Change in β-Cell Mass in Japanese Nondiabetic Obese Individuals

• Published in: The journal of clinical endocrinology and metabolism Vol. 98; no. 9; pp. 3724 - 3730
• Main Authors: Kou, Kinsei, Saisho, Yoshifumi, Satoh, Seiji, Yamada, Taketo, Itoh, Hiroshi
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Oxford University Press 01.09.2013; Copyright by The Endocrine Society; Endocrine Society
• Subjects: Adult; Aged; Apoptosis; Apoptosis - physiology; Asian Continental Ancestry Group; Autopsy; Beta cells; Biological and medical sciences; Body mass index; Cell Division - physiology; Cell Size; DNA biosynthesis; Endocrinopathies; Feeding. Feeding behavior; Female; Fundamental and applied biological sciences. Psychology; Humans; Insulin; Insulin-Secreting Cells - pathology; Japan; Medical sciences; Middle Aged; Obesity; Obesity - pathology; Obesity - physiopathology; Organ Size - physiology; Pancreas; Pancreas - pathology; Pancreas - physiopathology; Replication; Retrospective Studies; Single-stranded DNA; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vertebrates: endocrinology; Asia; Japan; Human; Mass; Obesity; Nutrition; Nutrition disorder; Metabolic diseases; β Cell; Change; Pancreas; Japanese; Endocrinology; Nutritional status
• ISSN: 0021-972X; 1945-7197; 1945-7197
• DOI: 10.1210/jc.2013-1373

Aim:The aim of this study was to clarify the change in β-cell mass in Japanese obese individuals.Methods:We obtained the pancreas at autopsy from 39 lean and 33 obese Japanese nondiabetic individuals (aged 47 ± 13 vs 47 ± 12 y, P = .83, body mass index 20.4 ± 1.6 vs 28.5 ± 3.9 kg/m2, P < .01). Pancreatic sections were stained for insulin, and β-cell area (%BCA) was measured as the fraction of the β-cell area to the total pancreas area. β-Cell mass was then calculated as the product of %BCA and estimated pancreas weight. β-Cell replication and apoptosis were assessed by double staining for insulin and Ki67 and insulin and single-stranded DNA, respectively. The frequencies of insulin-positive duct cells and scattered β-cells were assessed as the surrogate markers of β-cell neogenesis. The α-cell area (%ACA) was also measured, and the %ACA to %BCA ratio was determined.Results:There was no increase in β-cell mass in obese individuals compared with lean individuals (0.6 ± 0.4 vs 0.7 ± 0.4 g, P = .12). β-Cell replication, β-cell neogenesis, and β-cell apoptosis were not significantly increased in the presence of obesity. There was no significant difference in %ACA to %BCA ratio between obese and lean individuals (0.91 ± 1.09 vs 0.75 ± 0.51, P = .47).Conclusion:There was no increase in β-cell mass and no detectable change in β-cell turnover in Japanese obese individuals.