Association between phthalate exposure and sleep quality in pregnant women: Results from the Korean Children's Environmental Health Study with repeated assessment of exposure.

Background: Evidence linking environmental toxicants to sleep quality is growing; however, these associations during pregnancy remain unclear. We examined the associations of repeated measures of urinary phthalates in early and late pregnancy with multiple markers of sleep quality among pregnant women. Methods: The study population included 2324 pregnant women from the Korean Children's Environmental Health Study. We analyzed spot urine samples collected at two time points during pregnancy for exposure biomarkers of eight phthalate metabolites. We investigated associations between four summary phthalates (all phthalates: ∑Phthalates; di-(2-ethylhexyl) phthalate: ∑DEHP; phthalates from plastic sources: ∑Plastic; and antiandrogenic phthalates: ∑AA) and eight individual phthalates and self-reported sleep measures using generalized ordinal logistic regression and generalized estimating equations models that accounted for repeated exposure measurements. The models were adjusted for age, body mass index, education, gestational age, income, physical activity, smoking, occupation, chronic diseases, depression, and urinary cotinine levels. Results: Multiple individual phthalates and summary measures of phthalate mixtures, including ∑Plastic, ∑DEHP, ∑AA, and ∑Phthalates, were associated with lower sleep efficiency. To illustrate, every 1-unit log increase in ∑AA was associated with a reduction of sleep efficiency by 1.37 % (95% confidence interval [CI] = -2.41, -0.32). ∑AA and ∑Phthalates were also associated with shorter sleep duration and longer sleep latency. Associations between summary phthalate measures and sleep efficiency differed by urinary cotinine levels (P for subgroup difference < 0.05). Conclusions: Findings suggest that higher phthalate exposure may be related to lower sleep efficiency, shorter sleep duration, and prolonged sleep latency during pregnancy.

GWAS Meta-Analysis of Suicide Attempt: Identification of 12 Genome-Wide Significant Loci and Implication of Genetic Risks for Specific Health Factors.

OBJECTIVE: Suicidal behavior is heritable and is a major cause of death worldwide. Two large-scale genome-wide association studies (GWASs) recently discovered and cross-validated genome-wide significant (GWS) loci for suicide attempt (SA). The present study leveraged the genetic cohorts from both studies to conduct the largest GWAS meta-analysis of SA to date. Multi-ancestry and admixture-specific meta-analyses were conducted within groups of significant African, East Asian, and European ancestry admixtures. METHODS: This study comprised 22 cohorts, including 43,871 SA cases and 915,025 ancestry-matched controls. Analytical methods across multi-ancestry and individual ancestry admixtures included inverse variance-weighted fixed-effects meta-analyses, followed by gene, gene-set, tissue-set, and drug-target enrichment, as well as summary-data-based Mendelian randomization with brain expression quantitative trait loci data, phenome-wide genetic correlation, and genetic causal proportion analyses. RESULTS: Multi-ancestry and European ancestry admixture GWAS meta-analyses identified 12 risk loci at p values <5×10-8. These loci were mostly intergenic and implicated DRD2, SLC6A9, FURIN, NLGN1, SOX5, PDE4B, and CACNG2. The multi-ancestry SNP-based heritability estimate of SA was 5.7% on the liability scale (SE=0.003, p=5.7×10-80). Significant brain tissue gene expression and drug set enrichment were observed. There was shared genetic variation of SA with attention deficit hyperactivity disorder, smoking, and risk tolerance after conditioning SA on both major depressive disorder and posttraumatic stress disorder. Genetic causal proportion analyses implicated shared genetic risk for specific health factors. CONCLUSIONS: This multi-ancestry analysis of suicide attempt identified several loci contributing to risk and establishes significant shared genetic covariation with clinical phenotypes. These findings provide insight into genetic factors associated with suicide attempt across ancestry admixture populations, in veteran and civilian populations, and in attempt versus death.

Sex-specific and sex-independent steroid-related biomarkers in early second trimester maternal serum associated with autism.

BACKGROUND: Prenatal exposure to maternal metabolic conditions associated with inflammation and steroid dysregulation has previously been linked to increased autism risk. Steroid-related maternal serum biomarkers have also provided insight into the in utero steroid environment for offspring who develop autism. OBJECTIVE: This study examines the link between autism among offspring and early second trimester maternal steroid-related serum biomarkers from pregnancies enriched for prenatal metabolic syndrome (PNMS) exposure. STUDY DESIGN: Early second trimester maternal steroid-related serum biomarkers (i.e., estradiol, free testosterone, total testosterone, and sex hormone binding globulin) were compared between pregnancies corresponding to offspring with (N = 68) and without (N = 68) autism. Multiple logistic regression analyses were stratified by sex and gestational duration. One-way ANCOVA with post hoc tests was performed for groups defined by autism status and PNMS exposure. RESULTS: Increased estradiol was significantly associated with autism only in males (AOR = 1.13 per 100 pg/ml, 95% CI 1.01-1.27, p = 0.036) and only term pregnancies (AOR = 1.17 per 100 pg/ml, 95% CI 1.04-1.32, p = 0.010). Autism status was significantly associated with decreased sex hormone binding globulin (AOR = 0.65 per 50 nmol/L, 95% CI 0.55-0.78, p < 0.001) overall and when stratified by sex and term pregnancy status. The inverse association between sex hormone binding globulin and autism was independent of PNMS exposure. LIMITATIONS: The relative racial and ethnic homogeneity of Utah's population limits the generalizability of study results. Although significant differences by autism status were identified in concentrations of sex hormone binding globulin overall and of estradiol in participant subgroups, differences by PNMS exposure failed to reach statistical significance, which may reflect insufficient statistical power. CONCLUSION: Both elevated maternal serum estradiol in males only and low maternal serum sex hormone binding globulin in both sexes are associated with increased autism risk. Further investigation is merited to identify how steroid, metabolic, and inflammatory processes can interact to influence neurodevelopment in early second trimester.

Dietary creatine intake and depression risk among U.S. adults.

Creatine monohydrate is actively being researched for its antidepressant effects, yet little is known about the link between dietary creatine and depression risk. This study examines the association between dietary creatine and depression in U.S. adults, using data from the 2005 to 2012 National Health and Nutrition Examination Survey (NHANES). Patient health questionnaire, dietary creatine intake and covariates were obtained on 22,692 NHANES participants ≥20 years of age. Depression prevalence was calculated within quartiles of dietary creatine intake. Adjusted logistic regression models were formulated to determine the relationship between dietary creatine intake and depression risk. Additional covariates included income to poverty ratio, race/ethnicity, sex, age, education level, body mass index, healthcare access, smoking status, physical activity, and antidepressant/anxiolytic medication use. Models were further stratified by sex, age group, and antidepressant/anxiolytic medication use. Depression prevalence was 10.23/100 persons (95% CI: 8.64-11.83) among NHANES participants in the lowest quartile of dietary creatine intake compared with 5.98/100 persons (95% CI: 4.97-6.98) among participants in the highest quartile (p < 0.001). An inverse association was measured between dietary creatine and depression (adjusted odds ratio (AOR) = 0.68, 95% CI: 0.52-0.88). Dietary creatine's negative association with depression was strongest in females (AOR = 0.62, 95% CI: 0.40-0.98), participants aged 20-39 years (AOR = 0.52, 95% CI: 0.34-0.79) and participants not taking antidepressant/anxiolytic medication (AOR = 0.58, 95% CI: 0.43-0.77). Study results indicate a significant negative relationship between dietary creatine and depression in a nationally representative adult cohort. Further research is warranted to investigate the role creatine plays in depression, particularly among women and across the lifespan.

Early Second Trimester Maternal Serum Steroid-Related Biomarkers Associated with Autism Spectrum Disorder.

Epidemiologic studies link increased autism spectrum disorder (ASD) risk to obstetrical conditions associated with inflammation and steroid dysregulation, referred to as prenatal metabolic syndrome (PNMS). This pilot study measured steroid-related biomarkers in early second trimester maternal serum collected during the first and second trimester evaluation of risk study. ASD case and PNMS exposure status of index offspring were determined through linkage with autism registries and birth certificate records. ASD case (N = 53) and control (N = 19) groups were enriched for PNMS exposure. Higher estradiol and lower sex hormone binding globulin (SHBG) were significantly associated with increased ASD risk. Study findings provide preliminary evidence to link greater placental estradiol activity with ASD and support future investigations of the prenatal steroid environment in ASD.

Brief Report: The Prevalence of Neurofibromatosis Type 1 among Children with Autism Spectrum Disorder Identified by the Autism and Developmental Disabilities Monitoring Network.

Neurofibromatosis type 1 (NF1) is an inherited neurocutaneous disorder associated with neurodevelopmental disorders including autism spectrum disorder (ASD). The frequency of ASD/NF1 co-occurrence has been subject to debate since the 1980s. This relationship was investigated in a large population-based sample of 8-year-old children identified with ASD (N = 12,271) by the Centers for Disease Control and Prevention's Autism and Developmental Disabilities Monitoring (ADDM) Network. Twenty-two (1-in-558) children with ASD had diagnosed NF1, exceeding NF1 general population estimates by four to five fold. Children with ASD/NF1 versus ASD without NF1 were significantly less likely to receive a community-based ASD diagnosis (p = 0.04) and understand non-verbal communication (p = 0.001). These findings underscore the importance of including social-communication ability among relevant developmental concerns in children with NF1.

CYP2A6 Longitudinal Effects in Young Smokers.

INTRODUCTION: The present study sought to identify time-dependent within-participant effects of CYP2A6 genotypes on smoking frequency and nicotine dependence in young smokers. METHODS: Predicted nicotine metabolic rate based on CYP2A6 diplotypes (CYP2A6 diplotype predicted rate [CDPR]) was partitioned into Normal, Intermediate, and Slow categories using a metabolism metric. Growth-curve models characterized baseline and longitudinal CDPR effects with data from eight longitudinal assessments during a 6-year period (from approximately age 16-22) in young smokers of European descent (N = 296, 57% female) who had smoked less than 100 cigarettes lifetime at baseline and more than that amount by Year 6. Phenotypes were number of days smoked during the previous 30 days and a youth version of the Nicotine Dependence Syndrome Scale (NDSS). A zero-inflated Poisson growth-curve model was used to account for the preponderance of zero days smoked. RESULTS: At baseline, Intermediate CDPR was a risk factor relative to both Normal and Slow CDPR for smoking frequency and the NDSS. Slow CDPR was associated with the highest probability of smoking discontinuation at baseline. However, due to CDPR time trend differences, by young adulthood these baseline effects had been reordered such that the greatest risks for smoking frequency and the NDSS were associated with Normal CDPR. CONCLUSIONS: Reduced metabolism CYP2A6 genotypes are associated with both risk and protective effects in novice smokers. However, differences in the time-by-CDPR effects result in a reordering of genotype effects such that normal metabolism becomes the risk variant by young adulthood, as has been reliably reported in older smokers.