Catalina Lopez-Quintero

Meta-analysis of Telomere Length in Alzheimer’s Disease

BACKGROUND Alzheimers disease (AD) is a common and severe neurodegenerative disorder. Human telomeres are fundamental for the maintenance of genomic stability and play prominent roles in both cellular senescence and organismal aging. Regulation of telomere length (TL) is the result of the complex interplay between environmental and genetic factors. Alterations in TL are increasingly being studied as a possible risk factor for AD, and published studies on TL in AD show discrepant results, highlighting the need for a meta-analysis. METHODS In the current study, we carried out a meta-analysis of published studies of TL in AD patients and healthy controls. PubMed, Web of Science and Google Scholar databases (from inception to September 2015) were used to identify relevant articles reporting TL in humans with AD, from which we retrieved data such as sample size, experimental methods, and mean TL for cases and controls. A random-effects model was used for meta-analytical procedures. RESULTS The meta-analysis included 13 primary studies and demonstrated a significant difference in TL between 860 AD patients and 2,022 controls, with a standardized mean difference of -0.984 (confidence interval: -1.433 to -0.535; p value: <.001). CONCLUSIONS Our results show a consistent evidence of shorter telomeres in AD patients and highlight the importance of the analysis of epigenomic markers associated with neurodegeneration and with the risk for common and severe neurological diseases, such as AD.

Telomere length in Parkinson's disease: A meta-analysis

Parkinsons disease (PD) is a common and severe movement disorder. Differences in telomere length (TL) have been reported as possible risk factors for several neuropsychiatric disorders, including PD. Results from published studies for TL in PD are inconsistent, highlighting the need for a meta-analysis. In the current work, a meta-analysis of published studies for TL in PD was carried out. PubMed, Web of Science and Google Scholar databases were used to identify relevant articles that reported TL in groups of PD patients and controls. A random-effects model was used for meta-analytical procedures. The meta-analysis included eight primary studies, derived from populations of European and Asian descent, and did not show a significant difference in TL between 956 PD patients and 1284 controls (p value: 0.246). Our results show that there is no consistent evidence of shorter telomeres in PD patients and suggest the importance of future studies on TL and PD that analyze other populations and also include assessment of TL from different brain regions.

Mortality among heroin users and users of other internationally regulated drugs: A 27-year follow-up of users in the Epidemiologic Catchment Area Program household samples.

BACKGROUND In contrast to research on more restricted samples of drug users, epidemiological studies open up a view of death rates and survivorship of those who have tried heroin a few times, with no acceleration toward sustained use patterns often seen in treatment and criminal justice samples. At their best, epidemiological estimates of heroin effects on risk of dying are not subject to serious selection biases faced with more restricted samples. METHODS Data are from 7207 adult participants aged 18-48 years in United States Epidemiologic Catchment Area Program field surveys, launched in 1980-1984. US National Death Index (NDI) records through 2007 disclosed 723 deaths. NDI enabled estimation of heroin-associated risk of dying as well as survivorship. RESULTS Estimated cumulative mortality for all 18-48 year old participants is 3.9 deaths per 1000 person-years (95% confidence interval, CI=3.7, 4.2), relative to 12.4 deaths per 1000 person-years for heroin users (95% CI=8.7, 17.9). Heroin use, even when non-sustained, predicted a 3-4 fold excess of risk of dying prematurely. Post-estimation record review showed trauma and infections as top-ranked causes of these deaths. CONCLUSIONS Drawing strengths from epidemiological sampling, standardized baseline heroin history assessments, and very long-term NDI follow-up, this study of community-dwelling heroin users may help clinicians and public health officials who need facts about heroin when they seek to prevent and control heroin outbreaks. Heroin use, even when sporadic or non-sustained, is predictive of premature death in the US, with expected causes of death such as trauma and infections.

Prevalence and determinants of resistance to use drugs among adolescents who had an opportunity to use drugs

Background As drugs remain ubiquitous and their use increasingly viewed as socially normative, vulnerable population groups such as adolescents face continued and growing risk. A better understanding of the factors that discourage individuals from initiating drug use, particularly in enabling scenarios, is therefore needed. This study aims to identify individual, interpersonal and school-contextual factors associated with resistance to using drugs in the presence of a drug use opportunity among adolescents in Bogotá, Colombia. Methods Data are analyzed from 724 school-attending adolescents (15.1 years, SD=1.3) who have had an opportunity to use drugs. Schools were selected in a multistage probability cluster sample. Random intercept multilevel logistic regression models were implemented to estimate the effect of individual, interpersonal and school-contextual level variables on the likelihood of resisting using drugs. Results Drug use resistance was observed in less than half (41.4%) of those students who experienced an opportunity to use drugs. Drug use resistance was strongly associated with having experienced a passive drug use opportunity (AOR=3.1, 95%CI=2.0, 4.9), the number of drugs offered (AOR=0.7, 95% CI=0.6, 0.8) and family factors such as not having a drug-using first-degree relative (AOR=2.3, 95%CI=1.2, 4.3) and a high degree of parental supervision (AOR=1.9, 95%CI=1.0, 3.2). Conclusions A large proportion of students who experienced a drug-use opportunity did not initiate drug use despite living in a context of high drug availability and social disorganization. The findings highlight the need for effective family-based drug use prevention interventions within the Colombian context.

Drug use disorders in the polydrug context: new epidemiological evidence from a foodborne outbreak approach

As epidemiologists studying foodborne illness outbreaks, we do not ask luncheon attendees to say which food caused their illnesses. Instead, we use measurement and analysis methods to estimate food‐specific risk variations. Here, we adapt the foodborne outbreak approach to develop new estimates of drug use disorder risk for single‐drug and polydrug users, without attributing the syndrome to a specific drug when multiple drugs have been used. We estimate drug use disorder risk for cannabis‐only users as a reference value. We then derive comparative relative risk estimates for users of other drug subtypes, including polydrug combinations. Data are from the 2002 to 2003 U.S. National Comorbidity Survey Replication, a nationally representative sample of household residents (18+ years), with standardized drug use and drug dependence assessments. Multiple logistic regression provides odds ratio estimates of relative risk. With this approach, for every 1000 cannabis‐only users, an estimated 17 had become cases (1.7%). By comparison, polydrug users and cocaine‐only users had much greater cumulative incidence (>10%), even with adjustment for covariates and local area matching (P < 0.001). Using this approach, we find exceptionally low risk for cannabis‐only users and greater risk for polydrug and cocaine‐only users.

HIV testing practices among Latina women at risk of getting infected: a five-year follow-up of a community sample in South Florida

ABSTRACT Latinos are more likely to delay HIV testing, present to care with an AIDS defining illness, and die within one year of learning their HIV-positive status than non-Latino blacks and whites. For this paper, we explore the role of partner-relationship characteristics and health behaviors, in predicting HIV testing among Latina adult women who engaged in risky sexual behaviors (i.e., unprotected vaginal and/or anal sex). Data from a convenience sample of 168 Latina adult women who engaged in risky sexual behavior in the year prior to assessment were analyzed for this paper. Rates and predictors of HIV testing among this sample were assessed after a five-year follow-up. Descriptive and analytical estimates include incidence rates and adjusted odds ratios (AOR) from multilevel models. At five-year follow-up, 63.7% (n = 107) women reported having been tested for HIV, of whom 12.2% (n = 13) were women who never tested before. Main reasons for not having been tested at follow-up included: low risk perception (62.1%) and trusting their partner(s)/being in a monogamous relationship/knowing their partners HIV status (17.2%). Predictors of HIV testing included: age (AOR: 0.96; 95% CI = 0.92–0.99), provider endorsement of HIV testing (AOR: 4.59; 95% CI = 1.77–11.95), poor quality of their romantic relationships (AOR: 1.12; 95% CI = 1.03–1.26), and knowing the HIV sero-status of sexual partner (AOR: 3.61; 95% CI = 1.46–8.95). This study characterizes a group of Latina women at high risk for HIV infection and their HIV testing behaviors. Our findings underscore the need of increasing access to quality health-care services and HIV behavioral interventions, and to strengthen the adherence to HIV/sexually transmitted disease testing recommendations and guidelines among local health-care providers serving the Latino community in South Florida.

The association between adolescent cannabis use and anxiety: A parallel process analysis

INTRODUCTION Associations between anxiety symptoms and cannabis use have been previously explored, yet the directionality of these associations remains highly debatable. The present study aims to prospectively examine patterns of cannabis use and anxiety during adolescence focusing on their co-development and bidirectional influences. METHODS Adolescents (n=250) of predominantly Hispanic ethnicity, aged 14-17 at baseline, exposed to drugs, alcohol, or cigarettes completed three (bi-annual) assessments across a 1-year period. Latent growth curve modeling (LGCM) and parallel process growth curves were conducted to examine potential associations in the joint development of anxiety and cannabis use. RESULTS Our results suggest that, during adolescence, early cannabis use has a greater influence on prospective reports of anxiety, than vice versa. Specifically, adolescents exhibiting higher initial levels of cannabis use displayed more persisting self-reported anxiety across time, as compared to those with less frequent use (b=0.28, p=0.024). In contrast, early levels of anxiety were not found to influence rates of change in cannabis use. These analyses considered concurrent depression, alcohol, and nicotine use. CONCLUSIONS Our findings suggest that prevention and targeted intervention programs for cannabis use in adolescence would benefit from anxiety management strategies; in order to reduce subsequent anxiety associated with cannabis use. Future studies should continue to employ longitudinal designs across larger time periods and aim to replicate these findings with more diverse samples.

Age of onset or age at assessment—that is the question: Estimating newly incident alcohol drinking and rapid transition to heavy drinking in the United States, 2002–2014

Age‐specific incidence estimates are important and useful facts in psychiatric epidemiology, but incidence estimation can be challenging. Methods artifacts are possible. In the United States, where the minimum legal drinking age is 21 years, recent cross‐sectional field research on 12‐ to 25‐year‐olds applied conventional “age‐at‐assessment” approaches (AAA) for incidence estimation based on 12‐month recall. Estimates disclosed unexpected nonlinear patterns in age‐specific incidence estimates for both drinking onset and for transitioning from first drink to heavy drinking. Here, our aim is to draw attention to an “age of onset” (AOO) alternative to AAA approaches and to verify whether the AOO approach also discloses nonlinearity. Yearly data are from U.S. nationally representative samples drawn and assessed for National Surveys on Drug Use and Health, 2002–2014, with standardized audio computer‐assisted self‐interview assessments for drinking outcomes. Both AAA and AOO approaches show nonlinearities, with an unexpected dip in drinking incidence rates after age 18 and before the age 21 minimum legal drinking age. The AOO and the AAA approaches disclosed similar age‐specific patterns. We discuss advantages of the AOO approach when nonlinear incidence patterns can be anticipated, but we conclude that the AAA approach has not created an artifactual nonlinear pattern.

Transition to drug co-use among adolescent cannabis users: The role of decision-making and mental health

BACKGROUND Co-use of cannabis and drugs other than cannabis (DOTC) influences the risk of experiencing cannabis disorders. Accordingly, we explored whether speed of transition to drug co-use, the number of DOTC used, and/or being an experimental cannabis-only user, a regular cannabis-only user, or a regular cannabis user who co-uses DOTC (i.e., cannabis-plus user) were associated with decision-making (DM), mental health disorder symptoms, or cannabis use-related characteristics. METHODS We analyzed baseline data from a sub-sample of 266 adolescent (ages 14 to 16) cannabis users (CU) participating in an ongoing longitudinal study. Assessments included semi-structured interviews, self-report questionnaires, and measures of drug use, DM (measured via the Iowa Gambling Task), mental health disorders, and cannabis use-related problems. RESULTS Endorsing a larger number of mood disorders symptoms was associated with being a regular cannabis-plus user rather than a regular cannabis-only user (AOR = 1.08, C.I.95% 1.01, 1.15). Poorer DM was associated with a faster transition to co-use, such that for each one unit increase in DM performance, the years to onset of drug co-use increased by 1% (p = 0.032). Endorsing a larger number of cannabis use-related problems was positively associated with endorsing a larger number of DOTC used (p = 0.001). CONCLUSIONS This study provides new evidence on the process of drug co-use among CU. Specifically, mood disorder symptoms were associated with use of DOTC among regular CU. Furthermore, poorer DM was associated with a faster transition to drug co-use. Poorer DM and mood disorder symptoms may aggravate or accelerate the onset of adverse consequences among adolescent CU.

Newly incident cannabis use in the United States, 2002–2011: a regional and state level benchmark

Background Cannabis use and cannabis regulatory policies recently re-surfaced as noteworthy global research and social media topics, including claims that Mexicans have been sending cannabis and other drug supplies through a porous border into the United States. These circumstances prompted us to conduct an epidemiological test of whether the states bordering Mexico had exceptionally large cannabis incidence rates for 2002–2011. The resulting range of cannabis incidence rates disclosed here can serve as 2002–2011 benchmark values against which estimates from later years can be compared. Methods The population under study is 12-to-24-year-old non-institutionalized civilian community residents of the US, sampled and assessed with confidential audio computer-assisted self-interviews (ACASI) during National Surveys on Drug Use and Health, 2002–2011 (aggregate n ∼ 420,000) for which public use datasets were available. We estimated state-specific cannabis incidence rates based on independent replication sample surveys across these years, and derived meta-analysis estimates for 10 pre-specified regions, including the Mexico border region. Results From meta-analysis, the estimated annual incidence rate for cannabis use in the Mexico Border Region is 5% (95% CI [4%–7%]), which is not an exceptional value relative to the overall US estimate of 6% (95% CI [5%–6%]). Geographically quite distant from Mexico and from states of the western US with liberalized cannabis policies, the North Atlantic Region population has the numerically largest incidence estimate at 7% (95% CI [6%–8%]), while the Gulf of Mexico Border Region population has the lowest incidence rate at 5% (95% CI [4%–6%]). Within the set of state-specific estimates, Vermont’s and Utah’s populations have the largest and smallest incidence rates, respectively (VT: 9%; 95% CI [8%–10%]; UT: 3%; 95% CI [3%–4%]). Discussion Based on this study’s estimates, among 12-to-24-year-old US community residents, an estimated 6% start to use cannabis each year (roughly one in 16). Relatively minor variation in region-wise and state-level estimates is seen, although Vermont and Utah might be exceptional. As of 2011, proximity to Mexico, to Canada, and to the western states with liberalized policies apparently has induced little variation in cannabis incidence rates. Our primary intent was to create a set of benchmark estimates for state-specific and region-specific population incidence rates for cannabis use, using meta-analysis based on independent US survey replications. Public health officials and policy analysts now can use these benchmark estimates from 2002–2011 for planning, and in comparisons with newer estimates.