ABSTRACT
Objective To investigate the relationship between HbA1c in blood and IL-6 in tear fluid of the elderly patients with diabetic retinopathy ( DR ) in Shijiazhuang urban communities , and the relationship between IL-6 in tear fluid and the severity of DR. Methods The elderly people who lived more than 5 years , older than ≥45 year old. in nine urban communities of Shijiazhuang were stratified randomly sampled and received cross-sectional epidemiology questionnaire survey and OGTT. A total of 1 447 subjects (509 males and 938 females) were included. Each participant underwent epidemiological surveys and oral glucose tolerance test (OGTT), according to the 1999 WHO diabetes mellitus (DM) diagnostic criteria established. For patients who were newly or previously diagnosed as DM. HbA1c level, tear fluid IL-6 and serum IL-6 tested.The severity of DR was evaluated by fundus examination, the people were divided into normal group(NGT), non-diabetic retinopathy ( NDR ) , non-proliferative diabetic retinopathy ( NPDR ) , and proliferative diabetic retinopathy ( PDR ) . The correlation of serum IL-6 and tear fluid IL-6,blood HbA1c and tear fluid IL-6 were assessed by SPSS 19.0 statistical software. Results Concentrations of tear fluid IL-6 were (3.10 ± 1.25)pg/mL in the NGT group, (10.25 ± 3.22)pg/mL in the NDR group,(16.80 ± 5.76)pg/mL in the NPDR group,(25.11 ± 5.20)pg/mL in the PDR group(P < 0.01). SNK-q test revealed significant differences between every two groups (P < 0.01,P <0.05,P < 0.05) Concentrations of serum IL-6 were (88.04 ± 17.06)pg/mL in the NGT group,(126.38 ± 20.73) pg/mL in the NDR group, (239.83 ± 40.33)pg/mL in the NPDR group, (268.36 ± 27.72)pg/mL in the PDR group(P < 0.01). SNK-q test revealed significant differences between every two groups (P < 0.01). Tear fluid IL-6 level was positively correlated with serum IL-6 level(R = 0.756,P < 0.01). Tear fluid IL-6 level was positively correlated with blood IL-6 level (R = 0.338, P < 0.01). Conclusion The tear fluid IL-6 levels of the elderly patients with DM in Shijiazhuang urban communities , increased; with the increased severity of DR , the levels of tear fluid IL-6 gradually increase. The level of tear fluid IL-6, serum IL-6, HbA1c closely correlates with the severity of DR.