Effects of isometric handgrip exercise on protein homeostasis among older patients with high normal blood pressure or hypertension

• Autor(a) principal: Graça, Inês Catarina Rosa
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/40940
• topic: Hypertension; Isometric handgrip training; FTIR spectroscopy; Proteostasis; Metabolomics

Hypertension is a global, multifactorial condition that represents one of the most important preventable causes of death worldwide. Recently, a study showed that exercise in adults with hypertension may contribute to better protein homeostasis, however the effects of isometric resistance training (IRT) on hypertension and its pathophysiology are very limited. Fourier Transform Infrared (FTIR) spectroscopy is an inexpensive, rapid, and sensitive method, widely used in biomedical research. It allows to screen the metabolome of the sample, being sensitive to structure of proteins. Our goal was to study the effects of IRT in possible changes in metabolome and particularly on protein secondary structure and therefore the aggregation profile and protein homeostasis, in human plasma samples from older patients with high normal blood pressure or hypertension, using FTIR spectroscopy. Using an ATR-FTIR, we acquired spectra from plasma samples from 61 individuals with pre-hypertension and hypertension, divided in three groups that enrolled in an 8-week program: isometric handgrip training (IHT) group that performed IHT (n= 19); aerobic exercise training (AET) group that performed AET (n= 23); and an attention-control (CON) group that did not perform exercise (n= 19). Samples were collected at the beginning of the study and at the end of the 8 weeks. Spectra were analyzed using multivariate statistical analysis. Partial least squares-discriminant analysis (PLS-DA) was applied to the normalized second-derivative spectra. We performed comparisons between the 3 groups and compared moment A and B in IHT, AET and CON groups in each spectral region. FTIR results show differences between the groups at moment A, which change little at moment B. When comparing the two moments in each group, results show that after intervention, IHT and AET groups are characterized by a peak at 2871 cm-1 associated with CH3 groups of lipid acyl chains. In CON group, samples are mainly characterized by peaks at 2959 cm-1 and 2871 cm-1 that are associated with CH3 groups of lipid acyl chains. Furthermore, we observed that after the 8-week program there was an increase in β-sheet structures in IHT and AET group, being characterized by peaks at 1696 cm-1, 1682 cm-1 and 1636 cm-1, that are associated with antiparallel β-sheets, loops or β-turns and β-sheets, respectively, but there is a decrease in β-sheet structures in CON group. After intervention, all groups, IHT, AET and CON groups show a decrease in glucose. Besides, there is also an increase in glycogen in IHT group. In conclusion, IHT and AET have similar effects on the metabolome. Both IHT and AET increase lipid acyl chain length, but neither reduces protein aggregation, as β-sheet structures increase in both exercise groups, whereas the CON group shows a decrease. Additionally, the IHT and AET groups exhibit improved lipid profiles, decreased glucose, and increased glycogen, as expected, compared to the control group.