Table 3. Proposed glipizide and metformin challenge endpoints.
| Glipizide Challenge | Metformin Challenge |
|---|---|
| Glucose-based | Glucose-based |
| Glucose trough | Δ fasting glucose Visit 1 and Visit 2 |
| Glucose trough adjusted for baseline glucose * | Fasting glucose at Visit 2 adjusted for fasting glucose at Visit 1 * |
| Δ (glucose 0 min to trough) | Δ fasting glucose Visit 1 and Visit 2 adjusted for BMI |
| Δ (glucose 0 to 90 min) | Fasting glucose at Visit 2 adjusted for baseline glucose at Visit 1 and BMI |
| Glucose at 120 min adjusted for baseline glucose | |
| Δ (glucose 0 to 120 min) | |
| Area over the glucose curve from 0 to 120 min | |
| Time to glucose trough * | |
| Time to glucose trough adjusted for baseline glucose * | |
| Δ (glucose 0 min to trough)/time to trough | |
| Insulin-based | Insulin-based |
| Insulin peak | Δ fasting insulin Visit 1 and Visit 2 |
| Insulin peak adjusted for baseline insulin * | Fasting insulin at Visit 2 adjusted for fasting insulin at Visit 1 |
| Insulin at 60 min adjusted for baseline insulin | Δ fasting insulin Visit 1 and Visit 2 adjusted for BMI |
| Δ (insulin 0 min to peak insulin) | Fasting insulin at Visit 2 adjusted for fasting insulin at Visit 1 and BMI |
| Δ (insulin 0 to 60 min) | |
| Area under the insulin curve from 0 to 240 min | |
| Time to insulin peak | |
| Δ (insulin 0 min to peak insulin) / time to peak insulin | |
| Recovery period | HOMA-IR based |
| Δ (glucose 120 to 240 min) | Δ HOMA-IR Visit 1 and Visit 2 |
| Δ (glucose trough to 240 min) | HOMA-IR at visit 2 adjusted for HOMA-IR at Visit 1 |
| Δ (glucose trough to 240 min) /time from trough to 240 min * | Δ HOMA-IR Visit 1 and Visit 2 adjusted for BMIHOMA-IR at Visit 2 adjusted for HOMA-IR at Visit 1 and BMI |
Δ: change
* Selected endpoints
Δ: change
BMI: body mass index; HOMA-IR: homeostatic model assessment of insulin resistance.