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

Evaluating the association between opium abuse, blood lead levels, and the complexity of coronary artery disease

Opium abuse and exposure to heavy metals elevate the risk of coronary artery disease (CAD). Therefore, we aimed to determine the association between opium abuse and blood lead levels (BLLs) and the CAD complexity. We evaluated patients with acute coronary symptoms who underwent coronary angiography, and those with >50% stenosis in at least one of the coronary arteries were included. Furthermore, Synergy between PCI with Taxus and Cardiac Surgery I (SYNTAX I) score and BLLs were measured. Based on the opium abuse, 95 patients were subdivided into opium (45) and control (50) groups. Differences in demographics and CAD risk factors were insignificant between the two groups. The median BLLs were remarkably higher in the opium group than in controls (36 (35.7) and 20.5 μg/dL (11.45), respectively, p = 0.003). We also revealed no significant differences in SYNTAX score between the two groups (15.0 (9.0) and 17.5 (14.0), respectively, p = 0.28). Additionally, we found no significant correlation between BLLs and the SYNTAX scores (p = 0.277 and r = -0.113). Opium abuse was associated with high BLLs. Neither opium abuse nor high BLLs were correlated with the complexity of CAD. Further studies are warranted to establish better the relationship between opium abuse, BLLs, and CAD.

Prevalence and determinants of opioid use disorder among long-term opiate users in Golestan Cohort Study

BACKGROUND

Number of opiate users worldwide has doubled over the past decade, but not all of them are diagnosed with opioid use disorder. We aimed to identify the prevalence and risk factors for OUD after ten years of follow-up.

METHODS

Among 8,500 chronic opiate users at Golestan Cohort Study baseline (2004-2008), we recalled a random sample of 451 subjects in 2017. We used three questionnaires: a questionnaire about current opiate use including type and route of use, the drug use disorder section of the Composite International Diagnostic Interview lifetime version, and the validated Kessler10 questionnaire. We defined opioid use disorder and its severity based on the DSM-5 criteria and used a cutoff of 12 on Kessler10 questionnaire to define psychological distress.

RESULTS

Mean age was 61.2 ± 6.6 years (84.7% males) and 58% were diagnosed with opioid use disorder. Starting opiate use at an early age and living in underprivileged conditions were risk factors of opioid use disorder. Individuals with opioid use disorder were twice likely to have psychological distress (OR = 2.25; 95%CI: 1.44-3.52) than the users without it. In multivariate regression, former and current opiate dose and oral use of opiates were independently associated with opioid use disorder. Each ten gram per week increase in opiate dose during the study period almost tripled the odds of opioid use disorder (OR = 3.18; 95%CI: 1.79-5.63).

CONCLUSIONS

Chronic opiate use led to clinical opioid use disorder in more than half of the users, and this disorder was associated with psychological distress, increasing its physical and mental burden in high-risk groups.

Opium use and risk of colorectal cancer: a multi-center case-referent study in Iran

BACKGROUND

Opium use has been associated with an increased risk of cancers of the lung, oesophagus, and pancreas, and it was recently classified by the International Agency for Cancer Research as carcinogenic to humans. It is not clear whether opium also increases the risk of colorectal cancer (CRC). The aim of our study was to assess the association between various metrics of opium use and the risk of CRC.

METHODS

This case-referent study from seven provinces in Iran comprised 848 CRC cases and 3215 referents. Data on opium use (duration, amount, frequency) and potential confounders were collected by trained interviewers. Multivariable unconditional logistic regression models were used to measure odds ratios (OR) adjusted for age, gender, province, marital status, family history of CRC-linked cancers, consumption of red meat, fruits and vegetables, body shape, occupational physical activity, and socioeconomic status.

RESULTS

Regular opium consumption was not associated with the risk of CRC (OR 0.9, 95% confidence interval, CI: 0.7, 1.2) compared to subjects who never used opium. However, frequent opium use more than twice a day was associated with an increased risk of CRC compared to non-users of opium (OR: 2.0, 95% CI: 1.1, 3.8; p for quadratic trend 0.008).

CONCLUSION

There seems to be no overall association between opium use and CRC, but the risk of CRC might be increased among persons who use opium many times a day.

Blood-lead level in humans and drug addiction: a comprehensive study in Iran

Drug abuse has a high prevalence worldwide and causes many health-related disorders. There are limited human exposure studies on establishing lead exposure levels and their propensity for drug addiction. In the present study, blood samples were tested for lead (Pb) concentrations in illicit drug users together with the related symptoms in comparison with control group of non-drug users. The study was performed on 250 volunteers divided equally in four drug groups, namely, opioids, hashish, methadone, and methamphetamine, and one control group of non-drug users. Participants were recruited from drug addiction clinics and camps in Kashan city, Iran, who were using drugs continuously for more than 1 year. Control group was recruited from companions of the patients with no drug use history. In the investigated groups of drug users, the highest blood-lead level (BLL) concentrations were observed in the opioid group (mean 37.57 µg/dL) with almost 3.7 times higher than in the control group (mean 3.39 µg/dL). In the methamphetamine group, type of occupation had the significant association with BLL concentrations. The positive correlation was revealed in the opioid and methadone groups for BLL concentrations and the duration of drug usage. In the opioid group, the highest BLL concentrations were observed among users who used both methods of drug use: smoking and eating. Also, several behavioral and life-style factors were identified which influence the blood-lead concentration in the drug users. The results of our study revealed that the BLL concentrations in investigated drug users' groups were significantly higher than in the control group (P < 0.001). That can be related with the Pb contents in illicitly used drugs. Apart other adverse health effects, long-term illicit drug use might cause to lead poisoning.

The carcinogenicity of opium consumption: a systematic review and meta-analysis

The carcinogenicity of opium consumption was recently evaluated by a Working Group convened by the International Agency for Research on Cancer (IARC). We supplement the recent IARC evaluation by conducting an extended systematic review as well as a quantitative meta-analytic assessment of the role of opium consumption and risk for selected cancers, evaluating in detail various aspects of study quality on meta-analytic findings. We searched the published literature to identify all relevant studies on opium consumption and risk of selected cancers in humans through 31 October, 2022. Meta-relative risks (mRRs) and associated 95% confidence intervals (CIs) were estimated using random-effects models for studies of cancer of the urinary bladder, larynx, lung, oesophagus, pancreas, and stomach. Heterogeneity among studies was assessed using the I2 statistic. We assessed study quality and conducted sensitivity analyses to evaluate the impact of potential reverse causation, protopathic bias, selection bias, information bias, and confounding. In total, 2 prospective cohort studies and 33 case-control studies were included. The overall pooled mRR estimated for 'ever or regular' versus 'never' use of opium ranged from 1.50 (95% CI 1.13-1.99, I2 = 0%, 6 studies) for oesophageal cancer to 7.97 (95% CI 4.79-13.3, I2 = 62%, 7 studies) for laryngeal cancer. Analyses of cumulative opium exposure suggested greater risk of cancer associated with higher opium consumption. Findings were robust in sensitivity analyses excluding studies prone to potential methodological sources of biases and confounding. Findings support an adverse association between opium consumption and cancers of the urinary bladder, larynx, lung, oesophagus, pancreas and stomach.

Biomarkers of Tobacco Carcinogenesis in Diverse Populations: Challenges and Opportunities

Biomarkers can provide distinct information about cancer risk factors in populations from diverse ancestries and with different exposure patterns by measuring the internal dose of carcinogens. While similar environmental exposures can lead to different cancer risks across racial or ethnic groups, seemingly different exposures can cause the same cancers because they produce the same biomarkers in the body. Smoke-related biomarkers are among the most commonly studied biomarkers in relation to cancer, and they include tobacco-specific biomarkers (nicotine metabolites and tobacco-specific nitrosamines) and biomarkers which can result from exposure to tobacco and non-tobacco pollutants (polycyclic aromatic hydrocarbon and volatile organic compounds). Biomonitoring is superior to self-reported exposure assessment because it is less prone to information and recall biases. However, biomarkers generally reflect recent exposure determined by their metabolism and half-life and how they are stored in and excreted from the body. Many biomarkers are correlated because the sources of exposure usually contain several carcinogens at the same time, making it difficult to identify specific chemicals which lead to cancer. Despite these challenges, biomarkers will continue to be essential to cancer research. Prospective studies, with detailed exposure assessment and large sample sizes from diverse backgrounds, along with studies designed to enrich the methodology of biomarker research are the necessary steps in that direction. See related article by Cigan et al., p. 306.