Life-Course Associations Between Smoking and Depressive Symptoms. A 30-Year Finnish Follow-up Study.

INTRODUCTION: Relatively little is known about whether the association between smoking and depressive symptoms changes with age and how the trajectories of smoking and depressive symptoms are intertwined during the life course. In this population-based study, these associations were examined from young adulthood to middle age. METHODS: Participants of a Finnish cohort study (N = 1955) were assessed at the ages of 22, 32, 42, and 52 using questionnaires covering daily smoking (yes/no) and the short 13-item Beck Depression Inventory. Longitudinal latent class and longitudinal latent profile analyses were used to identify life course trajectories of smoking and depressive symptoms. RESULTS: The proportions of daily smokers decreased, while levels of depressive symptoms increased among both females and males from age 22 to 52 years. Smoking was associated with higher levels of depressive symptoms from age 22 to 42 years, while not at 52. Associations among males prevailed when adjusting for education, marital status, and alcohol use. Four life course classes of daily smoking (nonsmokers, decreasing prevalence of smoking, persistent smokers, and increasing prevalence of smoking) and four trajectories of depressive symptoms (low, increasing/moderate, decreasing/moderate, and high) were identified. In males, persistent daily smokers (relative risk ratio (RRR) = 4.5, 95% confidence interval (CI): 2.2 to 9.2) and those in the class with increasing smoking prevalence (RRR = 3.2, 95% CI: 1.1 to 9.1) had an increased risk of belonging to the high depressive symptoms profile. In females these associations were nonsignificant. CONCLUSIONS: Compared to females, the relationship between smoking and depressive symptoms seems more robust among males during adulthood. Specifically, males smoking persistently from young adulthood to middle age have an increased risk of high depressive symptoms trajectory. IMPLICATIONS: This population-based cohort with 30 years of follow-up showed that the life course trajectories of daily smoking and depressive symptoms are associated. Persistent daily smokers and those starting late had an increased risk of belonging to the profile with constantly high levels of depressive symptoms during the life course. However, these associations were statistically significant only in males. Actions should be strengthened, especially in males, to prevent smoking initiation, to help smoking cessation, and to identify and treat depression in smokers with significant depressive symptoms.

A Nationally Representative Study of the Hardening Hypothesis Among Educational Groups Over Four Decades.

INTRODUCTION: As smoking prevalence has decreased, there has been debate about "hardening" (smokers are more resistant to established tobacco control measures) or "softening" (smokers are more responsive to interventions) of the remaining smoking population. Despite growing evidence to reject the "hardening" hypothesis, there is lack of long-term population-based studies to test this hypothesis by educational level. AIMS AND METHODS: Repeated cross-sectional population-based surveys during 1978-2014 and in 2018 were utilized. The target population consisted of ~5000 25-64-year-old Finns annually. The data included 109 257 respondents of which 53 351 ever-smoking individuals were included in the analyses. Response rates varied between 84% and 43%. Five hardening indicators considering smoking frequency, intensity and smoking cessation were used as the dependent variables. The main independent variable was study year (time). Statistical analyses were based on regression models using restricted cubic splines by educational level. RESULTS: Contrary to the hardening hypothesis, hardening indicators showed softening over time among all educational groups. However, educational groups differed from each other. Compared with the highly educated, the quit ratio was lower, number of cigarettes per day (CPD) was higher, the proportions of daily smokers among current smokers and heavy smokers among daily smokers were higher among the less educated. CONCLUSIONS: In accordance with growing evidence, also the Finnish smoking population has "softened" over time. Although the change has been predominantly in the same direction for all educational groups, the rate of change has been stronger among the highly educated, highlighting the continued burden of smoking among the less educated. IMPLICATIONS: Even though "softening" of smoking has occurred, lighter smoking also poses health risks. Therefore, tobacco control policies and cessation services should be developed and targeted to a greater extent also for people who smoke less than daily and for those who smoke fewer CPD. Furthermore, interventions should focus on special requirements of the lower educational groups to promote health equity.

Smoking remains associated with education after controlling for social background and genetic factors in a study of 18 twin cohorts.

We tested the causality between education and smoking using the natural experiment of discordant twin pairs allowing to optimally control for background genetic and childhood social factors. Data from 18 cohorts including 10,527 monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs discordant for education and smoking were analyzed by linear fixed effects regression models. Within twin pairs, education levels were lower among the currently smoking than among the never smoking co-twins and this education difference was larger within DZ than MZ pairs. Similarly, education levels were higher among former smoking than among currently smoking co-twins, and this difference was larger within DZ pairs. Our results support the hypothesis of a causal effect of education on both current smoking status and smoking cessation. However, the even greater intra-pair differences within DZ pairs, who share only 50% of their segregating genes, provide evidence that shared genetic factors also contribute to these associations.

Life course associations between smoking and depressive symptoms. A 30-year Finnish follow-up study.

BACKGROUND: While the association between smoking and depressive symptoms has been studied quite extensively, only little is known whether the association changes and how the trajectories of smoking and depressive symptoms are intertwined during the life course. In this population-based study, we examined these associations from young adulthood to middle age. METHODS: Participants of a Finnish cohort study (N = 1955) were addressed at ages 22, 32, 42 and 52 using postal questionnaires including questions of daily smoking and depressive symptoms (the short 13-item Beck Depression Inventory). Linear and logistic regression analyses and longitudinal latent class and profile analyses were used. RESULTS: The percentages of daily smokers decreased, while levels of depressive symptoms increased among both women and men from age 22 to 52 years. Daily smoking was associated with higher levels of depressive symptoms between ages 22 and 42, while not at age 52. Associations among men prevailed also in the adjusted models. Four life course trajectories of daily smoking (non-smokers, quitters, persistent smokers, and late starters) and four depressive symptoms (low, increasing/moderate, decreasing/moderate, and high) were identified. In the adjusted models, persistent daily smokers and late starters had significantly higher risk of belonging to the high depressive symptoms profile in men, but not in women. CONCLUSIONS: Compared to women the associations between daily smoking and depressive symptoms seem more robust among men during adulthood. Especially those men smoking persistently from young adulthood to middle age have an increased risk of high depressive symptoms trajectory during the life course.

The associations of smoking dependence motives with depression among daily smokers.

AIMS: To investigate how strongly smoking dependence and smoking dependence motives are associated with depressive symptoms among daily smokers and if these associations are independent of measured confounders and shared familial factors. DESIGN: Cross-sectional individual-based and within-pair analyses. SETTING: Fourth wave of the population-based Finnish Twin Cohort conducted in 2011. PARTICIPANTS: 918 daily smokers born 1945-1957 (48% men), mean age 59.5 years including 38 twin pairs discordant for depression. MEASUREMENTS: Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression scale with a cut off value ≥20 for depression. Smoking dependence was assessed using the Fagerström Test for Cigarette Dependence (FTCD) and smoking dependence motives with three subscales from the multi-dimensional Brief Wisconsin Inventory of Smoking Dependence Motives (WISDM): primary dependence motives (PDM), affective enhancement (AE), and Taste. Logistic regressions, using standardized scores of independent variables and adjusted for multiple confounders with correction for sampling as twin pairs, were used in the individual-based analyses. Conditional logistic regression was used to control for shared familial factors in discordant twin pairs. FINDINGS: Prevalence of depression was 18% (n = 163: 61 [14%] in men, n = 102 [22%] in women). Higher smoking dependence measured by the FTCD (OR 1.45; 95% CI 1.20, 1.75), and dependence motives measured by the PDM (1.56; 1.30, 1.87) and the AE (1.54; 1.28, 1.85) were associated with higher odds of depression. The associations remained after adjusting for individual confounders, except for neuroticism, which attenuated all associations. FTCD, PDM, and AE showed associations with depression within depression-discordant monozygotic pairs, suggesting an association independent of familial factors. CONCLUSIONS: Depression appears to be associated with smoking dependence and smoking dependence motives related to heavy, automatic use and use to regulate affective states. The associations appear to be confounded or mediated by neuroticism but are independent of shared familial influences.

The Older Finnish Twin Cohort - 45 Years of Follow-up.

The older Finnish Twin Cohort (FTC) was established in 1974. The baseline survey was in 1975, with two follow-up health surveys in 1981 and 1990. The fourth wave of assessments was done in three parts, with a questionnaire study of twins born during 1945-1957 in 2011-2012, while older twins were interviewed and screened for dementia in two time periods, between 1999 and 2007 for twins born before 1938 and between 2013 and 2017 for twins born in 1938-1944. The content of these wave 4 assessments is described and some initial results are described. In addition, we have invited twin-pairs, based on response to the cohortwide surveys, to participate in detailed in-person studies; these are described briefly together with key results. We also review other projects based on the older FTC and provide information on the biobanking of biosamples and related phenotypes.

Association of current and former smoking with body mass index: A study of smoking discordant twin pairs from 21 twin cohorts.

BACKGROUND: Smokers tend to weigh less than never smokers, while successful quitting leads to an increase in body weight. Because smokers and non-smokers may differ in genetic and environmental family background, we analysed data from twin pairs in which the co-twins differed by their smoking behaviour to evaluate if the association between smoking and body mass index (BMI) remains after controlling for family background. METHODS AND FINDINGS: The international CODATwins database includes information on smoking and BMI measured between 1960 and 2012 from 156,593 twin individuals 18-69 years of age. Individual-based data (230,378 measurements) and data of smoking discordant twin pairs (altogether 30,014 pairwise measurements, 36% from monozygotic [MZ] pairs) were analysed with linear fixed-effects regression models by 10-year periods. In MZ pairs, the smoking co-twin had, on average, 0.57 kg/m2 lower BMI in men (95% confidence interval (CI): 0.49, 0.70) and 0.65 kg/m2 lower BMI in women (95% CI: 0.52, 0.79) than the never smoking co-twin. Former smokers had 0.70 kg/m2 higher BMI among men (95% CI: 0.63, 0.78) and 0.62 kg/m2 higher BMI among women (95% CI: 0.51, 0.73) than their currently smoking MZ co-twins. Little difference in BMI was observed when comparing former smoking co-twins with their never smoking MZ co-twins (0.13 kg/m2, 95% CI 0.04, 0.23 among men; -0.04 kg/m2, 95% CI -0.16, 0.09 among women). The associations were similar within dizygotic pairs and when analysing twins as individuals. The observed series of cross-sectional associations were independent of sex, age, and measurement decade. CONCLUSIONS: Smoking is associated with lower BMI and smoking cessation with higher BMI. However, the net effect of smoking and subsequent cessation on weight development appears to be minimal, i.e. never more than an average of 0.7 kg/m2.

Association between long-term smoking and leisure-time physical inactivity: a cohort study among Finnish twins with a 35-year follow-up.

OBJECTIVES: To investigate longitudinal associations of smoking and a change in smoking status with leisure-time physical inactivity. In addition, to control whether familial confounding (genetics and shared environment) influences the associations. METHODS: Data were based on the population-based Finnish Adult Twin Cohort of 5254 twin individuals born in 1945-1957 (41% men) and who participated in all four surveys over a 35-year follow-up (1975-2011). Logistic and conditional logistic regression models with multiple covariates were used for analyses. RESULTS: Compared to never-smokers, long-term daily smokers (1975-1990) had the highest likelihood for both long-term inactivity and to change into inactive by 2011. Recurrent smoking was associated with long-term inactivity. Instead, in comparison to persistent daily smokers, quitting smoking decreased the likelihood of becoming physically inactive at leisure time. The associations remained in the analyses which accounted for multiple covariates and/or familial confounding. CONCLUSIONS: Daily smoking increases the likelihood of remaining or becoming physically inactive over the decades. Our results emphasize not only the importance of preventing smoking initiation, but also to support early smoking cessation in promotion of lifelong physical activity.

Opioids, antiepileptic and anticholinergic drugs and the risk of fractures in patients 65 years of age and older: a prospective population-based study.

BACKGROUND: in men, the concomitant use of two or more benzodiazepines or two or more antipsychotics is associated with an increased risk of fracture(s). Potential associations between the concomitant use of drugs with central nervous system effects and fracture risk have not been studied. OBJECTIVE: the purpose was to describe the gender-specific risk of fractures in a population aged 65 years or over associated with the use of an opioid, antiepileptic or anticholinergic drug individually; or, their concomitant use with each other; or the concomitant use of one of these with a psychotropic drug. METHODS: this study was part of a prospective, population-based study performed in Lieto, Finland. Information about fractures in 1,177 subjects (482 men and 695 women) was confirmed with radiology reports. RESULTS: at 3 years of follow-up, the concomitant use of an opioid with an antipsychotic was associated with an increased risk of fractures in men. During the 6-year follow-up, the concomitant use of an opioid with a benzodiazepine was also related to the risk of fractures for males. No significant associations were found for females. CONCLUSION: the concomitant use of an opioid with an antipsychotic, or with a benzodiazepine may increase the risk of fractures in men aged 65 years and older.