Abstract
Purpose: :
The association of age-related macular degeneration (AMD) with cardiovascular disease and its risk factors such as hypertension, diabetes mellitus, and obesity is controversial. Previous research have been limited by the relative infrequency of this disease. This study examines the relationship between such risk factors and AMD using >25 years of hospital administrative data.
Methods: :
Cases were patients diagnosed with AMD from 1975-2003 (n=5321) at the Lions Eye Institute, and categorised as having dry AMD (ICD-9 code 362.51) or wet AMD (ICD-9 code 362.52). Controls were individually matched for age, sex and postcode. Mortality and hospital morbidity records from 1980-2006 were obtained from the Western Australian Data Linkage System (WADLS). The WADLS is a comprehensive, long-term database governed by legislation making provision of data from all hospitals compulsory. Diseases were coded in standard ICD format. This data was analysed for associations between all AMD, dry AMD, or wet AMD with diagnosed heart disease, stroke, diabetes mellitus, hypertension, atherosclerosis, peripheral vascular disease, obesity, smoking, and mortality.
Results: :
Smoking (OR = 1.43; 95% CI, 1.29-1.58) and ischaemic heart disease (OR = 1.14; 95% CI, 1.05-1.25) were significantly associated with all AMD groups in multivariate analyses. The relationship strengthened in the wet AMD group. Other factors associated with wet AMD were peripheral vascular disease (OR = 1.31; 95% CI, 1.09-1.58) and atherosclerosis (OR = 1.19; 95% CI, 1.06-1.33), with the relationship stronger in males for the former, and females for the latter. Hypertension was associated with wet AMD in men (OR = 1.21; 95% CI, 1.01-1.44). There was a borderline significant association between a history of cardiovascular disease with dry AMD in women (OR = 1.21; 95% CI, 1.00-1.46). Mortality, diabetes mellitus, stroke, and obesity were not associated with AMD.
Conclusions: :
Smoking and cardiovascular disease are associated with AMD, particularly for wet AMD. Different risk profiles exist between dry and wet AMD, and between men and women. These findings suggest dry and wet AMD may have different pathogenesis, and that cardiovascular disease and AMD may share similar underlying systemic processes.
Keywords: age-related macular degeneration • clinical (human) or epidemiologic studies: risk factor assessment