Diminished circadian blood pressure variability in elderly individuals with nuclear cataracts: cross-sectional analysis in the HEIJO-KYO cohort

The present study aimed to determine the relationship between cataract subtypes and circadian blood pressure (BP) variability in elderly individuals. In this cross-sectional study of a community-based cohort, we assessed bilateral lens opacity using slit lamp photographs of 458 elderly individuals (mean age, 69.1 years). Cataract status was defined as a bilateral Lens Opacities Classification System III grade of ≥3 for nuclear cataract, ≥2 for cortical cataract, and ≥2 for posterior subcapsular cataract (PSC). Ambulatory BP monitoring was performed at 30-min intervals for 48 h. A nondipper pattern of BP was defined as a <10% decline in the mean nighttime systolic BP relative to the mean daytime systolic BP. The prevalence of nondipper patterns was 42.4% and 25.9% in the groups with nuclear cataracts (n = 66) and without cataracts for both eyes (n = 290), respectively. Multivariable logistic regression analysis adjusted for potential confounders revealed a significantly higher odds ratio (OR) for nondipper pattern in the group with nuclear cataract than in that without cataract (OR, 1.81; 95% confidence interval, 1.01–3.24; P = 0.047) but not in the group with cortical cataract (P = 0.61) or PSC (P = 0.95). In conclusion, circadian BP variability was significantly diminished in elderly individuals with nuclear cataracts but not in those with cortical cataracts or PSCs. These associations were independent of daytime light exposure, physical activity, and known risk factors of cataracts, such as aging, obesity, and diabetes.