Published online Jun 15, 2020. doi: 10.4239/wjd.v11.i6.252
Peer-review started: December 31, 2019
First decision: March 24, 2020
Revised: April 9, 2020
Accepted: April 24, 2020
Article in press: April 24, 2020
Published online: June 15, 2020
Processing time: 153 Days and 23.4 Hours
Bariatric surgeries, including gastric bypass and sleeve gastrectomy, are generally accepted to be effective in controlling body weight and blood glucose in obese patients. Researchers have found matrix metalloproteinases (MMPs) as biomarkers in many disorders. The levels of MMPs were reported to be increased in obese and type 2 diabetes mellitus (T2DM) patients.
Previous research reported decreased MMPs, along with reduced body weight, in the exercise group rather than the control group. We hypothesized that the MMP-2, -7, -9 levels would decrease in patients who underwent bariatric surgeries and further explained the mechanism of body weight loss and blood sugar control caused by bariatric surgeries.
The results disclosed that the MMP-2, -7, and -9 levels did not differ before or after bariatric surgery. Bariatric surgeries are helpful for weight loss and blood sugar control without significantly affecting MMP-2, -7, and -9 levels. How bariatric surgeries regulate body weight and blood sugar in obese T2DM patients needs further investigation. Whether MMPs other than MMP-2, -7, and -9 play roles demands further study.
Overall, 6 men and 17 women who received gastric bypass (GB), and 14 men and 5 women who received sleeve gastrectomy (SG) were included. All of the above subjects had a hemoglobin A1c (HbA1c) level > 8% under regular medication by endocrinologists and a body mass index (BMI) ranging from 27.5-35 kg/m2. We measured their clinical anthropometry and serum levels of total cholesterol, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting blood sugar, HbA1c, C-peptide, homeostasis model assessments of insulin resistance, and MMPs-2, -7, and -9 on the day before surgery as the baseline (M0 and at 3 mo (M3), 12 mo (M12), and 24 mo (M24) postoperatively. We use the validated enzyme immunoassays (QuickZyme Biosciences B.V., CK Leiden, The Netherlands) for the concentration of MMPs-2, -7, and -9. The procedure was performed in a blinded manner. For data analyses, the statistical package for Social Science, version 12.0 (SPSS, Inc., Chicago, Illinois, IL, United States) was used. The statistical methods included the Wilcoxon signed-rank test, Friedman’s one-way repeated measures analysis of variance on ranks followed by a post-hoc test, and Spearman’s correlation analysis.
In both the GB and SG groups, waist circumference, BMI, HbA1c, and fasting blood sugar were significantly decreased 2 years postoperatively. However, serum MMP-2, -7, and -9 levels did not significantly change after both surgeries. Our study added on the knowledge about the relationship between the biomarkers MMP-2, -7, and -9 and GB and SG surgeries.
Our study demonstrated that the MMP-2, -7, and -9 levels did not differ before or after the bariatric surgeries, which indicated that bariatric surgeries might be helpful for body weight and glucose management without altering MMP-2, -7, and -9 levels. The mechanism of weight loss and glucose management by bariatric surgeries in obese T2DM patients needs more exploration.
The study population was relatively small, and there were more women than men who received GB, and more men than women who received SG. Also, neither of the MMP levels nor their activities in adipose tissue were measured. In future studies, the sex ratio should be kept balanced in both groups. Furthermore, the MMP levels and activities in adipose tissue should be taken into consideration.