LINE-1 methylation in visceral adipose tissue of severely obese individuals is associated with metabolic syndrome status and related phenotypes

• Published in: Clinical epigenetics 2012-07, Vol.4 (1), p.10-10, Article 10
• Main Authors: Turcot, Valérie, Tchernof, André, Deshaies, Yves, Pérusse, Louis, Bélisle, Alexandre, Marceau, Simon, Biron, Simon, Lescelleur, Odette, Biertho, Laurent, Vohl, Marie-Claude
• Format: Article
• Language: English
• Subjects: Adipose tissues; Analysis; Blood lipids; Blood pressure; Dextrose; DNA; Epigenetic inheritance; Epigenetics; Fasting glucose; Genes; Genetic aspects; Global DNA methylation; Glucose; Heart diseases; LINE-1; Metabolic syndrome; Methamphetamine; Methylation; Obesity; Phenotype; Physiological aspects; Risk factors; Severe obesity; Sulfites; Surgery; Type 2 diabetes; Visceral adipose tissue
• ISSN: 1868-7075; 1868-7083; 1868-7083
• DOI: 10.1186/1868-7083-4-10

Epigenetic mechanisms may be involved in the regulation of genes found to be differentially expressed in the visceral adipose tissue (VAT) of severely obese subjects with (MetS+) versus without (MetS-) metabolic syndrome (MetS). Long interspersed nuclear element 1 (LINE-1) elements DNA methylation levels (%meth) in blood, a marker of global DNA methylation, have recently been associated with fasting glucose, blood lipids, heart diseases and stroke. To test whether LINE-1%meth levels in VAT are associated with MetS phenotypes and whether they can predict MetS risk in severely obese individuals. DNA was extracted from VAT of 34 men (MetS-: n = 14, MetS+: n = 20) and 152 premenopausal women (MetS-: n = 84; MetS+: n = 68) undergoing biliopancreatic diversion for the treatment of obesity. LINE-1%meth levels were assessed by pyrosequencing of sodium bisulfite-treated DNA. The mean LINE-1%meth in VAT was of 75.8% (SD = 3.0%). Multiple linear regression analyses revealed that LINE-1%meth was negatively associated with fasting glucose levels (β = -0.04; P = 0.03), diastolic blood pressure (β =  -0.65; P = 0.03) and MetS status (β = -0.04; P = 0.004) after adjustments for the effects of age, sex, waist circumference (except for MetS status) and smoking. While dividing subjects into quartiles based on their LINE-1%meth (Q1 to Q4: lower %meth to higher %meth levels), greater risk were observed in the first (Q1: odds ratio (OR) = 4.37, P = 0.004) and the second (Q2: OR = 4.76, P = 0.002) quartiles compared to Q4 (1.00) when adjusting for age, sex and smoking. These results suggest that lower global DNA methylation, assessed by LINE-1 repetitive elements methylation analysis, would be associated with a greater risk for MetS in the presence of obesity.