Association Between Cataracts and Incident Fractures Among Older Women From the Study of Osteoporotic Fractures (SOF)

Abstract

Purpose:: To study relationship between cataracts and incident non-spine fractures in older ambulatory women who participated in the Study of Osteoporotic Fractures (SOF).

Methods:: A total of 5,482 women attended SOF V6 clinic visit in 1997-99. In a case-cohort design, lens photographs were graded for women who suffered incident non-spine fractures during follow-up (April, 2005) and a random sample of 5,482 women who attended V6 clinic visit. Cortical opacity, posterior subcapsular opacity, and nuclear sclerosis were independently measured by two masked, trained graders using the modified Wisconsin lens opacity grading protocol. Status of aphakia/pseudophakia, or intraocular lens (IOL) was also determined for all women with gradable external and/or lens photographs. Primary outcomes were 6-year non-spine fractures. Cox proportional-hazards regression models were used to analyze the relationship between lens status and various types of cataracts and incident fractures after adjusting for potential confounders including study sites, age, race and cognitive function.

Results:: Lens and cataract status were assessed by evaluating external and lens photographs of 1,274 women in the random sample (mean age: 79.5 ± 4.5 years) and 499 women who suffered incident non-spine fractures (mean age: 80.6 ± 4.4years). Over an average of 6.0 (± 1.7) years of follow-up, women with IOL in both eyes were at a higher risk for hip fractures (hazard ratio [HR]=1.36, 95% confidence interval [CI]=1.03-1.78, p=0.028) than those who were phakic in at least one eye, regardless of the status of cataracts. Women with 5% or greater PSC in at least one eye were at a lower risk (HR=0.80, 95% CI=0.66-0.98, p=0.032) for any non-spine fractures when compared to women with PSC less than 5% in both eyes, regardless of the status of IOL.

Conclusions:: Our findings suggest that individuals with IOL placement in both eyes are at higher risk for hip fractures and that PSC is protective against any non-spine fractures. These paradoxical results could possibly be associated with increased activity in patients with IOLs vs. decreased activity in patients with PSC secondary to visual impairment.

Keywords: cataract • vision and action