(ChemotherapyAdvisor) – Low, prediagnostic plasma levels of circulating adiponectin, an adipocyte-secreted hormone with insulin-sensitizing and anti-inflammatory properties, were found to be associated with an elevated risk of pancreatic cancer, a prospective study concluded in the Journal of the National Cancer Institute online December 14.
“Although development of pancreatic cancer is associated with states of insulin resistance and chronic inflammation, the mechanistic basis of the associations is poorly understood,” reported Ying Bao, MD, ScD, of Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, and colleagues.
The investigators pooled data from five U.S. cohorts—the Health Professionals Follow-up Study, the Nurses’ Health Study, the Physicians’ Health Study, the Women’s Health Initiative, and the Women’s Health Study—to conduct a nested case-control study of 468 cases with pancreatic cancer and 1,080 controls matched by prospective cohort, year of birth, smoking and fasting status, and month of blood draw.
“All samples for plasma adiponectin were handled identically in a single batch,” they reported.
The cases had a median plasma adiponectin of 6.2 µg/mL compared with 6.8 µg/mL among the controls (P=0.009), Dr. Bao reported. “Plasma adiponectin was inversely associated with pancreatic cancer risk, which was consistent across the five prospective cohorts (Pheterogeneity=0.49) and independent of other markers of insulin resistance (eg, diabetes, body mass index, physical activity, plasma C-peptide).”
Cases in adiponectin quintiles 2 to 5—compared with the lowest quintile of adiponectin—had multivariable odds ratios (OR) of 0.61 (95% CI 0.43–0.86) for quintile 2; OR 0.58 (95% CI 0.41–0.84) for quintile 3; OR 0.59 (95% CI 0.40–0.87) for quintile 4; and OR 0.66 (95% CI 0.44–0.97) for quintile 5 (Ptrend=0.04); an additional analysis confirmed a nonlinear association (P<0.01).
Sex, smoking, body mass index, physical activity, or C-peptide did not modify this association (all Pinteraction>0.10).