Basic Research
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. May 21, 2005; 11(19): 2900-2905
Published online May 21, 2005. doi: 10.3748/wjg.v11.i19.2900
Six-year follow-up of pancreatic β cell function in adults with latent autoimmune diabetes
Lin Yang, Zhi-Guang Zhou, Gan Huang, Ling-Li Ouyang, Xia Li, Xiang Yan
Lin Yang, Zhi-Guang Zhou, Gan Huang, Xia Li, Xiang Yan, Institute of Metabolism and Endocrinology, the Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
Ling-Li Ouyang, the First Affiliated Hospital, Guangxi Medical University, Nanning 530021, Guangxi Province, China
Lin Yang, Institute of Metabolism and Endocrinology, the Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China
Author contributions: All authors contributed equally to the work.
Supported by the National Natural Science Foundation of China, No. 39370343, the National Ministry of Health Youth Talents Foundation, No. Q9420, and the Hunan Health Bureau Key Scientific Funds, No. 9736, 2001-Z04
Correspondence to: Dr. Zhi-Guang Zhou, Institute of Metabolism and Endocrinology, the Second Xiangya Hospital, Central South University, Changsha 410011, Hunan Province, China. zhouzg@hotmail.com
Telephone: +86-731-5550254 Fax: +86-731-5533525
Received: June 24, 2004
Revised: June 25, 2004
Accepted: July 15, 2004
Published online: May 21, 2005
Abstract

AIM: To investigate the characteristics of the progression of islet β cell function in Chinese latent autoimmune diabetes in adult (LADA) patients with glutamic acid decarboxylase antibody (GAD-Ab) positivity, and to explore the prognostic factors for β cell function.

METHODS: Forty-five LADA patients with GAD-Ab positivity screened from phenotypic type 2 diabetic (T2DM) patients and 45 T2DM patients without GAD-Ab matched as controls were followed-up every 6 mo. Sixteen patients in LADA1 and T2DM1 groups respectively have been followed-up for 6 years, while 29 patients in LADA2 and T2DM2 groups respectively for only 1.5 years. GAD-Ab was determined by radioligand assay, and C-peptides (CP) by radioimmune assay.

RESULTS: The percentage of patients whose fasting CP (FCP) decreased more than 50% compared with the baseline reached to 25.0% at 1.5th year in LADA1 group, and FCP level decreased (395.8±71.5 vs 572.8±72.3 pmol/L, P<0.05) at 2.5th year and continuously went down to the end of follow-up. No significant changes of the above parameters were found in T2DM1 group. The average decreased percentages of FCP per year in LADA and T2DM patients were 15.8% (4.0-91.0%) and 5.2% (-3.5 to 35.5%, P = 0.000) respectively. The index of GAD-Ab was negatively correlated with the FCP in LADA patients (rs = -0.483, P = 0.000). The decreased percentage of FCP per year in LADA patients were correlated with GAD-Ab index, body mass index (BMI) and age at onset (rs = 0.408, -0.301 and -0.523 respectively, P<0.05). Moreover, GAD-Ab was the only risk factor for predicting β cell failure in LADA patients (B = 1.455, EXP (B) = 4.283, P = 0.023).

CONCLUSION: The decreasing rate of islet β cell function in LADA, being highly heterogeneous, is three times that of T2DM patients. The titer of GAD-Ab is an important predictor for the progression of islet β cell function, and age at onset and BMI could also act as the predictors.

Keywords: Latent autoimmune diabetes in adults; Type 2 diabetes; Islet β cell function; Glutamic acid decarboxylase antibody