Determinants and Risk Factors for Central Corneal Thickness in Japanese Persons: The Funagata Study

Abstract

Purpose: To examine the association between glucose metabolism and central corneal thickness (CCT) in Japanese adults.

Methods: A sub-sample of 322 Japanese adults participating in the Funagata Study was included in this analysis. CCT was measured using a specular microscope. Glucose metabolism was examined using 75-g oral glucose tolerance test. Mean differences in CCT (μm) and 95% confidence intervals were estimated with univariate, age–sex-adjusted and multivariate models using multiple linear regression.

Results: The mean (± standard deviation) age of the study sample was 63.7 ± 11.4 years and 44% were men. The mean fasting plasma glucose (FPG), 2-hour post-load plasma glucose (2hPG) and haemoglobin A1c (HbA1c) concentrations were 96.8 ± 12.6mg/dl, 123.6 ± 41.2mg/dl and 5.3 ± 0.4%, respectively. CCT was normally distributed in the study sample, and the mean CCT was 544.7 ± 34.6μm. After multivariate adjustment, characteristics associated with increased CCT were 2hPG and HbA1c concentrations, impaired glucose tolerance, diabetes, body weight or body mass index and current smoking.

Conclusion: Impaired glucose tolerance, diabetes, obesity and current smoking are associated with increased CCT. Additional studies are required to examine whether interventions to affect these characteristics may reduce CCT.

Keywords::

• Central corneal thickness
• Glucose metabolism
• Obesity
• Smoking

ACKNOWLEDGMENTS

This study was supported by the 21st century Center of Excellence (COE) project #F03 (“Molecular Epidemiological Study utilizing the Regional Characteristics”, Yamagata University) funded by the Japanese Society for the Promotion of Science, Japan, and by a Grant-in Aid from the Global COE program of the Japan Society for the Promotion of Science.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.