Zhu Z, et al. - Investigators examined in this cohort to investigate the association between age-related macular degeneration (AMD) and the risk of all-cause and specific-cause mortality in a representative US specimen. They considered late AMD as a marker of biological aging due to its independent association with all-cause mortality and mortality except for cardiovascular disease and cancer.

Methods

• They included 5603 subjects 40 years or older who responded to the National Health and Nutrition Examination Survey (NHANES) [2005-2008 phase] in this population-based prospective cohort study .
• They graded retinal photographs as early, late, or no AMD.
• They accounted all analyses for the complex and stratified design of NHANES with weighted data.
• They estimated the risks of all-cause mortality with Cox proportional hazards regression models and the risks of specific-cause mortality with Fine and Gray competing risks regression models.
• They counted time to death from the baseline to date of death or December 31, 2011, whichever came first.
• From April 1 through 30, 2018, data analysis was conducted.
• Exposures included age-related macular degeneration status as determined by digital fundus images.
• Main outcomes and measures involved mortality resulting from all causes and specific causes until December 31, 2011.

Results

• They measured 6.6% prevalence of any AMD , with 386 (5.8%) having early AMD and 55 (0.8%) having late AMD among the 5603 candidates (52.6% female [n = 2793] and 77.1% white [n = 3017]; mean [SE] age, 56.4 [0.4] years).
• They observed 433 (5.3%) died of all causes, and out of them, 361 (83.1%) had no AMD, 54 (11.5%) had signs of early AMD, 18 (5.4%) had symptomss of late AMD, and 72 (16.9%) had any AMD at baseline after a median follow-up of 4.5 years (interquartile range, 3.6-5.6 years).
• They also found higher unadjusted all-cause and specific-cause mortality rates for those who had early, late, or any AMD compared with no AMD.
• However, only late AMD was noted linked with more than a doubling of all-cause mortality (hazard ratio [HR], 2.01; 95% CI, 1.00-4.03) and more than a 3-fold higher risk of mortality due to causes other than cardiovascular disease and cancer (HR, 3.42; 95% CI, 1.38-8.49) after adjusting confounding factors.
• They identified no correlation between AMD presence or early AMD and all-cause or specific-cause mortality.