Decreased Chromosomal Damage in Lymphocytes of Obese Patients After Bariatric Surgery

Abstract

The number of bariatric surgeries being performed worldwide has markedly risen. While the improvement in obesity-associated comorbidities after bariatric surgery is well-established, very little is known about its impact on cancer risk. The peripheral lymphocyte micronucleus test is a widely used method for the monitoring of chromosomal damage levels in vivo, and micronucleus frequency positively correlates with cancer risk. Therefore, the aim of this study was to compare the micronucleus frequency before and after bariatric surgery in obese subjects. Peripheral blood mononuclear cells were collected from 45 obese subjects before and at two time-points after bariatric surgery (6 and 12 months) to assess spontaneous micronucleus frequency. Consistent with the increased cancer risk previously shown, bariatric surgery-induced weight loss led to a significant reduction in lymphocyte micronucleus frequency after 12 months. Interestingly, comorbidities such as type 2 diabetes mellitus and metabolic syndrome further seemed to have an impact on the lymphocyte micronucleus frequency. Our findings may indicate a successful reduction of cancer risk in patients following weight loss caused by bariatric surgery.

Figure 1

Body weight, BMI and weight loss before and after bariatric surgery. (A) Body weight in kg, (B) Body Mass Index (BMI kg/m²), (C) Weight loss in kg and (D) Weight reduction in %. Before surgery, n = 45; 6 M, n = 35; 12 M, n = 45. *p ≤ 0.05 significant vs. Before and °p ≤ 0.05 significant vs. 6 M.

Figure 2

Micronucleus frequency per mill (%_o) in isolated lymphocytes of obese subjects. (A) Representative picture of a micronucleus in a binucleated cell indicated by the white arrow. (B) Micronucleus frequency per mill (%_o) before and after surgery. Before, n = 45; 6 M, n = 35 and 12 M, n = 45. *p ≤ 0.05 significant vs. before.

Figure 3

Micronucleus frequency per mill (%_o) among the subgroups of obese subjects before surgery. (A) Comparison of micronucleus frequency between all patients, nondiabetic (ND), IR/T2DM, nonhypertensive (NH), hypertensive (H), nonmetabolic syndrome (NMetS) and metabolic syndrome (MetS). (B) Comparison of micronucleus frequency between IR/T2DM, hypertensive (H) and metabolic syndrome (MetS) before and after surgery. (C) Comparison of micronucleus frequency between a subgroup of HbA1c < 6 and HbA1c ≥ 6 before and after surgery. Before surgery, n_All = 45, n_ND = 19, n_IR/T2DM = 26, n_NH = 16, n_H = 29, n_NMetS = 31 and n_MetS = 14; 6 M, n_IR/T2DM = 21, n_H = 21, and n_MetS = 10; 12 M, n_IR/T2DM = 26, n_H = 29 and n_MetS = 14. *p ≤ 0.05 significant vs. All or vs. Before_IR/T2DM or vs. Before_MetS, ^#p ≤ 0.05 significant vs. ND or vs. Before_HbA1c≥6 and op ≤ 0.05 significant vs. NMetS.