Pancreatic α-cell mass in obesity

While it is well recognized that obesity is associated with an increased β-cell mass, it is less clear with respect to α-cell mass. Type 2 diabetes associated with obesity is a bihormonal disease characterized by inadequate insulin secretion and hyperglucagonemia. We examined β- and α-cell mass of obese and lean human subjects throughout the pancreas. Pancreatic tissue of the head-, body- and tail-region of the pancreas was examined from 15 obese subjects (Body Mass Index (BMI) ≥ 27 kg/m2) and 15 age-matched lean subjects (BMI ≤ 25 kg/m2) without diabetes. In obese subjects both β- and α-cell mass were proportionally higher compared to lean subjects, thereby maintaining the α- to β-cell ratio. The adaptation to obesity occurred preferentially in the head of the pancreas. As data so far have been derived from histological studies of β- and α-cell adaptation in which the head-region of the human pancreas was not included, the adaptive capacity of humans to obesity has previously been underestimated. Obesity is associated with an increased α-cell mass which could contribute to the hyperglucagonemia observed in type 2 diabetes.