A 48-year-old woman from urban Delhi attends a screening camp. She is asymptomatic. Her BMI is 26 kg/m², waist circumference 92 cm, blood pressure 132/85 mmHg. Fasting blood glucose is 118 mg/dL, 2-hour post-glucose load glucose is 168 mg/dL. She has no family history of diabetes. Based on current epidemiological data and diagnostic criteria, which category best describes her glucose tolerance status and what is her estimated 5-year diabetes risk in the Indian population?

Explanation

## Glucose Tolerance Categories and Diabetes Risk Stratification ### Diagnostic Classification **Key Point:** This patient meets criteria for **Impaired Glucose Tolerance (IGT)**, not IFG, based on the 2-hour post-glucose load value. | Category | Fasting Glucose (mg/dL) | 2-Hour Post-Glucose (mg/dL) | HbA1c (%) | |----------|------------------------|-----------------------------|----------| | **Normal** | < 100 | < 140 | < 5.7 | | **IFG** | 100–125 | < 140 | 5.7–6.4 | | **IGT** | < 126 | 140–199 | 5.7–6.4 | | **Type 2 DM** | ≥ 126 | ≥ 200 | ≥ 6.5 | **Clinical Pearl:** This patient has: - Fasting glucose 118 mg/dL → **IFG range** (100–125) - 2-hour glucose 168 mg/dL → **IGT range** (140–199) - **When both IFG and IGT are present, IGT is the dominant diagnosis and carries higher diabetes risk.** ### 5-Year Diabetes Risk in Indian Populations **High-Yield:** The **Indian Diabetes Prevention Programme (IDPP)** and subsequent epidemiological studies show: | Glucose Tolerance Category | 5-Year Diabetes Incidence (%) | Notes | |----------------------------|-------------------------------|-------| | **Normal glucose tolerance** | 2–5 | Very low risk | | **IFG alone** | 10–15 | Moderate risk | | **IGT alone** | 20–30 | **Highest risk** | | **IFG + IGT** | 25–35 | Highest risk category | | **Type 2 DM** | 100 | Already diabetic | **IGT is a stronger predictor of future diabetes than IFG** in most populations, including Indians. This patient's 2-hour glucose of 168 mg/dL places her in the IGT category with 20–30% risk of developing diabetes within 5 years without intervention. ### Additional Risk Factors in This Patient **Metabolic Syndrome Features Present:** - Waist circumference 92 cm (≥ 80 cm in women is abnormal) - Blood pressure 132/85 mmHg (elevated) - Glucose intolerance (IGT) These compound her diabetes risk. However, the **primary classification is IGT**, which carries the stated 20–30% 5-year risk. **Mnemonic — OGTT Interpretation (2-hour glucose):** - **< 140:** Normal - **140–199:** IGT (Impaired Glucose Tolerance) - **≥ 200:** Diabetes [cite:Park 26e Ch 9; WHO 2019 Guidelines on Diabetes]