SHORT REPORT - LOW-LEVEL LEAD-EXPOSURE DOES NOT INCREASE THE BLOOD-PRESSURE IN THE GENERAL-POPULATION

Objective: Long-term exposure to high concentrations of lead may adversely affect several organ systems, but the possible influence of low-level lead exposure on blood pressure remains debatable. The present study examined this relationship in a cross-sectional population survey. Methods: Blood pressure and lead exposure were measured in 1648 subjects (827 males, 821 females; mean age 45 years), drawn at random from the general population, but not being treated for hypertension. Results: Systolic/diastolic blood pressure averaged 131/77 mmHg in the males and 124/74 mmHg in the females. Blood lead was higher in males than in females (0.5 versus 0.3 mumol/l), but the opposite was observed for zinc protoporphyrin (1.0 versus 1.1 mug/g haemoglobin). After adjustment for significant covariates (age, body mass index, pulse rate, serum creatinine and serum calcium, and for contraceptive pill intake and menopause in females), systolic pressure was negatively correlated with blood lead in males; the partial correlations with blood lead were not significant for systolic pressure in females nor for diastolic pressure in either sex. Neither males nor females showed a significant relationship between blood pressure and lead exposure assessed from the zinc protoporphyrin level in blood. Conclusions: This study does not support the hypothesis that exposure to lead is associated with increased blood pressure in the population at large.