Analysis Of Clinical Features Of GAD-Ab Positive Patients With Newly Diagnosed Diabetes Mellitus

Objective To investigate the clinical characteristics of GAD-Ab positive patients with primary diabetes mellitus. At the same time, to explore the clinical characteristics of latent autoimmune diabetes in adults in order to improve the level of diagnosis and treatment.Methods 152 cases of inpatients and outpatients with primary diabetes mellitus in our hospital were collected into measurement of glutamic acid decarboxylase antibody(GAD-Ab) by radioligand assay.The patients were asked about medical history and recorded the general information include name, sex, age, height, weight, waistline, hipline, history of hypertension, history of hyperlipidemia, family history of diabetes, history of insulin treatment,also calculated the index weight(BMI)and waist-hip ratio(WHR).All of the patients were measured systolic blood pressure,diastolic blood pressure,fasting plasma glucose, 2-hour post-meal blood glucose, fasting C peptide, 2-hour post-meal C peptide, glycosylated hemoglobin,total cholesterol,triglyceride,high density lipo-protein cholesterol and low density lipoprotein cholesterol. Analyzed the positive detection rate of GAD-Ab and compared the clinical features of GAD-Ab positive and negative patients. Then according to the consensus of CDS2012 about LADA, 152 patients were divided into LADA group, type 1 diabetes mellitus group and type 2 diabetes mellitus group, and analyzed the difference of clinical features between the three groups.Results(1)The positive rate of GAD-Ab was 9.2%(14/152) in 152 patients with primary diabetes mellitus. GAD-Ab positive patients had lower body mass index, systolic blood pressure, the level of serum C peptide and triglyceride than GAD-Ab negative patients,and the difference was statistically significant(P<0.05).(2)GAD-Ab positive rates of patients with primary diabetes were significantly different in distrinct range of BMI and C peptide levels(P<0.01); BMI, fasting C peptide and 2-hour post-meal C peptide were negatively correlated with the positive rate of GAD-Ab(P<0.05).(3)152 patients were further divided into 8 patients with latent autoimmune diabetes in adults(5.3%), 8 patients with type 1 diabetes(5.3%), 136 patients with type 2diabetes(89.4%). Patients with age, BMI, diastolic blood pressure,serum C peptide and cholesterol,triglyceride,low density lipoprotein cholesterol in type 1 diabetes mellitus group were significantly lower than LADA and type 2 diabetic patients(P<0.05), while the level of 2-hour post-meal blood glucose were higher than LADA and type 2 diabetes mellitus(P<0.05).(4)There were no significant difference between Primary LADA and type 2 diabetes mellitus patients in gender, age, body mass index, waist to hip ratio, history of hypertension, history of hyperlipidemia, family history of diabetes, blood glucose and serum C peptide level, total cholesterol, triglyceride,high density lipoprotein cholesterol(P > 0.05),but low density lipoprotein were higher than type 2 diabetes group(P <0.05).Conclusion(1)The positive detection rate of GAD-Ab had a big difference around the world, but the positive rate of GAD-Ab was generally higher in the newly diagnosed diabetic patients with low body mass index and the serum C peptide level;(2)Currently, the body mass index and C peptide level of the primary LADA patients were not lower than type 2 diabetes.Therefore, it is recommended that the newly diagnosed diabetic patients routinely combined screen for islet autoimmune antibody in order to improve the sensitivity of early detection and diagnosis of LADA and reduce the rate of missed diagnosis.