Addressing the Smoking-Hypertension Paradox in Pregnancy: Insight from a Multiethnic US Birth Cohort

Background

Smoking during pregnancy has been associated with reduced risk of a spectrum of hypertensive (HTN) disorders, known as the "smoking-hypertension paradox."

Objective

We sought to test potential epidemiologic explanations for the smoking-hypertension paradox.

Methods

We analyzed 8,510 pregnant people in the Boston Birth Cohort, including 4,027 non-Hispanic Black and 2,428 Hispanic pregnancies. Study participants self-reported tobacco, alcohol, cannabis, opioids, or cocaine use during pregnancy. We used logistic regression to assess effect modification by race/ethnicity, and confounding of concurrent substances on hypertensive disorders or prior pregnancy. We also investigated early gestational age as a collider or competing risk for pre-eclampsia, using cause-specific Cox models and Fine-Gray models, respectively.

Results

We replicated the paradox showing smoking to be protective against hypertensive disorders among Black participants who used other substances as well (aOR: 0.61, 95% CI: 0.41, 0.93), but observed null effects for Hispanic participants (aOR: 1.14, 95% CI: 0.55, 2.36). In our cause-specific Cox regression, the effects of tobacco use were reduced to null effects with pre-eclampsia (aOR: 0.81, 95% CI: 0.63, 1.04) after stratifying for preterm birth. For the Fine-Gray competing risk analysis, the paradoxical associations remained. The smoking paradox was either not observed or reversed after accounting for race/ethnicity, other substance use, and collider-stratification due to preterm birth.

Conclusions

These findings offer new insights into this paradox and underscore the importance of considering multiple sources of bias in assessing the smoking-hypertension association in pregnancy.

Alcohol-induced risk behaviors among Brazilian nightclub patrons: a latent class analysis

OBJECTIVE

The aim of this study is to identify risk behavior profiles associated with alcohol consumption among patrons during or just after departure from nightclubs in São Paulo, Brazil.

STUDY DESIGN

Cross-sectional survey.

METHODS

The study used a two-stage cluster sampling survey design. Data were collected on a probabilistic sample of nightclub patrons. Overall, 2422 patrons were interviewed at the entrance of 31 nightclubs. Latent class analysis (LCA) was used to identify risk behavior profiles with an emphasis on risky driving, fights, alcoholic blackouts, and harm and unsafe sex.

RESULTS

A 3-class LCA model was selected, with classes consisting of low (43%), medium (33%), and high (24%) risk patrons. Compared to patrons in the low-risk class, patrons in the medium- and high-risk classes were more likely to be men (odds ratio [OR] = 2.2, 95% confidence interval {CI} [1.2-4.0] and OR = 3.2, 95% CI [1.8-5.8], respectively), to have engaged in binge drinking during the last year (OR = 15.0, 95% CI [7.2-31.3] and OR = 14.3, 95% CI [9.4-21.8]), to be in the highest socioeconomic stratum (OR = 2.6, 95% CI [1.3-5.1] and OR = 2.0, 95% CI [1.2-3.5]) and to have been interviewed at a hip-hop music nightclub (OR = 2.8, 95% CI [1.1-6.8] and OR = 3.7, 95% CI [1.5-9.1]).

CONCLUSIONS

Risk behaviors were not equally distributed among nightclubs. Individual- and environmental-level characteristics are associated with higher risk. Alcohol harm reduction, such as the implementation of a responsible drinking service, should be implemented in São Paulo nightclubs.

A school-based epidemiological field survey: difficulties in collecting psychiatric outcome data in a middle-income country

BACKGROUND

Low- and middle-income countries (LMICs) face a lack of epidemiological data. The development of high-quality surveys is a key research priority in countries such as Brazil. Our aim is to discuss the difficulties in conducting a longitudinal epidemiological survey in a pilot study of a school-based sample in São Paulo.

METHODS

Data came from a cohort of school-attending adolescents in two neighborhoods with different levels of urbanicity in São Paulo. Students born in 2002 and in the 7th grade during 2014 were recruited from nine public schools. Adolescents and caregivers were interviewed separately at baseline and at one year follow-up, using several instruments, including the Schedule for Affective Disorders and Schizophrenia for School-Age Children/Present and Lifetime Version (K-SADS-PL).

RESULTS

Achieving unbiased sampling, keeping an updated register of participants' contact information, using a full clinical interview without an algorithm for its scoring, and maintaining a highly-trained research team were among the difficulties faced.

CONCLUSION

Working closely with community leaders, organizing group efforts to perform interviews, using a short, easy to understand instrument and providing some reward for participants were identified as alternatives to dealing with these difficulties, useful not only in Brazil, but also in other LMICs.