Beta-cell function and insulin resistance evaluated by HOMA in pancreatic cancer subjects with varying degrees of glucose intolerance.

BACKGROUND/AIMS: To gain insights into pathogenesis of pancreatic cancer-associated diabetes.

METHODS

Using homeostasis model assessment (HOMA), we estimated beta-cell function (BCF) and insulin resistance (IR) from fasting plasma glucose (FPG) and insulin in 67 normoglycemic controls and 62 age- and BMI-matched normoglycemic pancreatic cancer patients. In addition, we studied 73 pancreatic cancer subjects with glucose intolerance; 21 had impaired FPG and 51 had diabetes.

RESULTS

BCF was similar in controls and normoglycemic pancreatic cancer subjects (64 +/- 5 vs. 78 +/- 9, p = ns), while IR was higher in pancreatic cancer subjects with normal FPG (1.6 +/- 0.6 vs. 1.1 +/- 0.1, p = 0.002). Among pancreatic cancer subjects, those with impaired FPG had markedly decreased BCF compared to those with normal FPG (44 +/- 5 vs. 78 +/- 9, p < 0.02) without significant difference in IR (1.9 +/- 0.2 vs. 1.6 +/- 0.6, p = ns). In cancer subjects, those with diabetes had markedly increased IR compared to those with impaired FPG (3.2 +/- 0.3 vs. 1.9 +/- 0.2, p < 0.0001), while the BCF was similar (37 +/- 4 vs. 44 +/- 5).

CONCLUSION

Diabetes associated with pancreatic cancer is likely due to a combination of marked decline in BCF and increased insulin resistance.