Insulin resistance is a risk factor for increased intraocular pressure: The Hisayama study

PURPOSE. To investigate association of the homeostasis model assessment of insulin resistance (HOMA-IR), a surrogate index of insulin resistance, with IOP in a general Japanese population. METHODS. In 2007, a total of 3119 Japanese community-dwellers, aged 40 years or older, underwent eye examinations, including IOP measurement with a noncontact tonometer. Of these, 2254 residents participated in this study. Fasting serum glucose and plasma insulin were measured to determine the HOMA-IR. The association of HOMA-IR with IOP was assessed using a linear regression model, adjusted for age and possible risk factors that can elevate IOP. RESULTS. The mean IOP ± SD was 13.7 ± 2.7 mm Hg in the right eye and 13.6 ± 2.7 mm Hg in the left eye. After adjusting for age, sex, systolic blood pressure, diabetes, total cholesterol, high-density lipoprotein cholesterol, body mass index, waist circumference, smoking habits, alcohol intake, and regular exercise, increased HOMA-IR levels were significantly associated with increasing IOP (P < 0.05). In the subgroup analyses based on the presence or absence of possible confounding risk factors, there was no evidence of heterogeneity between all subgroups (P for heterogeneity > 0.08). CONCLUSIONS. The HOMA-IR is independently associated with elevated IOP levels after adjustment for confounding factors.