Familial Clustering Study Of Diabetic Retinopathy In Type 2 Diabetes Mellitus

Aim: The aim of the study is to determine whether familial clustering of diabetic retinopathy existed among type 2 diabetes mellitus (T2DM). Methods: One hundred and sixty-seven T2DM families were investigated together with endocrine division of our hospital during the period of December 2004 to December 2006. At least two diabetic siblings presented in each family and the one with the longest duration of diabetes was defined as the proband. Clinical features and relationships of prevalence of diabetic retinopathy were investigated among the siblings. Results: Albumin excretion rate was higher in probands with diabetic retinopathy (P=0.0033) and was an independent risk factor for probands(OR=1.003,95%CI=1.001~1.008,P=0.0136). Non-edterified fatty acid was higher in siblings of probands with retinopathy (P=0.0378) and was also an independent risk factor for these subjects (OR=2.108,95%CI=1.077~4.127,P=0.0295). Nevertheless, history of smoking played a protective role in retinopathy of the sibling group (OR=0.154,95%CI=0.044~0.540,P=0.0035). And in siblings without history of smoking, the odds ratio for retinopathy in the ones of probands with retinopathy was 3.52(P<0.0001). Duration of diabetes showed positive effect in all subjects (P<0.05). And while duration below five years, retinopathy was 5.5 times (P<0.001) easier to be found in siblings of probands with retinopathy. After adjusted of other factors, the odds ratio for retinopathy in siblings of probands with retinopathy was about 5.6(95%CI=2.344~13.209, P=0.0001). Statistical difference was not found in prevalence of proliferative diabetic retinopathy for siblings of probands, regardless of whether its proband with proliferative retinopathy or not. Conclusions: Albumin excretion rate and non-edterified fatty acid was respective an independent risk factor of retinopathy for the probands and siblings of probands. History of smoking was negatively related to prevalence of retinopathy in the sibling group and diabetic retinopathy was easier to be found in siblings without history of smoking but with family history of retinopathy. Duration was an independent risk factor for all the subjects. But in early stage, diabetic retinopathy may be more likely to occur on the one of probands with retinopathy. Familial clustering of diabetic retinopathy was found to exist among T2DM which indicate an genetic contribution to the onset of diabetic retinopathy. But severity aggregation of diabetic retinopathy was not found in the research and an enlarged sample size was suggested.