Fig. 5: Validation on independent cohort and translation to at-home CGM testing.

a, Study design of the validation cohort and at-home OGTT test via CGM to predict muscle IR and β-cell function. Participants underwent gold-standard testing at the research unit for insulin resistance (SSPG test) and B-cell function (16-point OGTT with C-peptide deconvolution adjusted for SSPG and expressed as DI) as described, as well as two OGTTs administered at home under standardized conditions during which glucose patterns were captured by a CGM within a single 10-day session (Dexcom G6 pro). b, CGM glucose curves between IR (red) and IS (green) during an OGTT, with the thicker line representing the mean curve. c, Examples of four participants, each with four glucose curves; two curves from OGTT at clinical setting via venous sampling and CGM, and two curves from at-home OGTT via CGM. Participants S28 and S93 are IS (SSPG < 120 mg dl⁻¹), and participants S32 and S103 are IR (SSPG > 120 mg dl⁻¹). The black vertical dashed line represents the 120-min timepoint when the glucose level was measured for clinical diagnosis of diabetes. A glucose value above 200 mg dl⁻¹ (red dashed line) represents a diabetes status, glucose value below 140 mg dl⁻¹ (orange dashed line) a normoglycaemic status, and glucose value between 140–200 mg dl⁻¹ a prediabetes status. d, Correlations among glucose time series measured via different OGTT settings (clinical settings vs at-home, plasma vs interstitial via CGM, and reproducibility of 2 at-home OGTT via CGM). Each point represents the correlation between two glucose series of the same person. High positive correlations indicate that time-series patterns are preserved among test settings. The line inside each box represents the median Pearson correlation coefficient for each OGTT setting. The lower and upper edges of the box correspond to the 25th (Q1) and the 75th (Q3) percentiles of the data, respectively. e, Muscle IR and β-cell function prediction performance using plasma glucose series from the independent validation cohort during an OGTT at CTRU. f, Muscle IR and β-cell function prediction performance on CGM glucose series from the independent validation cohort during an at-home OGTT. g, Muscle IR and β-cell function prediction performance using cross-validation on CGM glucose series from the at-home cohort during an OGTT at home.