T2D Stands for Type 2 Diabetes
T2D is the abbreviation for Type 2 Diabetes (or Type 2 Diabetes Mellitus), the most common form of diabetes characterized by insulin resistance and progressive impairment of pancreatic insulin secretion. 1
Definition and Pathophysiology
Type 2 diabetes is a metabolic disorder where hyperglycemia develops secondary to insulin resistance accompanied by impaired β-cell function, resulting in inadequate insulin production to compensate for the degree of insulin resistance. 1
- T2D accounts for approximately 91% of all diabetes cases in the United States, making it by far the most prevalent form of the disease 1
- Unlike Type 1 diabetes (T1D), which results from autoimmune destruction of pancreatic β-cells causing absolute insulin deficiency, T2D involves both peripheral insulin resistance and progressive β-cell dysfunction 1
- The condition develops gradually and is often asymptomatic at screening, meaning patients may be discovered to have T2D incidentally during hospitalization with chronic complications already present 1
Clinical Context for Your Patient
In a patient presenting with hyperglycemia, proteinuria, and hematuria, the T2D diagnosis becomes particularly relevant:
- Proteinuria in the context of T2D suggests diabetic kidney disease (DKD), which is most strongly associated with insulin resistance rather than just hyperglycemia alone 2
- Patients with severe insulin-resistant diabetes (SIRD subtype) have the highest risk for diabetic kidney disease and require aggressive management 2
- The presence of both proteinuria and hematuria warrants evaluation for diabetic nephropathy as well as exclusion of other renal pathology 1
Diagnostic Criteria
T2D is diagnosed when any of the following criteria are met (with confirmation on a subsequent day unless classic symptoms are present): 3
- Fasting plasma glucose ≥126 mg/dL (7.0 mmol/L) after at least 8 hours fasting 1, 3
- 2-hour plasma glucose ≥200 mg/dL (11.1 mmol/L) during a 75-gram oral glucose tolerance test 1, 3
- HbA1c ≥6.5% using an NGSP-certified method 3
- Random plasma glucose ≥200 mg/dL (11.1 mmol/L) with classic symptoms of hyperglycemia (polyuria, polydipsia, unexplained weight loss) 1, 3
Key Distinguishing Features from Type 1 Diabetes
- T2D patients typically are overweight or obese (BMI ≥95th percentile in youth), have strong family history, demonstrate substantial residual insulin secretory capacity with normal or elevated C-peptide levels, and lack evidence of diabetic autoimmunity (negative autoantibodies) 1
- T2D patients are more likely to have hypertension and dyslipidemia compared to those with T1D 1
- Physical findings suggesting insulin resistance include acanthosis nigricans and central obesity 4
Common Pitfall to Avoid
Do not assume all diabetes in adults is T2D—in younger patients or those without typical risk factors, consider testing for islet autoantibodies to exclude Type 1 diabetes, as misclassification can lead to inappropriate treatment. 3