These studies also reported decreased insulin (glucose-stimulated and random circulating) concentrations following STZ treatment, which may be explained in part by reduced [beta]-cell mass, rather than solely impaired p-cell function.
These data suggest that p-cells in low fat-fed mice treated with STZ do not face increased demand for insulin secretion and thus can afford a deficit in [beta]-cell mass before any impairment in glycemic status ensues.
from China (manuscript titled "Circulating PGRN Levels Are Increased but Not Associated with Insulin Sensitivity or p-Cell
Function in Chinese Obese Children") investigated the association of progranulin with insulin sensitivity or [beta]-cell function in a Chinese paediatric cohort, (ii) N.
However, it is unknown whether p-cell apoptosis is increased in offspring of diabetic rats.
2, Apoptotic p-cell was identified by TUNEL staining.
Zinman, "Short-term intensified insulin treatment in type 2 diabetes: long-term effects on P-cell function," Diabetes, Obesity & Metabolism, vol.
Holst, "Effect of 6-week course of glucagon-like peptide 1 on glycaemic control, insulin sensitivity, and P-cell function in type 2 diabetes: a parallel-group study," The Lancet, vol.
 Other mechanisms such as lipotoxicity  and inflammation  resulting owing to high calorie intake are also likely causes of decline in p-cell
Recent findings indicate that defects in P-cell
function and increased insulin resistance occur early in the natural history of T2DM and can be present for 3 to 6 years before diagnosis.
The probable cause for hyperinsulinemia is increased basal insulin secretion and decreased hepatic insulin clearance. In both non-obese and obese PCOS women, insulin secretion is inappropriately low for their degree of insulin resistance, suggesting the presence of pancreatic P-cell
dysfunction in these patients.[10,11] Ehrmann and colleagues have demonstrated decreased postprandial insulin secretory responses as well as abnormalities in entrainment of insulin secretion to an oscillatory glucose infusion in PCOS women, consistent with P-cell
dysfunction can precede glucose intolerance in PCOS.
It has been suggested that the best treatment, and a potential cure, for both type 1 mellitus (T1DM) and type 2 diabetes mellitus (T2DM), is to replace or regenerate the pancreatic p-cell
Type 2 diabetes, though poorly understood, is also known to be a disease characterized by an inadequate p-cell
response to the progressive insulin resistance that typically accompanies advancing age, inactivity, & weight gain.