. 2016 Dec 8;60(3):432–441. doi: 10.1007/s00125-016-4165-3

Table 1.

OGTT-based indices of BCF

BCF index	Literature reference	Calculation
Fasting indices
HOMA-B1 (%)	[5]	(20 × I₀)/(G₀ - 3.5)
HOMA-B2 (%)	[32]	Web-based calculator using the HOMA2 model [33]
Insulin:glucose ratio t₀	[34]	I₀/G₀
C-peptide:glucose ratio t₀	[35]	CP₀/G₀
Early-phase indices
Insulin ratio t₃₀	[36]	I₃₀/I₀
C-peptide ratio t₃₀	[36]	CP₃₀/CP₀
Insulinogenic index t₃₀	[35]	(I₃₀ - I₀)/(G₃₀ - G₀)
Modified insulinogenic index t₃₀	[37]	(I₃₀ - I₀)/(G₃₀)
C-peptidogenic index t₃₀	[35]	(CP₃₀ - CP₀)/(G₃₀ - G₀)
CIR₃₀ × 10⁻²	[38]	I₃₀/[G₃₀ × (G₃₀ - 3.89)]
Stumvoll early-phase × 10⁻²	[39]	1283 + (1.829 × I₃₀) - (138.7 × G₃₀) + (3.772 × I₀)
BIGTT-AIR_0.30.120 × 10⁻²	[40]	Exp[8.20 + (0.00178 × I₀) + (0.00168 × I₃₀ ) - (0.000383 × I₁₂₀) - (0.314 × G₀) - (0.109 × G₃₀) + (0.0781 × G₁₂₀) + (0.180 × sex) - (0.032 × BMI)]
BIGTT-AIR_0.60.120 × 10⁻²	[40]	Exp[8.19 + (0.00339 × I₀) + (0.00152 × I₆₀) - (0.000959 × I₁₂₀) - (0.389 × G₀) - (0.142 × G₆₀) + (0.164 × G₁₂₀) + (0.256 × sex) + (0.038 × BMI)]
Late-phase indices
Stumvoll second phase	[39]	287 + (0.4164 × I₃₀) - (26.07 × G₃₀) + (0.9226 × I₀)
Insulin ratio t₁₂₀	[36]	I₁₂₀/I₀
C-peptide ratio t₁₂₀	[36]	CP₁₂₀/CP₀
Insulinogenic index t₁₂₀	[35]	(I₁₂₀ - I₀)/(G₁₂₀ - G₀)
C-peptidogenic index t₁₂₀	[35]	(CP₁₂₀ - CP₀)/(G₁₂₀ - G₀)
CIR₁₂₀ × 10⁻²	[38]	I₁₂₀/(G₁₂₀ × (G₁₂₀ - 3.89))
Overall indices
AUC insulin:glucose ratio	[41]	[(30 - 0) × (I₀ + I₃₀)/2] + [(60 - 30) × ( I₃₀ + I₆₀) / 2] + [(120 - 60) × ( I₆₀ × I₁₂₀)/2)] / [(30 - 0) × (G₀ + G₃₀) / 2] + [(60 - 30) × ( G₃₀ + G₆₀) / 2] + [(120 - 60) × ( G₆₀ × G₁₂₀) / 2]
AUC C-peptide:glucose ratio	[41]	[(30 - 0) × (CP₀ + CP₃₀) /2] + [(60 - 30) × (CP₃₀ + CP₆₀) / 2] + [(120 - 60) × (CP₆₀ × CP₁₂₀) /2)] / [(30 - 0) × (G₀ + G₃₀) / 2] + [(60 - 30) × (G₃₀ + G₆₀) / 2) + ((120 - 60) × (G₆₀ × G₁₂₀) / 2)]

BIGTT-AIR, beta cell function, insulin sensitivity and glucose tolerance testing; t, time point during OGTT, min in subscript