Peripheral Monocyte Count and Age-Related Macular Degeneration. The Tongren Health Care Study.

PURPOSE:To assess potential associations between the prevalence of age-related macular degeneration (AMD) and systemic parameters in a Chinese population. DESIGN:Cross-sectional study. METHODS:The Tongren Health Care Study included individuals attending regular health care check-up examinations in the Beijing Tongren Hospital from 2017 to 2019. Detailed medical examinations and ophthalmic examinations were applied, including fundus photography. AMD was evaluated according to the Beckman Initiative guidelines. RESULTS:The study included 7,719 participants (mean age: 60.5 ± 8.1 years; range: 50-97 years). The prevalence of any, early, intermediate, and late AMD was 1,607 of 7,719 (20.8%; 95% confidence interval [CI]: 20.1%, 21.9%), 832 of 7,719 (10.8%; 95% CI: 10.1%, 11.5%), 733 of 7,719 (9.5%; 95% CI: 8.9%, 10.2%), and 42 of 7,719 (0.50%; 95% CI: 0.40%, 0.70%), respectively. In multivariate analysis, the prevalence of any AMD increased with higher blood monocyte count (odds ratio [OR]:3.49; 95% CI: 2.26, 5.38; P < .001), after adjusting for older age (OR: 1.06; 95% CI: 1.05, 1.07; P < .001), higher serum concentration of calcium (OR: 2.52; 95% CI: 1.32, 4.84; P = .005), high-density lipoproteins (OR: 1.39; 95% CI: 1.19, 1.61; P < .001), and lower lipoprotein a (OR: 0.99; 95% CI: 0.98, 0.99; P = .02). Similar findings were obtained for the prevalence of intermediate and late AMD combined. The association between higher monocyte count and higher AMD prevalence showed the highest odds ratio for the age group of 50-59 years (any AMD: OR: 4.35, P < .001; intermediate and late AMD: OR: 6.14, P < .001). Individuals with a monocyte count of ≥0.5 × 109/L as compared to participants with a monocyte of 0.1-0.4 × 109/L had a 1.45-fold increased risk for any AMD (OR: 1.45; 95% CI: 1.27, 1.64; P < .001) and 1.58 fold increase risk for intermediate/late AMD (OR: 1.58; 95% CI: 1.33, 1.87; P < .001). CONCLUSION:A higher prevalence of early AMD, intermediate AMD, late AMD, and any AMD was associated with a higher peripheral monocyte count. In agreement with previous studies, the observation suggests monocytes playing a role in the pathogenesis of AMD.