Association between Cardiovascular Risk Factors and Early Age-related Macular Degeneration: Findings from a Rural Chinese Adult Population - The Handan Eye Study

1. Ke Yang¹
2. Yuan Bo Liang¹
3. Ning li Wang¹
4. Tien Yin Wong²
5. Jie Jin Wang³
6. Paul Mitchell³

¹Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Science Key Lab, Beijing, China.
²Singapore Eye Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
³Centre for Vision Research, Department of Ophthalmology, Westmead Millennium Institute, University of Sydney, Australia.

PURPOSE: To assess associations between cardiovascular risk factors and the prevalence of early age-related macular degeneration (AMD) in a rural population of Han Chinese.

METHODS: Rresidents aged 30+ years of Yongnian County, Handan, Hebei province, China, were recruited during 2006-07 (90.4% response rate). Retinal photographs were graded following the modified Wisconsin Age-related Maculopathy Grading System, used in the Blue Mountains Eye Study. Cardiovascular risk factors were collected during interviews using standardized questionnaires, or via examinations including fasting blood tests. Logistic regression models were constructed to assess odds ratio (OR) and 95% confidence intervals (CI).

RESULTS: Two hundreds of 6830 participans (3.0%) had early AMD. After age- and gender-adjustment, current smoking ≥ 5 packs per week were significantly associated with early AMD (OR, 1.55; 95% CI, 1.00-2.46), hyper-pigmentation (OR, 2.66; 95% CI, 1.11-6.39) and hypo-pigmentation (OR, 1.66; 95% CI, 1.05-2.63), compared to person who never smoked. After further adjusting for smoking, alcohol consumption and the presence of hypertension and diabetes, a history of coronary heart disease was associated with early AMD prevalence (OR, 2.40; 95% CI, 1.18-4.89), and serum lipids were protectively associated with early AMD: per 1 mmol/l increase in triglycerides, OR 0.75; 95% CI, 0.61-0.94); total cholesterol, OR 0.79; 95% CI, 0.66-0.94; low-density lipoprotein cholesterol, OR 0.77; 95% CI, 0.59-0.99.

CONCLUSION: Our findings support the associations between smoking, a history of coronary heart disease and early AMD prevlaence. The protective associations between serum lipids and early AMD contrast against their associations with cardiovascular diseases, and warrant further investigation.