Secondhand smoke exposure is longitudinally associated with shorter parent-reported sleep duration during childhood

Short sleep duration and smoking initiation in university students: a retrospective cohort study

PURPOSE

The aim of this study was to clarify an association between short sleep duration and smoking initiation.

METHODS

Participants eligible for this retrospective cohort study were university students who were admitted to a single national university in Japan between 2007 and 2015. Baseline sleep duration and smoking status were measured using general questionnaires at health checkups at admission. During a 6-year observation period, smoking initiation was assessed using general questionnaires at annual health checkups. Cox proportional hazards models adjusted for clinically relevant factors were used to assess the association between sleep duration and smoking initiation.

RESULTS

Of 17,493 men, including 540, 5,568, 8,458, 2,507, and 420 men with sleep duration of < 5, 5-6, 6-7, 7-8, and ≥ 8 h, respectively, smoking initiation was observed in 16.1%, 12.5%, 11.2%, 10.0%, and 11.7%, respectively, during a median observation period of 3.0 years. Men with shorter sleep duration were at a higher risk of smoking initiation (adjusted hazard ratio 1.49 [95% confidence interval 1.19-1.85], 1.11 [1.01-1.22], 1.00 [reference], 0.92 [0.80-1.06], and 1.00 [0.75-1.34], respectively). Of 8,880 women, including 267, 3,163, 4,220, and 1,230 women with sleep duration of < 5, 5-6, 6-7, and ≥ 7 h, respectively, smoking initiation was observed in 4.9%, 2.3%, 2.0%, and 2.2%, respectively, during a median observation period of 3.0 years. A similar dose dependent association was ascertained in women (2.50 [1.39-4.49], 1.18 [0.86-1.62], 1.00 [reference], and 1.22 [0.79-1.89], respectively).

CONCLUSION

This study clarified that university students with short sleep duration were vulnerable to smoking initiation.

Association of second-hand smoking with sleep quality among adults in Ibadan, Nigeria: a cross-sectional evaluation of data from the COMBAT-CVDs study

PURPOSE

Sleep quality (SQ) is essential in the overall well-being and quality of life, but little is known about the association of secondhand smoking (SHS) with SQ. This study assessed the relationship between SHS and SQ among adults who had never smoked in Ibadan, Nigeria.

METHODS

We identified 3193 respondents who had never smoked or used any form of tobacco product in the Community-based Investigation of the Risk Factors for Cardiovascular Diseases in the Ibadan and suburbs (COMBAT-CVDs) study. SHS was self-reported, SQ assessed using a sleep quality scale, and SQ scores were classified by the quartile distributions of SQ scores in this sample as good (< 7), moderate (7-13), fair (14-20), and poor (≥ 21), and logistic regression models were used to estimate the multivariable-adjusted odds ratio and 95% confidence interval (CI) of the association between SHS and SQ in a two-sided test at P < 0.05.

RESULTS

The mean (SD) of age in this sample was 34.8 ± 15.1 years; 1621 (50.8%) were females, and 848 (26.6%) experienced SHS. The multivariable-adjusted odds by categories of SQ scores (using good SQ as reference) in the light of SHS were OR: 1.64 (95%CI 1.28, 2.12) for moderate SQ, OR: 1.88 (95%CI 1.46, 2.42) for fair SQ and OR: 2.14 (95%CI 1.66, 2.75) for poor SQ; P < 0.0001 after adjusting for relevant covariates. The sex- and age groups- stratified analyses revealed similar trends.

CONCLUSION

SHS is associated with higher odds of poor SQ in this study. Culturally relevant interventions for mitigating exposure to SHS might improve SQ and overall quality of life, particularly among vulnerable populations.