P-selectin Plasma Levels and Genetic Variant Associated With Diabetic Retinopathy in African Americans.

PURPOSE

To report the prevalence and risk factors for retinopathy in African Americans with impaired fasting glucose (IFG) and type 2 diabetes in the Jackson Heart Study and to determine if P-selectin plasma levels are independently associated with retinopathy in this population.

DESIGN

Prospective, cross-sectional observational study.

METHODS

setting: Community-based epidemiologic study.

STUDY POPULATION

Total of 629 patients with type 2 diabetes and 266 participants with impaired fasting glucose.

OBSERVATION PROCEDURES

Bilateral, 7-field fundus photographs were scored by masked readers for diabetic retinopathy (DR) level. Covariate data including P-selectin plasma levels and genotypes were collected in a standardized fashion.

MAIN OUTCOME MEASURES

Association between risk factors, including P-selectin plasma levels and genotypes, and retinopathy.

RESULTS

The prevalences of any retinopathy among participants with IFG and type 2 diabetes were 9.4% and 32.4%, respectively. Among those with type 2 diabetes, in multivariate models adjusted for age, sex, and other traditional risk factors, higher P-selectin levels were associated with any DR (odds ratio = 1.11, 95% confidence interval = 1.02-1.21, P = .02) and proliferative DR (odds ratio = 1.23, 95% confidence interval = 1.03-1.46, P = .02). To further investigate the relationship between P-selectin and DR, we examined the association between P-selectin genotype and DR. Minor allele homozygotes for the variant rs6128 were less likely to develop DR (P after Bonferroni correction = 0.03).

CONCLUSIONS

Both serologic and genetic data show an association between P-selectin and DR in the Jackson Heart Study. If confirmed in other studies, this association may provide insight into the pathogenesis of retinopathy.