Association between blood lead level and blood pressure: An occupational population-based study in Jiangsu province, China

Abstract

Studies about the association between lead exposure and the elevation of blood pressure and risk of hypertension are varied, while available data on blood lead levels (BLL) in workers with lead-exposure are scarce. This research aimed to evaluate associations between BLL and blood pressure in an occupational population-based study in Jiangsu province, China. We enrolled 21,688 workers in this study. Information on socioeconomic and occupational background was obtained with face-to-face interviews. BLL, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured, and hypertension status was confirmed. We found that workers in mini-factories had the highest average BLL (20.3 μg/dL; 95% CI, 19.0–21.6 μg/dL) for overall participants. The employees in private factories had higher BLL (9.6 μg/dL; 95% CI, 9.5–9.8 μg/dL). However, BLL was much lower (4.0 μg/dL; 95%CI, 3.7–4.2 μg/dL) in state-owned factories. Participants working in the electrical machinery and equipment manufacturing industry had higher BLL (9.1 μg/dL; 95% CI, 9.0–9.3μg/dL). Compared to those workers with ≤ 4.6 μg/dL BLL, workers with > 17.5 μg/dL BLL presented 1.34 mmHg and 0.70 mmHg average difference in SBP and DBP, respectively. The adjusted OR for hypertension was 1.11 (95%CI, 1.08–1.15) compared to the workers with > 17.5 μg/dL BLL and to those with ≤ 4.6 μg/dL BLL. In summary, we found that BLL was positively associated with SBP and DBP and with the morbidity of hypertension in occupational populations with a high concentration of lead exposure. It is important to formulate new standards of blood lead levels to screen for elevated lead exposure. In addition, a series of new systems of risk assessment should be established to further reduce and prevent lead exposure.

The Blood Lead, Blood Pressure Connection: An Evaluation of Apparently Healthy Lead Exposed Workers in Nigeria

“…Were et al [21] in a study of an occupational population in Kenya reported a high prevalence of hypertension as approximately 30% of workers had hypertensive range blood pressure with an average systolic and diastolic blood pressure (BP) of 134.7 ± 12.7 mmHg and 86.4 ± 8.9 mmHg, respectively, in comparison with the findings of this study which also showed higher prevalence of Hypertension in lead exposed workers. The finding of this study of a higher risk of hypertension in workers with higher lead levels also matches the report from Han et al [7] in an occupational exposed population study in China reporting higher rates and risk of hypertension in workers with higher levels of lead exposure; and Nomiyama et al [23] who reported a positive association between blood lead and systolic blood and diastolic blood pressure in lead workers especially at concentrations higher than 40 µg/dl. Other population based studies [4] [5] [6] [20] and studies among hypertensive populations [24] also report higher prevalence and risk of elevated blood pressure in relation to higher blood lead levels.…”

“…Lead induced hypertension has been shown to occur even in the absence of symptomatic lead intoxication and even before the onset of clinically apparent renal impairment [2] [3] [4]. Several epidemiologic studies [5] [6] [7] [8] [9] have shown that relatively low level of lead exposure is associated with a significant increase in blood pressure. This epidemiological association of lead exposure and elevated blood pressure has been shown to contribute largely to the disease burden attributable to lead, as a result of its associated cardiovascular risk [10] [11].…”

Association between blood lead level and risk of stroke in Korean adults: a cross-sectional study in the Korea National Health and Nutrition Examination Survey 2008–2013

“… 69 70 Lead as a heavy metal contributes to elevated blood pressure. 62 71 Patients with hypertension were often had high lead concentrations 28 72–74 and resistant hypertension was also related to high lead levels. 75 Moreover, lead exposure in individuals with hypertension might contribute to the risk of stroke due to the hypertensive effects of lead, including high blood pressure and impaired blood vessels.…”

“…25 Until now, few studies have assessed the association between lead and stroke in the Korean population. Preceding diseases such as hypertension, dyslipidaemia and diabetes have been associated with lead [26][27][28] and are risk factors for stroke. 29 30 However, previous studies were not adequately controlled for potential confounding factors such as preceding diseases.…”

Effects of Lead on Reproductive Health

“…A large number of investigations provide evidence that exposure to lead is associated with hypertension in adults [78][79][80][81]. For this reason, the question of whether lead is associated with gestational hypertension (GH) and preeclampsia (PE) has gained a great importance in recent years.…”