RESUMEN
BACKGROUND/OBJECTIVES: Oxidative stress (OS) is thought to be involved in both development of type 1 diabetes (T1D) and its further complications. In this study, certain biomarkers of OS were compared among the subjects with T1D, their non-diabetic siblings and unrelated healthy controls. SUBJECTS/METHODS: Known cases of T1D from both sexes aged 5-25 years were enrolled in a case-control study (n(1)=60). There were two control groups; non-diabetic siblings (n(2)=60) and unrelated apparently healthy subjects (n(3)=60). Anthropometric, dietary and laboratory assessments were done. RESULTS: There was no significant difference in dietary data among the groups. Total antioxidant capacity was significantly lower in T1D than both related and unrelated controls (1.6 ± 0.05, 1.7 ± 0.05 and 1.8 ± 0.06 mmol BSA equivalent/l, respectively, P=0.044). Both T1D subjects and their siblings showed lower glutathione peroxidase (GSH-px) levels (median (interquartile range): 22.2 (28.6), 29.9 (23) and 41.8 (73.6) U/ml, respectively, P=0.006). On the contrary, superoxide dismutase concentrations were significantly higher in T1D group and the siblings than unrelated healthy controls (243 (45.3), 157.8 (176.9) and 27.9 (8.7) U/l, respectively, P<0.001). Serum concentrations of GSH correlated with energy intake in the siblings (r=0.521, P<0.001) and unrelated controls (r=0.268, P=0.042) but not in T1D group. The associations remained significant after controlling for blood glucose (r=0.437, P=0.001 and r=0.420, P=0.011, respectively) in both the groups. CONCLUSION: Augmented OS in the siblings may indicate an increased requirement for antioxidants in genetically diabetes-prone subjects.
Asunto(s)
Diabetes Mellitus Tipo 1/metabolismo , Estrés Oxidativo/fisiología , Adolescente , Adulto , Glucemia/metabolismo , Estudios de Casos y Controles , Niño , Preescolar , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/enzimología , Femenino , Glutatión/sangre , Glutatión Peroxidasa/sangre , Humanos , Irán , Masculino , Hermanos , Estadísticas no Paramétricas , Superóxido Dismutasa/sangre , Adulto JovenRESUMEN
BACKGROUND: Vitamin D status has been linked to both T helper (Th)1/Th2 balance and susceptibility to type 1 diabetes (T1D). The present study aimed to evaluate vitamin D status and its relation to Th1/Th2 balance in subjects with T1D, their siblings and unrelated healthy controls during autumn and winter 2008-2009. METHODS: A case-control study was conducted on subjects with T1D (n(1) = 60) and two control groups comprising nondiabetic siblings (n(2) = 60) and unrelated healthy controls (n(3) = 60). Assessments of dietary intake, anthropometry, intact parathyroid hormone (iPTH) and 25(OH)D were performed. Serum levels of immunoglobulin (Ig)G(2) and IgE, as well as the IgG2/IgE ratio, were used to evaluate Th1/Th2 balance. Vitamin D status was defined based on circulating 25(OH)D as deficiency: <27.5 nm; insufficiency 27.5 ≤ 25(OH)D <50 nm; and sufficiency ≥50 nm. RESULTS: Vitamin D status did not differ significantly among the groups. Similarly, no significant difference in 25(OH)D, iPTH, IgG(2), IgE and IgG(2)/IgE was found. In multiple regression analysis of pooled data, PTH and body mass index were the predictors of IgG(2)/IgE. In the diabetic group, both PTH and age and, in siblings, PTH only, were the predictors of IgG(2)/IgE ratio. CONCLUSIONS: These data suggest PTH as the major predictor of immune deviance towards the Th1 response in both type 1 diabetic subjects and their siblings. Considering that the active form of vitamin D suppresses PTH production, it is hypothesised that vitamin D replenishment of just those who are genetically prone to the disease (i.e. siblings) may be regarded as a preventive measure against T1D.
Asunto(s)
Diabetes Mellitus Tipo 1/inmunología , Inmunoglobulinas/sangre , Estado Nutricional , Linfocitos T Colaboradores-Inductores/inmunología , Deficiencia de Vitamina D/diagnóstico , Vitamina D/análogos & derivados , Adolescente , Adulto , Índice de Masa Corporal , Estudios de Casos y Controles , Niño , Preescolar , Diabetes Mellitus Tipo 1/sangre , Ingestión de Energía , Femenino , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina G/sangre , Irán , Masculino , Hormona Paratiroidea/sangre , Células TH1/inmunología , Células Th2/inmunología , Vitamina D/sangre , Deficiencia de Vitamina D/sangre , Deficiencia de Vitamina D/inmunologíaRESUMEN
OBJECTIVE: To investigate the consumption of industrial trans-fatty acids (TFAs) in Iranian homes and the proportion of coronary heart disease (CHD) events in Iran attributable to such intake. DESIGN, SETTING AND PARTICIPANTS: The consumption of industrial TFAs was determined using (1) detailed in-home assessments of dietary intake among 7158 urban and rural households containing 35 924 individuals and (2) gas chromatography to determine TFA contents of the most commonly consumed partially hydrogenated oils. The population-attributable risk for CHD owing to TFA consumption was calculated on the basis of (1) documented effects of TFAs on total:high-density lipoprotein (HDL) cholesterol in randomized controlled dietary trials and (2) relationships of TFA intake with incidence of CHD in prospective observational studies. RESULTS: Partially hydrogenated oils were used extensively for cooking in Iranian homes with average per-person intake of 14 g/1000 kcal. TFAs accounted for 33% of fatty acids in these products, or 4.2% of all calories consumed (12.3 g/day). On the basis of total:HDL cholesterol effects alone, 9% of CHD events would be prevented by replacement of TFA in Iranian homes with cis-unsaturated fats (8% by replacement with saturated fats). On the basis of relationships of TFA intake with CHD incidence in prospective studies, 39% of CHD events would be prevented by replacement of TFA with cis-unsaturated fats (31% by replacement with saturated fats). These population-attributable risks may be overestimates owing to competing risks and because not all the fat used for cooking might actually be consumed. If actual TFA consumption were only half as large, the estimated proportion of CHD events prevented by TFA elimination would be 5% on the basis of total:HDL cholesterol effects and replacement with cis-unsaturated (4% for replacement with saturated fats), and 22% on the basis of prospective studies and replacement with cis-unsaturated fats (17% for replacement with saturated fats). These estimates do not include possible additional benefits derived from replacing TFAs with vegetable oils containing n-3 fatty acids. CONCLUSIONS: Intake of TFAs is high in Iranian homes and contributes to a sizeable proportion of CHD events. Replacement of partially hydrogenated oils with unhydrogenated oils would likely produce substantial reductions in CHD incidence. SPONSORSHIP: National Heart, Lung and Blood Institute, National Institutes of Health, USA. National Nutrition & Food Technology Research Institute, Tehran, Iran.