Toxic metals, such as mercury (Hg), lead (Pb), cadmium (Cd), and copper (Cu), are widespread in the biosphere, and human activities have contributed to their continuous release into the ecosystems. Metal-induced toxicity has been extensively studied in mammals; however, the effects of these metals on insects’ behavior have been explored to far lesser degree. As the main mechanism of toxicity, the cationic metals, explored in this review, have high affinity for thiol-containing molecules, disrupting the function of several proteins and low-molecular-weight thiol-containing molecules. Existing literature has corroborated that Hg, Pb, Cd, and Cu can disrupt locomotor and mating behaviors, but their effects on insects’ memory and learning have yet to be fully characterized. Though field studies on metal-induced toxicity in insects are limited, results from Drosophila melanogaster as an experimental model suggest that insects living in contaminated environments can have behavioral foraging and reproductive deficits, which may cause population decline. In this review, we address the interaction between metals and endogenous thiol groups, with emphasis on alterations in insect behavior. 

Toxic metals that interact with thiol groups and alteration in insect behavior.

Lead (Pb) exposure has been a serious environmental and public health problem throughout the world over the years. The major sources of lead in the past were paint and gasoline before they were phased out due to its toxicity. Meanwhile, people continue to be exposed to lead from time to time through many other sources such as water, food, soil and air. Lead exposure from these sources could have detrimental effects on human health, especially in children. UNICEF reported that approximately 800 million children have blood lead levels (BLLs) at or above 5 micrograms per deciliter (µg/dL) globally. This paper reports on the potential risks of lead exposure from early life through later life. The articles used in this study were searched from databases such as Springer, Science Direct, Hindawi, MDPI, Google Scholar, PubMed and other academic databases. The levels of lead exposure in low income and middle-income countries (LMICs) and high-income countries (HICs) were reported, with the former being more affected. The intake of certain nutrients could play an essential role in reducing (e.g., calcium and iron) or increasing (e.g., high fat foods) lead absorption in children. Elevated blood lead levels may disturb the cells’ biological metabolism by replacing beneficial ions in the body such as calcium, magnesium, iron and sodium. Once these ions are replaced by lead, they can lead to brain disorders, resulting in reduced IQ, learning difficulties, reduced attention span and some behavioral problems. Exposure to lead at an early age may lead to the development of more critical problems later in life. This is because exposure to this metal can be harmful even at low exposure levels and may have a lasting and irreversible effect on humans. Precautionary measures should be put in place to prevent future exposure. These will go a long way in safeguarding the health of everyone, most especially the young ones.

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Potential Health Risks of Lead Exposure from Early Life through Later Life: Implications for Public Health Education

Lead is an environmental hazard that should be addressed worldwide. Over time, human lead exposure in the western world has decreased drastically to levels comparable to those among humans living in the preindustrial era, who were mainly exposed to natural sources of lead. To re-evaluate the potential health risks associated with present-day lead exposure, a two-pronged approach was applied. First, recently published population metrics describing the adverse health effects associated with lead exposure at the population level were critically assessed. Next, the key results of the Study for Promotion of Health in Recycling Lead (SPHERL; NCT02243904) were summarized and put in perspective with those of the published population metrics. To our knowledge, SPHERL is the first prospective study that accounted for interindividual variability between people with respect to their vulnerability to the toxic effects of lead exposure by assessing the participants' health status before and after occupational lead exposure. The overall conclusion of this comprehensive review is that mainstream ideas about the public and occupational health risks related to lead exposure urgently need to be updated because a large portion of the available literature became obsolete given the sharp decrease in exposure levels over the past 40 years. 

https://www.nature.com/articles/s41440-022-01069-x.pdf

Public and occupational health risks related to lead exposure updated according to present-day blood lead levels

Abstract Background Cardiovascular diseases (CVD) are rapidly increasing in low-middle income countries (LMICs). Accurate risk assessment is essential to reduce premature CVD by targeting primary prevention and risk factor treatment among high-risk groups. Available CVD risk prediction models are built on predominantly Caucasian risk profiles from high-income country populations, and have not been evaluated in LMIC populations. We aimed to compare six existing models for predicted 10-year risk of CVD and identify high-risk groups for targeted prevention and treatment in Haiti. Methods We used cross-sectional data within the Haiti CVD Cohort Study, including 1345 adults ≥ 40 years without known history of CVD and with complete data. Six CVD risk prediction models were compared: pooled cohort equations (PCE), adjusted PCE with updated cohorts, Framingham CVD Lipids, Framingham CVD Body Mass Index (BMI), WHO Lipids, and WHO BMI. Risk factors were measured during clinical exams. Primary outcome was continuous and categorical predicted 10-year CVD risk. Secondary outcome was statin eligibility. Results Sixty percent were female, 66.8% lived on a daily income of ≤ 1 USD, 52.9% had hypertension, 14.9% had hypercholesterolemia, 7.8% had diabetes mellitus, 4.0% were current smokers, and 2.5% had HIV. Predicted 10-year CVD risk ranged from 3.6% in adjusted PCE (IQR 1.7–8.2) to 9.6% in Framingham-BMI (IQR 4.9–18.0), and Spearman rank correlation coefficients ranged from 0.86 to 0.98. The percent of the cohort categorized as high risk using model specific thresholds ranged from 1.8% using the WHO-BMI model to 41.4% in the PCE model (χ 2 = 1416, p value &lt; 0.001). Statin eligibility also varied widely. Conclusions In the Haiti CVD Cohort, there was substantial variation in the proportion identified as high-risk and statin eligible using existing models, leading to very different treatment recommendations and public health implications depending on which prediction model is chosen. There is a need to design and validate CVD risk prediction tools for low-middle income countries that include locally relevant risk factors. Trial registration clinicaltrials.gov NCT03892265 . 

/pdf/comparing-six-cardiovascular-risk-prediction-models-in-haiti-3j1k5xmb.pdf

Comparing six cardiovascular risk prediction models in Haiti: implications for identifying high-risk individuals for primary prevention

Prehypertension and Retinal Arteriolar Narrowing in PWH in Tanzania

Cardiovascular disease is the leading cause of death in lower-income countries including Haiti. Environmental lead exposure is associated with high blood pressure and cardiovascular mortality in hi...

High Lead Exposure Associated With Higher Blood Pressure in Haiti: a Warning Sign for Low-Income Countries

Background People living with HIV (PLWH) are at increased risk of cardiovascular disease (CVD) and death, with greater burdens of both HIV and CVD in lower-middle income countries. Treating prehypertension in PLWH may reduce progression to hypertension, CVD risk and potentially mortality. However, no trial has evaluated earlier blood pressure treatment for PLWH. We propose a randomized controlled trial to assess the feasibility, benefits, and risks of initiating antihypertensive treatment among PLWH with prehypertension, comparing prehypertension treatment to standard of care following current WHO guidelines. Methods A total of 250 adults 18-65 years and living with HIV (PLWH) with viral suppression in the past 12 months, who have prehypertension will be randomized to prehypertension treatment versus standard of care. Prehypertension is defined as having a systolic blood pressure (SBP) 120-139 mmHg or diastolic blood pressure (DBP) 80-89 mmHg. In the prehypertension treatment arm, participants will initiate amlodipine 5 mg daily immediately. In the standard of care arm, participants will initiate amlodipine only if they develop hypertension defined as SBP ≥ 140 mmHg or DBP ≥ 90 mmHg. The primary outcome is the difference in mean change of SBP from enrollment to 12 months. Secondary outcomes include feasibility, acceptability, adverse effects, HIV viral suppression, and medication adherence. Qualitative in-depth interviews with providers and participants will explore attitudes about initiating amlodipine, satisfaction, perceived CVD risk, and implementation challenges. Discussion PLWH have a higher CVD risk and may benefit from a lower BP threshold for initiation of antihypertensive treatment. Trial registration Clinicaltrials.gov registration number NCT04692467, registration date December 15, 2020, protocol ID 20-03021735.

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Treatment of early hypertension among persons living with HIV in Haiti: Protocol for a randomized controlled trial.

/pdf/treatment-of-early-hypertension-among-persons-living-with-39j9t0n0rz.pdf

Treatment of Early Hypertension among Persons Living with HIV in Haiti: protocol for a randomized controlled trial

BackgroundCardiovascular diseases (CVD) are rapidly increasing in low-middle income countries (LMICs). Accurate risk assessment is essential to reduce premature CVD by targeting primary prevention and risk factor treatment among high-risk groups. Available CVD risk prediction models are built on predominantly Caucasian, high-income country populations, and have not been evaluated in LMIC populations. ObjectiveTo compare the predicted 10-year risk of CVD and identify high-risk groups for targeted prevention and treatment in Haiti. MethodsWe used cross-sectional data within the Haiti CVD Cohort Study, including 653 adults [≥] 40 years without known history of CVD and with complete data. Six CVD risk prediction models were compared: pooled cohort equations (PCE), adjusted PCE with updated cohorts, Framingham CVD Lipids, Framingham CVD Body Mass Index (BMI), WHO Lipids, and WHO BMI. Risk factors were measured during clinical exams. Primary outcome was continuous and categorical predicted 10-year CVD risk. Secondary outcome was statin eligibility. ResultsSeventy percent were female, 65.5% lived on a daily income of [≤]1 USD, 57.0% had hypertension, 14.5% had hypercholesterolemia, 9.3% had diabetes mellitus, 5.5% were current smokers, and 2.0% had HIV. Predicted 10-year CVD risk ranged from 3.9% in adjusted PCE (IQR 1.7-8.4) to 9.8% in Framingham-BMI (IQR 5.0-17.8), and Spearman rank correlation coefficients ranged from 0.87 to 0.98. The percent of the cohort categorized as high risk using the uniform threshold of 10-year CVD risk [≥] 7.5% ranged from 28.8% in the adjusted PCE model to 62.0% in the Framingham-BMI model ({chi}2 = 331, p value < 0.001). Statin eligibility also varied widely. ConclusionsIn the Haiti CVD Cohort, there was substantial variation in the proportion identified as high-risk and statin eligible using existing models, leading to very different treatment recommendations and public health implications depending on which prediction model is chosen. There is a need to design and validate CVD risk prediction tools for low-middle income countries that include locally relevant risk factors. Trial registrationclinicaltrials.gov NCT03892265

/pdf/cardiovascular-disease-risk-prediction-models-in-haiti-4klgzcxri9.pdf

Stephano St-Preux

Papers

High Lead Exposure Associated With Higher Blood Pressure in Haiti: a Warning Sign for Low-Income Countries

Treatment of early hypertension among persons living with HIV in Haiti: Protocol for a randomized controlled trial.

Treatment of Early Hypertension among Persons Living with HIV in Haiti: protocol for a randomized controlled trial

Cardiovascular Disease Risk Prediction Models in Haiti: Implications for Primary Prevention in Low-Middle Income Countries