Fetal Exposure to Carcinogens With Tobacco Use in Pregnancy: Phase 1 MAW Study Findings

The Effect of Tobacco Use on the Expression of Placental Transporters in Alaska Native Women

Prenatal tobacco use among Alaska Native (AN) women has decreased substantially over the past two decades. Previous research suggests that providing AN women with feedback regarding fetal exposure to tobacco may further promote cessation. Transporters in the placenta regulate fetal exposure to nutrients and xenobiotics, including compounds associated with tobacco use. We examined whether prenatal tobacco use impacts transporter expression in the placenta, and whether this is influenced by fetal sex, degree of tobacco exposure, or transporter genotype. At delivery, we obtained placental samples from AN research participants who smoked cigarettes, used commercial chew or iqmik (oral tobacco), or did not use tobacco during pregnancy. Transporter expression was evaluated using qRT-PCR and Western blotting and tested for correlations between transcript levels and urinary biomarkers of tobacco use. The impact of BCRP/ABCG2 and OATP2B1/SLCO2B1 genotypes on protein expression was also examined. Oral tobacco use was associated with decreased P-gp and increased MRP1, MRP3, LAT1, and PMAT mRNA expression. Transcript levels of multiple transporters significantly correlated with tobacco biomarkers in maternal and fetal urine. In women carrying male fetuses, both smoking and oral tobacco were associated with decreased P-gp. Oral tobacco was also associated with decreased LAT1 in women carrying female fetuses. BCRP and OATP2B1 genotypes did not appear to impact protein expression. In conclusion, prenatal tobacco use is associated with altered expression of multiple placental transporters which differs by fetal sex. As transcript levels of multiple transporters were significantly correlated with tobacco use biomarkers, eliminating prenatal tobacco use should alleviate these changes.

Healthy Pregnancies Project: Cluster Randomized Controlled Trial of a Community Intervention to Reduce Tobacco Use among Alaska Native Women

Substantial gaps remain in the evidence base for prenatal tobacco use interventions among Indigenous women. Using a cluster randomized controlled trial (RCT), the Healthy Pregnancies Project evaluated a community-level intervention for Alaska Native (AN) women in rural western Alaska. Sixteen villages were randomly assigned to usual care (control, n = 8 villages) or usual care plus a community-level intervention delivered by local AN "Native Sisters" (n = 8 villages). Outcomes were tobacco use rate at delivery and at 2 and 6 months postpartum, with biochemical confirmation obtained at 6 months. The program had high reach, enrolling 73% of all eligible women screened. Of the 352 participants, 67% used tobacco at baseline. No significant differences emerged between study groups on follow-up in tobacco use rates. More intervention than control participants made a quit attempt at 2 months postpartum (70% vs. 51%, respectively, p = 0.012). Participants in both study groups reported the program helped to raise awareness of healthy pregnancies in the study villages. This trial supports the reach of a community-level intervention, but not its efficacy for reducing tobacco use during pregnancy or postpartum. Efforts to sustain early quit attempts appear warranted. The community involvement, and reported impact on raising awareness of the importance of healthy pregnancies, supports the value of the research program in this community.

Follow-up Study Methods for a Longitudinal Cohort of Alaska Native and American Indian People Living within Urban South Central Alaska: The EARTH Study

Longitudinal data are needed to investigate chronic disease causation and improve prevention efforts for Alaska Native and American Indian (ANAI) people. This paper describes the methods used to conduct follow-up data collection of a longitudinal cohort that enrolled ANAI adults between 2004 and 2006 in south central Alaska. The follow-up study re-examined ANAI participants in a large, urban centre in south central Alaska between 2015 and 2017. Computerized surveys were used to collect self-reported health, lifestyle, physical activity, and diet data. Clinical measurements included blood pressure, fasting blood glucose and lipid panel, urine albumin/creatinine, height, weight, and waist and hip circumference. Participants were provided individual results at the conclusion of their visit. A total of 1320 south central Alaska study participants completed the baseline visit. Study staff attempted to contact all living cohort members for inclusion in the follow-up study. More than 11,000 attempted contacts were made. Of the 637 available for participation, 388 completed the follow-up visit. The proportion of women increased from baseline to follow-up examinations (67 vs. 72%, p < 0.01). Self-reported health status of being married or living as married (46% vs. 39%, p < 0.01), and those reporting being employed or self-employed (55% vs. 47%, p < 0.01) were higher at follow-up when compared to baseline. Almost all participants at follow-up (97%) agreed to long-term storage of biological specimens for future study. Despite demographic differences between the follow-up and baseline cohorts, longitudinal data collected will provide novel insight on chronic disease development and prevention for ANAI people as well as other populations.

Postpartum Tobacco Use and Perceived Stress among Alaska Native Women: MAW Phase 4 Study

Prior research explored reasons for tobacco use among pregnant Alaska Native (AN) women but did not address the postpartum period. This study followed up with AN women one to three years postpartum who had participated in a prenatal smoking cessation intervention study (Motivate Alaska Women (MAW) Phase 3) and had consented to be re-contacted for future studies. Of 47 eligible women, 32 (68%) participated. A semi-structured phone interview was conducted a mean of 2.0 years after delivery (range 1.6-2.8). Measures assessed self-reported tobacco use status in the 12 months after delivery, at 12 months postpartum, and at the time of the interview; reasons for maintaining abstinence, continued use, or relapse; and included the Perceived Stress Scale (PSS) and Negative Affect (NA) scale. Content analysis was used to generate themes from open-ended response items. Tobacco use was reported by 23 women (72%) at delivery, 30 (94%) within the 12 months after delivery, 27 (84%) at 12 months postpartum, and 29 (91%) at the time of the interview. Among nine women not using tobacco at delivery, seven (78%) relapsed during the 12 months after delivery. Of the 29 current tobacco users, 28 (97%) smoked cigarettes. Twenty-seven participants (84%) reported stress and 15 (52%) indicated addiction as reasons for continuing, starting, or resuming tobacco use. Types of stressors were related to parenting and traumatic experiences. Among current tobacco users, mean NA score (18.7) was significantly higher (p = 0.01) than the normative mean (14.8), but no differences were detected for PSS score. In this sample of AN women, postpartum tobacco use was highly prevalent, and stress was a primary reason that women endorsed for using tobacco. These preliminary results have several practice and research implications for exploring ways to support non-tobacco use among postpartum AN women.

The Healthy Pregnancies Project: Study protocol and baseline characteristics for a cluster-randomized controlled trial of a community intervention to reduce tobacco use among Alaska Native pregnant women

BACKGROUND

Tobacco use prevalence is high among pregnant Alaska Native (AN) women but few interventions have been evaluated for this group. The Healthy Pregnancies Project aims to evaluate a multicomponent intervention for reducing tobacco use during pregnancy and the postpartum period among AN women. This report describes the study protocol and participant baseline characteristics.

DESIGN

Cluster-randomized controlled trial with village as the unit of assignment. Sixteen villages in rural southwest Alaska were stratified on village size and randomized to a multicomponent intervention (n = 8 villages) or usual care (n = 8 villages).

METHODS

Pregnant AN women from the study villages were enrolled. All participants receive the usual care provided to pregnant women in this region. Participants from intervention villages additionally receive individual phone counseling on healthy pregnancies plus a social marketing campaign targeting the entire community delivered by local AN "Native Sisters." Baseline measurements for all enrolled pregnant women have been completed. Follow-up assessments are ongoing at delivery, and at 2 and 6 months postpartum. The primary outcome is biochemically verified tobacco use status at 6 months postpartum.

RESULTS

Recruitment was feasible with 73% of eligible women screened enrolled. The program reached more than half (56%) of AN pregnant women from the study villages during the recruitment period. Participants are N = 352 pregnant AN women, 188 enrolled from intervention villages and 164 from control villages. At baseline, participants' mean (SD) age was 25.8 (5.0) years, they were at 26.8 (9.8) weeks gestation, and 66.5% were current tobacco users.

DISCUSSION

Processes and products from this project may have relevance to other Native American populations aiming to focus on healthy pregnancies in their communities.

Biomarker feedback intervention for smoking cessation among Alaska Native pregnant women: Randomized pilot study

OBJECTIVE

There is some evidence for biomarker feedback when combined with cessation counseling for reducing smoking in pregnancy. This randomized controlled pilot study evaluated feasibility and potential efficacy of a social-cognitive theory (SCT)-based biomarker feedback intervention among pregnant Alaska Native (AN) smokers.

METHODS

Participants were randomly assigned to receive three study calls (10-20 min each): (1) biomarker feedback intervention (n = 30) including personalized cotinine results and feedback on their baby's likely exposure to carcinogen metabolite NNAL, or (2) contact control usual care condition based on the 5As (n = 30). Assessments were conducted at baseline, post-treatment, and delivery.

RESULTS

High rates of treatment compliance, study retention, and treatment acceptability were observed in both groups. 7-day point prevalence smoking abstinence rates at delivery verified with urinary cotinine were the same in both study groups (20% intent-to-treat analysis, 26% per-protocol). SCT-based measures did not change differentially from baseline by study group.

CONCLUSION

This trial supports the feasibility and acceptability of providing biomarker feedback within the clinical care delivery system, but the intervention did not promote increased smoking cessation during pregnancy compared to usual care.

PRACTICE IMPLICATIONS

Efforts are needed to promote the usual care and to develop alternative biomarker feedback messaging for pregnant AN women.

Urine 4-(methylnitrosamino)-1-(3) pyridyl-1-butanol and cotinine in Alaska native postpartum women and neonates comparing smokers and smokeless tobacco users

OBJECTIVE

Foetuses and neonates of women who use tobacco are exposed to nicotine and tobacco-derived carcinogens. We determined the relationship between urine biomarkers of tobacco toxicant exposure postpartum and in the neonates of Alaska Native (AN) women, comparing smokers and smokeless tobacco (ST) users, including iqmik, a homemade ST product.

METHODS

AN women, including 36 smokers, 9 commercial ST and 16 iqmik users their neonates participated. Urine from the woman at the time of delivery and her neonate's first urine were analysed for cotinine, the major metabolite of nicotine, and 4-(methylnitrosamino)-1-(3) pyridyl-1-butanol (NNAL), a tobacco-specific carcinogen biomarker.

RESULTS

Maternal urine cotinine and neonatal urine cotinine were strongly correlated in all tobacco use groups (r from 0.83 to 0.9, p < 0.002). Correlations between maternal cotinine and neonatal NNAL were moderately strong for cigarettes and commercial smokeless but weaker for iqmik users (r 0.73, 0.6 and 0.36, respectively).

CONCLUSION

Correlations between maternal and neonatal biomarkers of tobacco toxicant exposure vary, dependent on tobacco product use.

SIGNIFICANCE

This study provides novel data on biomarkers of tobacco exposure among postpartum AN women and their neonates. The results could be useful to guide future epidemiological studies of health risks associated with use of various tobacco products during pregnancy.

Developing a Biomarker Feedback Intervention to Motivate Smoking Cessation During Pregnancy: Phase II MAW Study

INTRODUCTION

The prevalence of smoking during pregnancy for Alaska Native (AN) women is more than triple that of non-Native Alaska women. In this qualitative study, we solicited input from AN women and others to determine how best to present findings from an earlier study demonstrating a strong correlation between biomarkers for maternal smoking (cotinine) and neonatal exposure to a tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) to motivate cessation.

METHODS

We developed a brochure incorporating generalized biomarker information. Using in-depth individual interviews with pregnant and postpartum AN women and partners/family members, we explored applicability and acceptability of the information. Postpartum women, who had participated in the earlier correlation study, additionally received their individual biomarker results. We assessed whether being presented general or individual biomarker information would motivate cessation using content analysis.

RESULTS

We conducted 39 interviews: 16 pregnant women, 12 postpartum women, and 11 partners/family members. Overall, participants agreed the biomarker information was new, but understandable as presented. Postpartum women shared that learning their personal results inspired them to want to quit or cut back smoking while pregnant women indicated the generalized correlation information was less helpful in motivating cessation.

CONCLUSION

Generalized information about fetal exposure to carcinogens may be more effective in motivating pregnant women to quit smoking when combined with individual cotinine testing.

IMPLICATIONS

Using feedback from this study, we refined and are currently evaluating an intervention incorporating generalized correlation information from Phase I and cotinine testing to determine its effectiveness in motivating smoking cessation among pregnant AN women.

Research Article. Relationship Between High Levels of Salivary Cotinine Test and Demographic Characteristics of Pregnant Smokers from Mures County

Objectives: To evaluate the relationship between the frequency of self-declared status regarding smoking in a group of pregnant women from Mures county, Romania and the high levels of Salivary Cotinine (SC) like biomarkers. Material and methods: It was conducted a retrospective study among 230 pregnant women presented for prenatal care at 50 General Practitioners cabinets in Mures county, Romania, in 2015. Data were collected with a validated questionnaire which included age, level of education, socioeconomic status and ethnicity, also the self-reported smoking status. The Salivary Cotinine level was evaluated using NicAlert Saliva test kits. Results: Using salivary test we identified a high prevalence of involuntary exposure to cigarette smoke among both non-smokers and those who quit smoking before pregnancy. Also we registered pregnant women that although declared smoking cessation before pregnancy their salivary Cotinine levels were high, almost like to an active smoker, probably because of second-hand exposure or because they didn’t say the truth about their habit. Conclusions: We underline the importance of implementing more efficient community interventions among this vulnerable group in order to reduce the frequency of smoking and sustain quitting.