Abstract
Purpose: :
We aimed to investigate the effects of aging and systemic parameters on change in intraocular pressure (IOP) among Japanese subjects who visited health examination. We took into consideration of the variation in intercepts of subjects’ characteristics and the variation in coefficients of the characteristics, as a longitudinal analysis.
Methods: :
60,728 subjects who underwent health examination between April 1999 and March 2009 were examined. We employed two studies, a cross-sectional study and a longitudinal study. We investigated the association of aging, age, sex, systolic blood pressure (SBP), body mass index (BMI), hemoglobin A1c (HbA1c), gamma-GTP, and total cholesterol on IOP. The analysis took into consideration the intercept variation and the variation of coefficients among subjects. Statistical analyses were performed using SAS v9.2.(Cary, NC, USA) for descriptive statistics.
Results: :
A total of 20,007subjects were employed in the cross-sectional study. There were 10122 males and 9885 females and the mean age was 54.6 years old (SD=11.4). Non-linear regression analysis revealed that IOP showed a significantly positive correlation to SBP and BMI in male and female, while IOP slightly declined along with age. 60,728 subjects (28,433 males and 32,295 females) were employed in the longitudinal study through 10 years (from 1999 to 2008). The mean age was 50.8 years old (SD=11.4), and the mean IOP was 13.2mmHg (SD=3.0). We used the linear mixed model analysis. The longitudinal analysis revealed that change in SBP (coefficient 0.013: p<0.0001), BMI (0.17: p<0.0001), HbA1c (0.15: p<0.0001), gamma-GTP (0.00016: p=0.51), and total cholesterol (0.0021: p<0.0001) had a significantly positive association on IOP, while aging (-0.066: p<0.0001) and age on 1 April 1999 (-0.044: p<0.0001) had a significantly negative association on IOP.
Conclusions: :
Our results revealed that IOP reduced by aging and age among Japanese which is consistent with some previous reports from Japan. This study also revealed a significant correlation of IOP change with some systemic parameters (i.e. HbA1c, gamma-GTP, and total cholesterol) that could be candidates contributing IOP control in cases of glaucoma.
Keywords: intraocular pressure • clinical (human) or epidemiologic studies: health care delivery/economics/manpower • aging