Retinal vascular calibres are significantly associated with cardiovascular risk factors: the Tromsø Eye Study

Purpose: To describe the association between retinal vascular calibres and cardiovascular risk factors. Methods: Population-based cross-sectional study including 6353 participants of the TromsO Eye Study in Norway aged 38-87years. Retinal arteriolar calibre (central retinal artery equivalent) and retinal venular calibre (central retinal vein equivalent) were measured computer-assisted on retinal photographs. Data on blood pressure, body mass index (BMI), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, glycosylated haemoglobin (HbA1c) and smoking were collected. Association between retinal vessel calibre and the cardiovascular risk factors was assessed by multivariable linear and logistic regression analyses. Results: Retinal arteriolar calibre was independently associated with age, blood pressure, HbA1c and smoking in women and men, and with HDL cholesterol in men only. Blood pressure had the strongest effect on arteriolar calibre, with a decrease in calibre of 3.6m (women)/4.1m (men) per standard deviation increase in mean arterial blood pressure. Retinal venular calibre was independently associated with age, blood pressure, BMI, HDL and LDL cholesterol and smoking in men and women. The effect of BMI and HDL cholesterol on venular calibre was significantly stronger in men than in women. Current smoking was the most important factor for venular calibre, where smokers had 13.2m (women)/15.2m (men) wider calibre than nonsmokers. Conclusion: All the explored cardiovascular risk factors were independently associated with retinal vascular calibre, with stronger effect of HDL cholesterol and BMI in men than in women. Blood pressure and smoking contributed most to the explained variance.