Abstract
Purpose: :
To assess the association between age-related macular degeneration (AMD) and coronary heart disease (CHD) with regard to genetic and environmental risk factors, age of AMD onset and AMD subgroups.
Methods: :
A total of 1040 AMD patients (72%) and 412 age-matched control subjects (28%) age 68 to 95 years were included in the case-control study. All participants underwent a general ophthalmologic examination including a general health interview to determine the presence of systemic diseases, the current use of systemic medication and smoking habits. Each AMD patient underwent fundus autofluorescence-, digital fundus imaging and, eventually fluorescein angiography. AMD patients were classified into subgroups based on the convention of the international classification system. Age of disease onset was recorded for all AMD patients.
Results: :
Factors associated with AMD were (besides the known genetic risk variants) a history of CHD (odds ratio [OR], 0.71; 95% confidence interval [CI], 0.52, 0.97, p = 0.031), smoking ≥ 20 pack/years ([OR], 3.60; 95% [CI], 1.97, 6.57, p<0.005), and the regular intake of antihyperuricemic agents ([OR], 0.43; 95% [CI], 0.26, 0.73, p=0.002). There were no associations between a history of stroke, arterial hypertension, the regular intake of cholesterol-lowering drugs, or aspirin and AMD or subgroups of AMD.In contrast to AMD, no significant association between a history of CHD, stroke or arterial hypertension with coding polymorphisms in ARMS2 or CFH was found. AMD patients with homozygous variations in CFH and ARMS2 variants and smokers ≥ 20 pack/years were significantly earlier affected by AMD (CFH hom: p=0.019; ARMS2 hom: p=0.00063; smokers: p=0.00001) than AMD patients without homozygous variations in CFH/ ARMS2 and smokers < 20 pack/years. AMD patients with a history of CHD developed AMD-symptoms significantly later in life compared to AMD patients without a history of CHD (p=0.015). A history of stroke or hypertension showed no significant association with the age of AMD onset.
Conclusions: :
Our study suggests three major conclusions. First, the age of AMD onset is substantially influenced by both genetic and environmental risk factors. Second, the two major genetic risk factors CFH and ARMS2 do not appear to play a major role in cardiovascular disorders and its risk factors. And finally, a history of CHD was inversely associated with AMD. Novel therapeutic strategies aiming at preventing the development of AMD may considerably differ from those that have been developed to treat cardiovascular disorders as both disorders may underlie different pathogenetic mechanisms.
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: risk factor assessment • genetics