Relationship of Bone Disease and Calcium Supplementation with Indicators of Pb Exposure in Postmenopausal Women
Augusti, P.R.2; Conterato, G.M.M2.; Hahn, M2; Soares, F.A.A.2; Mattos, J.C.P.2; Dressler, V.L.2; Flores, E.M.M.2; Silva, J.C.N.3; Somacal, S.1; Emanuelli, T.1-2.
1- Depto. Tecnol. e Ciência dos Alimentos, CCR; 2- Depto. Química, CCNE; 3- Hospital Universitário de Santa Maria (HUSM). UFSM. e-mail: paula_augusti@terra.com.br
Bone lead mobilization into the bloodstream may increase significantly during conditions of bone demineralization, such as osteoporosis. δ-Aminolevulinic acid dehydratase (ALA-D) of erythrocytes, is a sensitive biological indicator of the lead exposure.
The objective of this study was to evaluate the influence bone disease and calcium supplementation on blood lead levels, ALA-D activity and % of reactivation in postmenopausal women exposed to background lead levels in a non contaminated region. Women (n=70) were recruited in the Santa Maria University Hospital and divided into six groups, according to bone densitometry results: (1) healthy, no calcium supplementation, (2) healthy, calcium supplementation, (3) osteopenia, calcium supplementation, (4) osteopenia, no calcium supplementation, (5) osteoporosis, calcium supplementation and (6) osteoporosis, no calcium supplementation. Blood lead levels were determined by inductively coupled plasma mass absorption spectrometry. ALA-D activity and reactivation were measured as described by Berling and Schaller (1974), before and after adding zinc and DTT. There were no significant differences ALA-D activity or % of reactivation among groups, but multiple regression analyses showed that there was a negative correlation (β = -0.42, p < 0.05) between ALA-D, % of reactivation and bone mineral density of femur. Our results suggest that although bone disease and calcium supplementation did not affect blood lead levels, there was a relationship between bone mineral density and ALA-D activity.
Supported by CNPq and CAPES
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