RESUMO
OBJECTIVE: To determine whether environmental perchlorate exposure adversely affects thyroid function in women in the first trimester of pregnancy. METHODS: First-trimester pregnant women were recruited from prenatal clinics in the Los Angeles County Hospital, Los Angeles, California, and in the Hospital Universitario de Maternidad dependent Universidad Nacional de Córdoba, Córdoba, Argentina, between 2004 and 2007. Spot urine and blood specimens were obtained during the clinic visit. Urinary perchlorate, iodine, and creatinine were measured, and thyroid function tests were performed. RESULTS: The study included 134 pregnant women from Los Angeles, California (mean gestational age ± SD = 9.1 ± 2.2 weeks), and 107 pregnant women from Córdoba, Argentina (mean gestational age = 10.0 ± 2.0 weeks). Median urinary iodine values were 144 µg/L in California and 130 µg/L in Argentina. Urinary perchlorate levels were detectable in all women (California: median, 7.8 µg/L [range, 0.4-284 µg/L] and Argentina: median, 13.5 µg/L [range, 1.1-676 µg/L]). Serum thyroperoxidase antibodies were detectable in 21 women from California (16%) and in 17 women from Argentina (16%). Using Spearman rank correlation analyses, there was no association between urinary perchlorate concentrations and serum thyrotropin, free thyroxine index, or total triiodothyronine values, including within the subset of women with urinary iodine values less than 100 µg/L. In multivariate analyses using the combined Argentina and California data sets and adjusting for urinary iodine concentrations, urinary creatinine, gestational age, and thyroperoxidase antibody status, urinary perchlorate was not a significant predictor of thyroid function. CONCLUSIONS: Low-level perchlorate exposure is ubiquitous, but is not associated with altered thyroid function among women in the first trimester of pregnancy.
Assuntos
Percloratos/efeitos adversos , Gestantes , Glândula Tireoide/efeitos dos fármacos , Argentina/epidemiologia , California/epidemiologia , Exposição Ambiental/efeitos adversos , Feminino , Humanos , Iodo/urina , Los Angeles/epidemiologia , Percloratos/farmacologia , Percloratos/urina , Gravidez , Complicações na Gravidez/induzido quimicamente , Complicações na Gravidez/epidemiologia , Primeiro Trimestre da Gravidez/sangue , Primeiro Trimestre da Gravidez/efeitos dos fármacos , Doenças da Glândula Tireoide/induzido quimicamente , Doenças da Glândula Tireoide/diagnóstico , Doenças da Glândula Tireoide/epidemiologia , Doenças da Glândula Tireoide/urina , Testes de Função Tireóidea , Poluentes Químicos da Água/efeitos adversos , Poluentes Químicos da Água/farmacologiaRESUMO
OBJECTIVE: To describe the alterations in the bone metabolism of HIV-seropositive patients and evaluate the effects of antiretroviral therapies. DESIGN: Cross-sectional analytical study. METHOD AND MATERIALS: A total of 142 subjects (113 male, 29 female), aged 20-45 years were divided into four groups: group A, 33 HIV-seropositive antiretroviral-naive patients; group B1, 36 HIV-seropositive patients on antiviral therapy for over 1 year, without protease inhibitors (PI); group B2, 42 HIV-seropositive patients on combined therapy containing PI for over 1 year; and group C, 15 healthy, HIV-seronegative subjects. Bone mineral density (BMD) were determined by dual energy X-ray absorptiometry in total body, lumbar spine and proximal femur; and evaluation of serum osteocalcin, d-pyridinoline, parathyroid hormone (THP), calcium and phosphate, and urine calcium. RESULTS: BMD was significantly lower in HIV-seropositive patients in comparison with healthy controls, in all sites studied. However, no statistical differences were observed among all groups of HIV-infected patients, independently of the antiretroviral therapy. There was a significantly higher occurrence of osteopenia and osteoporosis in HIV-infected patients in comparison with controls (P < 0.0001), with no differences among treatment-naive patients and either of the treatment groups. Bone formation and resorption markers were similar among all studied groups. There was a significant correlation in all bone sites between time of infection and BMD (P < 0.02). CONCLUSIONS: BMD was significantly lower in HIV-seropositive patients in comparison with controls in lumbar spine, proximal femur and total body, without significant differences among treatment-naive patients and either of the treatment groups. Only time with HIV infection and not specific therapy was associated with BMD decreases.