Introduction: Obesity is a chronic disease that affects millions of individuals and is related to several metabolic alterations. The interactions between genes and environment have been studied to identify possible factors that influence the responses of individuals to different metabolic conditions. In line with this DNA methylation is an important epigenetic marker in the determination of various biological processes and diseases in humans, including obesity.
Aim: The aim of this study was to identify the modifications in DNA methylation pattern involved with inflammation pathway genes before and after hypocaloric dietary intervention in women with grade III obesity.
Materials and Methods: This was a cross-sectional study with a sample of women admitted to a university hospital, classified into two different groups: Intervention group (G1) - grade III obesity women (body mass index (BMI) ≥40 kg/m2] pre and post hypocaloric dietary intervention (1200 kcal/day) for 6 weeks; Control Group (G2) - healthy eutrophic women (BMI between 18.5 and 24.9 kg/m2). Anthropometric data [weight, height, BMI and abdominal circumference (AC)], body composition [fat-free mass (FFM) and fat mass (FM)] and peripheral blood for methylation analysis were collected. Normality test (Shapiro-Wilk), descriptive statistics (mean and standard deviation), t-tests (paired and independent) were used for the statistical analysis. Significance level was accepted for p<0.05.
Results: Twenty-one women were evaluated, 10 normal weight and 11 obese. The mean age was 35.5±6.8 years for G1 and 33.5±11.2 years for G2. A significant weight loss of 8.4±4.3 kg (5.2%, p<0.001) was observed in G1 after 6 weeks of dietary intervention, in addition to a reduction in BMI (58.5±10.5 to 55.3±9.1kg/m2; p<0.001), FFM (65.4±8.6 to 63.1±7.1 kg; p=0.009) and FM (89.5±23.0 to 83.4±21.0 kg; p=0.001). Indeed, BMI, AC, FFM and FM from obese individuals` values remained statistically different from the G2 group both in the pre- and post-dietary periods.
Conclusion: Our results show that individuals with obesity who received hypocaloric dietary intervention had significant weight, BMI, FFM and FM reduction. The next stage of the present study will be to identify the DNA methylation changes of inflammatory genes of women with grade III obesity before and after dietary intervention and to compare them with the control group.
Acknowledgements: São Paulo Research Foundation (FAPESP), Coordination of Improvement of Higher Level Personnel (CAPES)