OBJECTIVE—Latent autoimmune diabetes in adults (LADA) is often considered a slowly progressing subtype of type 1 diabetes, although the clinical picture more resembles type 2 diabetes. One way to improve classification is to study whether LADA shares genetic features with type 1 and/or type 2 diabetes. RESEARCH DESIGN AND METHODS—To accomplish this, we studied whether LADA shares variation in the HLA locus or INS VNTR and PTPN22 genes with type 1 diabetes or the TCF7L2 gene with type 2 diabetes in 361 LADA, 718 type 1 diabetic, and 1,676 type 2 diabetic patients, as well as 1,704 healthy control subjects from Sweden and Finland. RESULTS—LADA subjects showed, compared with type 2 diabetic patients, increased frequency of risk for the HLA-DQB1 *0201/*0302 genotype (27 vs. 6.9%; P < 1 × 10−6), with similar frequency as with type 1 diabetes (36%). In addition, LADA subjects showed higher frequencies of protective HLA-DQB1 *0602(3)/X than type 1 diabetic patients (8.1 vs. 3.2%, P = 0.003). The AA genotype of rs689, referring to the class I allele in the INS VNTR, as well as the CT/TT genotypes of rs2476601 in the PTPN22 gene, were increased both in type 1 diabetic (P = 3 × 10−14 and P = 1 × 10−10, respectively) and LADA (P = 0.001 and P = 0.002) subjects compared with control subjects. Notably, the frequency of the type 2 diabetes–associated CT/TT genotypes of rs7903146 in the TCF7L2 were increased in LADA subjects (52.8%; P = 0.03), to the same extent as in type 2 diabetic subjects (54.1%, P = 3 × 10−7), compared with control subjects (44.8%) and type 1 diabetic subjects (43.3%). CONCLUSIONS—LADA shares genetic features with both type 1 (HLA, INS VNTR, and PTPN22) and type 2 (TCF7L2) diabetes, which justifies considering LADA as an admixture of the two major types of diabetes.

Latent autoimmune diabetes in adults (LADA) is a disorder in which, despite the presence of islet antibodies at diagnosis of diabetes, the progression of autoimmune ␤-cell failure is slow. LADA patients are therefore not insulin requiring, at least during the first 6 months after diagnosis of diabetes. Among patients with phenotypic type 2 diabetes, LADA occurs in 10% of individuals older than 35 years and in 25% below that age. Prospective studies of ␤-cell function show that LADA patients with multiple islet antibodies develop ␤-cell failure within 5 years, whereas those with only GAD antibodies (GADAs) or only islet cell antibodies (ICAs) mostly develop ␤-cell failure after 5 years. Even though it may take up to 12 years until ␤-cell failure occurs in some patients, impairments in the ␤-cell response to intravenous glucose and glucagon can be detected at diagnosis of diabetes. Consequently, LADA is not a latent disease; therefore, autoimmune diabetes in adults with slowly progressive ␤-cell failure might be a more adequate concept. In agreement with proved impaired ␤-cell function at diagnosis of diabetes, insulin is the treatment of choice. Diabetes 54 (Suppl. 2):S68 -S72, 2005

Aims/hypothesis The receptor for AGE (RAGE) is considered to be mainly an intracellular signal-transducer or pro-inflammatory peptide of possible importance for inflammation and autoimmune diseases. Our aim was to study whether the −374 T/A polymorphism in the gene encoding RAGE (AGER) is associated with diabetes type and presence of diabetic complications. Methods The AGER −374 T/A polymorphism was genotyped in 867 type 1 diabetic patients, 2,467 type 2 diabetic patients and 205 non-diabetic control subjects of Scandinavian origin. Results AGER polymorphism was related to different HLA-DQB1 genotypes and the presence of diabetic complications. Type 1 diabetic patients had a higher frequency of the AGER −374 A/A or T/A genotypes than type 2 diabetic patients (51.1 vs 44.9%, p=0.002) and control subjects (51.1 vs 47.6%, p=0.0006). The RAGE −374 T/A polymorphism was associated with HLA-DQB1 genotypes; patients with HLA risk genotypes had a higher frequency of the A/A or T/A genotypes than patients with other HLA-DQB1 genotypes (60.3 vs 40.3%, p<0.000001). In type 1 diabetic patients, the frequency of the A/A or T/A genotypes was higher in patients with diabetic nephropathy than without (61.1 vs 46.8%, p=0.006) and with sightthreatening retinopathy than without (56.1 vs 47.6%, p=0.03). In type 2 diabetic patients with HbA 1c values below the median, the T/T genotype was more frequent in patients with diabetic nephropathy than without (54.3 vs 38.2%, p=0.02). Conclusions/interpretation Our results show an association between the AGER −374 T/A polymorphism and type 1 diabetes. This association was HLA-DQB1-dependent. The polymorphism was associated with diabetic nephropathy in both type 1 and type 2 diabetes, in an HbA 1c -dependent manner in the latter group, and also with sight-threatening retinopathy in type 1 diabetic patients.

Low MNFD may predict progression of neurophysiological dysfunction and links obesity to myelinated nerve fiber loss.

Aims/hypothesis Type 1 diabetes in children is characterised by autoimmune destruction of pancreatic beta cells and the presence of certain risk genotypes. In adults the same situation is often referred to as latent autoimmune diabetes in adults (LADA). We tested whether genetic markers associated with type 1 or type 2 diabetes could help to discriminate between autoimmune and non-autoimmune diabetes in young (15-34 years) and middle-aged (40-59 years) diabetic patients.Methods In 1,642 young and 1,619 middle-aged patients we determined: (1) HLA-DQB1 genotypes; (2) PTPN22 and INS variable-number tandem repeat (VNTR) polymorphisms; (3) two single nucleotide polymorphisms (rs7903146 and rs10885406) in the TCF7L2 gene; (4) glutamic acid decarboxylase (GAD) and IA-2-protein tyrosine phosphatase-like protein (IA-2) antibodies; and (5) fasting plasma C-peptide. Results Frequency of risk genotypes HLA-DQB1 (60% vs 25%, p=9.4×10 −34 ; 45% vs 18%, p=1.4×10 −16 ), PTPN22 CT/TT (34% vs 26%, p=0.0023; 31% vs 23%, p=0.034), INS VNTR class I/I (69% vs 53%, p=1.3×10 −8 ; 69% vs 51%, p=8.5×10 −5 ) and INS VNTR class IIIA/IIIA (75% vs 63%, p= 4.3×10 −6 ; 73% vs 60%, p=0.008) was increased in young and middle-aged GAD antibodies (GADA)-Diabetologia

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