DNA methylation and hydroxymethylation levels in relation to two weight loss strategies: energy-restricted diet or bariatric surgery
Weight loss can be influenced by genetic factors and epigenetic mechanisms that participate in the regulation of body weight. This study aimed to investigate whether the weight loss induced by two different obesity treatments (energy restriction or bariatric surgery) may affect global DNA methylation (LINE-1) and hydroxymethylation profile, as well as the methylation patterns in inflammatory genes.
This study encompassed women from three differents groups: 1. control group (n = 9), normal weight individuals; 2. energy restriction group (n = 22), obese patients following an energy-restricted Mediterranean-based dietary treatment (RESMENA); and 3. bariatric surgery group (n = 14), obese patients underwent a hypocaloric diet followed by bariatric surgery. Anthropometric measurements and 12-h fasting blood samples were collected before the interventions and after 6 months. Lipid and glucose biomarkers, global hydroxymethylation (by ELISA), LINE-1, SERPINE-1, and IL-6 (by MS-HRM) methylation levels were assessed in all participants.
Baseline LINE-1 methylation was associated with serum glucose levels whereas baseline hydroxymethylation was associated with BMI, waist circumference, total cholesterol, and triglycerides. LINE-1 and SERPINE-1 methylation levels did not change after weight loss, whereas IL-6 methylation increased after energy restriction and decreased in the bariatric surgery group. An association between SERPINE-1 methylation and weight loss responses was found.
Global DNA methylation and hydroxymethylation might be biomarkers for obesity and associated comorbidities. Depending on the obesity treatment (diet or surgery), the DNA methylation patterns behave differently. Baseline SERPINE-1 methylation may be a predictor of weight loss values after bariatric surgery.