Cystatin C, other markers of kidney disease, and incidence of age-related cataract.

Abstract

To investigate the 15-year incidence of 3 specific types of age-related cataract as related to cystatin C and other measures of kidney function. Examinations of a population-based cohort (n = 4926) occurred at 5-year intervals for 15 years. Assessment of medical history, examination, and photographs of the lens after pupil dilation were performed at each examination. Protocols for photography and grading were used. Laboratory measures were from specimens collected at baseline. In multivariable analyses, a 1-SD increase in the logarithm of cystatin C was associated with 15-year incidence of cortical (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.09-1.41) and posterior subcapsular (OR, 1.24; 95% CI, 1.02-1.50) cataracts. One SD increase in the logarithm of blood urea nitrogen and creatinine were associated with 15-year incidence of posterior subcapsular cataract (OR, 1.22; 95% CI, 1.04-1.42 and OR, 1.26; 95% CI, 1.03-1.54, respectively). Increased levels of cystatin C are associated with increased risk of specific types of age-related cataract. Whether the associations are due to the metabolic changes associated with decreased renal function, common genes, or both awaits further research.