RESUMO
Type 1 diabetes mellitus (T1DM) and estrogen deficiency are associated with several alterations in bone turnover. Zinc (Zn) is required for growth, development, and overall health. Zinc has been used in complementary therapy against bone loss in several diseases. We hypothesized that Zn supplementation represents a potential therapy against severe bone loss induced by the combined effect of estrogen deficiency and T1DM. We evaluated the protective effect of Zn against bone alterations in a chronic model of these disorders. Female Wistar rats were ramdomized into 3 groups (5 rats each): control, OVX/T1DM (ovariectomized rats with streptozotocin-induced T1DM), and OVX/T1DM+Zn (OVX/T1DM plus daily Zn supplementation). Serum biochemical, bone histomorphometric, and molecular analyses were performed. Histomorphometric parameters were similar between the control and OVX/T1DM+Zn groups, suggesting that Zn prevents bone architecture alterations. In contrast, the OVX/T1DM group showed significantly lower trabecular width and bone area as well as greater trabecular separation than the control. The OVX/T1DM and OVX/T1DM+Zn groups had significantly higher serum alkaline phosphatase activity than the control. The supplemented group had higher levels of serum-ionized calcium and phosphorus than the nonsupplemented group. The RANKL/OPG ratio was similar between the control and OVX/T1DM+Zn groups, whereas it was higher in the OVX/T1DM group. In conclusion, Zn supplementation prevents bone alteration in chronic OVX/T1DM rats, as demonstrated by the reduced RANKL/OPG ratio and preservation of bone architecture. The findings may represent a novel therapeutic approach to preventing OVX/T1DM-induced bone alterations.
Assuntos
Densidade Óssea/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Suplementos Nutricionais , Osteoprotegerina/metabolismo , Ligante RANK/metabolismo , Zinco/administração & dosagem , Fosfatase Alcalina/sangue , Animais , Glicemia/metabolismo , Osso e Ossos/efeitos dos fármacos , Cálcio/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Feminino , Osteoprotegerina/genética , Ovariectomia , Fósforo/sangue , Ligante RANK/genética , Ratos , Ratos WistarRESUMO
AIMS: To investigate early alterations on bone mineral density (BMD) and RANK, RANKL and OPG mRNA expression in peripheral blood leukocytes (PBL) in children and adolescents with type 1 diabetes (T1D) and the relationship with glycemic control and bone biomarkers. METHODS: This cross-sectional study included 75 children and adolescents with T1D and 100 individuals without diabetes (normoglycemic-NG) aged 6-20 years old. T1D individuals were considered to have good (T1DG) or poor (T1DP) glycemic control according to the values of HbA1c. Phosphorus, magnesium, total and ionized calcium, osteocalcin, alkaline phosphatase and tartaric-resistant acid phosphatase (TRAP) values were determined in blood samples. BMD was measured by DEXA. RANK, RANKL and OPG mRNA expression was measured in PBL by real-time PCR. RESULTS: Osteocalcin values were decreased in diabetic groups in comparison to NG group (p<0.05), and a negative correlation with both serum glucose (r=-0.265, p<0.01) and Hb1Ac (r=-0.252, p<0.01) in T1D group was found. BMD was lower in diabetic groups in comparison with NG group (p<0.05) and a negative correlation was observed between BMD and both serum glucose (r=-0.357, p<0.01) and HbA1c (r=-0.351, p<0.01) in T1D group. OPG mRNA expression was significantly increased in T1D and T1DP groups in comparison with NG group (p<0.05). In conclusion, children and adolescents with early onset T1D presented low bone mineral density associated to unsatisfactory glycemic control, increased OPG mRNA expression and low osteocalcin concentration.
Assuntos
Biomarcadores/sangue , Densidade Óssea , Diabetes Mellitus Tipo 1/fisiopatologia , Hiperglicemia/etiologia , Hipoglicemia/etiologia , Osteoprotegerina/genética , Adolescente , Adulto , Fosfatase Alcalina/sangue , Cálcio/sangue , Estudos de Casos e Controles , Criança , Estudos Transversais , Feminino , Humanos , Hiperglicemia/diagnóstico , Hipoglicemia/diagnóstico , Leucócitos Mononucleares , Masculino , Osteocalcina/sangue , Osteoprotegerina/sangue , Fósforo/sangue , Ligante RANK/sangue , Ligante RANK/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Receptor Ativador de Fator Nuclear kappa-B/sangue , Receptor Ativador de Fator Nuclear kappa-B/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto JovemRESUMO
OBJETIVO: Identificar o perfil lipídico e a peroxidação de lipídeos no plasma de crianças e adolescentes com sobrepeso e obesidade atendidos no Ambulatório de Endocrinologia Pediátrica do HOSPED/UFRN. MÉTODOS: Foram constituídos grupos com crianças e adolescentes com sobrepeso (n = 15), obesidade (n = 30) e controle (n = 21). O perfil lipídico foi avaliado por meio do colesterol total, LDL-colesterol, HDL-colesterol e triglicerídeos. A peroxidação de lipídeos no plasma foi medida pelo marcador malonildialdeído (MDA). A análise estatística foi realizada através do teste t de Student, teste de Tukey, ANOVA e correlação de Pearson. RESULTADOS: As alterações de colesterol total e LDL-colesterol estavam mais presentes nos grupos sobrepeso e obesidade masculinos. O HDL-colesterol mostrou-se em condições limítrofes nos grupos sobrepeso e obesidade em ambos sexos. As maiores concentrações de triglicerídeos foram registradas no grupo obesidade feminino. Identificou-se elevada peroxidação de lipídeos no plasma no grupo obesidade, principalmente no sexo masculino. CONCLUSÕES: Na amostra estudada, maiores alterações do perfil lipídico foram observadas no sexo masculino nos grupos sobrepeso e obesidade, e a peroxidação de lipídeos estava mais evidente no grupo obesidade em ambos sexos.