Clinical features of slowly progressive type 1 (insulin-dependent) diabetes mellitus: a comparative study based on degree of obesity at diagnosis of diabetes

Clinical features among adult-onset type 1 diabetes, distribution of subtypes, and differences in probable and definite slowly progressive insulin-dependent diabetes mellitus: A single hospital-based study over a 13-year period

AIMS

In Japan, type 1 diabetes (T1D) is classified into three subtypes based on its onset patterns; however, the proportion of each subtype remains unexplored. To elucidate the heterogeneity in adult-onset type 1 diabetes, we compared the frequencies of subtypes and clinical features by age at onset.

MATERIALS AND METHODS

This cross-sectional, observational, single-institution study included 482 individuals (161 male) with T1D. The clinical and laboratory data, including glutamic acid decarboxylase autoantibodies, were extracted from the medical records.

RESULTS

The number of adults who developed T1D decreased with age. Among all patients, 62% (n = 299) had acute-onset T1D, 27% (n = 131) had slowly progressive T1D (SPIDDM), and 11% (n = 52) had fulminant T1D. The proportion of patients with fulminant T1D was approximately equivalent in all age groups; however, the percentage of patients with acute-onset T1D decreased from 78% in the 20-29 age group to 27% in the 70-79 age group. The proportion of patients with SPIDDM significantly increased with age, ranging from 16% in the 20-29 age group to 60% in the 70-79 age group. Among patients with SPIDDM, the prevalence of definite SPIDDM was 89%, and this prevalence did not differ based on the age at onset. Body mass index and C-peptide levels among patients with probable SPIDDM were significantly higher than those among patients with definite SPIDDM.

CONCLUSIONS

The proportion of adult-onset T1D subtypes differed according to the age at onset. In adult-onset T1D, some etiological differences may be based on age at onset.

Glutamic Acid Decarboxylase Autoantibody-negative Slowly Progressive Type 1 Diabetes Mellitus: A Case Report and Literature Review

A 59-year-old non-obese Japanese woman developed diabetes mellitus with a negative glutamic acid decarboxylase autoantibody (GADA) test result. Her hyperglycemia was initially well controlled by oral hypoglycemic agents; however, despite continued treatment the hyperglycemia gradually worsened. As she had endogenous insulin deficiency and tested positive for insulin autoantibody (IAA), insulin therapy was initiated. Few studies have investigated GADA-negative patients with slowly progressive type 1 diabetes mellitus (SPT1D). Our IAA-positive SPT1D patient progressed from the clinical onset of diabetes mellitus to starting insulin therapy relatively quickly (1.5 years), similarly to other previously reported non-obese patients with GADA-positive SPT1D.

Relationship between HLA haplotype and BMI change in Japanese slowly progressive type 1 diabetes patients

We investigated the association between susceptible HLA and BMI change rate from diagnosis of diabetes to diagnosis of slowly progressive type 1 diabetes in Japanese diabetic patients. Subjects with the HLA DRB1*04:05-DQB1*04:01 haplotype were more likely to show weight loss than those without. This HLA haplotype might affect weight loss.