Changes of local cerebral blood flow concomitant to lead-exposure in adult rabbits

Comparison of blood lead concentrations in patients with acute ischemic stroke and healthy subjects

BACKGROUND AND OBJECTIVES

Stroke is the main cause of mortality and long-term disability in the general population. With the increased application of metals in industries and human environment, lead has become a health hazard. In this study, we aimed to evaluate the relationship between the blood concentration of lead and the incidence of acute stroke.

MATERIALS AND METHODS

We performed this study during 2016-17 at Vali-e-Asr Hospital in Birjand, Iran, among 80 ischemic stroke patients visiting the hospital and 80 healthy gender- and age-matched controls. Blood lead concentration (BLC) was measured using graphite furnace atomic absorption spectrometry.

RESULTS

BLC medians in the case and control groups were 20.65 [5.37-34.87] μg/dL and 2.65 [1.75-13.85] μg/dL, respectively (p < 0.05). The case group had significantly lower mean levels of HDL and phosphors, whereas the mean levels of white blood cells and uric acid were higher in this group. After adjusting for lipid profile and fasting blood sugar, multiple logistic regression indicated that the serum levels of uric acid and BLC were significant for predicting ischemic stroke. It is estimated that the odds ratio of ischemic stroke increases by 1.04 per 1 μg/dl increase in BLC.

CONCLUSION

This study showed that lead can be a risk factor for ischemic stroke. Since it does not have any beneficial effects on the health of individuals, screening serum concentrations of lead can be considered as a preventive strategy for those at risk of stroke.

Association between heavy metal levels and acute ischemic stroke

Background

Few studies have examined the relationship between the amounts of heavy metal and stroke incidence. The aim of this study was to explore the relationship between levels of heavy metals, including Pb, Hg, As, and Cd, in patients with acute ischemic stroke (AIS).

Methods

We selected patients with first-ever AIS onset within 1 week as our study group. Healthy controls were participants without a history of stroke or chronic disease, except hypertension. The serum levels of Pb, Hg, As, and Cd in participants in the experimental and control groups were determined. All participants received a 1-g infusion of edetate calcium disodium (EDTA). Urine specimens were collected for 24 h after EDTA infusion and measured for heavy metal levels.

Results

In total, 33 patients with AIS and 39 healthy controls were enrolled in this study. The major findings were as follows: (1) The stroke group had a significantly lower level of serum Hg (6.4 ± 4.3 μg/L vs. 9.8 ± 7.0 μg/L, P = 0.032, OR = 0.90, 95% CI = 0.81–0.99) and a lower level of urine Hg (0.7 ± 0.7 μg/L vs. 1.2 ± 0.6 μg/L, P = 0.006, OR = 0.27, 95% CI = 0.11–0.68) than the control group. (2) No significant difference in serum Pb (S-Pb), As (S-As), and Cd (S-Cd) levels and urine Pb (U-Pb), As (U-As) and Cd (U-Cd) levels was observed in either group.

Conclusions

Our study found low levels of serum and urine Hg in first-ever patients with AIS, providing new evidence of dysregulated heavy metals in patients with AIS.

Electronic supplementary material

The online version of this article (10.1186/s12929-018-0446-0) contains supplementary material, which is available to authorized users.

Association of high body lead store with severe intracranial carotid atherosclerosis

OBJECTIVE

Lead is involved in the pathogenesis of atherosclerosis and hypertensive disease and may be related to cerebrovascular disease. We studied the association of body lead level with stroke subtypes and severity of cerebral atherosclerosis in order to identify the significance of lead exposure to cerebrovascular disease.

METHODS

From April, 2002 to March, 2005, we studied the lead level in all patients receiving digital subtraction angiography. Diameter stenosis at extracranial carotid, intracranial carotid and vertebrobasilar system was calculated according to the NASCET criteria. A blood sample and a mobilization test of 72-h urine sample were collected for lead measurement.

RESULTS

In a total of 213 subjects, 19 were free of stroke (blood lead level=4.62+/-2.41 microg/dL, body lead store=39.04+/-20.91 microg) and 194 were stroke patients (4.89+/-2.75 microg/dL, 45.13+/-29.8 microg; all stroke vs. non-stroke, P>0.05). In the 153 subjects with atherosclerotic origin, body lead store but not blood lead level in the intracranial carotid system was significantly higher in > or =50% group than <50% group (blood lead: 5.61+/-3.02 microg/dL vs. 4.80+/-2.50 microg/dL, Student's t-test, P=0.129; body lead store: 51.7+/-27.0 microg vs. 41.9+/-23.5 microg, Student's t-test, P=0.038, multivariate logistic regression, odds ratio=1.02, 95% CI: 1.00-1.03, P=0.043). However, there was no significant association between lead level and stenotic severity in extracranial and vertebrobasilar systems (P>0.05).

CONCLUSION

Our study demonstrated that long-term lead exposure as measured by body lead store might carry a potential risk of intracranial carotid atherosclerosis.