The primary objective of this study was to assess beta cell function of recently diagnosed young onset type 2 diabetes mellitus (T2DM) individuals. The secondary objective examined the association between C- peptide with metabolic factors and diabetes complications. A cross-sectional study was conducted for young onset T2DM individuals aged 18-35 years with disease duration not more than 5 years. Plasma basal and stimulated C-peptide was measured before and after intravenous glucagon injection.  Demographic data, medical history and complications were obtained from medical records and clinical assessment. A total of 113 participants with young onset T2DM with mean age of 29 years and median disease duration of 24 months were included in this study. The median (interquartile range) basal and stimulated C-peptide was 619 (655) pmol/L and 1231(1024) pmol/L . Adequate beta cell function was present in 78-86% of the participants based on the basal and stimulated C-peptide levels. Obesity and hypertension were independently associated with higher basal and stimulated C-peptide while diabetic kidney disease was independently associated with higher basal C-peptide. We found most recently diagnosed young onset T2DM have adequate beta cell function. Elevated C-peptide levels associated with obesity, hypertension and diabetic kidney disease suggests insulin resistance as the key driving factor for complications.

The authors have declared no competing interest.

This study was funded by a diabetes and endocrine subspecialty research grant awarded to the primary author , Dr Shamharini Nagaratnam by the Malaysian Endocrine and Metabolic Society (MEMS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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his study was approved by the Medical Research and Ethics Committee (MREC) of Ministry of Health Malaysia (MOH),National Medical Research Registry (NMMR) ID : NMRR-19-1048-47849.

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