Precursors of Age-Related Macular Degeneration: Associations with Physical Activity, Obesity and Serum Lipids in the Inter99 Eye Study

PURPOSE: To investigate associations of small, hard macular drusen and larger macular drusen with obesity-related risk factors. METHODS: Cross-sectional study of 888 subjects aged 30-60 years characterized using anthropometric measurements and blood sample analyses. Physical activity was assessed by questionnaire. Digital grayscale fundus photographs were recorded in red-free illumination and graded for the presence of macular drusen >63µm in either eye and the presence of 20 or more small, hard macular drusen as a mean of both eyes. RESULTS: Macular drusen >63µm were associated with the level of physical activity, the age- and sex adjusted odds ratio being 0.33 (95% confidence interval 0.13-0.82, P=0.016) for participants who were physically active more than 7 h/week compared with participants active 0-2 h/week. In women, macular drusen >63µm were associated with higher serum triglycerides (P=0.0005). A waist circumference in the top quartile increased the odds for drusen >63µm in men whereas in women having a waist circumference in the middle quartiles reduced these odds. The presence of 20 or more small, hard macular drusen was associated with lower levels of serum high-density lipoprotein cholesterol (HDL) (P=0.029) and with moderately elevated triglycerides. CONCLUSIONS: Precursors of AMD were associated with modifiable obesity-related risk factors, notably low physical activity with drusen >63 µm and lower serum HDL and moderately elevated serum triglycerides with 20 or more small, hard macular drusen per eye. These findings support that a physically active, heart-healthy lifestyle prevents the earliest manifestation of AMD.