In 63 adults undergoing partial pancreatectomy, this study compared in vivo β cell function (OGTT with model-based indices) to ex vivo islet secretory capacity (stimulation index at 16.7 mmol/L glucose, SI16.7) in people with and without T2D.
SI16.7 was reduced in T2D islets but showed wide, overlapping variability across groups. In non-diabetic individuals, no significant associations were found between SI16.7 and OGTT-derived indices. In T2D, SI16.7 correlated positively with glucose-driven insulin secretion measures and inversely with potentiation; a composite intrinsic β cell competence index remained independently linked to SI16.7 in multivariable analysis.
Small sample size (n=63) limits statistical power and generalizability. The surgical cohort (partial pancreatectomy) may not represent the broader T2D population. Cross-sectional design precludes causal inference.
Ex vivo islet testing most closely mirrors in vivo insulin secretion specifically in people with T2D, not in non-diabetic individuals. Combined in vivo–ex vivo β cell phenotyping may help functionally stratify T2D patients, though clinical workflows for this remain to be established.
Explore related topics
