Association between macular degeneration and mild to moderate chronic kidney disease

Abstract

Chronic kidney disease (CKD) and macular degeneration (MD) are 2 grave diseases leading to significant disability secondary to renal failure and blindness. The 2 diseases share not only common risk factors but also similar pathogenic mechanisms to renal and retinal injuries. Previous epidemiological studies indicated association between these 2 diseases. However, this concept is challenged by recent investigations. Patients with mild to moderate CKD (n = 30,696) between January 1, 1995 and December 31, 2005 were selected from the Taiwan National Health Insurance Database. Controls (n = 122,784) were matched by age, gender, diabetes mellitus type 2, and hypertension status (1:4 ratios). The risk of MD was compared between the 2 groups. The mean age of patients was 54.9 ± 15.7 years. The proportion of MD was 2.7% in mild to moderate CKD patients and 1.9% in normal controls (P < 0.001); and, 0.39% and 0.26% (P < 0.001) in advanced MD. Mild to moderate CKD patients had higher risk for MD [adjusted odds ratio (OR), 1.301; 95% confidence interval (CI), 1.200–1.411; P < 0.001] than normal renal function subjects. The association was more pronounced for advanced MD. From all age strata (10 years increase), the presence of CKD in those patients aged less than 40 years had highest OR for all MD (OR = 2.125, 95% CI: 1.417–3.186, P < 0.001). The results were consistent in interaction terms, highlighting the importance of CKD in young age patient for risk of MD. The high risk for MD in mild to moderate CKD patients remains significant after adjustment for personal habits (alcohol drinking and smoking, model 1; OR: 1.371; 95% CI: 1.265–1.486; P < 0.001), comorbidities (dyslipidemia, cerebrovascular disease, and peripheral vascular disease, model 2; OR: 1.369; 95% CI: 1.264–1.484; P < 0.001) and all these factors (model 3; OR: 1.320, 95% CI: 1.218–1.431, P < 0.001). This association was consistent in the subanalysis, excluding those patients with diabetic retinopathy. Proper diagnosis and timely intervention should be warranted to retard visual loss of these patients.

Age-Related Macular Degeneration in Chronic Kidney Disease: A Meta-Analysis of Observational Studies

“…The existence of different distinct risk factors for both CKD and AMD suggests that the 2 diseases might be associated independently of the common risk factors. Moreover, several studies had identified CKD as an independent predictor of AMD after adjusting for multiple common risk factors [35][36][37][38][39]. These evidences again suggest the possibility that the 2 diseases might be independently associated.…”

“…Thus, age distribution may influence the occurrence rate of AMD. Several studies included in this review enrolled participants as young as 18-25 years [36,38,39]. The inclusion of younger populations may be a factor for the variation in effect size between studies.…”

“…Geographic distribution included 2 studies from the United States, 3 from Australia, 2 from Taiwan, 2 from Singapore, 1 from South Korea, 1 from China, and 1 from the United Kingdom. The lower limits for enrolled age ranged from 18 [39] to 75 [41] years, and the upper limits for enrolled age ranged from 80 [42,46] years to unlimited [38,39,41,47] (Table 1).…”

“…One study [38] compared the risk ratio of "ESRD on dialysis" vs. "no ICD-9 diagnosis code for kidney disease (ICD-9-CM 580-589)". The remaining study [39] compared the risk ratio of "population with ICD-9 diagnosis of mild or moderate kidney disease but without dialysis" vs. "those without any ICD-9 diagnosis code of kidney disease. "…”

“…These 9 population-based studies comprised 2 studies using a nationwide health insurance database [38,39], 3 nationwide surveys [42,46,47], and 4 community-based surveys [35,41,43,45]. The setting of the 3 hospital-based studies included 1 renal clinic [36] in a teaching hospital, 1 health examination center [40], and 1 health promotion center [37] in hospitals.…”