Fig. 4: Donor and islet processing traits correlate with islet function.

a, b Heatmaps depicting regression coefficients of each islet processing trait after being incorporated into multivariable regression models for each (a) insulin and (b) glucagon secretion trait. Each model included the following covariates: age, sex, reported race or ethnicity, BMI, HbA1c, and islet isolation center. Pre-shipment culture time and islet transit time were included as additional covariates for all subsequent models, unless noted otherwise. c, d Heatmaps depicting regression coefficients of donor age, BMI, and prediabetes status after being incorporated into multivariable regression models for each (c) insulin and (d) glucagon secretion trait while controlling for the other seven final covariates. Shading represents different regression coefficients. All p-values are based on the two-sided t-tests. Adjusted p-values using the false discovery rate correction are indicated, where *p < 0.05, **p < 0.01, and **p < 0.001, and are reported in Source Data Fig. 4. For associations that are significant prior to adjusting to multiple comparisons, the unadjusted p-value is noted in italics. e, f Tables summarizing the global adjusted P-value when comparing differences by donor sex, reported race or ethnicity, genetic ancestry, and isolation center for each (e) insulin and (f) glucagon secretion trait. The global adjusted p-values for race, genetic ancestry, and isolation center are based on the one-sided F-tests while controlling for the other seven covariates. The p-values for sex are based on the two-sided t-tests while controlling for the other seven covariates. Analyses involving genetic ancestry controlled for all covariates except reported race or ethnicity. n.s. indicates an insignificant global adjusted p-value and unadjusted p-value. For results that were significant prior to adjusting to multiple comparisons, the unadjusted p-value is noted in italics. n = 299 for all analyses except those involving islet purity (n = 269), elevated HbA1c (n = 76 elevated HbA1c, n = 223 normal HbA1c), and genetic ancestry (n = 268). Abbreviations: IEQ islet equivalents; AUC area under the curve; G glucose (mM); IBMX isobutylmethylxanthine (μM); Ad adrenaline (μM); KCl potassium chloride (mM).