RESUMEN
BACKGROUND: Lead is a metal with many important industrial uses. The relationship between lead exposure and the rise of blood pressure has received a great deal of attention as it was implicated that the mortality from cardiovascular diseases might be reduced by lowering lead levels in the environment. OBJECTIVES: The study was to investigate the correlation between the blood lead (B-Pb) levels and the values of blood pressure in hypertensive patients. Moreover, the plasma activities of angiotensin converting enzyme (ACE), plasma levels of nitric oxide (NO), total antioxidants (TAOX) and malondialdehyde (MDA) were estimated to investigate the correlations between the measured parameters and B-Pb levels in hypertensive patients. METHODS: Fifty-five hypertensive patients were compared with fifty-three age and sex matched control group. The B-Pb levels were detected by flame atomic absorption spectrometry. The plasma levels of ACE activities, NO, TAOX and MDA were measured by colorimetric methods. RESULTS: In the hypertensive patients, B-Pb levels were significantly higher than controls. Concomitantly, the plasma levels of ACE activities and MDA were significantly increased while the plasma levels of NO and TAOX were significantly reduced in the hypertensive patients in comparison with controls. There were significant positive correlations between B-Pb and each of MDA, and systolic as well as diastolic blood pressure. Conversely, a significant negative correlation was found between B-Pb and NO. CONCLUSIONS: Our study indicated that a positive relationship exists between blood pressure and B-Pb levels. The increased B-Pb levels were associated with oxidative stress. Moreover, The B-Pb level was negatively correlated with NO and this may clarify the implication of Pb as leading risk factor for the cardiovascular diseases and hypertension. These findings provide support for continued efforts to reduce lead concentration in the population at Qassim region.
