Association of dopamine-related gene alleles, smoking behavior and decline in FEV1 in subjects with COPD: findings from the lung health study.

Cigarette smoking is the major risk factor for chronic obstructive pulmonary disease (COPD). Specific dopamine related gene alleles have previously been found to be associated with smoking initiation, maintenance and cessation. We investigated the association between specific dopamine related gene alleles and both change in smoking behavior and lung function change over time in individuals with mild-to-moderate COPD. Subjects included a subset of participants in the Lung Health Study (LHS), a smoking intervention study in smokers with mild to moderate COPD. Smoking status was determined and lung function performed at baseline and annually for 5 years. In post-hoc analyses, we assessed the association of the dopamine receptor (DRD2) TaqI A1(+) allele (A1A1, A1A2 genotypes) and A1(-) allele (A2A2 genotype), and the dopamine transporter (DAT) 9R(+) allele (9R9R and 9R10R genotypes) and 9R(-) allele (10R10R genotype) with both changes in smoking status and lung function in a subset of LHS subjects. No significant associations were noted between variants in these genes and success in smoking cessation. However, in exploratory analyses that did not adjust for multiple comparisons, sustained male (but not female) quitters with the DRD2 A1(-) allele and/or the DAT 9R(+) allele showed an accelerated decline in FEV(1) similar to that of continuing smokers over 5 years after quitting smoking. These preliminary findings suggest that dopamine-related genes may play a role in the progression of COPD, at least in the subset of male ex-smokers whose disease continues to progress despite sustained quitting, and warrants additional confirmatory and mechanistic studies.

Impact of changes in regular use of marijuana and/or tobacco on chronic bronchitis.

We sought to evaluate possible changes in the prevalence of chronic bronchitis in relation to continuing or changing smoking status for marijuana and/or tobacco. For this purpose we followed 299 participants in a longitudinal cohort study of the impact of heavy habitual use of marijuana alone or with tobacco on respiratory symptoms over a mean of 9.8 years during which subjects underwent repeated administration of a detailed drug use and respiratory questionnaire at intervals of ≥1 yr. Using logistic regression, we calculated odds ratios to assess the relationship between chronic bronchitic symptoms and smoking status for marijuana and tobacco at the first visit (current smoking versus never smoking) and at the last follow-up visit (continuing smoking versus, separately, never smoking and former smoking). We found that continuing smokers of either marijuana or tobacco had a significantly increased likelihood of having chronic bronchitis at follow-up compared to both never smokers and former smokers. On the other hand, former smokers of either substance were no more likely to have chronic respiratory symptoms at follow-up than never smokers. These findings demonstrate the benefit of marijuana smoking cessation in resolving pre-existing symptoms of chronic bronchitis.

Somnology 101: a primer on sleep disorders, their impact on society, and a role for dentistry.

Sleep is necessary for our existence. It is one-third of a commitment to health along with nutrition and exercise. While we spend one-third of our lives asleep, studies show one-third of the U.S. population suffers with a significant sleep disorder at some point in their lifetime. This manuscript introduces sleep and sleep disorders, focuses on those sleep disorders within the domain of dentistry, and addresses contributions the dental community can make toward specific sleep problems.

Dentistry-based approaches to sleep-disordered breathing, algorithms, and multidisciplinary perspectives.

Sleep disorders affect more than 20 percent of the U.S. population, but less than 7 percent have been medically diagnosed. Dentists are ideally positioned to identify many patients who fall under the grouping of sleep-disordered breathing. This paper presents perspectives on sleep-related issues from various medical specialties with a goal to broaden the dentist's appreciation of this topic and open avenues of communication. Algorithms are proposed to guide dentists following positive screenings for sleep-disordered breathing.

Sociodemographic characteristics of cannabis smokers and the experience of cannabis withdrawal.

BACKGROUND: Cannabis withdrawal can be a negative reinforcer for relapse, but little is known about its association with demographic characteristics. OBJECTIVES: Evaluate the association of demographic characteristics with the experience of cannabis withdrawal. METHODS: Retrospective self-report of a "serious" cannabis quit attempt without formal treatment in a convenience sample of 104 non-treatment-seeking, adult cannabis smokers (mean age 35 years, 52% white, 78% male) with no other current substance use disorder (except tobacco) or chronic health problems. Reasons for quitting, coping strategies to help quit, and 18 specific withdrawal symptoms were assessed by questionnaire. RESULTS: Among withdrawal symptoms, only anxiety, increased sex drive, and craving showed significant associations with age, race, or sex. Women were more likely than men to report a physical withdrawal symptom (OR = 3.2, 95% CI = .99-10.4, p = .05), especially upset stomach. There were few significant demographic associations with coping strategies or reasons for quitting. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: This small study suggests that there are few robust associations between demographic characteristics and cannabis withdrawal. Future studies with larger samples are needed. Attention to physical withdrawal symptoms in women may help promote abstinence.

The potentially harmful medical consequences of untreated sleep-disordered breathing: the evidence supporting brain damage.

BACKGROUND: The authors conducted a literature review to evaluate whether current scientific evidence supports the fact that brain damage results from episodic hypoxia (EH) as seen during sleep-disordered breathing (SDB). TYPES OF STUDIES REVIEWED: In their review, the authors included models that re-created circumstances seen in EH during SDB. They reviewed animal and human studies, including those with children and animal pups as subjects. These studies addressed neurocognitive and neurobehavioral effects, physical changes found on a cellular level as seen in brain imaging and the effects of treatment. RESULTS: The evidence suggests that EH as seen during SDB causes damage to the brain with specific areas of gray- and white-matter loss, alteration in autonomic and motor regulation, and damage to higher cognitive functions. While there is evidence of spontaneous reactive mechanisms, it is not clear if they limit ongoing brain damage or contribute to additional damage. Retention of deficits in the brain even after treatment suggests long-term injury. CLINICAL IMPLICATIONS: Evidence shows that EH during SDB may cause permanent brain changes and can start early in the progression of sleep disorders even in childhood. SDB should be identified and treated early to reduce and possibly prevent brain damage and permanently decreased cognitive function. Dentists are in the unique position of being able to screen patients for SDB during periodic examinations while providing routine dental health care. When dentists catch SDB early in the progression and refer patients to and coordinate care with patients' physicians, they can provide better service to their patients and may prolong and improve their patients' quality of life.

Quitting among non-treatment-seeking marijuana users: reasons and changes in other substance use.

This study examines the self-reported reasons for quitting marijuana use, changes in other substance use during the quit attempt, and reasons for the resumption of use in 104 non-treatment-seeking adult marijuana smokers. Reasons for quitting were shown to be primarily motivated by concerns about the negative impact of marijuana on health and on self- and social image. The spontaneous quitting of marijuana use is often associated with an increase in the use of legal substances such as alcohol, tobacco, and sleeping aids, but not with the initiation of new substance use. These findings suggest areas for further research on spontaneous recovery from marijuana use.

Cannabis withdrawal among non-treatment-seeking adult cannabis users.

This study investigates the clinical significance of a cannabis withdrawal syndrome in 104 adult, non-treatment-seeking, primarily cannabis users who reported at least one serious attempt to stop using cannabis. Retrospective self-report data were obtained on eighteen potential cannabis withdrawal symptoms derived from the literature, including co-occurrence, time course, and any actions taken to relieve the symptom. Study findings provide evidence for the clinical significance of a cannabis withdrawal syndrome, based on the high prevalence and co-occurrence of multiple symptoms that follow a consistent time course and that prompt action by the subjects to obtain relief, including serving as negative reinforcement for cannabis use.

Cost-effectiveness of split-night polysomnography and home studies in the evaluation of obstructive sleep apnea syndrome.

STUDY OBJECTIVES: Split-night polysomnography (PSG) and unattended home sleep studies have come into use as less-expensive tests for obstructive sleep apnea syndrome, but their impact on cost-effectiveness of the overall evaluation and treatment is unknown. We compared the cost-effectiveness of evaluations that employ these 2 procedures with a conventional approach using full-night PSG. METHODS: We used a decision-tree model that incorporated typical clinical algorithms for each of the 3 strategies to compare their cost-effectiveness from a third-party payer perspective over a 5-year period. Probabilities and test characteristics were derived from data from the published literature. Cost estimates were based on the 2004 Medicare Fee Schedule. Survival rates were taken from National Center for Health Statistics data and published studies. Effectiveness was measured as quality-adjusted life years. RESULTS: Trade-offs of overall costs versus effectiveness were identified. The home-studies strategy was less costly and less effective than split-night PSG and full-night PSG, as was split-night PSG compared with full-night PSG. Costs to attain additional quality-adjusted life years were below commonly accepted thresholds. A probabilistic analysis suggested that the home-studies approach was most cost-effective at the lowest amounts of third-party willingness to pay, whereas split-night PSG or full-night PSG was most cost-effective at higher amounts. CONCLUSIONS: Home studies and split-night PSG are cost-effective alternatives to full-night PSG. Willingness-to-pay is an important consideration in choosing the most cost-effective approach. This study points out the importance of considering the complexities within the entire process of obstructive sleep apnea syndrome evaluation when comparing costs among different procedures.

Strategies for quitting among non-treatment-seeking marijuana smokers.

This study examines self-reported quitting strategies used by adult, non-treatment-seeking marijuana smokers. Sixty-five subjects rated the use and effectiveness of thirteen strategies on a self-developed instrument, the Marijuana Quit Questionnaire. The strategies clustered into three categories/factors, whether grouped by principal components analysis, mean helpfulness rating, or frequency of endorsement: Change Environment, Seeking Organized/Professional Help, and Social Support. Changing one's environment was rated as most helpful while seeking help from professionals was the least helpful. Clinicians are likely to see marijuana users in their practice and should be proactive in offering assistance, incorporating the strategies reported here into treatment plans for their marijuana-using patients.

Evidence of chronic damage to the pulmonary microcirculation in habitual users of alkaloidal ("crack") cocaine.

STUDY OBJECTIVE: To evaluate BAL cells obtained from habitual users of alkaloidal ("crack") cocaine alone or in combination with tobacco, for evidence of cocaine-associated alveolar injury. DESIGN: Prospective cohort study. PATIENTS: A total of 36 healthy men and women (mean age [SD], 37.5 [7.5] years), including 10 cocaine-only smokers (CS), 6 cocaine-plus-tobacco smokers (CTS), 10 tobacco smokers (TS), and 10 nonsmokers (NS), underwent fiberoptic bronchoscopy and BAL. METHODS: Cytospins were prepared from BAL cells and stained with Wright-Giemsa for cell differentials and Gomori's stain for detection of hemosiderin. Endothelin (ET)-1 levels were determined from lavage fluid by enzyme-linked immunosorbent assay. RESULTS: None of the cocaine users reported episodes of hemoptysis or respiratory distress, and routine spirometry findings were within normal limits in all subjects. While there was little effect on total cell numbers or differential counts, the percentages of hemosiderin-positive alveolar macrophages (AMs) were markedly increased in CS (33.8 +/- 8.7% [SEM]) compared to TS and NS (< 2%; p < 0.05). The percentages of hemosiderin-laden AMs were also numerically increased in CTS (11.8 +/- 7.8%), but this value was not statistically significant from that of TS or NS. ET-1 levels were significantly increased in the fluid recovered from CS (6.2 +/- 0.8 pg/mL) when compared to NS (1.2 +/- 0.4 pg/mL) and TS (1.3 +/- 0.2 pg/mL) [p < 0.05], while ET-1 levels were elevated to a lesser extent in CTS (2.5 +/- 0.6 pg/mL). ET-1 levels correlated with the percentage of hemosiderin-positive AMs when CS were analyzed in conjunction with CTS (r = 0.64; p = 0.0004). CONCLUSION: Clinically inapparent alveolar hemorrhage occurs frequently in otherwise healthy crack cocaine smokers and is associated with elevated levels of ET-1, indicative of cocaine-induced pulmonary microvascular injury.