Cigarette smoking may modify the association between cannabis use and adiposity in males

Depressive Symptoms and Cigarette Smoking in Adolescents and Young Adults: Mediating Role of Friends Smoking

INTRODUCTION

We examined the mediating role of friends smoking in the association between depressive symptoms and daily/weekly cigarette smoking from adolescence into adulthood.

METHODS

Data were drawn from the Nicotine Dependence In Teens study (NDIT, Canada) and the Avon Longitudinal Study of Parents and Children (ALSPAC, UK) studies. Three age groups were investigated in NDIT: age 13-14 (n=1189), 15-16 (n=1107), and 17-18 (n=1075), and one in ALSPAC (n=4482, age 18-21). Multivariable mediation models decomposed the total effect (TE) of depressive symptoms on smoking into a natural direct effect (NDE) and natural indirect effect (NIE) through friends smoking.

RESULTS

The ORs for the TE were relatively constant over time with estimates ranging from 1.12 to 1.35. Friends smoking mediated the association between depressive symptoms and smoking in the two youngest samples (OR (95%CI) 1.09 (1.01,1.17) in 13-14-year-olds; 1.10 (1.03,1.18) in 15-16-year-olds). In the two older samples, NDE of depressive symptoms was close to the TE, suggestive that mediation was absent or too small to detect.

CONCLUSION

Friends smoking mediates the association between depressive symptoms and daily/weekly cigarette smoking in young adolescents.

IMPLICATIONS

If young adolescents use cigarettes to self-medicate depressive symptoms, then interventions targeting smoking that ignore depressive symptoms may be ineffective. Our results also underscore the importance of the influence of friends in younger adolescents, suggestive that preventive intervention should target the social environment including social relationships.

Urinary 11-nor-9-carboxy-tetrahydrocannabinol elimination in adolescent and young adult cannabis users during one month of sustained and biochemically-verified abstinence

BACKGROUND

Despite adolescents and young adults being the most frequent users of cannabis, all information on cannabis drug testing interpretation is based on data from adults.

AIMS

This study aimed to define the time course of urinary 11-nor-9-carboxy-tetrahydrocannabinol (THCCOOH) excretion among 70 adolescent and young adult cannabis users during 1 month of biochemically-verified cannabis abstinence.

METHODS

Urine specimens were collected at non-abstinent baseline and after 2, 3, 8, 15, 21 and 28 days of abstinence. Specimens were tested for THCCOOH with a 'rapid' immunoassay drug test and a confirmatory assay using liquid chromatography-tandem mass spectrometry, with a 5 ng/mL limit of quantitation. Elimination rate was tested using a population pharmacokinetics model.

RESULTS/OUTCOMES

Participants had an average of 26 days of abstinence (SD = 6). Initial creatinine-adjusted THCCOOH concentration (CN-THCCOOH) was 148 ng/mg (SD = 157). Half-life was 2 days (SD = 5), with a 10-day window of detection (estimated range: 4-80 days). At the final timepoint and among those with > 25 days of abstinence (n = 62), 40% (n = 25) had THCCOOH concentrations > 5 ng/mL (i.e. detectable on confirmatory assay) and 19% (n = 12) were 'positive' per federal drug testing guidelines (i.e. values greater than 50 ng/mL on the screening immunoassay and 15 ng/mL on the confirmatory assay). More frequent past month cannabis use was associated with higher baseline CN-THCCOOH concentrations, but not with rate of elimination. Nested five-fold cross-validation suggested high model reliability and predictive validity.

CONCLUSIONS/INTERPRETATION

Findings underscore that, as with adults, detectable cannabinoid metabolites do not necessarily indicate recent use in adolescents and young adults. Algorithms that account for THCCOOH levels, assessed longitudinally and time between specimen collections are best equipped to confirm abstinence.

CLINICAL TRIAL REGISTRATION

NCT03276221; https://clinicaltrials.gov/ct2/show/NCT03276221?term=Randi+Schuster&rank=1.

Early Risk Factors for Daily Cannabis Use in Young Adults

OBJECTIVES

Daily cannabis use can portend problematic use or dependence. We aimed to identify early risk factors for daily cannabis use in young adults.

METHODS

Data were available in a longitudinal investigation of 1294 grade 7 students age 12 to 13 years at inception recruited in 10 secondary schools in Montreal, Canada, in 1999. Data on daily cannabis use were collected in mailed self-report questionnaires from 878 participants (67.9% of 1294) at age 20. The associations between each of 23 potential risk factors measured in grade 7 and daily cannabis use at age 20 were modeled using logistic regression.

RESULTS

At age 20, 44% of participants reported past-year cannabis use; 10% reported daily use. Older age; male sex; higher levels of family stress and other stress; use of alcohol, cigarettes, and other tobacco products; parent(s), sibling(s), and friend(s) smoke cigarettes; higher body mass index; higher impulsivity and novelty seeking; and lower self-esteem increased the odds of daily cannabis use.

CONCLUSIONS

Children at risk of daily cannabis use as young adults can be identified early. They may benefit from early intervention to prevent problematic cannabis use.

Associations Between Cannabis Use and Cardiometabolic Risk Factors: A Longitudinal Study of Men

OBJECTIVE

This study tested longitudinal associations between cannabis use and cardiometabolic risk factors that underlie the development of cardiovascular diseases.

METHODS

Participants were men from the youngest cohort of the Pittsburgh Youth Study who were followed prospectively from approximately age 7 to 32 years (N = 253). Frequency of cannabis use was assessed yearly from approximately ages 12 to 20 years and again at approximately ages 26, 29, and 32 years. The following cardiometabolic risk factors were assessed during a laboratory visit at approximately age 32 years: body mass index (BMI), waist-hip ratio, high- and low-density lipoprotein cholesterol, triglycerides, fasting glucose, insulin resistance, blood pressure, interleukin 6, and C-reactive protein.

RESULTS

Greater cannabis exposure was associated with relatively lower BMI (β = -0.31, p < .001), smaller waist-hip ratio (β = -0.23, p = .002), better high- (β = 0.14, p = .036) and low-density lipoprotein cholesterol (β = -0.15, p = .026), lower triglycerides (β = -0.17, p = .009), lower fasting glucose (β = -0.15, p < .001) and insulin resistance (β = -0.21, p = .003), lower systolic (β = -0.22, p < .001) and diastolic blood pressure (β = -0.15, p = .028), and fewer metabolic syndrome criteria (β = -0.27, p < .001). With exception of BMI, cannabis users' mean levels on cardiometabolic risk factors were generally below clinical cutoffs for high risk. Most associations between cannabis use and cardiometabolic risk factors remained after adjusting for tobacco use, childhood socioeconomic status, and childhood health. However, after adjusting for adult BMI, these associations were no longer apparent, and mediation tests suggested that cannabis users' relatively lower BMI might explain their lower levels of risk on other cardiometabolic risk factors.

CONCLUSIONS

Cannabis use is associated with lower BMI, and lower BMI is related to lower levels of risk on other cardiometabolic risk factors.

Effects of cannabis use on body mass, fasting glucose and lipids during the first 12 months of treatment in schizophrenia spectrum disorders

While acute cannabis use stimulates appetite, general population studies suggest that chronic use is associated with reduced risk of obesity and other cardiometabolic risk factors. In this study we investigated changes in body mass index (BMI), fasting blood glucose and lipids, and rates of metabolic syndrome risk factors in cannabis users vs. non-users in 109 minimally treated patients with first-episode schizophrenia, schizophreniform or schizo-affective disorder who were treated according to a standardized treatment regime with depot antipsychotic medication over 12 months. Participants underwent repeated urine toxicology tests for cannabis and those testing positive at any time during the study (n = 40), were compared with those who tested negative at all time points (n = 69). There was a significant group*time interaction effect (p = 0.002) with the cannabis negative group showing a greater increase in BMI than the cannabis positive group, after adjusting for age, sex, methamphetamine use and modal dose of antipsychotic. There were no group*time interaction effects for fasting blood glucose or lipids. Post hoc tests indicated significant increases in fasting blood glucose and triglycerides and a decrease in high-density lipoprotein cholesterol for the cannabis negative group, with no significant changes in the cannabis positive group. Rates of metabolic syndrome did not differ significantly between groups, although more cannabis negative patients had elevated waist-circumference at endpoint (p = 0.003). It may be that chronic cannabis use directly suppresses appetite, thereby preventing weight gain in users. However, other indirect effects such as dietary neglect and smoking may be contributory and could explain our findings.

Association Between Use of Cannabis in Adolescence and Weight Change into Midlife

Cannabis use has been found to stimulate appetite and potentially promote weight gain via activation of the endocannabinoid system. Despite the fact that the onset of cannabis use is typically during adolescence, the association between adolescence cannabis use and long-term change in body weight is generally unknown. This study aims to examine the association between adolescence cannabis use and weight change to midlife, while accounting for the use of other substances. The study applied 20 to 22 years of follow-up data on 712 Danish adolescents aged between 15 and 19 years at baseline. Self-reported height and weight, cannabis, cigarette and alcohol use, socioeconomic status (SES) and physical activity levels were assessed in baseline surveys conducted in 1983 and 1985. The follow-up survey was conducted in 2005. In total 19.1% (n = 136) of adolescents reported having used/using cannabis. Weight gain between adolescence and midlife was not related to cannabis exposure during adolescence in either crude or adjusted models, and associations were not modified by baseline alcohol intake or smoking. However, cannabis use was significantly associated with cigarette smoking (p<0.001) and alcohol intake (p<0.001) and inversely associated with physical activity levels (p = 0.04). In conclusion, this study does not provide evidence of an association between adolescence cannabis use and weight change from adolescence to midlife.

Comorbid Cannabis and Tobacco Use in Adolescents and Adults

The prevalence of comorbid cannabis and tobacco use has been increasing among adolescents and adults and has been shown to be associated with a range of changes or deficits in physical, psychological and behavioral outcomes. Moreover, comorbid use has been shown to have a differential effect on the structure and function of the brain, especially as it relates to the reward circuitry and learning and memory. This interaction might be mediated by the involvement of the endocannabinoid system and alterations in dopamine signaling in regions associated with reward and cognitive functioning. While current findings demonstrate a differential effect of comorbid use on neurobiological and behavioral correlates compared with single substance use, additional studies are needed controlling for potential psychiatric comorbidities, age of onset of use and use of other substances. Understanding the neurobiological mechanisms associated with comorbid cannabis and tobacco use will be important in developing successful treatment outcomes in the future.

E-Cigarettes: A Review of New Trends in Cannabis Use

The emergence of electronic cigarettes (e-cigs) has given cannabis smokers a new method of inhaling cannabinoids. E-cigs differ from traditional marijuana cigarettes in several respects. First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette. Recreational cannabis users can discretely “vape” deodorized cannabis extracts with minimal annoyance to the people around them and less chance of detection. There are nevertheless several drawbacks worth mentioning: although manufacturing commercial (or homemade) cannabinoid-enriched electronic liquids (e-liquids) requires lengthy, complex processing, some are readily on the Internet despite their lack of quality control, expiry date, and conditions of preservation and, above all, any toxicological and clinical assessment. Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear. More simply ground cannabis flowering heads or concentrated, oily THC extracts (such as butane honey oil or BHO) can be vaped in specially designed, pen-sized marijuana vaporizers. Analysis of a commercial e-liquid rich in cannabidiol showed that it contained a smaller dose of active ingredient than advertised; testing our laboratory-made, purified BHO, however, confirmed that it could be vaped in an e-cig to deliver a psychoactive dose of THC. The health consequences specific to vaping these cannabis preparations remain largely unknown and speculative due to the absence of comprehensive, robust scientific studies. The most significant health concerns involve the vaping of cannabinoids by children and teenagers. E-cigs could provide an alternative gateway to cannabis use for young people. Furthermore, vaping cannabinoids could lead to environmental and passive contamination.