Nicotine dependence in a prospective population-based study of adolescents : the protective role of a functional tyrosine hydroxylase polymorphism

Dopamine is a key neurotransmitter of the mesolimbic reward pathway in the human brain, and tyrosine hydroxylase (TH) is the rate-limiting enzyme in dopamine biosynthesis. Consequently, the gene encoding TH is a strong candidate for involvement in the genetic component of addiction. The importance of this gene in nicotine dependence is supported by many studies showing a link between nicotine administration and TH expression. A functional tetranucleotide repeat polymorphism within intron 1 of the TH gene (HUMTH01-VNTR) has been shown to modify tobacco use in two independent Caucasian samples from the USA and Australia. Using information drawn from an eight-wave Australian population-based longitudinal study of adolescent health, we tested the effect of the HUMTH01-VNTR on nicotine dependence. Comparisons were made between dependent smokers and non-dependent smokers. These data provide further support for a protective association between the K4 allele and dependent smoking (odds ratio 0.54, 95% confidence interval 0.28-1.0). No associations were observed at any of three other common TH polymorphisms (rs6356, rs6357 and HUMTH01-PstI). Including these data, three independent studies, two of which use identical phenotypes, have now identified a protective relationship between the K4 allele of the functional HUMTH01-VNTR polymorphism and high-level smoking.

Low serum 25-hydroxyvitamin D is associated with increased risk of the development of the metabolic syndrome at five years : results from a national, population-based prospective study (the Australian Diabetes, Obesity and Lifestyle Study : AusDiab)

Context: Serum 25-hydroxyvitamin D [25(OH)D] concentration has been inversely associated with the prevalence of metabolic syndrome (MetS), but the relationship between 25(OH)D and incident MetS remains unclear.

Objective: We evaluated the prospective association between 25(OH)D, MetS, and its components in a large population-based cohort of adults aged 25 yr or older.

Design: We used baseline (1999–2000) and 5-yr follow-up data of the Australian Diabetes, Obesity, and Lifestyle Study (AusDiab).

Participants: Of the 11,247 adults evaluated at baseline, 6,537 returned for follow-up. We studied those without MetS at baseline and with complete data (n = 4164; mean age 50 yr; 58% women; 92% Europids).

Outcome Measures: We report the associations between baseline 25(OH)D and 5-yr MetS incidence and its components, adjusted for age, sex, ethnicity, season, latitude, smoking, family history of type 2 diabetes, physical activity, education, kidney function, waist circumference (WC), and baseline MetS components.

Results: A total of 528 incident cases (12.7%) of MetS developed over 5 yr. Compared with those in the highest quintile of 25(OH)D (≥34 ng/ml), MetS risk was significantly higher in people with 25(OH)D in the first (<18 ng/ml) and second (18–23 ng/ml) quintiles; odds ratio (95% confidence interval) = 1.41 (1.02–1.95) and 1.74 (1.28–2.37), respectively. Serum 25(OH)D was inversely associated with 5-yr WC (P < 0.001), triglycerides (P < 0.01), fasting glucose (P < 0.01), and homeostasis model assessment for insulin resistance (P < 0.001) but not with 2-h plasma glucose (P = 0.29), high-density lipoprotein cholesterol (P = 0.70), or blood pressure (P = 0.46).

Conclusions: In Australian adults, lower 25(OH)D concentrations were associated with increased MetS risk and higher WC, serum triglyceride, fasting glucose, and insulin resistance at 5 yr. Vitamin D supplementation studies are required to establish whether the link between vitamin D deficiency and MetS is causal.

Cigarette smoking, nicotine dependence and anxiety disorders : a systematic review of population-based, epidemiological studies

Background Multiple studies have demonstrated that rates of smoking and nicotine dependence are increased in individuals with anxiety disorders. However, significant variability exists in the epidemiological literature exploring this relationship, including study design (cross-sectional versus prospective), the population assessed (random sample versus clinical population) and diagnostic instrument utilized.

Methods We undertook a systematic review of population-based observational studies that utilized recognized structured clinical diagnostic criteria (Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD)) for anxiety disorder diagnosis to investigate the relationship between cigarette smoking, nicotine dependence and anxiety disorders.

Results In total, 47 studies met the predefined inclusion criteria, with 12 studies providing prospective information and 5 studies providing quasiprospective information. The available evidence suggests that some baseline anxiety disorders are a risk factor for initiation of smoking and nicotine dependence, although the evidence is heterogeneous and many studies did not control for the effect of comorbid substance use disorders. The identified evidence however appeared to more consistently support cigarette smoking and nicotine dependence as being a risk factor for development of some anxiety disorders (for example, panic disorder, generalized anxiety disorder), although these findings were not replicated in all studies. A number of inconsistencies in the literature were identified.

Conclusions Although many studies have demonstrated increased rates of smoking and nicotine dependence in individuals with anxiety disorders, there is a limited and heterogeneous literature that has prospectively examined this relationship in population studies using validated diagnostic criteria. The most consistent evidence supports smoking and nicotine dependence as increasing the risk of panic disorder and generalized anxiety disorder. The literature assessing anxiety disorders increasing smoking and nicotine dependence is inconsistent. Potential issues with the current literature are discussed and directions for future research are suggested.

Positive effects of nicotine on cognition: the deployment of attention for prospective memory

Rationale 

The effect of peer influence and selection processes on adolescent alcohol use : a systematic review of longitudinal studies.

Adolescent alcohol use remains an important public health concern. One of the most salient and consistent predictors for drinking behaviour among young people is peer influence. A systematic review of longitudinal studies that examined the effect of peer influence on adolescent alcohol use between January 1997 and February 2011 is presented. Twenty-two studies fulfilled inclusion criteria and were reviewed. All but one study confirmed affiliation with alcohol-using or deviant peers as prospective predictors for the development of adolescent alcohol use. Findings revealed that existing longitudinal studies that have used multivariate analytic techniques to segregate peer influence (whereby adolescents start drinking after exposure to alcohol-using friends) and peer selection (whereby adolescents that start drinking without alcohol-using friends subsequently seek out drinking peers) effects consistently report significant peer influence effects. However, studies are unable to elucidate the relative contribution and developmental sequence of peer influence and selection. Existing research is synthesised to model the developmental influence of peer processes on adolescent alcohol use. Future research directions are recommended to inform better designed investigations that can lead to more effective endeavours to address peer processes in prevention efforts.

Perceived neighbourhood environmental attributes and prospective changes in TV viewing time among older Australian adults

There has been a growing interest in environmental initiatives to reduce sedentary behaviour. A few existing studies on this topic are mostly cross-sectional, focused on the general adult population, and examining neighbourhood walkability. This study examined associations of perceived environmental attributes with change in TV viewing time over seven years among older Australian adults in the Australian Diabetes, Obesity and Lifestyle (AusDiab) study.

Prospective observational study of emergent endotracheal intubation practice in the intensive care unit and emergency department of an Australian regional tertiary hospital

Objective: The present study aimed to describe the characteristics and outcomes of intubation occurring in the ICU and ED of an Australian tertiary teaching hospital. Methods: This was a prospective observational study of intubation practice across the Geelong Hospital over a 6 month period from 1 August 2012 to 31 January 2013. Data were entered by the intubating team through an online data collection form. Results: There were 119 patients intubated and 134 attempts at intubation in the ED and ICU over a 6 month period. The first-pass success rate was 104/119 (87.4%), and all but a single patient was intubated by the second attempt. Propofol, fentanyl, midazolam and suxamethonium were the most common drugs used in rapid sequence induction. AEs were reported in 44/134 (32.8%) of intubation attempts, with transient hypoxia and hypotension being the most common. A significant adverse outcome, namely aspiration pneumonitis, occurred in one patient. There were no peri-intubation deaths. Conclusion: The majority of airways are managed by ICU and ED consultants and trainees, with success rates and AE rates comparable with other published studies. © 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Homocysteine as a potential biomarker in bipolar disorders: a critical review and suggestions for improved studies

Introduction: Homocysteine levels have been associated with major depression, but associations with bipolar disorder remain less clear. Some data suggest homocysteine levels have potential as a biomarker of treatment response; however the literature is mixed.

Areas covered: Oxidized forms of homocysteine can be potentially neurotoxic leading to glutamate toxicity, apoptotic transformation and neurodegenerative processes. High homocysteine may be a risk biomarker for bipolar disorders, but the empirical base remains too weak for firm conclusions. This review discusses the current literature for homocysteine levels as a biomarker.

Expert opinion: It is premature to foreclose the utility of homocysteine levels as a biomarker for bipolar disorder due the methodological inadequacies in the existing literature. These methodological design issues include lack of control for the confounding variables of concurrent medication, phase of bipolar disorder, gender, age, nutritional status, thyroid, liver and renal function, smoking or lean body mass. Well-powered association studies with confounder control could help shed more light on the important clinical question of homocysteine's utility as a biomarker in bipolar disorder. Future experiments are needed to examine the outcome of interventions modulating homocysteine for treating bipolar disorder. Only prospective randomized control trials will provide definitive evidence of the utility of homocysteine as a biomarker or therapeutic target.

Impact of automated dispensing cabinets on medication selection and preparation error rates in an emergency department: a prospective and direct observational before-and-after study

RATIONALE, AIMS AND OBJECTIVES: The implementation of automated dispensing cabinets (ADCs) in healthcare facilities appears to be increasing, in particular within Australian hospital emergency departments (EDs). While the investment in ADCs is on the increase, no studies have specifically investigated the impacts of ADCs on medication selection and preparation error rates in EDs. Our aim was to assess the impact of ADCs on medication selection and preparation error rates in an ED of a tertiary teaching hospital. METHODS: Pre intervention and post intervention study involving direct observations of nurses completing medication selection and preparation activities before and after the implementation of ADCs in the original and new emergency departments within a 377-bed tertiary teaching hospital in Australia. Medication selection and preparation error rates were calculated and compared between these two periods. Secondary end points included the impact on medication error type and severity. RESULTS: A total of 2087 medication selection and preparations were observed among 808 patients pre and post intervention. Implementation of ADCs in the new ED resulted in a 64.7% (1.96% versus 0.69%, respectively, P = 0.017) reduction in medication selection and preparation errors. All medication error types were reduced in the post intervention study period. There was an insignificant impact on medication error severity as all errors detected were categorised as minor. CONCLUSION: The implementation of ADCs could reduce medication selection and preparation errors and improve medication safety in an ED setting.

Problem gambling patterns among Australian young adults: associations with prospective risk and protective factors and adult adjustment outcomes

There is instability in the developmental course of problem gambling [PG] over time; however, studies that examine PG at an aggregate level obscure these variations. The current study employed data from a longitudinal study of Australian young adults to investigate: 1) PG patterns (i.e., resistance, persistence, desistence, and new incidence); 2) prospective risk and protective factors for these patterns; and 3) behavioural outcomes associated with these patterns. A sample of 2261 young adults (55.73% female) from Victoria, Australia, who were part of the International Youth Development Study completed a survey in 2010 (T1, age 21) and 2012 (T2, age 23) measuring PG (two items based on established measures), risk and protective factors, and behavioural outcomes. The majority of the sample (91.69%) were resistors (no PG at T1 and T2), 3.62% were new incidence PG cases, 2.63% were desistors (PG at T1 but not T2), and 2.07% reported persistent PG at T1 and T2. Individual civic activism was protective of new incidence PG, while affiliation with antisocial peers and frequent alcohol use increased the risk of persistence. Persistent problem gamblers also experienced the greatest number of poor behavioural outcomes at T2. New incidence was associated with internalising symptoms at T2, while desistance was not associated with any behavioural outcomes. In conclusion, each PG pattern was associated with different predictors and outcomes, highlighting the need to consider variation in the course of young adult PG in order to provide efficacious prevention and intervention approaches, and to protect against relapse.

Prospective memory while driving : comparison of time- and event-based intentions

Prospective memories can divert attentional resources from ongoing activities. However, it is unclear whether these effects and the theoretical accounts that seek to explain them will generalise to a complex real-world task such as driving. Twenty-four participants drove two simulated routes while maintaining a fixed headway with a lead vehicle. Drivers were given either event-based (e.g. arriving at a filling station) or time-based errands (e.g. on-board clock shows 3:30). In contrast to the predominant view in the literature which suggests time-based tasks are more demanding, drivers given event-based errands showed greater difficulty in mirroring lead vehicle speed changes compared to the time-based group. Results suggest that common everyday secondary tasks, such as scouting the roadside for a bank, may have a detrimental impact on driving performance. The additional finding that this cost was only evident with the event-based task highlights a potential area of both theoretical and practical interest. Practitioner Summary: Drivers were given either time- or event-based errands whilst engaged in a simulated drive. We examined the effect of errands on an ongoing vehicle follow task. In contrast to previous non-driving studies, event-based errands are more disruptive. Common everyday errands may have a detrimental impact on driving performance.

Adherence to a Mediterranean-style diet and effects on cognition in adults: a qualitative evaluation and systematic review of longitudinal and prospective trials

The Mediterranean-style diet (MedDiet) involves substantial intake of fruits, vegetables, and fish, and a lower consumption of dairy, red meat, and sugars. Over the past 15 years, much empirical evidence supports the suggestion that a MedDiet may be beneficial with respect to reducing the incidence of cardiovascular disease, cancer, metabolic syndrome, and dementia. A number of cross-sectional studies that have examined the impact of MedDiet on cognition have yielded largely positive results. The objective of this review is to evaluate longitudinal and prospective trials to gain an understanding of how a MedDiet may impact cognitive processes over time. The included studies were aimed at improving cognition or minimizing of cognitive decline. Studies reviewed included assessments of dietary status using either a food frequency questionnaire or a food diary assessment. Eighteen articles meeting our inclusion criteria were subjected to systematic review. These revealed that higher adherence to a MedDiet is associated with slower rates of cognitive decline, reduced conversion to Alzheimer's disease, and improvements in cognitive function. The specific cognitive domains that were found to benefit with improved Mediterranean Diet Score were memory (delayed recognition, long-term, and working memory), executive function, and visual constructs. The current review has also considered a number of methodological issues in making recommendations for future research. The utilization of a dietary pattern, such as the MedDiet, will be essential as part of the armamentarium to maintain quality of life and reduce the potential social and economic burden of dementia.