Background: The development and incidence of microvascular complications of diabetes are strongly related to glycemic control. Epidemiologic studies have shown that one-fifth of all diabetic subjects suffer from more than one micro vascular complication. The complications compromise the quality of life and are also the source of morbidity and mortality. 
Objective: To estimate the incidence of microvascular complications among type 2 diabetics at a tertiary care hospital of Karachi, Pakistan. 
Methodology: This retrospective longitudinal follow-up study assessed the data records of type 2 diabetic subjects who visited the outpatient department of Baqai Institute of Diabetology and Endocrinology from January 2005 to April 2016. Subjects of gestational diabetes, type 1 diabetes and with history of any microvascular complication at first visit, were excluded. Medical records were obtained through electronic database (Health Management System). Incidence rate were estimated by different intervals of duration of diabetes, glycemic control (HbA1c≤7% vs HbA1c>7%) and blood pressure control (≤130/85 mmHg vs >130/85 mmHg). Statistical analyses were conducted using STATA version 14 and SPSS version 20. 
Results: Out of 4633 patients, 2336 (50.4%) were male and 2297(49.6%) were female. At baseline, 3175 (85.9%) of the patients had HbA1c level >7% and 1976(57.2%) were hypertensive, while positive family history of diabetes was found in 2419 (69.4%) patients. 
Incidence rate of microvascular complications was 92.9, 130.2 and 106.2 per 1000 person-years for retinopathy, neuropathy and nephropathy respectively. The incidence rate ratio (IRR) shows that all microvascular complications were significantly high among diabetic patients with duration of diabetes >10 years followed by 5-10 years. 
Incidence of retinopathy and nephropathy was significantly higher in patients who had HbA1c>7% than patients with HbA1c≤7% (p-value<0.05). Similarly, incidence rate of neuropathy and nephropathy was significantly higher in patients with hypertension (IRR of neuropathy=1.22; IRR of nephropathy= 1.223, p-value=0.005) than patients without hypertension.
Conclusion: The incidence of microvascular complications was higher in people with type 2 diabetes, particularly in subjects who had longer duration of diabetes, poor glycemic control and hypertension

Incidence of microvascular complications among patients with type 2 diabetes at a tertiary care hospital