Associations between physical activity and cataract treated surgically in patients with diabetes: findings from the 45 and Up Study

Aim: To investigate the association between physical activity (PA) and incidence of cataract surgery among patients with diabetes.

Methods: We obtained data from all diabetic subjects aged 45-65 years from the baseline of the prospective 45 and Up Study from 2006 to 2009 and linked to the Medicare Benefits Schedule (MBS) and Pharmaceutical Benefits Scheme (PBS) until 2016. Diabetes was defined as self-reported on questionnaire or diabetes medication history based on PBS. Cataract surgery was determined based on the MBS, and metabolic equivalent intensity level number of PA sessions per week was used to assess PA. Cox regression was used to assess the association between baseline PA and cataract surgery during the follow-up.

Results: A total of 9113 diabetic participants in the 45 and Up Study were included in the current analysis with a mean age of 57.3±5.2 years (43.6% female). During a mean follow-up of 8.8 years, 950 participants (10.4% of baseline) received cataract surgery with a corresponding incidence of 12.4/1000 person-years. Cox regression analysis showed that people with less PA (p=0.01), older age (p<0.001), female gender (p<0.001), higher educational level (p<0.001) and longer diabetic duration (p<0.001) had significantly higher cataract surgery risk. Participants with a PA level of ≥14 sessions per week had 19% decreased risk of cataract surgery compared to those with <5 sessions per week. Stratification analysis showed that participants with more obesity (p value for interaction=0.03), not taking insulin (p value for interaction=0.01) and without cardiovascular disease (p value for interaction=0.008) could benefit significantly more from PA in reducing their cataract surgery risk.

Conclusions: More vigorous PA was independently associated with a reduced risk of cataract surgery in working-aged patients with diabetes.