Reduced total plasma homocyst(e)ine in children and adolescents with type 1 diabetes

Objectives: The objective was to investigate total plasma homocyst(e)ine (t Hcy), methylenetetrahydrofolate reductase (MTHFR) genotype, and the contrib ution of diet to homocysteine values in children and adolescents with type 1 diabetes and a control group. Study design: A total of 78 children with type 1 diabetes and 59 members of an age- and sex-matched control group were recruited. Fasting samples were collected for tHcy, MTHFR genotype, serum vitamin B-12, serum folate, red cell folate, and plasma creatinine. Food frequency questionnaires targeted intake of folate, vitamin B-6, and vitamin B-12. Results: Fasting tHcy was reduced in patients compared with the control gro up (4.7 vs 5.9 mu mol/L, P < .001), Serum folate (P = .002), red cell folat e (P < .001), and serum vitamin B-12 (P = .005) were higher, and plasma cre atinine was lower. A significant difference in tHcy values between patients and the control group persisted after correction was done for these factor s (r = 0.1, P = .02). No difference was seen in the frequency of MTHFR poly morphisms, tHcy was not elevated in those patients with the 677TT or 677T/1 298C genotypes, although red cell folate was significantly higher in member s of the case (P = .01) and control groups (P = .05) with a 677 TT genotype . Dietary intake of folate correlated with serum folate (r = 0.4, P= .005). Conclusion: tHcy values are lower in children and adolescents with type 1 d iabetes. Higher serum levels of folic acid and vitamin B-12, reflecting dif ferences in dietary intake between children with diabetes and members of a control group, partially account for this difference.