Definition: Insulin analogues are genetically engineered or chemically modified forms of human insulin designed to alter their pharmacokinetic profiles (onset, peak, duration of action) for better glycemic control.
- Key Types and Modifications:
- Rapid-acting analogues (e.g., insulin lispro, aspart, glulisine):
- Mechanism: Reversal of proline and lysine residues (lispro) or substitution of aspartic acid (aspart) to accelerate absorption.
- Rationale: Faster onset (~15–30 mins) and shorter duration (~3–5 hours) for postprandial glucose control.
- Long-acting analogues (e.g., glargine, detemir, degludec):
- Mechanism: Modifications to delay absorption (e.g., glargine’s pH-dependent solubility, detemir’s fatty acid chain binding).
- Rationale: Prolonged action (~20–24+ hours) for basal insulin coverage.
- Clinical Use:
- Gestational diabetes: Limited evidence (Singh et al., 2009), but rapid-acting analogues may be considered for postprandial control.
- Insulin resistance: Concentrated preparations (e.g., U-500) for high-dose requirements.
- Guidelines: ADA/EASD recommend analogues for flexibility in dosing, but cost and access remain barriers.