Association of blood lead to blood pressure in men aged 55 to 75 years: effect of selected social and biochemical confounders. NFR Study Group.

The association of blood lead (B-Pb) concentration to blood pressure was investigated in men aged 55 to 75 years living in the Rome area, who had no history of exposure to lead in the workplace and who participated between 1989 and 1990 in an epidemiologic survey for coronary heart disease (New Risk Factor Project). Of the 1856 individuals eligible for the study, 59 were excluded from analyses because not all relevant data were available; and 478 were excluded because they were treated for hypertension. In the remaining subjects (n = 1319) the median B-Pb concentration was 113 micrograms/l (range: 40-442 micrograms/l). Systolic blood pressure (SBP) averaged 140 +/- 18 (standard deviation) mm Hg (range 98-220) and diastolic blood pressure (DBP) 84 +/- 9 mm Hg (range 56-118). Median B-Pb values increased significantly from 111 micrograms/l in subjects with normal blood pressure (n = 668) to 113.5 micrograms/l in subjects with borderline high blood pressure (n = 373) and to 120 micrograms/l in subjects with increased blood pressure (n = 278). After log-normal conversion of B-Pb, the linear correlation coefficient between In[B-Pb(ug/l)] and both SBP and DBP was statistically significant (r = 0.1332, p < 0.001 and r = 0.0737, p = 0.007, respectively). The linear regression coefficient was 6.8 mm Hg/In(micrograms/l) for SBP and 1.8 mm Hg/In(microgram/l) for DBP. Multiple regression analyses revealed that, after correction for body mass index (BMI), age, heart rate, skinfold thickness, serum lipids, and glucose levels; blood lead was still a significant predictor of increased SBP and DBP.(ABSTRACT TRUNCATED AT 250 WORDS)