In this paper, the islet autoimmunity status and relation to clinical characteristics, beta cell function and cardio-metabolic risk factors in young-onset Asian diabetic patients are evaluated at baseline. The study population consisted of 912 patients (from China, India, Malaysia and Singapore) with age 12-40 years and diabetes duration <12 months. Autoantibodies to glutamic acid decarboxylase (GADA) and tyrosine phosphatase (IA-2A), beta cell function and cardio-metabolic risk parameters were assessed. Among our young patient cohort, 105 (11.5%) patients were GADA and/or IA-2A positives (Ab +ve). Ab +ve patients were younger, leaner, had more severe hyperglycaemia and lower beta cell function. The frequency of metabolic syndrome was significantly lower in Ab +ve patients (27%) compared to Ab -ve patients (54%). However, a substantial proportion of patients in both groups of patients had atherogenic dyslipidaemia, hypertension and albuminuria (micro or macro). In our study cohort, only one in 10 Asian youth with new-onset diabetes had evidence of islet autoimmunity. At least 60% of Ab +ve and 50% of Ab -ve patients demonstrated classical features of type 1 and type 2 diabetes respectively. Regardless of autoimmunity status, the cardio-metabolic risk factors, in particular atherogenic dyslipidaemia, hypertension and albuminuria were common in our patients with young-onset diabetes.
Backgrounds and aims: The Asian Young Diabetes (ASDIAB) project is a five-year prospective study on the clinical and immunological characterisation of diabetes in newly diagnosed young Asians. This paper aims at evaluating the aetiological classification of diabetes in these patients based on presence/absence of islet autoantibodies and beta cell function at disease presentation and one year.
Materials and methods: A total of 919 patients (from Beijing, Shanghai, Hong Kong, India, Malaysia and Singapore) with age at diagnosis 12-40 years and diabetes duration <12 months were recruited between 1997 and 1999. Complete information on autoantibodies to glutamic acid decarboxylase (GAD) and IA-2 and fasting C-peptide at baseline and 1 year were available in 633 patients. Antibody positivity (Ab+) was defined by presence of GADab and/or IA-2 abo Poor beta-cell function was defined with fasting C-peptide <0.3nM at one year. TlDM was identified in patients Ab+ at diagnosis (irregardless of p cell function status) and in those Ab- at diagnosis and I-year, but demonstrated poor beta-cell function at I-year. Patients who were Ab- at diagnosis and I-year but had good beta cell function (fasting C-peptide >=0.3nM) at I-year were classified as having type 2 diabetes (T2DM).
Results: 139 patients (22%) were classified as having T1DM. Of these, 90 were Ab+ and 49 were Ab- and had poor beta cell function. The remainder 494 patients (78%) were classified as having T2DM. The ethnic distribution of T1DM patients (73% Chinese, 16% Indians and 11 % Malays) was similar to the T2DM. Compared to T2DM, T1DM patients were significantly younger at diagnosis (mean age 28.0 vs 32.9 yrs), leaner (mean BMI 21.5 kg/m' vs 25.9 kg/m' at diagnosis, 22.0 kg/m2 vs 26.1 kg/m2 at 1 year), and had significantly higher HbA1 , (11.8% vs 9.7% at diagnosis; 8.9% vs 8.0% at 1 year) . Median fasting C-peptides were significantly lower in T1DM than T2DM patients (0.2 vs 0.7 nM at diagnosis; 0.2 vs 0.8 nM at 1 year). T2DM were more insulin resistant than T1DM patients as assessed by HOMA index (median 5.8 vs 4.4 at diagnosis, 4.9 vs 3.4 at 1 year).
Conclusions: In Asians with young onset diabetes, assessment at diagnosis and one year for islet autoantibodies (GADab and lor IA-2Aab), together with estimation of p-cell function with fasting serum C-peptide levels, were useful for classifying patients as having T1DM and T2DM .
Grant from Novo Nordisk Asia Pacific, Singapore
40th EASD Annual Meeting of the European Association for the Study of Diabetes : Munich, Germany, 5-9 September 2004
AIM: To describe the clinical, biochemical and immunological characteristics of young-onset diabetes in Asia.
METHODS: Clinical, biochemical and immunological variables were assessed in 919 newly diagnosed (duration less than 12 months) young onset Asian diabetic patients aged between 12 and 40 years. The subjects constituted 57% Chinese, 29% Indians and 14% Malays, recruited from diabetes centres in China, Hong Kong, India, Malaysia and Singapore.
RESULTS: The mean age (+/- sd) was 31.6 +/- 7.2 years, with the majority (66%) in the 31-40 years age group. Mean body mass index (BMI) (+/- sd) was 25.3 +/- 5.0 kg/m2 with 47% exceeding the suggested Asian cut-off point for obesity (BMI > or = 25). Ethnic difference in clinical characteristics included BMI, blood pressure, mode of treatment and degree of insulin resistance. Most patients had a clinical presentation of Type 2 diabetes. About 10% had a classical combination of ketotic presentation, presence of autoimmune-markers and documented insulin deficiency indicative of Type 1 diabetes. Forty-eight percent were receiving oral hypoglycaemic agents (OHAs) while 31% were on diet only, 18% were receiving insulin and 2% were on a combination of insulin and OHA.
CONCLUSION: Young onset diabetes patients in Asia represent a heterogeneous group in terms of their clinical and biochemical characteristics and classical Type 1 diabetes is relatively uncommon. The 5-year follow up study will determine the progress of these patients and help to clarify the natural history.