Relationship Of Apelin-12,Retinal Vascular Quantitative Parameters And Arterial Stiffness

PurposeTo explore whether the arterial stiffness, quantified from pulse wave velocity wasassociated with retinal vascular quantitative factors. By combining the aorta and arteriola, thestudy was to investigate the relationship between Apelin-12and atherosclerosis as well asarteriolosclerosis.MethodsIt was a population-based cross-sectional study of3343Chinese population, involved812men and1357women, aged30to90years. All participants underwent an standardizedquestionnaires and physical examination to obtain cardiovascular factors including age, sex,smoking, drinking, past history, as well as body mass index, resting blood pressure, et al.Retinal vascular quantitative factors were measured and summarized from digital photographs.Brachial-ankle pulse wave velocity （baPWV） was used to measure aortic stiffness. Weassessed serum Apelin-12by enzyme-linked immunosorbent assay. Standarded laboratoryexamination was used to analysis biochemical markers such ascholesterol, glycosylatedhemoglobin A_1c(HbA_1c), serum uric acid.Results1. Smaller central retinal arteriolar equivalent （CRAE） was related to male, higher meanarterial pressure （MABP）. Larger Central retinal venular equivalent （CRVE） was relatedto cigarette smoking, higher HbA_1c, while smaller CRVE was related to older age, greaterpulse pressure （PP）. Smaller fractal dimension of retinal vessels （Df） was related to olderage, higher MABP, greater PP and higher HbA_1c.2. With the baPWV increasing, it was more likely to have narrower central retinal arteriola（OR:3.093,95%CI:2.010to4.760，comparing lowest versus highest quartiles of CRAE,P＜0.001）, and was more likely to have smaller Df （OR:3.746,95%CI:2.312to6.070,comparing lowest versus highest quartiles of CRAE, P＜0.001）. Further adjustment forother cardiovascular factors only slightly weakened the association.3. Serum Apelin-12was independently associated with SBP and Df. However, thecorrelation between serum Apelin-12and SBP （standard β=－0.33） was much strongerthan the correlation between Apelin-12and Df （standard β=－0.078）. Serum Apelin-12 was positively correlated with baPWV, and the baPWV did not contribute to theApelin-12model （P=0.115）. Further analysis showed significant interaction of Df andbaPWV with SBP in relationship to serum Apelin-12.Conclusions1. Female and cigarette smokers tended to have narrower retinal arteriolar, compared withmale and nonsmokers. CRAE was negatively related to blood pressure level. Cigarettesmokers and people with high level of HbA_1ctended to have wider retinal veinule, whilethe retinal venular caliber was negatively related to age and PP. Fractal dimension ofretinal vessels was negatively correlated with age, MABP, PP, HbA_1c, which indicatedthat Df may play its role in predicting cardiovascular disorders as a novel retinal vesselparameter.2. Increased aortic stiffness was negatively correlated with retinal arteriolar narrowing andsmall Df. These data suggested the association between mac-and microcirculation.3. Apelin-12was related to some protective factors of cardiovascular disorders; however,further analysis showed that increased Apelin-12was associated with smaller Df andgreater baPWV. Apelin may play a contradictory role in atherosclerosis andarteriolosclerosis.