Table 1 Insulin sensitivity indices description, reported cut points for normoglycemia, and insulin resistance classification in the present study

HOMA-IR

\(\mathrm{FPI }\times \frac{\mathrm{FPG }}{405}\)

Linear model that evaluates insulin resistance

Reflects the interaction between insulin secretion and hepatic glucose production

Based on fasting glucose and insulin plasma levels. [8, 9, 13]

 < 2–2.5

HOMA-IR increasing values depicts insulin resistance [13] (13)

HOMA-IR was not normally distributed and was logarithmically transformed implementing natural log (Ln) on the equation

Upper quartile (> 1.6) of Ln HOMA-IR (Q₄) was compared to the lower quartiles (< 1.6- Q_1-3)

HOMA-%B

\(360\times \frac{\mathrm{FPI}}{(\mathrm{FPG }-63)}\)

Linear model that evaluates pancreatic beta cell function

Reflects the interaction between insulin secretion and hepatic glucose production

Based on fasting glucose and insulin plasma levels. [8, 9, 13]

 > 100%

Depend on the population

[38, 39]

HOMA-%B decreasing values depicts beta cells dysfunction (13)

HOMA-%B was not normally distributed and was logarithmically transformed implementing natural log (Ln) on the equation

Ln HOMA-%B lower quartile (< 4.5- Q₁) was compared with upper Ln HOMA-%B quartiles (> 4.5- Q_2-4)

MISI

\(\frac{\mathrm{10,000}}{\sqrt{\left(\mathrm{FPG}\times \mathrm{FPI}\right)\times [\mathrm{mean glu x mean ins}]}}\)

Evaluate the total body insulin resistance levels

Based on fasting glucose and insulin plasma levels and OGTT [10]

 > 4.3

MISI decreasing values depicts insulin resistance (IR)

MISI mean glucose plasma levels were calculated using: fasting glucose, 60 and 120 min glucose after an oral administration of 100gr glucose. Mean insulin plasma levels were calculated using fasting insulin and insulin levels at 30, 60 and 120 min after the oral administration of 100gr glucose

MISI was not normally distributed and was logarithmically transformed implementing natural log (Ln) on the equation

Ln MISI lower quartile (< 0.89-Q₁) was compared with upper Ln MISI quartiles (> 0.89-Q_2-4)

QUICKI

\(\frac{1}{\mathrm{Log FPI}+\mathrm{Log FPG}}\)

Equivalent to the HOMA model and considered as log HOMA-IR

Based on fasting glucose and insulin plasma levels

Correlate better than HOMA with SI Clamp [11]

 > 0.38 in non-obese

QUICKI decreasing values depicts insulin resistance. Lower quartile (< 0.3-Q₁) of QUICKI was compared to upper QUICKI quartiles (> 0.3-Q_2-4)

MCAi

\({e}^{\left[2.63-0.28*Ln \mathrm{FPI}-0.31*Ln trig\right]}\)

Provide a simple screening tool for the assessment of insulin resistance in the population. Based on fasting insulin and triglycerides plasma levels (12)

 < 5.8;

 ≤ 0.63 in diabetes [44]

MCAi decreasing values depicts insulin resistance. MCAi lower quartile (< 3.2-Q₁) was compared to upper MCAi quartiles (> 3.2-Q_2-4)