Publicação
Body composition in non-alcoholic fatty liver disease patients
| Resumo: | The present thesis includes five original studies focusing on body composition (BC) in non-alcoholic fatty liver disease (NAFLD) patients, mainly in a clinical perspective, directed to clinical practice. The first study of this thesis aimed at analyzing the relation between body fat (BF) content and distribution, as assessed by dual energy x-ray absorptiometry (DXA), and cardiac autonomic control, more specifically with heart rate recovery after a maximal exercise test, which is an indirect clinical marker of parasympathetic reactivation, also known to be a strong risk factor for overall and cardiac mortality. The second study focused on the utility of waist circumference (WC) measurement, as a predictor of both BF content and distribution, and also on the comparison of different WC measurement protocols based on biological criteria, protocols’ precision and practical criteria, aiming to identify a preferential measurement protocol to be used in NAFLD patients. The third and fourth studies focused on the influence of using different WC measurement protocols in the relation of both waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) with BF content and distribution, as assessed by DXA, and aimed to identity a preferable measurement protocol. The fifth study focused on body indexes and circumferences usefulness as surrogates of BF content and distribution and aimed at identifying if there is a preferential clinical predictor of both BF content and distribution, as compared to the commonly used body mass index, in NAFLD patients. The results obtained confirmed the strong relation between BC and cardiac autonomic control and showed that BF distribution is more important than BF content in explaining cardiac autonomic control variation. It was also possible to conclude that WC measured just above the iliac crest seem preferable to be used in NAFLD patients, either singly or included in body indexes such as WHR or WHtR, mostly due to practical criteria but also because of it strong correlation with both BF content and distribution. WHtR appears to be the best BF content and distribution surrogate to be used in clinical practice with NAFLD patients. WC alone is a good practical alternative, when simplicity and time saving are important instrument/method selection criteria. |
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| Autores principais: | Magalhães, Nuno Manuel Queiroz Pimenta de |
| Assunto: | Anthropometry Autonomic nervous system Body composition Fat distribution Fatty liver Antropometria Composição corporal Distribuição de massa gorda Fígado gordo Sistema nervoso autónomo |
| Ano: | 2014 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | The present thesis includes five original studies focusing on body composition (BC) in non-alcoholic fatty liver disease (NAFLD) patients, mainly in a clinical perspective, directed to clinical practice. The first study of this thesis aimed at analyzing the relation between body fat (BF) content and distribution, as assessed by dual energy x-ray absorptiometry (DXA), and cardiac autonomic control, more specifically with heart rate recovery after a maximal exercise test, which is an indirect clinical marker of parasympathetic reactivation, also known to be a strong risk factor for overall and cardiac mortality. The second study focused on the utility of waist circumference (WC) measurement, as a predictor of both BF content and distribution, and also on the comparison of different WC measurement protocols based on biological criteria, protocols’ precision and practical criteria, aiming to identify a preferential measurement protocol to be used in NAFLD patients. The third and fourth studies focused on the influence of using different WC measurement protocols in the relation of both waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) with BF content and distribution, as assessed by DXA, and aimed to identity a preferable measurement protocol. The fifth study focused on body indexes and circumferences usefulness as surrogates of BF content and distribution and aimed at identifying if there is a preferential clinical predictor of both BF content and distribution, as compared to the commonly used body mass index, in NAFLD patients. The results obtained confirmed the strong relation between BC and cardiac autonomic control and showed that BF distribution is more important than BF content in explaining cardiac autonomic control variation. It was also possible to conclude that WC measured just above the iliac crest seem preferable to be used in NAFLD patients, either singly or included in body indexes such as WHR or WHtR, mostly due to practical criteria but also because of it strong correlation with both BF content and distribution. WHtR appears to be the best BF content and distribution surrogate to be used in clinical practice with NAFLD patients. WC alone is a good practical alternative, when simplicity and time saving are important instrument/method selection criteria. |
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