There are notable limitations to this study.As this is a pilot study,the authors acknowledge that future experiments will require more mice in each treatment group for an appropriately powered study.Assessments of the corpora cavernosa response to treatments were made based on histological and immunohistochemical changes.While these are adequate surrogates to determine how fibrosis can progress in a structural context,biochemical and physiological data may further corroborate these current findings.Future studies involving gene expression and protein synthesis would be helpful in elucidating mechanisms at play.Erectile function studies with electrical field stimulation and dynamic infusion cavernosometry are a planned next step to identify key structure-function implications to this research.Tobacco use is the leading cause of preventable morbidity and mortality in the US.Accumulating evidence consistently demonstrates that heavy or habitual marijuana use is associated with numerous short- and long-term deleterious health consequences,including but not limited to addiction,altered brain structure and connectivity,impaired memory and neuropsychological decline,psychosis,poor educational attainment,symptoms of chronic bronchitis,impaired motor coordination and traffic collisions,and diminished life satisfaction.Marijuana and tobacco use share potential common environmental influences,common mode of use,and are frequently used together.One study suggested that,during a lifetime period,57.9% of those who ever used tobacco reported ever using marijuana and 90% of those who ever used marijuana reported ever using tobacco.
Another study showed that,rolling bench during the past month,the prevalence of marijuana use was 17.8% among past-month tobacco users and the prevalence of tobacco use was 69.6% among past-month marijuana users.Across the lifespan,either concurrently or at different times,prior use of either tobacco or marijuana substantially elevates the risk of subsequent initiation of the other and is associated with the progression to tobacco and marijuana dependence.Heightened susceptibility has been linked togenetic predispositions and putative neurobiological mechanisms that may facilitate increased urge and intensity of using each substance,promote progression to other types of illicit drugs,and precipitate relapse or hamper the success of quitting use of either substance.Self-rated health is a brief,validated proxy measure of overall health status.Among a variety of populations,SRH is strongly predictive of future morbidity and mortality,even after extensive adjustment for many co-variates such as illness,depression status,functional and cognitive decline,and health care utilization.Although SRH is generated through a subjective,contextual,and non-arbitrary process,research shows that individuals with “poor” SRH have a two-fold higher mortality risk than that of those with “excellent” SRH.SRH has been adopted as a chronic disease indicator for overarching conditions and as a Foundation Health Measure for the Healthy People 2020 objectives that monitor progress toward promoting health,preventing disease and disability,eliminating disparities,and improving quality of life.Although epidemiologic studies have evaluated effects of marijuana and tobacco use on many health outcomes,combined patterns of marijuana and tobacco use and their impact on overall health are uncertain.To our knowledge,no study has assessed regular marijuana smoking,with and without current tobacco use,in relation to sub-optimal SRH among US adult ever users of marijuana.Ever users of marijuana are an important population of concern.Given that habitual marijuana use may affect health outcomes,and that tobacco use is a serious public health problem,such a study may provide observational evidence to inform prevention efforts.
Therefore,we sought to examine patterns of regular marijuana smoking and current tobacco use and their associations with sub-optimal SRH among a nationally representative household-based survey sample of US adult ever users of marijuana by analyzing data from the 2009– 2012 National Health and Nutrition Examination Survey.The NHANES is a program of studies designed to assess the health and nutritional status of adults and children in the US.NHANES participants were recruited using a household-based,multistage,stratified sampling designed to represent the non-institutionalized civilian US population.The response rates for 2009–2012 ranged from 69.5% to 77.2%.We limited this analysis to men and non-pregnant women aged 20–59 years who attended the medical examination and provided information on their lifetime marijuana use in the Mobile Examination Center interview.Of the participants who attended the MEC and reported marijuana use at least once during their lifetime,3253 adults provided blood by venipuncture for measurement of serum cotinine.After excluding participants with missing co-variate values,3210 participants remained as ever users of marijuana for our analyses.All procedures involving human participants and confidentiality were reviewed and approved by the Research Ethics Review Board of the National Center for Health Statistics.We defined ever users of marijuana as those participants who said yes to the question “Have you ever,even once,used marijuana or hashish?” We further classified ever users of marijuana into subgroups of regular and non-regular marijuana smokers based on their responses to the question “Have you ever smoked marijuana or hashish at least once a month for more than one year?” Respondents who reported “yes” were considered regular marijuana smokers.Cotinine is a metabolite of nicotine and a biomarker for both active and passive tobacco exposure.Previous studies have identified a nearly identical optimal cut point of using serum cotinine to distinguish tobacco users from non-tobacco users.
Because recent use of other tobacco products would be reflected in the measure of serum cotinine,and because non-tobacco users with exposures to secondhand smoking typically have serum cotinine below the cut point,we defined current tobacco use as having serum cotinine values ≥3.08 ng/mL in this study.Based on the status of regular marijuana smoking and current tobacco use,we created four mutually exclusive groups: non-regular marijuana smoking without current tobacco use; regular marijuana smoking without current tobacco use; non-regular marijuana smoking with current tobacco use; and regular marijuana smoking with current tobacco use.Based on the response to the question,“How long has it been since you last smoked marijuana or hashish at least once a month for one year?”,we considered those who reported ≤30 days and ≤60 days as recent regular marijuana smokers for the periods of past 30-day and 60- day,respectively.We estimated the crude prevalence for the four mutually exclusive groups of regular marijuana use and current tobacco use,both overall and among age subgroups.We also calculated the age-adjusted prevalence by the direct method to the year 2000 Census population for these patterns among participants and subgroups stratified by sex,race or ethnicity,education,marital status,alcohol use,physical activity,BMI,health care access,and a history of cardiovascular diseases,diabetes,arthritis,and cancer.We produced unadjusted and adjusted prevalence ratios with multi-variable generalized linear models for survey data.We used the variable for patterns of regular marijuana smoking and current tobacco use as the predictor and sub-optimal SRH as the outcome while adjusting for sociodemographic,behavioral,and health-related risk factors.To obtain additional information on current regular marijuana smoking,we estimated the prevalence for reporting sub-optimal SRH by status of previous 30-day and 60-day regular marijuana smoking among regular marijuana smokers with and without current tobacco use.To estimate relative excess risk due to interaction between current tobacco use and regular marijuana smoking,dry rack cannabis additional analyses were performed by using current tobacco use and regular marijuana smoking as two independent variables with their interaction term in regression models.Weighted analyses were performed to account for the complex sampling design to provide nationally representative estimates.
Consistent with previous studies,our results show that approximately 40% of ever users of marijuana were currently using tobacco.Our findings further indicate that,when compared to non-regular marijuana smoking without current tobacco use,regular marijuana smoking without current tobacco use was significantly associated with a 34% increased prevalence ratio of reporting sub-optimal SRH.A greater prevalence ratio was observed for current tobacco use and regular marijuana smoking,as well as current tobacco use and non-regular marijuana smoking.Results from previous research on effects of marijuana use are inconclusive.One study reported an improvement in capacity for recall of information was associated with cessation of marijuana use.Other studies showed persistent marijuana use was associated with long-lasting cognitive impairment,and that cessation of marijuana use does not fully restore neuropsychological functioning,especially among those marijuana users of adolescentonset.Another study found that marijuana use for up to 20 years was associated with periodontal disease but not with other physical health measures in early midlife.In this study,we did not detect any appreciable difference in reporting sub-optimal SRH among regular marijuana smokers with and without current tobacco stratified by status of their past 30- or 60-day regular marijuana smoking.Moreover,the results from this and previous studies show that many unhealthy lifestyle health behaviors are interrelated.Such behaviors frequently co-occur and are often associated with worse health outcomes.The findings of our study have a number of important public health implications.First,SRH is included in the public health key metrics such as Healthy People 2020 and CDC Healthy Day for guiding disease prevention and health promotion and for measuring health-related quality of life in the US population.Second,reducing tobacco use and initiation among youth and adults is an important public health goal.Given a high rate of overlap between marijuana and tobacco use among the participants,our study findings provide further support for implementing comprehensive tobacco control programs and underscore the importance of target interventions among high-risk populations,including those using marijuana,in order to enhance the reach and effectiveness of prevention.Third,multiple unhealthy behaviors tend to co-occur but they are amenable to concurrent or sequential interventions.A successful change in one unhealthy behavior may lead to increased self-efficacy to modify other co-occurring unhealthy behaviors for which individuals may have low motivation to change.Finally,the difference in the prevalence of unhealthy behaviors across a number of socio-demographic subgroups highlights the need for evidence-based research to identify interdisciplinary intervention strategies that integrate science,practice,and policy to address health disparities among the population.Our study results also have several important clinical implications.SRH is an assessment tool for Patient-Reported Outcomes Measurement Information System that measures patient–reported health status for physical,mental,and social well-being.In light of the legalization of medical and recreational marijuana use in some US states,patients may be more likely to ask their healthcare providers about potential health effects of marijuana use.
Many of the proposed health benefits and unintended consequences of marijuana use have not been fully explored.The findings of our study suggest that,in addition to receiving counseling about marijuana,patients with a history of marijuana use should obtain firm advice and support for not using tobacco.For those who plan to quit,evidence suggests that simultaneously quitting both tobacco and marijuana may yield important psychological and neurobiological benefits.Until more results from experimental research are forthcoming to provide guidance,it is important to encourage dual cessation.Our study has several limitations.It was cross-sectional and cannot establish cause and effect.With the ongoing changes in medical marijuana law in a growing number of states,people with certain health conditions might be drawn into marijuana use.It might be possible that poor perceived health resulted in marijuana use rather than marijuana use caused poor perceived health.Research shows that the predictive power of SRH for mortality is robust across many subgroups of country of origin even after extensively controlling for numerous co-variates.However,validation study has not been conducted among the population of US adult ever users of marijuana.We adopted serum cotinine as a biomarker to define current tobacco use,occasional tobacco users who had used tobacco beyond 3–5 days prior to examination may be included as non-current tobacco users.In addition,data on marijuana use were self-reported and were subject to potential recall bias or under-reporting of less socially desirable behaviors.Our study did not identify the use of specific tobacco products,including electronic cigarettes or electronic nicotine delivery systems that have been gaining popularity in recent years.Due to data constraints,we were unable to account for several potential con-founders such as medication use,drug abuse,and other co-morbid conditions,as well as the difference in patterns of recreational versus medical marijuana use that might have had an effect on sub-optimal SRH.Regular marijuana users may include both current and former marijuana users.In the present study,we assessed the impact of recent 30-day and 60-day regular marijuana use on sub-optimal SRH among regular marijuana smokers.Because of the limited analytical sample size,we could not explore additional harmful marijuana and tobacco usage patterns related to quantity,frequency,timing,and duration of usage.It is worth noting that although several subgroups of the adult population were not evaluated in the current study due to a limited sample size,such adults are especially vulnerable to a multitude of health consequences associated with unhealthy behaviors even at low threshold levels for exposure.Long-term change of unhealthy behaviors is challenging and may require multifaceted efforts to effectively address the interplay of behaviors with biological,health,and social factors across various subgroups and environmental settings over persons’ life course.Marijuana is the most frequently used illegal drug in the United States.In August 2013,the U.S.Department of Justice announced an updated marijuana enforcement policy,making clear that marijuana remains illegal federally.