Comparison of incidence of micro vascular complications in patients with youth onset type 1 and type 2 diabetes in India (Abstract Number -AD1121)

Background and aim: There is a global deficiency in the literature pertaining to burden of complication in youth onset diabetes with a notable scarcity in the Asian countries. The present study was designed to compare the incidence of micro vascular complications (any form of diabetic retinopathy, neuropathy and nephropathy) among youth onset type 1 and type 2 diabetes patients in India.
Methods: The study was conducted among a sub population of patients with youth onset type 1 and type 2 diabetes enrolled under the Registry of people with diabetes in India with young age at the onset (YDR). The baseline data of YDR patients collected between 1st January 2001 and 31st December 2012 and follow up data collected till 31st December 2014 were used to estimate the incidence of chronic diabetes complications.The final sample comprised of those who were aged >10 years at registration with no evidence of micro vascular complication of interest at baseline and had undergone at least one follow up visit during the above study period. The presence or absence of diabetic retinopathy was confirmed after a dilated fundus examination with direct ophthalmoscope by an experienced physician or ophthalmologist. The diabetic neuropathy status was assessed by clinical examination and monofilament test. Patients were labeled to have diabetic nephropathy if 24 hour urine protein excretion was greater than 500mg or urine albumin excretion was greater than 300mg.
Results: Data of 799 type 1 diabetes patients and 371 type 2 diabetes patients were analysed. The cumulative incidence per 1000 person years of all the three micro vascular complications were significantly higher among patients with type 2 diabetes compared to type 1 diabetes (Table-1). 17.1 % of the type 1 diabetes patients   developed at least one micro vascular complication during the fourteen years of follow up. Among patients with type 2 diabetes, the proportion was much higher with 33.5% of the patients developing at least one micro vascular complication during the follow up. In the multivariable cox regression analysis, the high risk for incidence of micro vascular complications in type 2 diabetes patients was independent of the diabetes duration and clinical characteristics such as obesity, high blood pressure and glycaemic control at the baseline (Table-1).
Conclusion: The study reports a high incidence of micro vascular complications among youth onset diabetes patients in India with an excess among youth onset type 2 diabetes. This is similar to that reported by the SEARCH Registry for youth onset diabetes in the US.

Table-1: Incidence of micro vascular complications among youth onset diabetes
 
  	                                       Incidence per 1000 person years  	Adjusted*  hazard ratio(95% CI)                                  P value
	
Diabetic Retinopathy 			
Type 1 diabetes 	                               25.5 (20.6, 31.6)	                                   Ref	
Type 2 diabetes 	                               60.6 (45.0, 81.7)	                              2.8 (1.8, 4.3)	                                                  <0.0001

Diabetic Neuropathy 			
Type 1 diabetes 	                               10.8 (7.8, 15.0)	                                  Ref	
Type 2 diabetes 	                               48.8 (34.8, 68.2)	                              3.7 (2.0, 7.0)	                                                   <0.0001

Diabetic Nephropathy 			
Type 1 diabetes 	                               9.2 (6.5, 13.0)	                                  Ref	
Type 2 diabetes 	                               22.7 (14.8, 34.8)	                              2.5 (1.2, 5.0)	                                                       0.01

*Adjusted for age, gender, duration of diabetes since diagnosis, obesity, high blood pressure and glycaemic control