Folate intake, markers of folate status and oral clefts: An updated set of systematic reviews and meta-analyses.

BACKGROUND: There has been a longstanding debate about the role of folate in the etiology of orofacial clefts (OFCs). Studies of different measures of nutritional intake or folate status have been done to investigate the possible role of folate in the prevention of OFC. Only one knowledge synthesis has attempted to bring together different types of evidence. The aim of the present work was to update it. METHODS: Evidence for associations between OFC and dietary folate, supplement use, folic acid fortification, biomarkers of folate status, and variants of MTHFR (C677T and A1298C) were included. Potentially eligible articles were systematically identified from PubMed, Medline, Embase, and Web of Science (2007-2020) and combined using random-effects meta-analysis when appropriate. Quality assessments were conducted using the Newcastle-Ottawa scale and Cochrane's risk of bias tool. RESULTS: Sixty-four studies published since the previous knowledge synthesis were identified, with eight of these identified through a supplementary search from October, 2018 to August, 2020. There was an inverse association between folic acid-containing supplement use before or during pregnancy and cleft lip with or without cleft palate (CL/P) (OR 0.60, 95% CI 0.51-0.69), with considerable between-study heterogeneity. The prevalence of CL/P showed a small decline post-folic acid fortification in seven studies (OR 0.94, 95% CI 0.86-1.02). No association was found between OFC and genetic markers of folate status. The coronavirus-19 pandemic has threatened food availability globally and therefore there is a need to maintain and even enhance surveillance concerning maternal intake of folate and related vitamins. CONCLUSIONS: The risk of non-syndromic OFC was reduced among pregnant women with folic acid-containing supplements during the etiologically relevant period. However, high heterogeneity between included studies, incomplete reporting of population characteristics and variation in timing of exposure and supplement types mean that conclusions should be drawn with caution.

Low radon exposures and lung cancer risk: joint analysis of the Czech, French, and Beaverlodge cohorts of uranium miners.

It is well established that high radon exposures increase the risk of lung cancer mortality. The effects of low occupational exposures and the factors that confound and modify this risk are not clear and are needed to inform current radiation protection of miners. The risk of lung cancer mortality at low radon exposures (< 100 working-level months) was assessed in the joint cohort analysis of Czech, French, and Canadian uranium miners, employed in 1953 or later. Statistical analysis was based on linear Poisson regression modeling with grouped cohort survival data. Two sensitivity analyses were used to assess potential confounding from tobacco smoking. A statistically significant linear relationship between radon exposure and lung cancer mortality was found. The excess relative risk per working-level month was 0.022 (95% confidence intervals: 0.013-0.034), based on 408 lung cancer deaths and 394,236 person-years of risk. Time since exposure was a statistically significant modifier; risk decreased with increasing time since exposure. A tendency for a decrease in risk with increasing attained age was observed, but this was not statistically significant. Exposure rate was not found to be a modifier of the excess relative risk. The potential confounding effect of tobacco smoking was estimated to be small and did not substantially change the radon-lung cancer mortality risk estimates. This joint cohort analysis provides strong evidence for an increased risk of lung cancer mortality from low occupational radon exposures. The results suggest that radiation protection measures continue to be important among current uranium miners.

Effectiveness of stop smoking interventions among adults: protocol for an overview of systematic reviews and an updated systematic review.

BACKGROUND: Tobacco smoking is the leading cause of cancer, preventable death, and disability. Smoking cessation can increase life expectancy by nearly a decade if achieved in the third or fourth decades of life. Various stop smoking interventions are available including pharmacotherapies, electronic cigarettes, behavioural support, and alternative therapies. This protocol outlines an evidence review which will evaluate the benefits and harms of stop smoking interventions in adults. METHODS: The evidence review will consist of two stages. First, an overview of systematic reviews evaluating the benefits and harms of various stop smoking interventions delivered in or referred from the primary care setting will be conducted. The second stage will involve updating a systematic review on electronic cigarettes identified in the overview; randomized controlled trials will be considered for outcomes relating to benefits while randomized controlled trials, non-randomized controlled trials, and comparative observational studies will be considered for evaluating harms. Search strategies will be developed and peer-reviewed by medical information specialists. The search strategy for the updated review on e-cigarettes will be developed using that of the candidate systematic review. The MEDLINE®, PsycINFO, Embase, and the Cochrane Library electronic databases will be searched as of 2008 for the overview of reviews and from the last search date of the selected review for the updated review. Organizational websites and trial registries will be searched for unpublished or ongoing reviews/studies. Two reviewers will independently screen the title and abstracts of citations using the liberal accelerated method. Full-text screening will be performed independently by two reviewers. Extracted data will be verified by a second reviewer. Disagreements regarding full-text screening and data extraction will be resolved by consensus or third-party adjudication. The methodological quality of systematic reviews, risk of bias of randomized and non-randomized trials, and methodological quality of cohort studies will be evaluated using AMSTAR 2, the Cochrane risk of bias tool, and a modified version of the Scottish Intercollegiate Guidelines Network critical appraisal tool, respectively. The GRADE framework will be used to assess the quality of the evidence for outcomes. DISCUSSION: The evidence review will evaluate the benefits and harms of various stop smoking interventions for adults. Findings will be used to inform a national tobacco cessation guideline by the Canadian Task Force on Preventive Health Care. SYSTEMATIC REVIEW REGISTRATION: PROSPERO (CRD42018099691, CRD42018099692).

Evaluating LINE-1 methylation in cleft lip tissues and its association with early pregnancy exposures.

AIM: To pilot investigation of methylation of long interspersed nucleotide element-1 in lip tissues from infants with nonsyndromic cleft lip, and its association with maternal periconceptional exposures. METHODS: The lateral and medial sides of the cleft lips of 23 affected infants were analyzed for long interspersed nucleotide element-1 methylation by bisulfite conversion and pyrosequencing. RESULTS: The medial side showed 1.8% higher methylation compared with the lateral side; p = 0.031, particularly in male infants (2.7% difference; p = 0.011) or when the mothers did not take folic acid during periconceptional period (2.4% difference; p = 0.011). These results were not statistically significant when Bonferroni adjustment was used. CONCLUSION: The observed differences in DNA methylation, although nonsignificant after correction for multiple comparisons, suggest that differential regulation of the two sides may impact lip fusion and warrant larger-scale replication.

Newborn Bilirubin Screening for Preventing Severe Hyperbilirubinemia and Bilirubin Encephalopathy: A Rapid Review.

According to the 2004 American Academy of Pediatrics guideline on the management of hyperbilirubinemia, every newborn should be assessed for the risk of developing severe hyperbilirubinemia with the help of predischarge total serum bilirubin or transcutaneous bilirubin measurements and/or assessments of clinical risk factors. The aim of this rapid review is 1) to review the evidence for 1) predicting and preventing severe hyperbilirubinemia and bilirubin encephalopathy, 2) determining the efficacy of home/community treatments (home phototherapy) in the prevention of severe hyperbilirubinemia, and 3) non-invasive/transcutaneous methods for estimating serum bilirubin level. METHODS: In this rapid review, studies were identified through the Medline database. The main outcomes of interest were severe hyperbilirubinemia and encephalopathy. A subset of articles was double screened and all articles were critically appraised using the SIGN and AMSTAR checklists. This review investigated if systems approach is likely to reduce the occurrence of severe hyperbilirubinemia. RESULTS: Fifty-two studies met the inclusion criteria. Included studies assessed the association between bilirubin measurement early in neonatal life and the subsequent development of severe hyperbilirubinemia and chronic bilirubin encephalopathy/kernicterus. It was observed that, highest priority should be given to (i) universal bilirubin screening programs; (ii) implementation of community and midwife practice; (iii) outreach to communities for education of prospective parents; and (iv) development of clinical pathways to monitor, evaluate and track infants with severe hyperbilirubinemia. CONCLUSIONS: We found substantial observational evidence that severe hyperbilirubinemia can be accurately predicted and prevented through universal bilirubin screening. So far, there is no evidence of any harm.

Genetic Interactions in Nonsyndromic Orofacial Clefts in Europe-EUROCRAN Study.

BACKGROUND: Nonsyndromic cleft lip with or without cleft palate (nsCL±P) and nonsyndromic cleft palate (nsCP) are caused by a combination of genetic and environmental risk factors. We investigated gene-environment and gene-gene joint effects in a large multicenter study of case-parent triads. METHODS: The nsCL±P or nsCP triads were recruited in 11 European countries between 2001 and 2005. We collected DNA samples from infants and from their mothers and fathers, and mothers completed a questionnaire on exposures, including smoking and folic acid supplement use during pregnancy. We used log-linear regression to estimate relative risks (RRs) and 95% confidence intervals (CIs) for associations between nsCL±P or nsCP and variants in MTHFR, MTHFD1, TGFA, SATB2, and MSX1, stratifying by environmental or genetic factors. RESULTS: We obtained genotype and exposure data for 728 nsCL±P triads and 292 nsCP triads. In male infants, there was no association between the mother's homozygous MSX1 p(CA) *4/*4 genotype and nsCL±P (RR, 0.98; 95% CI, 0.63-1.54), but this maternal genotype resulted in a doubling of risk for female infants (RR, 2.21; 95% CI, 1.13-4.34). There was evidence suggestive of gene-gene joint-effects between MTHFR-TGFA for nsCP but not for nsCL±P. CONCLUSION: Although we chose the genes and their variants and putative joint effects based on associations previously reported in the literature, we replicated few associations. These results do not provide evidence supporting associations between these genes and oral clefts in European populations, although gene-environment and gene-gene interactions could play a role in oral cleft etiology.

Effect of Folic Acid Food Fortification in Canada on Congenital Heart Disease Subtypes.

BACKGROUND: Previous studies have yielded inconsistent results for the effects of periconceptional multivitamins containing folic acid and of folic acid food fortification on congenital heart defects (CHDs). METHODS: We carried out a population-based cohort study (N=5 901 701) of all live births and stillbirths (including late-pregnancy terminations) delivered at ≥20 weeks' gestation in Canada (except Québec and Manitoba) from 1990 to 2011. CHD cases were diagnosed at birth and in infancy (n=72 591). We compared prevalence rates and temporal trends in CHD subtypes before and after 1998 (the year that fortification was mandated). An ecological study based on 22 calendar years, 14 geographic areas, and Poisson regression analysis was used to quantify the effect of folic acid food fortification on nonchromosomal CHD subtypes (n=66 980) after controlling for changes in maternal age, prepregnancy diabetes mellitus, preterm preeclampsia, multiple birth, and termination of pregnancy. RESULTS: The overall birth prevalence rate of CHDs was 12.3 per 1000 total births. Rates of most CHD subtypes decreased between 1990 and 2011 except for atrial septal defects, which increased significantly. Folic acid food fortification was associated with lower rates of conotruncal defects (adjusted rate ratio [aRR], 0.73, 95% confidence interval [CI], 0.62-0.85), coarctation of the aorta (aRR, 0.77; 95% CI, 0.61-0.96), ventricular septal defects (aRR, 0.85; 95% CI, 0.75-0.96), and atrial septal defects (aRR, 0.82; 95% CI, 0.69-0.95) but not severe nonconotruncal heart defects (aRR, 0.81; 95% CI, 0.65-1.03) and other heart or circulatory system abnormalities (aRR, 0.98; 95% CI, 0.89-1.11). CONCLUSIONS: The association between food fortification with folic acid and a reduction in the birth prevalence of specific CHDs provides modest evidence for additional benefit from this intervention.

Primary care role in expanded newborn screening: After the heel prick test.

OBJECTIVE: To examine the role of primary care providers in informing and supporting families who receive positive screening results. DESIGN: Cross-sectional survey. SETTING: Ontario. PARTICIPANTS: Family physicians, pediatricians, and midwives involved in newborn care. MAIN OUTCOME MEASURES: Beliefs, practices, and barriers related to providing information to families who receive positive screening results for their newborns. RESULTS: A total of 819 providers participated (adjusted response rate of 60.9%). Of the respondents, 67.4% to 81.0% agreed that it was their responsibility to provide care to families of newborns who received positive screening results, and 64.2% to 84.8% agreed they should provide brochures or engage in general discussions about the identified conditions. Of the pediatricians, 67.3% endorsed having detailed discussions with families, but only 24.1% of family physicians and 27.6% of midwives endorsed this practice. All provider groups reported less involvement in information provision than they believed they should have. This discrepancy was most evident for family physicians: most stated that they should provide brochures (64.2%) or engage in general discussions (73.5%), but only a minority did so (15.3% and 27.7%, respectively). Family physicians reported insufficient time (42.2%), compensation (52.2%), and training (72.3%) to play this role, and only a minority agreed they were up to date (18.5%) or confident (16.5%) regarding newborn screening. CONCLUSION: Providers of primary newborn care see an information-provision role for themselves in caring for families who receive positive newborn screening results. Efforts to further define the scope of this role combined with efforts to mitigate existing barriers are warranted.

Folic acid supplementation use and the MTHFR C677T polymorphism in orofacial clefts etiology: An individual participant data pooled-analysis.

BACKGROUND: This study examines gene-environment interaction between the MTHFR C667T polymorphism and folic acid in the etiology of orofacial clefts (OFC). We used a pooled-analytical approach on four studies that used similar methods. METHODS: We used logistic regression to analyze the pooled sample of 1149 isolated cases and 1161 controls. Fetal and maternal MTHFR C677T genotypes, and maternal periconceptional exposure to smoking, alcohol, vitamin containing folic acid and folic acid supplements were contrasted between the cleft types [non-syndromic clefts lip or without cleft palate (CL(P)) and non-syndromic cleft palate (CP)] and control groups. RESULTS: There was a reduced risk of CL(P) with maternal folic acid use (p = 0.008; OR = 0.70, 95% CI: 0.65-0.94) and with supplements containing folic acid (p = 0.028, OR = 0.80, 95% CI: 0.65-0.94). Maternal smoking increased the risk of both CL(P) (p < 10 e-3; OR = 1.62, 95% CI: 1.35-1.95) and CP (p = 0.028; OR = 1.38, 95% CI: 1.04-1.83). No significant risk was observed with either maternal or fetal MTHFR C677T genotypes. CONCLUSION: This individual participant data (IPD) meta-analysis affords greater statistical power and can help alleviate the problems associated with aggregate-level data-sharing. The result of this IPD meta-analysis is consistent with previous reports suggesting that folic acid and smoking influence OFC outcomes.

Variability in the clinical management of fatty acid oxidation disorders: results of a survey of Canadian metabolic physicians.

INTRODUCTION: There is little robust empirical evidence on which to base treatment recommendations for fatty acid oxidation disorders. While consensus guidelines are important, understanding areas where there is a lack of consensus is also critical to inform priorities for future evaluative research. METHODS: We surveyed Canadian metabolic physicians on the treatment of medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, very long-chain acyl-CoA dehydrogenase (VLCAD) deficiency, long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency, and mitochondrial trifunctional protein (MTP) deficiency. We ascertained physicians' opinions on the use of different interventions for the long-term management of patients as well as for the management of acute illness, focusing on identifying interventions characterized by high variability in opinions. We also investigated factors influencing treatment decisions. RESULTS: We received 18 responses (response rate 45%). Participants focused on avoidance of fasting and increased meal frequency as interventions for the management of MCAD deficiency. For the long-chain disorders, avoidance of fasting remained the most consistently endorsed intervention, with additional highly endorsed treatments differing for VLCAD versus LCHAD/MTP deficiency. L-carnitine supplementation and restriction of dietary fat were characterized by high variability in physicians' opinions, as were several interventions specific to long-chain disorders. Social factors and patient characteristics were important influences on treatment decisions. CONCLUSIONS: Based on our findings we suggest that high priority treatments for rigorous effectiveness studies could include L-carnitine supplementation (MCAD and LCHAD/MTP deficiencies), restriction of dietary fat, and, for the long-chain disorders, feeding practices for breastfed infants and the use of various supplements (essential fatty acids, carbohydrates, cornstarch, multivitamins).

Vitamin D status of Canadians as measured in the 2007 to 2009 Canadian Health Measures Survey.

BACKGROUND: Vitamin D deficiency is a global health problem, but little is known about the vitamin D status of Canadians. DATA AND METHODS: The data are from the 2007 to 2009 Canadian Health Measures Survey, which collected blood samples. Descriptive statistics (frequencies, means) were used to estimate 25-hydroxyvitamin D [25(OH)D] concentrations among a sample of 5,306 individuals aged 6 to 79 years, representing 28.2 million Canadians from all regions, by age group, sex, racial background, month of blood collection, and frequency of milk consumption. The prevalence of deficiency and the percentages of the population meeting different cut-off concentrations were assessed. RESULTS: The mean concentration of 25(OH)D for the Canadian population aged 6 to 79 years was 67.7 nmol/L. The mean was lowest among men aged 20 to 39 years (60.7 nmol/L) and highest among boys aged 6 to 11 (76.8 nmol/L). Deficiency (less than 27.5 nmol/L) was detected in 4% of the population. However, 10% of Canadians had concentrations considered inadequate for bone health (less than 37.5 nmol/L) according to 1997 Institute of Medicine (IOM) Standards (currently under review). Concentrations measured in November-March were below those measured in April-October. White racial background and frequent milk consumption were significantly associated with higher concentrations. INTERPRETATION: As measured by plasma 25(OH)D, 4% of Canadians aged 6 to 79 years were vitamin D-deficient, according to 1997 IOM standards (currently under review). Based on these standards, 10% of the population had inadequate concentrations for bone health.

Dietary flavonoid intake and colorectal cancer: a case-control study.

Diets rich in flavonoids may reduce the risk of developing colorectal cancer. Flavonoids are widely distributed in foods of plant origin, though in the UK tea is the main dietary source. Our objective was to evaluate any independent associations of total dietary and non-tea intake of four flavonoid subclasses and the risk of developing colorectal cancer in a tea-drinking population with a high colorectal cancer incidence. A population-based case-control study (264 cases with histologically confirmed incident colorectal cancer and 408 controls) was carried out. Dietary data gathered by FFQ were used to calculate flavonoid intake. Adjusted OR and 95 % CI were estimated by logistic regression. No linear association between risk of developing colorectal cancer and total dietary flavonol, procyanidin, flavon-3-ol or flavanone intakes was found, but non-tea flavonol intake was inversely associated with colorectal cancer risk (OR 0.6; 95 % CI 0.4, 1.0). Stratification by site of cancer and assessment of individual flavonols showed a reduced risk of developing colon but not rectal cancer with increasing non-tea quercetin intake (OR 0.5; 95 % CI 0.3, 0.8; P(trend) < 0.01). We concluded that flavonols, specifically quercetin, obtained from non-tea components of the diet may be linked with reduced risk of developing colon cancer.

Folate intake, markers of folate status and oral clefts: is the evidence converging?

BACKGROUND: The ability of folic acid in the periconceptional period to prevent the occurrence of neural tube defects has stimulated tremendous interest in its effects on other health outcomes. Its possible effect on oral clefts has generated considerable debate. The purpose of this systematic review and meta-analysis was to assemble evidence on the role of folate in the aetiology of cleft lip with or without cleft palate (CL/P) and cleft palate only (CPO). METHODS: Medline, PubMed, Embase, Science Citation Index and the HuGE Published Literature Database were searched to February 2007 for articles related to oral clefts and multivitamin use, dietary folate, folic acid fortification, biochemical markers of folate status and polymorphisms in 5,10-methylenetetrahydrofolate reductase (MTHFR) and other genes involved in folate metabolism. Random effects meta-analysis was conducted when appropriate. RESULTS: Maternal multivitamin use was inversely associated with CL/P [odds ratio (OR) 0.75, 95% CI 0.65-0.88, based on 5717 cases and 59 784 controls] but to a lesser extent CPO (OR 0.88, 95% CI 0.76-1.01, 2586 cases and 59 684 controls). The volume of evidence on dietary folate, fortification and biochemical and genetic measures of folate status is substantially less; in aggregate, the evidence suggests that no association exists but there is substantial heterogeneity between studies. CONCLUSIONS: The evidence is not converging and there is no strong evidence for an association between oral clefts and folic acid intake alone. Multivitamin use in early pregnancy, however, may protect against oral clefts, especially CL/P although this association may be confounded by other lifestyle factors associated with multivitamin use.