The Relationship of Low-Level Blood Lead to Plasma Renin Activity and Blood Pressure

Park, Soon Woo; Kim, Doo Hie

Abstract

A case-control study was conducted to investigate the effect of low-level blood lead on the blood pressure. The plasma renin activity (PRA) was measured also to investigate one of the possible mechanisms by which lead may play a role to influence on the blood pressure. Seventy-two hypertensive and sixty-nine control study subjects were selected from the workers who had no history of job-related lead exposure, in Ulsan city and it's vicinity, Korea. In addition to measuring blood lead levels and PRA, body mass index(BMI), hematocrit, serum sodium, potassium, creatinine, ionized calcium, and cholesterol were measured. Also, the habits of smoking, alcohol drinking and family history of hypertension were checked. The blood lead level of the hypertensive group was 19.8+/-5.5 microgram/dl, which was significantly higher than that of the control group, 12.5+/-4.7 microgram/dl (p<0.01). On multiple logistic regression analysis, the odds ratio of blood lead level on the occurrence of high blood pressure was 1.38, also statistically significant (p<0.01). There was no significant differences between the hypertensive and the control group in the PRA or In(PRA), but there was a marginally significant linear relationship between blood lead and PRA in the hypertensive group (p<0.1). In conclusion, blood lead level which has been known to be within normal limits may be one of the possible risk factors of hypertension and PRA alteration by lead may act as one of the mechanisms.