RESUMO
To describe the relationship of blood lead levels to menopause and bone lead levels, we conducted a cross-sectional study on 232 pre- or perimenopausal (PreM) and postmenopausal (PosM) women who participated in an osteoporosis-screening program in Mexico City during the first quarter of 1995. Information regarding reproductive characteristics and known risk factors for blood lead was obtained using a standard questionnaire by direct interview. The mean age of the population was 54.7 years (SD = 9.8), with a mean blood lead level of 9.2 microg/dL (SD = 4.7/dL) and a range from 2.1 to 32.1 microg/dL. After adjusting for age and bone lead levels, the mean blood lead level was 1.98 microg/dL higher in PosM women than in PreM women (p = 0.024). The increase in mean blood lead levels peaked during the second year of amenorrhea with a level (10.35 microg/dL) that was 3.51 microg/dL higher than that of PreM women. Other important predictors of blood lead levels were use of lead-glazed ceramics, schooling, trabecular bone lead, body mass index, time of living in Mexico City, and use of hormone replacement therapy. Bone density was not associated with blood lead levels. These results support the hypothesis that release of bone lead stores increases during menopause and constitutes an internal source of exposure possibly associated with health effects in women in menopause transition.
Assuntos
Densidade Óssea , Osso e Ossos/química , Chumbo/sangue , Menopausa , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , México , Pessoa de Meia-Idade , População Urbana , Saúde da MulherRESUMO
BACKGROUND: Pregnancy and breastfeeding mobilize lead stored in bone, which may be a hazard for the fetus and infant. We tested the hypothesis that in lactating women a dietary calcium supplement will lower blood lead levels. METHODS: Between 1994 and 1995 we conducted a randomized trial among women in Mexico City. Lactating women (N = 617; mean age = 24 years; mean blood lead level = 8.5 ug/dL) were randomly assigned to receive either calcium carbonate (1200 mg of elemental calcium daily) or placebo in a double-blind trial. Blood samples were obtained at baseline, and 3 and 6 months after the trial began. Blood lead was determined by graphite furnace atomic absorption spectroscopy. Bone lead was measured at baseline with a 109cd K x-ray fluorescence instrument. The primary endpoint was change in maternal blood lead level, which was analyzed in relation to supplement use and other covariates by multivariate generalized linear models for longitudinal observations. RESULTS: An intention-to-treat analysis showed that women randomized to the calcium supplements experienced a small decline in blood lead levels (overall reduction of 0.29 ug/dL; 95% confidence interval = -0.85 to 0.26). The effect was more apparent among women who were compliant with supplement use and had high bone lead levels (patella bone lead > or =5 microg/gm bone). Among this subgroup, supplement use was associated with an estimated reduction in mean blood lead of 1.16 ug/dL (95% confidence interval = -2.08 to -0.23), an overall reduction of 16.4%. CONCLUSIONS: Among lactating women with relatively high lead burden, calcium supplementation was associated with a modest reduction in blood lead levels.
Assuntos
Carbonato de Cálcio/administração & dosagem , Lactação/metabolismo , Chumbo/sangue , Adulto , Osso e Ossos/química , Osso e Ossos/metabolismo , Método Duplo-Cego , Feminino , Humanos , Chumbo/farmacocinética , Modelos Lineares , Placebos , Espectrofotometria Atômica , Inquéritos e QuestionáriosRESUMO
To evaluate the hypothesis that lactation stimulates lead release from bone to blood, the authors analyzed breastfeeding patterns and bone lead concentrations as determinants of blood lead levels among 425 lactating women in Mexico City for 7 months after delivery (1994-1995). The authors measured in vivo patella and tibia lead concentrations at 1 month postpartum using K x-ray fluorescence. Maternal blood samples and questionnaire information were collected at delivery and at 1, 4, and 7 months postpartum. Blood lead was analyzed using graphite furnace atomic absorption spectroscopy. Mean blood lead level at delivery was 8.4 microg/dl (range: 1.8--23.4). Mean cortical and trabecular lead levels were 10.6 microg/g (range: nondetectable to 76.5) and 15.3 microg/g (range: nondetectable to 85.9), respectively, reflecting a population with elevated and diverse past and current lead exposure. The association of bone lead and breastfeeding with blood lead was estimated using generalized estimating equations. Breastfeeding practices and maternal bone lead were important predictors of blood lead level. After adjustment for bone lead and environmental exposure, women who exclusively breastfed their infants had blood lead levels that were increased by 1.4 microg/dl and women who practiced mixed feeding had levels increased by 1.0 microg/dl, in relation to those who had stopped lactation. These results support the hypothesis that lactation is directly related to the amount of lead released from bone.
Assuntos
Lactação/fisiologia , Chumbo/farmacocinética , Adolescente , Adulto , Osso e Ossos/química , Estudos de Coortes , Feminino , Humanos , Chumbo/sangue , Estudos Longitudinais , Fatores de Risco , Espectrofotometria AtômicaRESUMO
Numerosos padecimientos prolongados en el adulto y en el niño, modifican algunos hábitos de la vida familiar. Se presenta una clasificación y un lineamiento sobre el manejo integral de estos padecimientos en pediatría, con el objeto de interesar al médico tratante, cirujano, etc. Desde las primeras entrevistas, se debe exponer cada uno de los puntos señalados, al conjunto familiar, lo que atenúa ostensiblemente las dificuldades generales del manejo, de sus posibles complicaciones y las modificaciones que toda la família tiene que adoptar en ocasiones, durante toda la vida. Se incluyen, los beneficios del control a largo prazo, el costo económico, alteraciones emocionales y algunas generalidades de orden ético, aspectos rara vez mencionados en la literatura