Variable/Parameter | Description |

$G\left(t\right)$ | Blood glucose concentration at time t |

$I\left(t\right)$ | Blood insulin concentration at time t |

$\beta \left(t\right)$ | Beta cell mass at time t |

${R}_{0}$ | The net rate of glucose production at zero glucose level |

${E}_{GO}$ | Total glucose effectiveness at zero insulin |

${S}_{I}$ | Total insulin sensitivity |

$\sigma $ | Maximum rate of insulin secretion |

$\alpha $ | Inflection point of sigmoidal function |

K | Insulin clearance rate for muscles, liver and kidney |

${d}_{0}$ | Beta cell natural death rate |

${r}_{1}$ and ${r}_{2}$ | Constant beta cell glucose tolerance ranges |

$\rho $ | Epinephrine effectiveness in suppressing insulin secretion |

${G}_{e}$ | Amount of glucose increase due to epinephrine secretion |