Plasma pancreatic polypeptide levels are associated with differences in body fat distribution in human subjects

• Published in: Diabetologia 2007-02, Vol.50 (2), p.439-442
• Main Authors: Tong, J, Utzschneider, K. M, Carr, D. B, Zraika, S, Udayasankar, J, Gerchman, F, Knopp, R. H, Kahn, S. E
• Format: Article
• Language: English
• Subjects: Abdomen - anatomy & histology; Adipose Tissue - anatomy & histology; Adult; Aged; Biological and medical sciences; Blood Glucose - metabolism; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Female; Fundamental and applied biological sciences. Psychology; Glucose Tolerance Test; Humans; Insulin - metabolism; insulin resistance; Insulin Secretion; Male; Medical sciences; Middle Aged; pancreatic polypeptide; Pancreatic Polypeptide - blood; parasympathetic nervous system; Peripheral nervous system. Autonomic nervous system. Neuromuscular transmission. Ganglionic transmission. Electric organ; Vertebrates: nervous system and sense organs; visceral fat
• ISSN: 0012-186X; 1432-0428
• DOI: 10.1007/s00125-006-0553-4

Aims/hypothesis Pancreatic polypeptide (PP) is produced by the F-cells of the pancreas, and its plasma concentration has been used as a marker of parasympathetic activity. Recent work in rodents suggests that there is both sympathetic and parasympathetic innervation of white adipose tissue and that parasympathetic activity is anabolic resulting in lipid accumulation. We have examined whether in humans increased PP levels are associated with increased intra-abdominal fat (IAF), and thereby insulin resistance. Materials and methods We measured PP levels in 177 non-diabetic subjects (75 male/102 female; age 32-75 years) 3 min after an i.v. glucose bolus during a frequently sampled intravenous glucose tolerance test. IAF and s.c. fat (SCF) areas were measured by CT scan. The insulin sensitivity index (S I) was quantified using Bergman's minimal model. Results PP levels were higher in men than in women (96.2 ± 72.2 vs 76.1 ± 55.0 pg/ml, mean ± SD, p = 0.037), as was IAF area (124.7 ± 67.4 vs 83.0 ± 57.7 cm², p < 0.001). While PP levels were significantly associated with IAF (r = 0.16, p = 0.031), WHR (r = 0.30, p < 0.001) and age (r = 0.37, p < 0.01), they were not associated with SCF (r = 0.02, p = 0.829). The association between PP and IAF was not independent of age and/or sex. S I was negatively associated with PP levels (r = -0.17, p = 0.026) and IAF area (r = -0.65, p < 0.001). The association between S I and PP disappeared after adjusting for IAF area, indicating that S I was not a major determinant of PP levels. Conclusions/interpretation In humans, age and sex may modulate the association between plasma PP level and IAF area, suggesting that they may be determinants of parasympathetic activity and thus IAF accumulation.