Systemic factors associated with intraocular pressure among subjects in a health examination program in Japan.

Background To elucidate the possible effect of various systemic factors on intraocular pressure (IOP) using a dataset from a health examination program database in Japan. Methods This cross-sectional study included 1569 subjects selected from the 2287 subjects who comprised the database. Various systemic parameters including age, sex, height, body weight, waist circumference, percent body fat, blood pressure (BP), pulse rate, body mass index, 28 blood examination values, intimal medial thicknesses of both carotid arteries, and intraocular pressure (IOP) values measured by non-contact tonometry in both eyes were collected. The possible correlation between the IOP and other parameters was assessed initially by univariate analyses followed by multivariate analyses. Results Stepwise multivariate analyses, which included all parameters extracted by the univariate analyses (p<0.1) and sex, identified the same six parameters as indicators of the IOP values for each right and left IOP model. Among the parameters, age (r = -0.05 and -0.04/year for right and left IOPs, respectively) was associated negatively and the percent body fat (r = 0.06 and 0.05/%), systolic BP (r = 0.02 and 0.03/mmHg), pulse rate (r = 0.03 and 0.03/counts/minutes), albumin (r = 1.12 and 1.00/g/dL), and hemoglobin A1c (r = 0.38 and 0.44/%) were associated positively with the IOP in each eye. Conclusions Older age was associated with low IOP, while factors reflecting the metabolic syndrome were associated with high IOP in our study population.