2.9. Statistics and Calculations
INSULIN RESISTANCE, INSULIN SENSITIVITY
For baseline data, normality was assessed visually by histograms and by Shapiro–Wilk test using RStudio (version 2023.06.1). Normally distributed data are presented as mean ± standard deviation (SD) and non-normally distributed data are presented as median (interquartile range (IQR)). Total area under the curve (AUC) and iAUC for glucose and insulin during the OGTT were calculated with GraphPad Prism (Version 9). In order to assess insulin sensitivity, homeostasis model assessment for insulin resistance (HOMA-IR) [Normality was evaluated using quantile–quantile plots of residuals, fitted values versus residuals plots, and histograms of residuals. The RStudio package emmeans was used to obtain estimated marginal means, which will be referred to as mean throughout the article, and to compare means. Normally distributed data are presented as the difference between pre- and post-values with standard error. Not normally distributed data were log-transformed, and they are presented as ratio and confidence intervals, e.g., 1.02 indicates a 2% increase from pre to post, whereas 0.98 indicates a 2% decrease.In cases where blood analyses revealed concentrations below the lower level of detection for the various assays, the values were computed as half of the lower level of detection.