Genetic polymorphisms in genes encoding antioxidant enzymes are associated with diabetic retinopathy in type 1 diabetes.

OBJECTIVE: Oxidative stress plays an important role in the development of microangiopathic complications in type 1 diabetes. We investigated polymorphic markers in genes encoding enzymes regulating production of reactive oxygen species in association with diabetic retinopathy or diabetic nephropathy. RESEARCH DESIGN AND METHODS: A total of 124 patients with type 1 diabetes were investigated in this case-control study. All subjects were matched for sex, age, and duration of diabetes. Genotyping was conducted using real-time PCR for p.Val16Ala polymorphism in the MnSOD gene and c.C-262T in the promoter region of the CAT gene. Multiplex PCR method was used for determination of GSTM1 and GSTT1 polymorphic deletions. Fluorescence-labeled PCR amplicons and fragment analysis was used for assessing the number of pentanucleotide (CCTTT)n repeats in inducible nitric oxide synthase. RESULTS: A positive association of MnSOD genotype Val/Val (odds ratio [OR] 2.49, 95% CI 1.00-6.16, P = 0.045) and GSTM1-1 genotype (2.63, 1.07-6.47, P = 0.031) with diabetic retinopathy but not with diabetic nephropathy was demonstrated. Additionally, the combination of the two genotypes conveyed an even higher risk (4.24, 1.37-13.40, P = 0.009). No other investigated genetic polymorphisms were associated with either diabetic retinopathy or diabetic nephropathy. CONCLUSIONS: Selected polymorphisms in genes encoding MnSOD and GSTM1 could be added to a panel of genetic markers for identification of individuals with type 1 diabetes at an increased risk for developing diabetic retinopathy.

Lifetime prevalence of suicidal and self-injurious behaviors in a representative cohort of Slovenian adolescents with type 1 diabetes.

OBJECTIVE: To determine lifetime prevalence of suicidal and self-injurious behaviors in Slovenian adolescents with type 1 diabetes compared with healthy controls. RESEARCH DESIGN AND METHODS: Adolescents (14-19 yr) with type 1 diabetes were compared with a normative control group of healthy secondary school students by means of a self-reported questionnaire (according to Kienhorst) containing questions on demographic and family characteristics, suicidal ideation, intended suicide, attempted suicide, possible future suicide, and self-injurious behavior. Patients received the questionnaires at regular outpatient visits to the pediatric diabetes clinic, completed them in private, and returned them by mail. Questionnaires for control subjects were administered in classrooms. RESULTS: The responses of 126 eligible patients and 499 controls were analyzed. The control group trended toward higher lifetime prevalence of all suicidal behaviors and self-injurious behavior. The lowest prevalence of all suicidal behaviors and self-injurious behavior was reported by males with diabetes. Compared with male controls, the differences were statistically significant for suicidal ideation (p < 0.05) and intended suicide (p < 0.05). Compared with females with diabetes, the differences were statistically significant for suicidal ideation (p < 0.001), intended suicide (p < 0.01), attempted suicide (p < 0.05), and self-injurious behavior (p < 0.05). Females with diabetes reported highest prevalence of all suicidal but not self-injurious behaviors. More patients than controls reported receiving counseling the year preceding the study (p < 0.001). CONCLUSIONS: In the study, type 1 diabetes showed a protective effect for suicidal behavior in adolescent males but not in adolescent females. Professionals working with adolescents with type 1 diabetes should be alert to possible suicidality, especially among females.