Background: Retinal arteriolar narrowing is a marker of chronic microvascular damage from hypertension. We hypothesized that the presence of retinal arteriolar narrowing increases the likelihood of chronic kidney disease (CKD) associated with hypertension.
Methods: We examined 3602 persons of Chinese, Malay and Indian ethnicities, aged at least 24 years residing in Singapore. CKD was defined as an estimated glomerular filtration rate of less than 60 ml/min per 1.73 m(2). Hypertension was defined as SBP of at least 140 mmHg or DBP of at least 90 mmHg or self-reported physician-diagnosed hypertension. Retinal arteriolar caliber was measured from retinal photographs and summarized. The lowest arteriolar caliber quartile was defined as retinal arteriolar narrowing.
Results: Both hypertension and retinal arteriolar narrowing were associated with CKD (n = 185), independent of major confounders, with multivariable odds ratio of 2.10 (95% confidence interval 1.46-3.02) for CKD associated with hypertension and odds ratio of 1.68 (95% confidence interval 1.04-2.71) for retinal arteriolar narrowing. The association between hypertension and CKD was stronger in the presence of retinal arteriolar narrowing (P for interaction 0.09), and joint exposure to both hypertension and retinal arteriolar narrowing was associated with a three-fold odds of having CKD (multivariable odds ratio 3.61, 95% confidence interval 1.88-6.93) compared with absence of hypertension and arteriolar caliber in the highest quartile (quartile 4).
Conclusion: These findings show that the presence of microvascular disease in the retina increases the likelihood of CKD associated with hypertension and suggest that examination of the retinal vasculature may aid in stratification of CKD risk in hypertensive patients.