Exposure to cadmium and conventional and ambulatory blood pressures in a prospective population study

This prospective population study investigated in a random sample of 692 su bjects (age 20-83 years) how changing environmental exposure to cadmium inf luenced blood pressure (BP) and the incidence of hypertension. At baseline (1985 to 1989; participation rate, 78%) and follow-up (1991 to 1995; re-exa mination rate, 81%), blood pressure was measured by conventional sphygmoman ometry (CBP; 15 readings in total) and, at follow-up, also by 24-h ambulato ry blood pressure monitoring (ABP). Systolic/diastolic CBP at baseline aver aged 128.4/77.3 mm Hg. At baseline, blood cadmium concentration (B-Cd) and urinary cadmium excretion (U-Cd) averaged (geometric means) 11.1 nmol/L and 10.2 nmol/24 h. Over 5.2 years (median follow-up), B-Cd fell by 29.6% and U-Cd by 15.2%. B-Cd fell less in subjects living closer to three zinc smelt ers and in premenopausal women. During follow-up, systolic CBP decreased by 2.2 mm Hg in men and remained unchanged in women, and diastolic CBP increa sed by 1.8 mm Hg in both sexes. No relationship could be demonstrated betwe en the secular trends in CBP and B-Cd or U-Cd or between B-Cd or U-Cd at ba seline and the incidence of hypertension. In addition, in cross-sectional a nalyses involving the average of all available CBP measurements in each par ticipant or 24-h ABP at follow-up (mean, 119.1/71.4 mm Hg), blood pressure was not correlated with B-Cd or U-Cd. In conclusion, environmental exposure to cadmium was not associated with higher CBP or 24-h ABP or with increase d risk for hypertension. The lesser fall in B-Cd in the residents living cl oser to the zinc smelters or in premenopausal women underscores the necessi ty to sanitize cadmium-polluted areas and to systematically reinforce the p reventive measures to be adopted by exposed communities to reduce cadmium u ptake. (C) 2000 American Journal of Hypertension, Ltd.