Double diabetes in Saudi Arabia: A new entity or an underestimated condition

AIM To determine the clinical and biological characteristics of double diabetes (DD) among young people in Saudi Arabia. METHODS This was a retrospective descriptive chart review study including 312 young newly diagnosed diabetic patients (aged 12-20 years), whom were admitted over a five year period (January 2009 to December 2013). Family history of diabetes mellitus (DM) (first degree), physical body mass index (BMI), acanthosis nigricans, history of auto-immune disease and laboratory information for glycosylated hemoglobin, basal C peptide level and diabetes autoantibody response (anti-GAD, anti-IA2 and anti-ICA) were collected from medical report. A mean follow-up of 3 years for these patients was performed. RESULTS Patients were categorized into 4 groups, based on the autoantibody response (Ab+ or Ab-) and C-peptide secretion (β+ for fasting level 0.4-2.1 ng/mL and β- if < 0.4 ng/mL). Group1 (type 1a): Ab+ β- (21%), group 2 (type 1b): Ab- β- (9%), group 3 (DD): Ab+ β+ (31%) and group 4 (classic type 2 DM): Ab- β+ (39%). The mean age of the DD patients in our study was 15.1 ± 6.4 years. A total of 41% of the study population presented with diabetic ketoacidosis and 61% of the study population presented with positive family history of DM. The mean BMI was 26.8 kg/m2 with 64% of overweight or obese patients. Ninety two percent of the patients were started on insulin at the time of diagnosis. During a mean follow-up of 3 years, only 32% of the patients with DD required insulin and 78% were on metformin alone or with insulin. CONCLUSION Our findings enable us to arrive at the conclusion that almost one-third of the young Saudi diabetic patients reveal atypical forms of DM (double diabetes) expressing features resulting from both T1D and T2D.