Figure 1.

Representative insulin (brown)-hematoxylin immunohistochemistry of pancreas (original magnification ×100). Examples of lean (male, 28 years of age, BMI 23.4) (A), obese (male, 44 years of age, BMI 33.6) (B), and elderly (male, 91 years of age, BMI 16.2; female, 100 years of age, BMI 24.9) (C and D) subjects. The fractional pancreatic insulin-positive area/pancreas parenchymal area, average islet size, and islet density are all modestly increased in obesity (B) compared with lean subjects (A). Pancreatic fat was also increased in obesity (B). Whereas atrophy, fibrosis, and fat accumulation are typical in the exocrine pancreas of elderly individuals (C and D), compared with a younger population (A), islet structure was remarkably maintained (C and D). As a result, fractional β-cell area/pancreas parenchymal area was increased in elderly vs. younger individuals (C and D vs. A). Scale bars, 200 μm. (A high-quality digital representation of this figure is available in the online issue.)