Yufei Xiang1, Bingwen Liu1, Chuan Yun1, Pengcheng Zhou2, Xiaojue Li1, Shuoming Luo1, Zhiguo Xie1, Zhihong Che1, Jian Lin1, Lin Yang1, Xia Li1, Gan Huang1, Aimin Xu2, Zhiguang Zhou1. 1. National Clinical Research Center for Metabolic Diseases, Key Laboratory of Diabetes Immunology (Central South University), Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha, China. 2. State Key Laboratory of Pharmaceutical Biotechnology, Department of Medicine, Department of Pharmacology and Pharmacy, University of Hong Kong, Hong Kong, China.
Abstract
AIM: To investigate the frequency, clinical phenotype, inflammatory cytokine levels and genetics of glutamic acid decarboxylase autoantibody (GADA)-positive phenotypic youth-onset type 2 diabetes. MATERIALS AND METHODS: This nationwide, multicentre, cross-sectional study included 5324 newly diagnosed subjects with phenotypic type 2 diabetes aged 15 years or older enrolled in the LADA China study. GADA was screened in 248 subjects with youth-onset type 2 diabetes aged 15-29 years. Subjects who presented as GADA-positive were defined as having latent autoimmune diabetes in youth (LADY). We added subjects with LADY, type 1 diabetes, type 2 diabetes and controls from the Diabetes Center of Central South University, and measured serum concentrations of interleukin-6, lipocalin 2, high-sensitivity C-reactive protein, adiponectin and human leukocyte antigen (HLA) genotyping in subjects with LADY, age- and sex-matched GADA-negative type 2 diabetes, type 1 diabetes and controls. RESULTS: Twenty-nine of the 248 subjects (11.7%) were GADA positive. Compared with subjects with type 2 diabetes, subjects with LADY were less probable to have metabolic syndrome (27.6% vs. 59.4%; p = .001). The fasting C-peptide levels tended to be lower in subjects with LADY than in subjects with type 2 diabetes, but the difference was not statistically significant (LADY vs. type 2 diabetes: 0.21 [0.17-0.64] vs. 0.47 [0.29-0.77] nmol/L; p = .11). The cytokine levels of subjects with LADY were indistinguishable from subjects with type 1 diabetes, but subjects with LADY presented increased adiponectin levels compared with subjects with type 2 diabetes after adjusting for age, sex and body mass index (7.19 [4.05-11.66] vs. 3.42 [2.35-5.74] μg/mL; p < .05). The frequency of total susceptible HLA genotypes (DR3/3, -3/9 and -9/9) in subjects with LADY and type 1 diabetes were similarly higher than controls (LADY and type 1 diabetes vs. controls: 21.4% and 30.8% vs. 2.6%, respectively; p < .001). CONCLUSIONS: A high GADA positivity was observed in youth-onset type 2 diabetes subjects in China. As subjects with LADY had an increased susceptible HLA genetic load and different cytokine levels compared with subjects with type 2 diabetes, differentiating LADY from phenotypic type 2 diabetes subjects is important.
AIM: To investigate the frequency, clinical phenotype, inflammatory cytokine levels and genetics of glutamic acid decarboxylase autoantibody (GADA)-positive phenotypic youth-onset type 2 diabetes. MATERIALS AND METHODS: This nationwide, multicentre, cross-sectional study included 5324 newly diagnosed subjects with phenotypic type 2 diabetes aged 15 years or older enrolled in the LADA China study. GADA was screened in 248 subjects with youth-onset type 2 diabetes aged 15-29 years. Subjects who presented as GADA-positive were defined as having latent autoimmune diabetes in youth (LADY). We added subjects with LADY, type 1 diabetes, type 2 diabetes and controls from the Diabetes Center of Central South University, and measured serum concentrations of interleukin-6, lipocalin 2, high-sensitivity C-reactive protein, adiponectin and human leukocyte antigen (HLA) genotyping in subjects with LADY, age- and sex-matched GADA-negative type 2 diabetes, type 1 diabetes and controls. RESULTS: Twenty-nine of the 248 subjects (11.7%) were GADA positive. Compared with subjects with type 2 diabetes, subjects with LADY were less probable to have metabolic syndrome (27.6% vs. 59.4%; p = .001). The fasting C-peptide levels tended to be lower in subjects with LADY than in subjects with type 2 diabetes, but the difference was not statistically significant (LADY vs. type 2 diabetes: 0.21 [0.17-0.64] vs. 0.47 [0.29-0.77] nmol/L; p = .11). The cytokine levels of subjects with LADY were indistinguishable from subjects with type 1 diabetes, but subjects with LADY presented increased adiponectin levels compared with subjects with type 2 diabetes after adjusting for age, sex and body mass index (7.19 [4.05-11.66] vs. 3.42 [2.35-5.74] μg/mL; p < .05). The frequency of total susceptible HLA genotypes (DR3/3, -3/9 and -9/9) in subjects with LADY and type 1 diabetes were similarly higher than controls (LADY and type 1 diabetes vs. controls: 21.4% and 30.8% vs. 2.6%, respectively; p < .001). CONCLUSIONS: A high GADA positivity was observed in youth-onset type 2 diabetes subjects in China. As subjects with LADY had an increased susceptible HLA genetic load and different cytokine levels compared with subjects with type 2 diabetes, differentiating LADY from phenotypic type 2 diabetes subjects is important.