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Descripción
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| Objectives. The objective of the present thesis was to study the influence of previously suggested candidate genes related to obesity on body weight and body composition variables, during and after a weight loss intervention. The main objective of the studies I and II was to examine if there were differences among genotype groups of the ADRB2 (Gln27Glu), ADRB3 (Trp64Arg), LEPR (Gln223Arg and Lys656Asn), and PPARG (Pro12Ala) genes during a controlled intervention in body weight, body mass index (BMI), fat mass, percentage fat, android fat or visceral adipose tissue. The secondary objective of the studies I and II was to evaluate the influence of these polymorphisms on baseline variables, body mass index and percentage fat. The objective of study III was to examine differences between MCT1 (Glu490Asp/T1470T) genotype groups in body weight, BMI, percentage fat and percentage fat free mass. The objective of the study IV was to observe differences among genotype groups of the ADRB2 (Gln27Glu), ADRB3 (Trp64Arg), LEPR (Gln223Arg and Lys656Asn), MCT1 (Glu490Asp/T1470T) and PPARG (Pro12Ala) genes 3 years after a free living follow up in body weight, BMI, fat mass and percentage fat. Research design. This thesis is part of de Programas de Nutrición y Actividad Física para el Tratamiento de la Obesidad (PRONAF) project carried out in Spain. The PRONAF project was a clinical trial including 22-week long controlled exercise and diet program. The weight loss intervention for overweight and obese participants applied a hypocaloric diet and aimed to compare different exercise protocols (supervised: strength, endurance, combined strength and endurance and non-supervised: physical activity recommendations) in order to see which is the most effective. Strengthening the project, genetic polymorphisms related to obesity phenotypes were incorporated too. Results. Glu27 carriers of the ADRB2 gene in the supervised men group reduced weight and BMI more than the non-carriers (p=0.019, 2.52 kg and p=0.019, 0.88 kg/m2). Non-supervised women carrying of the Arg64 allele of the ADRB3 gene ended up with higher fat mass values than non-carriers after the intervention (p=0.004, 7.22 kg). No differences were seen for body weight and body composition changes for the LEPR polymorphisms. Women non-supervised carriers of the Ala12 allele of the PPARG gene reduced visceral adipose tissue (VAT) less than non-carriers (p=0.024, 0.32 kg). No differences were found at baseline comparisons. Female non-carriers of the Glu490 allele of the MCT1 gene reduced weight and BMI more than Glu490 allele carriers (p=0.004, 3.88 kg, effect size (ES) moderate and most likely positive and p=0.00037, 1.48 kg/m2, ES large and most likely positive). In the female non-supervised group Glu490 allele carriers of the MCT1 gene ended up with higher values of percentage fat (p=0.025, 1.94%), while the contrary in men, Glu490 allele carriers reduced fat more (p=0.037, 1.87%). In women non-carriers of the Glu490 allele of the MCT1 gene finished the program with higher percentage fat free mass values than the carriers of the Glu490 allele (p=0.005, 2.76%, ES small and possibly negative). In the follow up study, carriers of the Arg64 allele of the ADRB3 gene in men regained more weight and increased BMI more than non-carriers, however effect size was unclear. Male carriers of the Arg223 allele of the LEPR gene had higher percentage fat values than non-carriers, however effect size also was unclear. No other differences were seen between polymorphisms and follow up phenotypes. Conclusions.. Our results suggest that some of these polymorphism might affect body weight and body composition during a weight loss intervention and during subsequent 3-year long follow up, however these effects are not determinant and results should be replicated. | |
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Internacional
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Si |
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ISBN
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Tipo de Tesis
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Doctoral |
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Calificación
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Sobresaliente cum laude |
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Fecha
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30/06/2017 |