Opium-Related Lead Toxicity: An Integrative Review and Case Series

Role of antioxidants in the neurobiology of drug addiction: An update

Relationships between protective enzymatic and non-enzymatic pro-antioxidant mechanisms and addictive substances use disorders (SUDs) are analyzed here, based on the results of previous research, as well as on the basis of our current own studies. This review introduces new aspects of comparative analysis of associations of pro-antixidant and neurobiological effects in patients taking psychoactive substances and complements very limited knowledge about relationships with SUDs from different regions, mainly Europe. In view of the few studies on relations between antioxidants and neurobiological processes acting in patients taking psychoactive substances, this review is important from the point of view of showing the state of knowledge, directions of diagnosis and treatment, and further research needed explanation. We found significant correlations between chemical elements, pro-antioxidative mechanisms, and lipoperoxidation in the development of disorders associated with use of addictive substances, therefore elements that show most relations (Pr, Na, Mn, Y, Sc, La, Cr, Al, Ca, Sb, Cd, Pb, As, Hg, Ni) may be significant factors shaping SUDs. The action of pro-antioxidant defense and lipid peroxidation depends on the pro-antioxidative activity of ions. We explain the strongest correlations between Mg and Sb, and lipoperoxidation in addicts, which proves their stimulating effect on lipoperoxidation and on the induction of oxidative stress. We discussed which mechanisms and neurobiological processes change susceptibility to SUDs. The innovation of this review is to show that addicted people have lower activity of dismutases and peroxidases than healthy ones, which indicates disorders of antioxidant system and depletion of enzymes after long-term tolerance of stressors. We explain higher level of catalases, reductases, ceruloplasmin, bilirubin, retinol, α-tocopherol and uric acid of addicts. In view of poorly understood factors affecting addiction, analysis of interactions allows for more effective understanding of pathogenetic mechanisms leading to formation of addiction and development the initiation of directed, more effective treatment (pharmacological, hormonal) and may be helpful in the diagnosis of psychoactive changes.

Lead poisoning among asymptomatic individuals with a long-term history of opiate use in Golestan Cohort Study

BACKGROUND

Recent reports of lead poisoning suggest that people who use opium may be exposed to high amounts of lead. Here, we investigate the association between opium use and blood lead levels (BLL) in a population-based cohort study.

METHODS

In 2017, we studied a random sample of 410 people who currently (both within the past year and the past month) used opium and 104 who did not from participants of the Golestan Cohort Study in northeast Iran. Participants were stratified by sex and tobacco use history, completed a comprehensive opiate and tobacco use questionnaire and provided blood. BLL was measured by Lead Care® II Blood Lead Test Kit, validated by inductively coupled plasma triple quadrupole mass spectrometry. BLL was categorized as "<5 µg/dL", "elevated" (5-10 µg/dL), "high" (10-50 µg/dL), and "very high" (above 50 µg/dL). To assess the association between BLL categories and opiate use, route of consumption and weekly use, we used ordered logistic regression models, and report OR (odds ratio) and 95% CI (confidence interval) adjusted for age, sex, place of residence, education, occupation, household fuel type, and tobacco use.

RESULTS

In the cohort, participants used only raw (teriak) or refined (shireh) opium, which were smoked (45%, n = 184), taken orally (46%, n = 189), or both (9%, n = 37), for a mean duration of 24.2 (standard deviation: 11.6) years. The median BLL was significantly higher in people who currently used opium (11.4 µg/dL; IQR: 5.2-23.4) compared with those who did not (2.3 µg/dL; IQR: 2.3-4.2), and the highest median BLL was seen in oral use (21.7 µg/dL; IQR: 12.1-34.1). The BLL was <5 µg/dL among 79.8% of people with no opiate use, compared with only 22.7% in those using opium. BLL was elevated in 21.7%, high in 50.5% and very high in 5.1% of people using opium. About 95% of those with oral (180/189) or dual use (35/37) and 55% (102/184) of those who smoked opium had levels of blood lead above 5 µg/dL. The OR for the association between any opium use and each unit of increase in BLL category was 10.5 (95%CI: 5.8-19.1), and oral use of opium was a very strong predictor of increasing BLL category (OR=74.1; 95%CI: 35.1-156.3). This odds ratio was 38.8 (95%CI: 15.9-95.1) for dual use and 4.9 (95%CI: 2.6-9.1) for opium smoking. There was an independent dose-response association between average weekly dose and BLL among people using opium, overall and when stratified by route of use.

CONCLUSION

Our results indicate that regular use of lead-adulterated opium can expose individuals to high levels of lead, which may contribute to mortality and cancer risks associated with long-term opium use.

A Systematic Review and Meta-analysis on Blood Lead Level in Opium Addicts: an Emerging Health Threat

This meta-analysis was conducted aiming to summarize the results obtained from the previous studies so that the effect of opium on blood lead levels (BLLs) can be investigated. Scopus, Embase, PubMed, and Web of Science (ISI) were systematically searched up to June 2020. Heterogeneity of the included studies was evaluated using Cochrane's Q test and the I² statistic. A random-effects model was used to pool the weighted mean differences (WMDs) and their 95% confidence intervals (CIs). Out of a total of 2372 citations, eleven articles with 916 participants (487 opium addicts and 429 controls) were included in the study. The meta-analysis results showed that there were higher lead levels (WMD = 14.59 μg/dL, 95% CI = 11.59 to 17.92, Z = 8.60, P < 0.001) in opium addicts than in the control group. The degree of heterogeneity observed (P < 0.001, I² = 98.1%) might be mainly the result of the type of sampling and of consumption. Moreover, the findings of meta-regression analyses indicated that publication year (β = 1.23, P = 0.287), total sample size (β = 0.05, P = 0.728), and quality scores (β = - 2.91, P = 0.546) had no effects on lead levels in opium addicts. In the sensitivity analysis, it was found that the pooled WMDs remained stable after excluding one by one study. Oral opium consumption increased the amount of lead in the bloodstream, and the measurement of lead levels in opium addicts' blood may be regarded as a useful test to diagnosis and prognosis of disorders that may lead poisoning causes.