Independent and combined influence of the FTO rs9939609 and MC4R rs17782313 polymorphisms on hypocaloric diet induced changes in body mass and composition and energy metabolism in non-morbid obese premenopausal women

Purpose: To examine the independent and combined influence of the FTOrs9939609 and the MC4Rrs17782313 polymorphisms on changes in fat mass (FM), resting energy expenditure (REE), leptin, and thyrotropin (TSH) levels, after a 12-week energy-restricted diet intervention in non-morbid premenopausal obese women. Methods: Fat mass (dual X-ray absorptiometry), REE (indirect calorimetry) and plasma leptin and thyrotropin levels were measured (before and after the intervention) in 77 obese (BMI: 33.9±2.8kg/m2) women (age: 36.8±7.0y). Results: There were no significant differences across FTOrs9939609 genotype groups (TT vs. A allele carriers, Ps>0.1) on changes in body mass (-8.6±3.2% vs.-8.7±3.3 %), FM (12.8±4.7% vs.-12.9±6.3%), REE (-11.3±4.7 vs.-9.4±8.1%), leptin (-34.1±25.1% vs.-43.5±24.1%) or TSH (5.2±34.5% vs.-1.7±27.1%) levels. Moreover, it was not observed any significant difference on changes in body mass (-8.6±3.6% vs.-8.9±2.6%), FM (-12.7±6.1% vs.-13.4±5.3%), REE (-9.8±7.4%-9.4±9.4%), leptin (-39.0±26.9% vs.-44.8±18.4%) or TSH (-1.0±30.0% vs. 1.5±26.5%) levels between non-C allele carriers and C allele carriers of the MC4Rrs17782313 (Ps>0.3). Finally, there were no significant difference on changes in body mass and composition, REE, leptin or TSH levels among non-risk allele carriers, carriers of the C allele risk of the MC4Rrs17782313, carriers of the A allele of the FTOrs9939609 and carriers of both risk alleles after the 12-week energy-restricted diet intervention (Ps>0.1). Conclusion: Carrying the A risk allele of the FTOrs9939609 and/or the C risk allele of the MC4Rrs17782313 did not influence body mass and FM loss, or REE decrease in obese women after a 12-week energy-restricted diet intervention.