META-AN ALY zyxw S i S zyx Hypertension caused by low-level lead exposure: myth or fact? Jan A. Staessen, Christopher J. Bulpitt*, Robert Fagard, Robert R. Lauwerysl, Harry Roelst, Lutgarde Thijs and Antoon Amery Background: Several reports on the possible association between low-level lead exposure and blood pressure reflect diverging views. This meta-analysis aimed to find a common denominator in the published literature and to estimate whether a relationship exists between blood pressure and levels of lead in the blood. Methods: O f the studies reviewed, 23 provided sufficient details to be considered. The meta-analysis included 33 groups with a total of 33 141 subjects, who had been recruited from the general population in 13 surveys and from occupational groups in 10 studies. In all but four studies the results were adjusted for age, and most studies took into account additional confounding factors. Results: The association between blood pressure and blood lead was similar in both men and women. In the combined studies, a twofold increase in blood lead concentration was associated with a 1 zyxwvu .O mmHg rise in systolic pressure (confidence interval 0.4-1.6 mmHg; zyxwvutsr P = 0.002) and with a 0.6 mmHg increase in diastolic pressure (confidence interval 0.2-1 .O mmHg; P = 0.02). The association with systolic pressure strongly relied on the inclusion of a large study (n=3851) in which women’s blood pressure was measured at the end of pregnancy. The association with diastolic pressure was largely due to a population survey in the USA (n=6289). There was no relationship across studies between the strength of the blood pressure-blood lead relationship and the mean blood lead concentration. Conclusion: The published evidence suggests that there can only be a weak positive association between blood pressure and lead exposure. Any such relationship may not be causal and is unlikely to entail any public-health implication in terms of hypertension-related complications. Nevertheless, these assumptions need to be confirmed in prospective population studies. Journal of Cardiovascular Risk 1994, 1:87-97 Keywords: blood pressure, hypertension, lead From the Hypertension and Cardiac Rehabilitation Unit, Department of Molecular and Cardiovascular Research, Katholieke Universiteit Leuven, Leuven, Belgium, the *Royal Postgraduate Medical School, Hammersmith Hospital, London, UK, and the tindustrial Toxicology and Occupational Medicine Unit, Universitk Catholique de Louvain, Brussels, Belgium. This meta-analysis was part of the preparations for the PheeCad (Public Health and Environmental Exposure to Cadmium) Study. Sponsorship: This population survey is supported by the Province of Limburg (Hasselt, Belgium), the municipalities Hechtel-Eksel and Lommel, the Belgian National Fund for Medical Research (Brussels, Belgium), the International Lead Zinc Research Organization (Research Triangle Park, North Carolina, USA), the Belgian Incentive Programme ’Health Hazards’ (Science Policy Office, Prime Minister’s Services, Brussels, Belgium) and Astra Pharmaceuticals Inc. (Brussels, Belgium). This meta-analysis was also supported by a travel grant from the British Council (Britannia House, Jozef Il-straat 30, B-I 040 Brussels, Belgium) to Professor C.J. Bulpitt, Dr A.E. Fletcher, Dr J. Staessen and Mrs L. Thijs. Requests for reprints to Dr Jan A. Staessen, Klinische Laboratorium-Hypertensie, lnwendige Geneeskunde-Cardiologie, U.Z. Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium. Date of receipt: 12 October 1993; revised: 4 January 1994; accepted: 13 January 1994. zyxw 0 Current Science Ltd ISSN 1350-6277 87 at PENNSYLVANIA STATE UNIV on September 18, 2016 cpr.sagepub.com Downloaded from