Evidence for augmented oxidative stress in the subjects with type 1 diabetes and their siblings: a possible preventive role for antioxidants.
OBJECTIVE
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.


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.


CONCLUSIONS
Augmented OS in the siblings may indicate an increased requirement for antioxidants in genetically diabetes-prone subjects.
Laboratory of Nutrition Research, National Nutrition and Food Technology Research Institute (NNFTRI), Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. t.neyestani@nnftri.ac.ir
T R
TR
Neyestani
Z
Z
Ghandchi
M-R
MR
Eshraghian
A
A
Kalayi
N
N
Shariatzadeh
A
A
Houshiarrad
D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000201:enzymology / Q000378:metabolism*; D005260:Female; D005978:Glutathione / Q000097:blood; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D007492:Iran; D008297:Male; D018384:Oxidative Stress / Q000502:physiology*; D035781:Siblings; D018709:Statistics, Nonparametric; D013482:Superoxide Dismutase / Q000097:blood; D055815:Young Adult
D001786:Blood Glucose; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione