Serum adiponectin, leptin, C-peptide, and homocysteine are indicators for obesity, hyperinsulinemia, and chronic inflammation, which have all been associated with colorectal cancer.
To determine whether serum adiponectin, leptin, C-peptide, and homocysteine are associated with fat, fiber, fruit & vegetable, flavonol, or dry bean intake, and colorectal adenoma recurrence.
Using logistic regression, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) for adenoma recurrence in 627 participants from the control arm of the Polyp Prevention Trial, a 4-year trial that examined the effectiveness of a low-fat, high-fiber, high-fruit & vegetable diet on adenoma recurrence.
Serum concentrations of C-peptide and homocysteine were inversely related to fiber, fruits & vegetables, and flavonol intake and positively related to percentage of calories from fat (all Ptrend ≤ 0.01). High homocysteine concentrations were associated with any (4th versus 1st quartile, OR = 2.26, 95% CI: 1.30-3.94) and more than one adenoma recurrence (OR = 2.11, 95% CI: 1.01-4.40). Individuals in the highest, versus lowest, tertile of serum leptin concentration had a decreased risk of advanced adenoma recurrence (OR = 0.22, 95% CI: 0.06-0.79).
Our results suggest that serum homocysteine may serve as an indicator of dietary exposure, including a low-fat and high-fiber, -fruit & vegetable, and -flavonol diet, as well as colorectal adenoma recurrence.
Discovering biomarkers that are both modifiable and can predict cancer risk is critical. We identified serum homocysteine as a novel indicator that is modified by diet and predicts risk of adenoma recurrence.