Conseqüências da deficiência isolada e vitalícia do hormônio do crescimento na isquemia miocárdica e aterosclerose carotídea

• Ano de defesa: 2005
• Autor(a) principal: Oliveira, Joselina Luzia Menezes
• Orientador(a): Oliveira, Manuel Hermínio de Aguiar
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Sergipe
• Programa de Pós-Graduação: Pós-Graduação em Ciências da Saúde
• País: BR
• Palavras-chave em Português: Hormônio de crescimento; Ecocardiografia sob estresse; Aterosclerose de carótidas; Doença arterial coronariana
• Palavras-chave em Inglês: Growth hormone; Stress echodopplercardiography; Carotid atherosclerosis; Coronary heart disease
• Área do conhecimento CNPq: CNPQ::CIENCIAS DA SAUDE::MEDICINA
• Link de acesso: https://ri.ufs.br/handle/riufs/3899

Insulin-Like growth factor I (IGF-I) is a peptide that has an important action on cell division, differentiation, migration and apoptosis for vascular smooth muscle cells (VSMCs), may intervene in atherosclerosis. It antiapoptotic factor and it also stimulates. Thus, potential reductions in IGF-I effects might be beneficial in certain pathologic conditions, such as hypertension and the early stages of atherosclerosclerotic plaque formation characterized by hypertrophy/hyperplasia of VSMCs, but detrimental in other conditions in which loss of VSMCs contributes to the disease process, such as destabilization of atherosclerotic plaques. Conversely, it has been suggested that serum IGF-1 levels are low in patients with coronary heart disease. Recently, we have described a GH naïve homogeneous population with a monogenic mutation that inactives the growth hormone-releasing hormone receptor (GHRHR) (IVS1+ 1GA) with extremely low levels of IGF-1. Moreover, they also presented central obesity, higher levels of systolic blood pressure and dyslipidemia unique opportunity to evaluate the impact of extremely low levels of IGF-1 on the myocardial ischemic and carotid atherosclerosisis in high risk cardiovascular population, pertaining to the research object. It has been studied 22 dwarfs with GHD and no past of growth hormone therapy (10M:12F; 44±12 yrs) and compared to 26 age-matched normal subjects, control group[CO]. It has been examined clinical, biochemical data, including insulin-like growth factor 1(IGF-1), rest and exercise echodopplercardiography and, carotid intima-media thickness by a high-resolution carotid ultrasonography. IGF-1 in GHD group was markedly lower (3,3±5,5 vs 228,4±134,7ng/Ml; p<0.001) and fasting insulin (3,37±3,9 vs 3,59±3,0 microU/mL; p=NS) were smaller but not significantly in GHD. In the resting echocardiographic study, we observed normal indices of both systolic and diastolic function. During exercise treadmill (Bruce Protocol), both groups reached similar peak heart rate (162±16,5 vs 168±15,7bpm; p=NS) and peak systolic blood pressure (49±20 vs 59,4±23,6mmHg p=NS). Comparison of exercise wall motion score index in GHD group (1±0.0) vs CO group (1±0.0) did not show differences. Moreover, intima-media thickness measured at the far wall of the distal common carotid artery (0,59 ± 0,10 mm vs 0,60 ± 0,14 mm; p=NS (GHD vs CO group) was not indicative of premature atherosclerosis in GHD population. Only one of the subjects in the population studied presented carotid atherosclerotic plaque. Our data suggest that in a very homogeneous population with isolated GHD is not associated with premature carotid atherosclerosis or a higher prevalence of myocardial ischemia. Extremely low levels of the IGF-1 may be a protective mechanism against premature atherosclerosis in this apparently high risk selected group.