Cellular arrangement of delta-cells.

<p><b>A:</b> Probabilities of delta-delta, delta-beta, and delta-alpha cell contacts in non-diabetic subjects (blue; 6886 islets with n = 14). Those were compared with the theoretical estimation for random mixtures of cells (gray) where cellular compositions were the same with the individual islets in non-diabetic subjects (mean ± SEM). B: Comparison between non-diabetic (blue) and T2D (red; 5359 islets with n = 12) subjects. Note that scattered single endocrine cells are excluded in the calculation because contacting cells does not exist for them. The numbers in parentheses represent effective islet diameters (µm) corresponding to the given logarithmic dimensionless islet areas. Student's <i>t</i>-test compared the results between non-diabetic and T2D subjects at each size bin with *P<0.05, **P<0.001, and ***P<0.0001.</p>