Increased Nighttime Blood Pressure in Patients with Glaucoma: Cross-sectional Analysis of the LIGHT Study.

PURPOSE: To determine whether the presence of glaucoma is associated significantly with nighttime blood pressure (BP) and dipping pattern.

DESIGN: Observational, cross-sectional study.

PARTICIPANTS: We assessed 109 glaucoma patients (mean age, 71.0 years) from the Longitudinal Study of Biological Circadian Rhythms in Glaucoma Patients: Home Testing of Circadian Intraocular Pressure and Biological Parameters (LIGHT) study and 708 healthy control participants without glaucoma (mean age, 70.8 years) from a community-based cohort.

METHODS: All of the glaucoma patients and healthy control participants underwent ophthalmic examinations. The ambulatory BP was measured every 30 minutes for 48 hours. The daytime and nighttime periods were based on the sleep diary entries. A nondipper pattern of BP was defined as a decrease in the mean nighttime systolic BP by less than 10% of the mean daytime systolic BP.

MAIN OUTCOME MEASURES: Nighttime BP and dipping pattern.

RESULTS: After adjusting for potential confounders, multivariable linear regression analyses indicated that nighttime systolic BP was significantly higher by 4.1 mmHg (95% confidence interval [CI], 1.0-7.2; P = 0.01) in the glaucoma group than in the control group. The prevalence of the nondipper pattern was significantly higher in the glaucoma group (45.0%) than in the control group (27.5%; P < 0.001). Multivariable logistic regression analyses indicated a significantly higher odds ratio (OR) for the nondipper pattern in the glaucoma group than in the control group (OR, 1.96; 95% CI, 1.26-3.05; P = 0.003).

CONCLUSIONS: The presence of glaucoma was associated significantly with increased nighttime BP and the nondipper pattern of the BP independent of potential confounders such as aging, obesity, and diabetes. Further prospective studies are needed to determine whether the glaucoma severity and progression are associated with the nighttime BP.