Nicotine dependence and sleep quality in young adults.

INTRODUCTION: More cigarette smokers report poor sleep quality than non-smokers, but the association between nicotine dependence (ND) and sleep quality has not been well-characterized. The objective of this study was to describe the associations among frequency and intensity of cigarette smoking, ND symptoms, and sleep quality in young adults. METHODS: Data on past-year smoking frequency, number of cigarettes smoked in the past month, five ND indicators (i.e., withdrawal, craving, self-medication symptoms, mFTQ, ICD-10 criteria for tobacco dependence), and sleep quality (measured with the Pittsburgh Sleep Quality Index (PSQI)) were collected in 2011-12 in self-report questionnaires completed by 405 young adult smokers (mean age 24 (0.6) years; 45% male; 45% daily smokers) participating in a longitudinal investigation of the natural course of ND. Associations between indicators of cigarette smoking, ND symptoms, and sleep quality were examined in multivariable logistic regression analyses controlling for age, sex, mother's education, and alcohol use. RESULTS: Thirty-six percent of participants reported poor sleep quality (PSQI>5). Higher cigarette consumption (OR(95% CI), 1.03(1.001-1.05)) but not frequency of past-year smoking, more frequent withdrawal symptoms (1.05(1.004-1.10)), more frequent cravings (1.05(1.004-1.10)), higher mFTQ scores (1.14(1.02-1.27)), and endorsing more ICD-10 criteria for tobacco dependence (1.19(1.04-1.36)) were also associated with poor sleep quality. CONCLUSION: Cigarette smoking and ND symptoms are associated with poor sleep quality in young adult smokers. Advice from practitioners to cut back on number of cigarettes smoked per day and treatment of ND symptoms may improve sleep quality in young adult smokers.

Distinguishing risk factors for the onset of cravings, withdrawal symptoms and tolerance in novice adolescent smokers.

AIM: While many studies report determinants of adolescent cigarette smoking, few identify risk factors for nicotine dependence (ND). This study distinguished between risk factors for three hallmarks of ND including cravings, withdrawal symptoms and tolerance. METHODS: A total of 319 novice smokers were followed every 3 months from first puff on a cigarette until the end of secondary school. Outcomes included time to first report of cravings, withdrawal symptoms and tolerance. RESULTS: Female sex, inhalation, smoking a whole cigarette, weekly smoking, daily smoking and alcohol use each independently increased the incidence of the onset of cravings. Inhalation, weekly smoking, daily smoking and alcohol use predicted the onset of withdrawal symptoms. Withdrawal symptoms, smoking a whole cigarette, monthly smoking, daily smoking and friends and siblings smoking increased the incidence of the onset of tolerance. None of parental education, impulsivity, novelty seeking, self-esteem, depression, stress, parental smoking, physical activity, or participation in sports teams was associated with the outcomes. CONCLUSION: The hallmarks of early ND are related to intensity and frequency of cigarette use. Avoidance of daily smoking may be particularly important in preventing the onset of ND symptoms and sustained smoking.

Reporting of ethnicity in research on chronic disease: update.

This paper examines the inclusion of ethnicity and race as variables in current, leading edge research on chronic disease and its risk factors. Of 100 randomly selected original research articles published in high-impact journals in 2005, 85% did not report either a definition of ethnicity or its conceptualisation in terms of theoretical reasoning, and 98% did not report an actual measurement item. Ethnicity and race remain non-standardised and largely underdescribed variables in research on chronic disease. This represents an important loss of opportunity to articulate and test hypotheses about the mechanisms underlying ethnic group differences in chronic disease.