The Experimental Study On Correlation Of Adiponectin With Diabetic Retinopathy

Objectives: 1. To measure the adiponectin levels in plasma of patients with type 2 diabetes and diabetic retinopathy(DR) and study the effect of adiponectin on the development of DR. 2. To investigate the genotype distribution of adiponectin +276 nucleotide G/T polymorphism in Chongqing Han population and explore the relationship of the polymorphism to DR. 3. To investigate the mechanism of DR and provide theoretical basis for the prevention and treatment of DR.Methods: First part: The study included 69 patients and 18 normal control subjects(NC). According to the DR degree, 69 patients with type 2 diabetes were assigned to different subgroups: 29 type 2 diabetes mellitus(DM) without retinopathy,26 non-proliferative diabetic retinopathy(NPDR) and 14 proliferative diabetic retinopathy(PDR). The heights,weights and blood pressures of all the subjects were measured, and plasma glucose,lipids and adiponectin were determined. adiponectin levels in plasma were measured using Enzyme-Linked Immunosorbent Assay(ELISA). Second part: 100 cases of type 2 diabetes mellitus, 98 cases diabetic retinopathy and 69 cases of normal controls were collected, and their adiponectin SNP+276 genotypes were detected by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). Adiponectin SNP+276 genotypes and alleles frequencies were compared among three groups.Results: First part: 1.No significance differences in age, blood pressures, plasma lipids and BMI were found among all the groups. There were no difference of male-female ratio.2. The fasting and postprandial blood glucose of the patients were significantly greater than those of controls. The fasting and postprandial blood glucose was similar for each subgroup.3. Adiponectin concentrations in the patients were significantly lower than those in controls(14.39±2.08 ug/ml for controls ,n=18; P < 0 .05). Plasma adiponectin concentrations in patients with proliferative diabetic retinopathy (n=14 , 4.29±2.32 ug/ml) or non-proliferative diabetic retinopathy (n =26,4.20±2.44 ug/ml) were significantly lower than those in patients without diabetic retinopathy (n=29,6.21±2.05 ug/ml; P <0 .05). 4. Plasma adiponectin of PDR patients was insignificant different from non-proliferative diabetic retinopathy (P>0 .05).Second part: 1. The frequencies of the genotypes(G/G,G/T,T/T)were respectively 42.0%,47.8%,10.1% in the normal controls , respectively 53.0%,39.0%,8.0% in the type 2 diabetes mellitus, and respectively 42.9%,37.8%,19.4% in the diabetic retinopathy. 2.No significance difference was found in the distributions of the genotypes among three groups.3.The frequencies of G alleles were respectively 65.9%,72.5%,61.7% in the normal controls, type 2 diabetes mellitus and diabetic retinopathy. There were no difference of adiponectin SNP+276 alleles frequencies among three groups.Conclusion: 1.Hypoadiponectinemia may participate in development of DR. 2. The results suggest that +276G/T single nucleotide polymorphism of the adiponectin gene were no associated with diabetic retinopathy in Chongqing Han population.