www.ijoehy.it - Italian Journal of Occupational and Environmental Hygiene PAPERS
© The Italian Association of Industrial Hygienists - AIDII [2018] 146 - 153 | Ital. J. Occup. Environ. Hyg., 2018, 9(3)
Background: The action of lead on blood pressure is always subject to discussion. To this, is added the possible
action of the lead on the pulse pressure. Objective: To evaluate the effect of lead on blood pressure and pulse pres-
sure by a longitudinal case-control study (275 exposed people and 282 controls). Method: The studied parameters of
this study came from the medical follow-up records of the workers. Multivariate analyses and the study of survival
time are made by SPSS version 20 software. Results: mean systolic and diastolic pressures were significantly higher
(p<0.000) in lead-exposed workers than in controls. Ditto for pulsed pressure (p<0.000). There are almost two times
more systolic and diastolic hypertension in lead-exposed workers. Survival was significantly much lower in the expo-
sed cohort. Conclusion: The average lead as well as the cumulative lead act both on the pressure parameters.
Cumulative lead exposure, blood pressure, and pulse pressure: a
longitudinal case-control study
Key words: Blood lead, cumulative blood lead index, blood pressure, hypertension, survival analysis
Esposizione cumulativa al piombo, pressione arteriosa, pressione di polso:
un caso studio di controllo longitudinale
e-ISSN 2464 - 8817
Ziadi Boukerma
1,*
, Lakhdar Ahmed Behlouli
2
, Ammar Terra
2
1
Université Farhat Abbas, Sétif 1 - Laboratoire Santé-environnement des Hauts Plateaux Sétifiens
2
Université Farhat Abbas, Sétif 1 - Service de Médecine du Travail Sétif 19000 Algérie (Algeria)
*Corresponding author:
Ziadi Boukerma, Université Farhat Abbas, Laboratoire Santé-environnement des Hauts Plateaux Sétifiens; e-mail: zboukerma@gmail.com
Introduction
Recognized as a major cardiovascular risk factor [Bénétos,
2007; Lim et al., 2013], high blood pressure has been the
cause of 9.4 million deaths worldwide in 2010 [Lim et al.,
2013]. Among the various risk factors for high blood pres-
sure, environmental lead exposure [Pirkle, Schwartz,
Landis, & Harlan, 1985; Pocock, Shaper, Ashby, Delves &
Clayton, 1988] or/and professional lead exposure
[Nomiyama et al., 2002; Sadeghniiat-Haghighi et al.,
2011] appears to be involved in the development of high
blood pressure. In fact, lead, whether industrial or environ-
mental, has been the topic of numerous studies, particular-
ly as regards its action on blood pressure. If one refers to
the numerous scientific publications, one notes that the
responsibility of the lead in the appearance of arterial
hypertension was differently appreciated. Indeed, some
authors have reported sufficient evidence of a statistical
link between the increased blood lead levels and increa-
sed blood pressure [Cheng et al., 2001; de Almeida Lopes
et al., 2017; Scinicariello, Yesupriya, Chang & Fowler,
2010], however others have reported a weak association
[Apostoli et al., 2005] or even no association [Den Hond,
Nawrot & Staessen, 2002; Wu et al., 1996]. Sadeghniiat-
Haghighi, meanwhile [Sadeghniiat-Haghighi et al., 2011]
has found a borderline significant association (p=0.057)
between systolic blood pressure (SBP) and blood lead con-
centration; but no association between diastolic blood
pressure (DBP) and blood lead. Cardiovascular predictivi-
ty of hypertension has evolved over time. Indeed, in addi-
tion to the two digits characterizing the blood pressure,
several observational studies suggest that pulse pressure
(PP) (systolic minus diastolic pressure) could be an inde-
pendent risk factor for cardiovascular morbidity and mor-
tality [Chalmers et al., 1999; Van Bortel, Struijker-Boudier,
& Safar, 2001]. On this subject, the age-dependent increa-
se in pulse pressure largely attributable to an increase in
arterial stiffness (Andersson et al., 1998) would get a bet-
ter predictor of cardiovascular complications in the elder-
ly [Kondo et al., 2006]. Recent studies have reported that
the increase in systolic blood pressure and pulse pressure
in the elderly is a factor in decreasing life expectancy
[Benetos, Thomas, Bean, Pannier & Guize, 2005; Franco,
Peeters, Bonneux & De Laet, 2005] but what about the
influence of chronic exposure to inorganic lead on pulse
pressure? Indeed, the world literature shows that the
impact of lead on pulsed pressure has been studied only
to a limited extent. In this regard, a study made by
Perlstein [Perlstein et al., 2007] shows that the cumulative
lead, as reflected by bone lead level, was associated with
pulse pressure in a cohort of middle-aged and older men.
This present study, based on data from Medical Records
Management of workers, aims to examine the association
between the concentration of lead in the blood and blood
pressure (systolic, diastolic, and pulse pressure) among
employees aged 21 - 59.
Materials and Methods
The present study is a retrospective case-control study
whose data come from the workers’ medical files of two
companies affiliated with our occupational medicine