse health outcomes. However, there is limited information about human exposure to these chemicals. This systematic review determined to which extent human populations worldwide, including children, pregnant women, and adults, are exposed environ...

Recent animal and small clinical studies have suggested depression is related to altered lipid and amino acid profiles. However, this has not been examined in a population-based sample, particularly in women. We identified multiple metabolites associated with depression as potential candidates from prior studies. Cross-sectional data from three ind...

Objectives To examine the association of urinary iodine concentration with all-cause and cause-specific mortality in a nationally representative sample of US middle-aged and older adults. Methods This study included 5,762 participants aged between 45–79 years from a nationally representative study, the National Health and Nutrition Examination Sur...

Objectives To evaluate the association of the ketogenic ratio of macronutrients (KR) with incidence of diabetes (DM). Methods Dietary information was obtained at baseline from postmenopausal women enrolled in the Women's Health Initiative (WHI) clinical trials (not including the intervention arm of dietary modification trial) and observational stu...

Polychlorinated biphenyls (PCBs) are a group of persistent organic pollutants that are carcinogenic, neurotoxic, and endocrine disrupting in humans. Although diet is the primary source of exposure, there is no consensus on the association between dietary intake and serum PCBs. Additionally, body mass index (BMI) – with its inverse association with...

Background Oxidative stress has been implicated in the pathogenesis of neurodevelopmental disorders. As an anti-oxidative agent, selenium plays an important role in human health. However, the relationship between selenium status and learning disability (LD), a common neurodevelopmental disorder, is unknown. Objective To examine the association bet...

Background Recent experimental work has shown that phthalates may increase inflammation. Prior research has not examined the role of exposure to phthalates in relation to inflammatory status among postmenopausal women who are at higher risk of developing inflammation-related chronic disorders. Objectives We aimed to examine the associations of uri...

Objective To examine the trends in obesity and adiposity measures, including body mass index, waist circumference, body fat percentage, and lean mass, by race or ethnicity among adults in the United States from 2011 to 2018. Design Population based study. Setting National Health and Nutrition Examination Survey (NHANES), 2011-18. Participants A...

Objective To examine the prevalence and the changing pattern of e-cigarette use from preconception to pregnancy. Methods This is a cross-sectional study using data from the multi-site Pregnancy Risk Assessment Monitoring System in the United States, 2016-2017. All participating mothers with information on e-cigarette use before and during pregnanc...

Background Dining out is a popular activity worldwide. Evidence on the association between eating meals away from home and long-term health outcomes is still limited. Objective The objective of this study was to examine the association of frequency of eating meals prepared away from home with all-cause and cause-specific mortality. Participants/s...

Background Dietary recommendations regarding protein intake have been focused on the amount of protein. However, such recommendations without considering specific protein sources may be simplistic and insufficient. Methods and Results We included 102 521 postmenopausal women enrolled in the Women’s Health Initiative between 1993 and 1998, and foll...

Introduction Cannabis is frequently used and increasingly legalized in the U.S., and 27.7 million Americans aged ≥12 years are currently using cannabis. However, the public health effects of cannabis use in the general population remain unclear. This study examines the associations of cannabis use with all-cause and cause-specific mortality in U.S....

Objective To examine the associations of anemia with autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), and learning disability in US children. Study design We included children and adolescents aged 3-17 years from the National Health Interview Survey (NHIS), 1997-2018. Information about physician-diagnosed history of...

Background: Asian Americans are among the fastest growing subpopulations in the United States. However, evidence about maternal prepregnancy body mass index (BMI) and preterm birth among Asian Americans is lacking. Methods: This population-based study used nationwide birth certificate data from the US National Vital Statistics System 2014 to 201...

Objective: To examine the association of maternal prepregnancy diabetes, gestational diabetes mellitus (GDM), and 12 subtypes of congenital anomalies of the newborn. Research design and methods: We included 29,211,974 live births with maternal age ranging from 18 to 49 years old documented in the National Vital Statistics System in the U.S. from...

Background Attention‐deficit/hyperactivity disorder (ADHD) is a childhood‐onset neurodevelopmental disorder that usually persists into adulthood. However, limited evidence is available regarding its influence on adult health outcomes beyond neuropsychiatric comorbidities. This study aimed to examine the association of ADHD with diabetes in US adult...

Background Food insecurity is a global leading public health challenge that affects not only developing countries but also developed countries, including the United States. About 50 million Americans are food insecure. In this study we examined the associations of the adult food insecurity with all‐cause and cardiovascular disease mortality in a na...

Study objectives: To examine the association between sleep structure and amnesic mild cognitive impairment (aMCI) in patients with insomnia disorder. Methods: A total of 256 patients with insomnia disorder were diagnosed by neurologists, 45 of whom were diagnosed with aMCI according to the Petersen criteria, and 45 participants with intact cogni...

Background Most of the women who smoke before pregnancy continue smoking during pregnancy, and some start to quit smoking after being pregnant, although existing guidelines for pregnancy recommend that women who smoke should quit smoking before pregnancy. Findings about the timing and intensity of maternal smoking, especially low-intensity smoking...

Importance Bisphenol A (BPA) is a major public health concern because of its high-volume industrial production, ubiquitous exposure to humans, and potential toxic effects on multiple organs and systems in humans. However, prospective studies regarding the association of BPA exposure with long-term health outcomes are sparse. Objective To examine t...

Purpose Personality traits have been reported to be associated with type 2 diabetes (T2DM) risk. The objective of this study was to examine whether and to what extent the associations between personality traits (dispositional optimism, hostility and negative emotional expressiveness (NEE)) and risk of T2DM were mediated by health behaviors and obes...

Pyrethroids are an important class of insecticides, and thousands of tons of these compounds are used in the United States every year. This study characterized exposures to pyrethroids and assessed demographic, socioeconomic, and lifestyle factors that modulate pyrethroid exposure using data from the National Health and Nutrition Examination Survey...

BACKGROUND Coronavirus Disease-19 (COVID-19) has become a global pandemic, and mental health of children and parents are affected by confinement in home. While parental mental health is critical to the whole family’s psychological reaction to unusual situations, they are also affected by their children’s behaviors and parent-child relationship. OB...

Background: In Western countries, phonological processing deficit was regard as a core deficit in developmental dyslexia (DD). As Chinese is a logographic language, it’s still controversial whether and how the articulatory suppression influences reading ability and processing of Chinese children with DD. The study aimed to examine how the phonologi...

Objectives Carotenoids are bioactive compounds abundant in plant foods and they are thought to provide health benefits in decreasing the risk of chronic diseases. However, studies about serum carotenoid levels and long-term mortality were limited and the findings were controversial. This study examined the association of serum levels of total and i...

Objectives Lignans are bioactive compounds exhibiting various biological properties, including anti-inflammatory, antioxidant and antitumor activities. Epidemiological studies regarding long-term health effects of lignans are sparse. In humans, most lignans in plant-based foods are converted by the intestinal microbiota to enterolactone and enterod...

Objectives To examine the association of chocolate consumption with all-cause and cause-specific mortality. Methods We included 84,709 postmenopausal women free of cardiovascular disease (CVD) and cancer at baseline in the prospective Women's Health Initiative cohort who were enrolled during 1993–1998. Chocolate consumption was assessed using a va...

Objectives To assess associations between individual and total circulating n-3 fatty acids (FAs) with self-reported sleep duration and difficulty sleeping in the Fatty Acids and Outcome Research Consortium (FORCE). Methods De novo harmonized individual-level analyses were performed and pooled in 10 prospective studies (N = 22,717) with data on sle...

Importance Perception of weight loss requirements before bariatric surgery varies among patients, physicians, and health insurance payers. Current clinical guidelines do not require preoperative weight loss because of a lack of scientific support regarding its benefits. Objective To examine the association of preoperative body mass index (BMI) and...

Importance Millions of Americans use electronic cigarettes (e-cigarettes). A growing number of state and local governments have started to draft and implement laws regarding the sale, marketing, and use of e-cigarettes. The association of US state regulations regarding e-cigarettes with e-cigarette use remains unknown. Objective To examine the ass...

Importance Widespread exposure to pyrethroid insecticides has been reported among the general population in the United States and worldwide. However, little is known about the association of pyrethroid exposure with long-term health outcomes in adults. Objective To examine the association of pyrethroid exposure with all-cause and cause-specific mo...

Objective: Mounting evidence suggests that higher optimism is associated with reduced risk of age-related morbidities and premature mortality. Yet, possible biological mechanisms underlying these associations remain understudied. One hypothesized mechanism is a slower rate of cellular aging, which in turn delays age-related declines in health. Me...

In Reply We appreciate the interest from Ahuja and Reddy as well as Braillon in our study.¹ We concur with Ahuja and Reddy that it is important to determine the patterns of electronic cigarette (e-cigarette) use by age and race/ethnicity. We performed an ad hoc analysis to assess the prevalence by age (age ranges of 18-24 years, 25-34 years, and 35...

Millions of Americans use electronic cigarettes (e-cigarettes). E-cigarettes may enable some people to quit smoking, but they may encourage others to start smoking, including susceptible populations, such as young people.¹ Despite an increase in the number of people trying e-cigarettes, current use of e-cigarettes among US adults declined from 2014...

Background: The relation between maternal pre-pregnancy obesity and preterm birth is controversial and inconclusive. We aimed to clarify the association between pre-pregnancy obesity and preterm birth by maternal age and race or ethnicity in a large, multiracial, multiethnic, and diverse population in the USA. Methods: We did a population-based...

Importance The updated 2018 Physical Activity Guidelines for Americans (PAG) reaffirmed key recommendations regarding aerobic activity in the 2008 edition and recently introduced health risks of sedentary behaviors and their association with physical activity. Objective To examine the concurrent changing trends in adherence to the PAG for aerobic...

Bisphenol A (BPA) has been recognized as an endocrine disrupting chemical and identified as an obesogen. Although once ubiquitous, human exposure to BPA is declining due to its substitution with other bisphenols. Two structurally similar substitutes, bisphenol S (BPS) and bisphenol F (BPF), have raised similar concerns, although fewer studies have...

Importance Current public health guidelines for obesity prevention and control focus on promoting a normal body mass index (BMI), rarely addressing central obesity, which is reflected by high waist circumference (WC) and common in the general population. Studies of the association of normal-weight central obesity with long-term health outcomes are...

Introduction: Several studies have suggested that vitamin B12 deficiency is more common in obese individuals. We evaluated the cross-sectional associations of serum vitamin B12 concentrations with obesity in a nationally representative sample of adults in the United States. Methods: We included 9,075 participants aged ≥20 years in the National Heal...

Objectives: Association between allergic conditions and attention deficit/hyperactivity disorder (ADHD) is still debated. Although there are several studies confirmed associations between ADHD and allergic rhinitis and asthma, little is known about the association between food allergy and ADHD. We examined the association of food allergy and other...

Objectives: The objective was to examine the prospective association of major dietary protein sources with all-cause and cause-specific mortality in U.S. women. Methods: We included 127,495 postmenopausal women aged 50 to 79 years old at study entry who were enrolled between 1993 and 1998 in the Women's Health Initiative from September 1993, and...

Objectives: DNA damage induced by oxidative stress is implicated in accelerated telomere shortening, a biomarker of biological aging. Although selenium has antioxidant properties, its impact on telomere length is largely unknown. This study aimed to examine the association between dietary selenium intake and leukocyte telomere length in a national...

Background: Skipping breakfast is common among U.S. adults. Limited evidence suggests that skipping breakfast is associated with atherosclerosis and cardiovascular disease. Objectives: The authors sought to examine the association of skipping breakfast with cardiovascular and all-cause mortality. Methods: This is a prospective cohort study of...

Pregnant women and developing fetuses are vulnerable to exposure to tobacco products. Some animal studies have shown that maternal use of electronic cigarettes (e-cigarettes) adversely affects offspring’s lung development¹ and cognitive function.² There is an urgent need for clinical and epidemiologic studies of e-cigarette use during pregnancy.³ E...

Background: Previous studies on health effects of trans fatty acids (TFA) have focused mainly on cardiovascular health. Little is known about the association of TFA with brain or mental health. In this study, we examined the associations of objectively-measured plasma TFA concentrations with depression in a large population-based cross-sectional st...

Background: Bisphenol F (BPF) and bisphenol S (BPS) are increasingly used as substitutes for bisphenol A (BPA), an environmental obesogen. However, health effects of BPF and BPS remain unclear. In this study, we evaluated the associations of BPA, BPF, and BPS with obesity in children and adolescents. Methods: We used data from the U.S. National...

Characteristics of population according to quartiles of urinary bisphenol A concentrations, National Health and Nutrition Examination Survey 2013 to 2014 (n=745)

Characteristics of population according to quartiles of urinary bisphenol S concentrations, National Health and Nutrition Examination Survey 2013 to 2014 (n=745)

Characteristics of population according to quartiles of urinary bisphenol F concentrations, National Health and Nutrition Examination Survey 2013 to 2014 (n=745)

Urinary concentrations of BPA, BPF, and BPS according to population characteristics

Associations of urinary BPA, BPF, and BPS concentrations with abdominal obesity by age

Associations of urinary BPA, BPF, and BPS concentrations with general obesity by race/ethnicity

Associations of urinary BPA, BPF, and BPS concentrations with general obesity by age

Associations of urinary BPA, BPF, and BPS concentrations with abdominal obesity by race/ethnicity

Objective To examine the prospective association of total and individual fried food consumption with all cause and cause specific mortality in women in the United States. Design Prospective cohort study. Setting Women’s Health Initiative conducted in 40 clinical centers in the US. Participants 106 966 postmenopausal women aged 50-79 at study ent...

Background: The organic food market has grown rapidly worldwide in the past 15 years. However, evidence concerning the health effects of organic foods is scarce. We evaluated the cross-sectional association of organic food purchase, as a proxy of organic food consumption, with diabetes in a nationally representative population. Methods: We included...

Background: Excess iron levels can induce oxidative stress and could therefore affect telomere attrition. However, little is known about the impact of body iron status on telomere length. Objective: Our aim was to examine the association between serum ferritin concentrations, an indicator of body iron status, and leukocyte telomere length in US adu...

Objective To estimate the prevalence of diagnosed total diabetes, type 1 diabetes, and type 2 diabetes in the US general population and the proportions of each among US adults with a diagnosis of diabetes. Design Nationwide, population based, cross sectional survey. Setting National Health Interview Survey, 2016 and 2017. Participants Adults age...

Objective: To estimate the prevalence of diagnosed total diabetes, type 1 diabetes, and type 2 diabetes in the US general population and the proportions of each among US adults with a diagnosis of diabetes. Design: Nationwide, population based, cross sectional survey. Setting: National Health Interview Survey, 2016 and 2017. Participants: Ad...

Supplementary information: figure showing flow of participants through study

Importance Attention-deficit/hyperactivity disorder (ADHD) is common in US children and adolescents. It is important to understand the most recent prevalence of ADHD and its long-term trends over the past decades. Objective To estimate the prevalence of diagnosed ADHD and 20-year trends from 1997 to 2016 among US children and adolescents using nat...

Bisphenol F (BPF) and bisphenol S (BPS) are replacing bisphenol A (BPA) in the manufacturing of products containing polycarbonates and epoxy resins. Data on current human exposure levels of these substitutes are needed to aid in the assessment of their human health risks. This study analyzed urinary bisphenol levels in adults (N = 1808) and childre...

Importance The prevalence of autism spectrum disorder (ASD) in US children has increased during the past decades. Immunologic dysfunction has recently emerged as a factor associated with ASD. Although children with ASD are more likely to have gastrointestinal disorders, little is known about the association between food allergy and ASD. Objective...

Background Animal studies indicate that chronic exposure to certain tin compounds induces pancreatic islet cell apoptosis and glucose intolerance. However, little is known about health effects of environmental tin exposure in humans. We therefore evaluated the association of tin exposure with diabetes in a nationally representative sample of US adu...

Tin is a naturally occurring heavy metal that occurs in the environment in both inorganic and organic forms. Human exposure to tin is almost ubiquitous; however, surprisingly little is known about factors affecting environmental tin exposure in humans. This study analyzed demographic, socioeconomic and lifestyle factors associated with total urinar...

Background: Lifestyle factors are important for cancer survival. However, empirical evidence regarding the effects of dietary changes on mortality in breast cancer survivors is sparse. Objective: The objective was to examine the associations of changes in overall diet quality, indicated by the Healthy Eating Index (HEI)-2010 score, with mortalit...