Role of nicotine dependence in the association between the dopamine receptor gene DRD3 and major depressive disorder.

Background: The aims of this study were to analyze associations of dopamine receptor genes (DRD1-5) with Major Depressive Disorder (MDD) and nicotine dependence (ND), and to investigate whether ND moderates genetic influences on MDD.

Methods: The sample was ascertained from the Finnish Twin Cohort. Twin pairs concordant for smoking history were recruited along with their family members, as part of the multisite Nicotine Addiction Genetics consortium.

Smoking, nicotine dependence and nicotine intake by socio-economic status and marital status.

Introduction: Low socio-economic status (SES) is strongly related to smoking, but studies examining the association of SES with nicotine dependence (ND) are scarce. The aim of this study was to examine the associations of SES and marital status with smoking, multiple measures of ND, and cotinine as a nicotine intake biomarker.

Methods: The sample comprised 1746 ever smokers, sampled from the National FINRISK 2007 Study, who had completed a tobacco specific questionnaire in addition to the standard clinical examination.

Long-term consistency of diurnal-type preferences among men.

Diurnal type (chronotype) differentiates individuals on an axis between the extremes of evening type to morning type. These diurnal-type preferences are thought to be relatively stable, but follow-up studies are sparse. The study aims were (1) to compare cross-sectional studies of diurnal type preferences between two decades and (2) to analyze the consistency of diurnal-type preferences using a longitudinal dataset.

Scrutiny of the CHRNA5-CHRNA3-CHRNB4 smoking behavior locus reveals a novel association with alcohol use in a Finnish population based study.

The CHRNA5-CHRNA3-CHRNB4 gene cluster on chromosome 15q25.1 encoding the cholinergic nicotinic receptor subunits is robustly associated with smoking behavior and nicotine dependence. Only a few studies to date have examined the locus with alcohol related traits and found evidence of association with alcohol abuse and dependence.

Genome-wide association study on detailed profiles of smoking behavior and nicotine dependence in a twin sample.

Smoking is a major risk factor for several somatic diseases and is also emerging as a causal factor for neuropsychiatric disorders. Genome-wide association (GWA) and candidate gene studies for smoking behavior and nicotine dependence (ND) have disclosed too few predisposing variants to account for the high estimated heritability. Previous large-scale GWA studies have had very limited phenotypic definitions of relevance to smoking-related behavior, which has likely impeded the discovery of genetic effects.

Diurnal Evening Type is Associated with Current Smoking, Nicotine Dependence and Nicotine Intake in the Population Based National FINRISK 2007 Study.

AIMS: To examine whether smoking habits, nicotine dependence (ND) and plasma cotinine levels differ by diurnal type. DESIGN: Data originated from the national FINRISK 2007 survey. Regression analyses were calculated to examine the association between diurnal type and smoking status, ND, and nicotine intake.

Increased genetic vulnerability to smoking at CHRNA5 in early-onset smokers.

Context: Recent studies have shown an association between cigarettes per day (CPD) and a nonsynonymous single-nucleotide polymorphism in CHRNA5, rs16969968.

Objective: To determine whether the association between rs16969968 and smoking is modified by age at onset of regular smoking.

Data Sources: Primary data.

Tendency toward eveningness is associated with unhealthy dietary habits.

Subjects with higher preference for evening hours in daily activities (eveningness) have been repeatedly shown to practice adverse health behaviors as compared to those preferring morning hours (morningness). However, associations between chronotype and dietary intake have not been explored intensively. The authors explored whether the human chronotype is associated with food and nutrient intakes in a random sample of the population aged 25 to 74 yrs.

Analysis of detailed phenotype profiles reveals CHRNA5-CHRNA3-CHRNB4 gene cluster association with several nicotine dependence traits.

Introduction: The role of the nicotinic acetylcholine receptor gene cluster on chromosome 15q24-25 in the etiology of nicotine dependence (ND) is still being defined. In this study, we included all 15 tagging single nucleotide polymorphisms (SNPs) within the CHRNA5-CHRNA3-CHRNB4 cluster and tested associations with 30 smoking-related phenotypes.

Methods: The study sample was ascertained from the Finnish Twin Cohort study.

Chromosome 20 shows linkage with DSM-IV nicotine dependence in Finnish adult smokers.

Introduction: Chromosome 20 has previously been associated with nicotine dependence (ND) and smoking cessation. Our aim was to replicate and extend these findings.

Methods: First, a total of 759 subjects belonging to 206 Finnish families were genotyped with 18 microsatellite markers residing on chromosome 20, in order to replicate previous linkage findings.

Heritability of lung function: a twin study among never-smoking elderly women.

Most studies on lung function heritability have been conducted in smokers and non-smokers using cross-sectional study design. Smoking patterns may, however, confound the contribution of genetic factors. We investigated heritability of forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio longitudinally, excluding the effects of smoking.

A 3p26-3p25 genetic linkage finding for DSM-IV major depression in heavy smoking families.

Objective: The authors tested for genetic linkage of DSM-IV-diagnosed major depressive disorder in families that were ascertained for cigarette smoking.

Method: Within a study that targeted families characterized by a history of smoking, analyses derived a subset of 91 Australian families with two or more offspring with a history of DSM-IV major depressive disorder (affected sibling pairs, N=187) and 25 Finnish families (affected sibling pairs, N=33). Within this affected sibling pairs design, the authors conducted nonparametric linkage analysis.

Nicotine, alcohol, and drug findings in young adults in a population-based postmortem database.

Introduction: To obtain reliable information on nicotine and drug use through a population-based study, the prevalence of nicotine use in deceased young adults was studied in the Finnish postmortem toxicology database for a 3-year period. The nicotine user and non-nicotine user groups were compared by alcohol, drug, and drug-of-abuse findings and by the manner of death.

Methods: Nicotine users were identified based on detection of nicotine, cotinine, and/or trans-3'-hydroxycotinine in urine from a population-based sample of deceased young adults aged 15-34 years at the time of death (n = 1,623, ∼60% of all fatalities).

Associations of nicotine intake measures with CHRN genes in Finnish smokers.

Introduction: Genetic effects contribute to individual differences in smoking behavior. Persistence to smoke despite known harmful health effects is mostly driven by nicotine addiction. As the physiological effects of nicotine are mediated by nicotinic acetylcholine receptors (nAChRs), we aimed at examining whether single nucleotide polymorphisms (SNPs) residing in nAChR subunit (CHRN) genes, other than CHRNA3/CHRNA5/CHRNB4 gene cluster previously showing association in our sample, are associated with smoking quantity or serum cotinine levels.

Cigarette smoking and dimensions of depressive symptoms: longitudinal analysis among Finnish male and female twins.

Introduction: The association of smoking and depression is established, but it remains unclear which depression dimensions are linked to smoking patterns.

Methods: The associations between smoking and depression dimensions were investigated among 4,980 male and 5,997 female Finnish twins. Longitudinal cigarette smoking patterns in 1975-1981 included multiple categories describing consistency and change.

Bruxism is associated with nicotine dependence: a nationwide Finnish twin cohort study.

Objectives: To investigate the association of smoking with bruxism while controlling for genetic and environmental factors using a co-twin-control design. Especially, the role of nicotine dependence was studied in this context.

Methods: The material derives from the Finnish Twin Cohort consisting of 12,502 twin individuals who responded to a questionnaire in 1990 (response rate of 77%).

Food neophobia in young adults: genetic architecture and relation to personality, pleasantness and use frequency of foods, and body mass index--a twin study.

Food neophobia has been studied extensively in children, but its causal origins and relationship to eating behavior in adults are not well understood. We studied genetic and environmental effects on variation in food neophobia, measured using the Food Neophobia Scale, and explored associations between food neophobia and personality, pleasantness and use frequency of food groups, and body mass index in young adult twins (N = 1175, aged 20-25 years, 54.7% women).

Evening types are more often current smokers and nicotine-dependent-a study of Finnish adult twins.

Aims: To examine the association between diurnal type and smoking status and nicotine dependence (ND).

Design: A cohort study using random-effects model regressions for repeated longitudinal panel data was used to analyse smoking status by diurnal type. Regression analyses examined the association between diurnal type and ND.

[Evaluation of tobacco addiction among adolescents and its treatment within the health care].

Evaluation and treatment of tobacco addiction among adolescents require partly different means than those for adults. Some adolescents are hooked already from the first cigarettes. Indicators of dependence designed for adults and based on regular smoking are suitable for daily smoking adolescents.

Smoking strongly predicts disability retirement due to COPD: the Finnish Twin Cohort Study.

No previous studies on the association of smoking behaviour with disability retirement due to register verified chronic obstructive pulmonary disease (COPD) exist. This 30-yr follow-up study examined how strongly aspects of cigarette smoking predict disability retirement due to COPD. The study population consisted of 24,043 adult Finnish twins (49.

Smoking affects diagnostic salivary periodontal disease biomarker levels in adolescents.

Background: The effects of smoking on periodontal biomarkers in adolescents are unknown. This study investigates matrix metalloproteinase (MMP)-8 and polymorphonuclear leukocyte elastase levels in saliva together with periodontal health indices accounting for body mass index and smoking in a birth cohort from Finland.

Methods: The oral health of boys (n = 258) and girls (n = 243) aged 15 to 16 years was examined clinically.

Key factors in smoking cessation intervention among 15-16-year-olds.

The authors aimed to investigate factors associated with smoking cessation among adolescents after tobacco intervention. They examined smokers (n = 127) from one birth cohort (n = 545) in the city of Kotka in Finland. These smokers were randomized in 3 intervention groups the dentist (n = 44) and the school nurse (n = 42 groups), and a control group (n = 39).

Long-term smoking behavior patterns predicting self-reported chronic bronchitis.

We examined the effects of long-term smoking patterns on self-reported symptoms of chronic bronchitis within the Finnish adult twin cohort including 21, 609 individuals responding to questionnaires in 1975 and 1981, of which 11,015 respondents participated also in 1990. We also explored the association between smoking and bronchitis among discordant twin pairs. Among those without chronic bronchitis at baseline we examined incidence of chronic bronchitis in 1981 both by 1975 smoking status, but also based on subgroups formed according to change in smoking behaviors between 1975 and 1981.