Diagnostic Evaluations for Diabetic Patients

Diagnostic Confirmation and Monitoring

Fasting blood glucose should be measured as the first-line test for diabetes diagnosis, with values ≥1.26 g/L (7.0 mmol/L) on two occasions confirming diabetes 1
HbA1c measurement is essential for diagnosing (≥6.5%) and monitoring long-term glycemic control, as recommended by the American Diabetes Association 2
Oral glucose tolerance test (OGTT) may be performed when needed, with plasma blood glucose ≥2 g/L (11.1 mmol/L) at 2 hours indicating diabetes, according to the American College of Endocrinology 1

Annual urine albumin excretion test should be performed in all type 2 diabetic patients starting at diagnosis and in type 1 diabetic patients with diabetes duration of ≥5 years, as recommended by the American Diabetes Association 3, 4
Serum creatinine and estimated GFR (eGFR) should be measured to assess kidney function, with a strength of evidence level of A, as recommended by the National Kidney Foundation 3

Initial dilated and comprehensive eye examination by an ophthalmologist or optometrist should be performed within 5 years after diagnosis for type 1 diabetes and shortly after diagnosis for type 2 diabetes, as recommended by the American Academy of Ophthalmology 5, 4
Subsequent examinations should be repeated annually, with less frequent exams (every 2-3 years) considered following normal eye exams, based on a moderate level of evidence 5, 4

Annual comprehensive foot examination to identify risk factors for ulcers and amputations, including inspection of feet, assessment of foot pulses, testing for loss of protective sensation, and testing at least one of the following: vibration, pinprick sensation, ankle reflexes, or vibration perception threshold, as recommended by the American Diabetes Association 5, 4

Lipid profile including LDL cholesterol, HDL cholesterol, and triglycerides should be measured, with a strength of evidence level of A, as recommended by the American College of Cardiology 6
Blood pressure measurement should be performed to assess hypertension status, with a high level of evidence, as recommended by the American Heart Association 3
Cardiovascular risk assessment should be performed to determine need for aspirin therapy and statin therapy, based on a moderate level of evidence, as recommended by the American Diabetes Association 5, 6

Screening for distal symmetric polyneuropathy should start at diagnosis of type 2 diabetes and 5 years after diagnosis of type 1 diabetes, as recommended by the American Academy of Neurology 4
Smoking status assessment should be performed, as smoking cessation counseling should be a routine component of diabetes care, with a high level of evidence, as recommended by the American Lung Association 5, 4

For patients presenting with previously undiagnosed dysglycemia, investigations should determine whether the condition corresponds to pre-existing dysglycemia or stress hyperglycemia, based on a low level of evidence 1
In patients with type 1 diabetes, consider evaluating for autoimmune conditions, as recommended by the American Autoimmune Related Diseases Association 2