Age at Diagnosis and C-Peptide Level Are Associated with Diabetic Retinopathy in Chinese

Abstract

ObjectiveTo find the associations between diabetic retinopathy and age at diagnosis, C-peptide level and thyroid-stimulating hormone (TSH) level in Chinese type 2 diabetes mellitus.Methods3100 hospitalized type 2 diabetic patients in Peking University People's Hospital were included in this retrospective study. Their medical history and the laboratory data were collected. All the patients received examination of diabetic retinopathy (DR) by professional ophthalmologist.ResultsComparisons among patients with NDR, NPDR and PDR showed that with the progression of diabetic retinopathy, patients turned to have older age but younger age at diagnosis of diabetes, and have higher SBP, longer duration of diabetes, higher mean HbA1c but lower fasting and 2 hours postprandial C-peptide level. Moreover, with the progression of diabetic retinopathy, patients turned to have higher prevalence of primary hypertension, higher prevalence of peripheral vascular sclerosis, higher proportion with insulin treatment. TSH level was comparable among the three groups of patients. Association analysis showed that after adjusting for age, sex, duration of diabetes, body mass index, HbA1c, blood pressure and albuminurea creatinine ratio and insulin treatment, age at diagnosis (OR 0.888, 95%CI 0.870–0.907, p = 0.00) and postprandial C-peptide (OR 0.920, 95%CI 0.859–0.937, p = 0.00) are the independent associated factors of DR in Chinese type 2 diabetes.ConclusionsAccording to the results, postprandial C-peptide level and age at diabetes may be two independent associated factors with DR in Chinese type 2 diabetes. The lower level of postprandial C-peptide, the younger age at diagnosis, may indicate the higher prevalence of DR.

Association between body mass index and diabetic retinopathy in Chinese patients with type 2 diabetes

“…In this study, DR prevalence was 27.7 %; DR was more prevalent in patients diagnosed with diabetes at an earlier age, with longer duration of diabetes, poorer glycemic control, and hypertension, which agrees with previous studies [11,[13][14][15][16][17][18][19].…”

“…On the other hand, elevated BMI may exert beneficial effects: Increased BMI was associated with greater pancreatic b cell mass and higher CP levels [19,35,36]. Moreover, higher FCP and postprandial CP reduce DR risk in both type 1 and type 2 diabetes [19,20,[37][38][39][40][41][42]. In our study, BMI was correlated with BP, lipid profile, HbA1c, and CP levels.…”

“…On one hand, higher BMI correlates with elevated BP and worse lipid profile [26,33,34], known DR risk factors [11,13,14,18,21]. On the other hand, elevated BMI may exert beneficial effects: Increased BMI was associated with greater pancreatic b cell mass and higher CP levels [19,35,36]. Moreover, higher FCP and postprandial CP reduce DR risk in both type 1 and type 2 diabetes [19,20,[37][38][39][40][41][42].…”

“…However, the association between BMI and DR is inconsistent. Earlier studies suggested that higher BMI increases DR risk [17,18,[21][22][23], and there was higher DR prevalence in obese patients compared with normal weight patients [24]; other studies reported no association [15,19,25]. Recently, lower DR prevalence was reported in patients with higher BMI [26][27][28].…”

“…age of diabetes, with longer duration of diabetes, poorer b cell function and glycemic control, dyslipidemia, and hypertension [11,[13][14][15][16][17][18][19][20]. However, the association between BMI and DR is inconsistent.…”