LINE-1 methylation levels, a biomarker of weight loss in obese subjects, are influenced by dietary antioxidant capacity

Abstract

Objectives: Epigenetic markers, and in particular DNA methylation, have come to the fore as new tools in the personalization of the treatment of obesity and its comorbidities. The objectives of the current investigation were to identify epigenetic biomarkers that might be predictive of response to a weight-loss intervention, and to better understand the influence of certain nutrients (particularly antioxidants) on the epigenome.

Methods: Global DNA (LINE-1) methylation levels were assessed in peripheral blood mononuclear cells (PBMCs) from 96 obese volunteers of the Metabolic Syndrome Reduction in Navarra study, using a methylation-sensitive high resolution melting approach after bisulfite modification.

Results: Baseline LINE-1 DNA methylation levels were significantly higher (5.41%) in high responders (>8% of weight loss) as compared to low responders (<8%) to the energy-restricted treatment. Indeed, a LINE-1 methylation higher than 84.15% may be predictive of a high response to the hypocaloric diet. Statistically significant correlations were found between LINE-1 baseline DNA methylation levels and the response to the treatment involving total fat mass and body weight. Furthermore, LINE-1 baseline methylation levels positively correlated with baseline dietary total antioxidant capacity (TAC).

Discussion: LINE-1 methylation levels in PBMCs might be used to predict response to a dietary weight-loss intervention, and seem to be related to the dietary TAC.

Trial registration: www.clinicaltrials.gov : NCT01087086.

Keywords: Antioxidants; Biomarkers; Energy-restriction; Epigenetic; LINE-1; Methylation; Obesity.

Conflict of interest statement

Conflict of interest The author(s) declare that they have no competing interests.

Figures

Figure 1

Baseline DNA methylation levels of low and high responders to the intervention. (A) Baseline DNA methylation levels (%) of low responders and high responders adjusted for age, gender, and number of plate. P from ANCOVA test: *0.05 < P < 0.01; ***P < 0.001. (B) Pearson's correlation between total fat mass loss (kg) and baseline DNA methylation levels (%) of LINE-1; (C) Pearson's correlation between body weight loss (as kg) and baseline DNA methylation levels (%) of LINE-1. r2 represents Pearson correlation coefficient and P is the stringency of the correlation. A P < 0.05 was considered statistically significant. Full circles: LR; empty circles: HR.

Figure 2

Pearson's correlation between baseline methylation levels (%) of LINE-1 and baseline dietary total antioxidant capacity (TAC; mmol/day), adjusted for age, sex, diet type, energy intake, and number of plate. r2 represents Pearson correlation coefficient.