Clinical, biochemical, and immunological characteristics of newly diagnosed nonobese diabetic patients aged 18–45 years in China

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Abstract

Background

The purpose was to characterize the clinical, biochemical, and immunological features of newly diagnosed adult-onset nonobese diabetic patients in China.

Methods

Newly diagnosed diabetic patients aged 18–45 years with body mass index<23 kg/m2 were included. Excluding one mitochondrial diabetes patient, there were 102 diabetic patients enrolled in this study. Clinical and biochemical data were collected and analyzed. Radioimmunoassay was used to detect islet autoantibodies.

Results

Among the 102 study participants, 68.6% had type 1 diabetes (T1DM), 20.6% had type 2 diabetes (T2DM), and 10.8% had latent autoimmune diabetes in adults (LADA). About 92% of the T1DM patients presented hyperglycemic symptoms. The corresponding number in T2DM and LADA patients was 13% and 38%, respectively (P<.01). C-peptide in T2DM patients (1.4±0.7 ng/ml) was significantly higher than that in T1DM (0.4±0.3 ng/ml) and LADA (0.4±0.2 ng/ml) patients (P<.01). The prevalence of glutamic acid decarboxylase antibody (GADA) (64.3%) in T1DM patients was higher than that of insulin autoantibody (17.1%) (P<.05). GADA and islet cell antibody (ICA) combination was positive in 75.7% of T1DM patients.

Conclusion

T1DM patients accounted for majority of the study sample. In addition, the clinical symptoms of T1DM patients were more severe compared with T2DM patients. GADA is the most sensitive autoantibody marker for adult-onset T1DM and LADA. GADA and ICA are the best test combination for adult-onset autoimmune diabetes. Specific types of diabetes should be in mind when diabetes presents itself with special transmission mode or with other extrapancreatic manifestations.

Introduction

Diabetes mellitus affected over 200 million people worldwide in 2003, and the number is projected to be 360 million by 2030 (Wild et al., 2004). In China, diabetes has become epidemic due to lifestyle westernization and physical inactivity.

Type 1 and type 2 diabetes mellitus (T1DM and T2DM) are the two most common forms of diabetes mellitus. In clinical practice, however, we often see patients who exhibit clinical presentations of both T1DM and T2DM. These patients cannot distinctly be allocated to either T1DM or T2DM and thus are referred to be in “a grey area.” Latent autoimmune diabetes in adults (LADA) has been shown to be in this grey area characterized by clinical features between T1DM and T2DM (Groop et al., 2006). The United Kingdom Prospective Diabetes Study showed that LADA accounted for about 10% of all adult-onset T2DM (Turner et al., 1997), and the percentage of autoimmune diabetes is likely higher among those nonobese diabetic patients. In China, there are more lean diabetic patients compared with Western countries. The aim of this study is to characterize the clinical, biochemical, and immunological features of the recent-onset nonobese diabetic patients aged 18–45 years in Peking Union Medical College Hospital from 2007 to 2009.

Section snippets

Study population

One hundred and three newly diagnosed (duration less than 3 months) diabetes patients aged 18–45 years old with body mass index (BMI)<23 kg/m2 were referred to the Department of Endocrinology at Peking Union Medical College Hospital from January 2007 to April 2009. Through careful clinical examination and follow-up, 70 of them were diagnosed as having T1DM, 21 had T2DM, 11 had LADA, and 1 had mitochondrial diabetes. The diagnosis of diabetes was made according to the guidelines of the American

The proportion of various types of diabetes of the study population and their general characteristics

Excluding one mitochondrial diabetes patient, there were 102 diabetic patients enrolled in this study. The percentage of T1DM was 68.6%, that of T2DM was 20.6%, and 11 (10.8%) patients met the diagnosis criteria of LADA. The mean age of onset of T1DM patients was (24.8±6.6 years) younger than that of T2DM (34.8±7.5 years) and LADA (42.2±5.1 years) patients (P<.01). Diabetes family history was more common in T2DM (70.6%) than in T1DM (27.4%) and LADA (28.6%) (P<.01). The mean blood pressure of

Discussion

This study reported the prevalence of autoimmune diabetes in lean adult-onset diabetic patients and characterized their clinical and biochemical profiles as well as autoimmune features. In general, overweight is defined as BMI≥25 kg/m2 in Western populations. However, we used BMI≥23 kg/m2 as a cutoff to define overweight in the study sample because previous studies have indicated that Asians tend to have obesity-related illnesses, e.g., diabetes and cardiovascular diseases, with lower BMI (Wen

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  • Cited by (3)

    1

    Tianjin Metabolic Disease Hospital, Tianjin Medical University, Key Laboratory of Hormone and Development, Ministry of Health, Tianjin 300070, China.

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