Análise dos parâmetros espaço-temporais da marcha, capacidade funcional e índices plasmáticos de mediadores inflamatórios e o efeito do treinamento aeróbico em idosas diabéticas da comunidade

Abstract

The high prevalence of diabetes mellitus type 2 (DM2), especially among elderly women, exposes this population to a higher decline in functional capacity and alterations in spatiotemporal gait parameters. Dysfunctions on these variables alter independence and quality of life of elderly women with DM2. Factors associated to ageing such as the presence of a chronic subclinical inflammatory process, with elevated inflammatory cytokines levels and obesity can lead to sarcopenia, reduction in functional capacity and worsening of the disease in elderly women with DM2. Physical exercise can attenuate the chronic inflammatory process related to ageing, however, there is no consensus about which exercise modality and parameters would be more adequate to influence inflammatory mediators. Aerobic treatment of moderate intensity may induce the liberation of muscular interleukin 6 (IL-6) with antiinflammatory properties and induce the liberation of other anti-inflammatory cytokines which can influence on sarcopenia, functional capacity and reduction of fat mass in diabetic elderly women. This way, the general objective of this thesis was to analyze spatiotemporal gait parameters, functional capacity and plasma levels of inflammatory markers and the effect of aerobic exercises in community-dwelling diabetic elderly women. The research was divided in three studies. I and II were observational cross sectional studies and study III had a quasi-experimental (pre-post test) design. The objective of study I was to analyze, through main component statistical analysis and discriminant analysis, spatiotemporal gait parameters of two groups of community-dwelling elderly women, with and without diabetes mellitus. 221 elderly were assessed, being 98 diabetic (71.4 ± 4.9 years) and 123 non-diabetic (71.4 ± 4.9 years). Seven spatiotemporal gait parameters (gait speed, cadency, step length, base of support, oscillation time, time of support and time of double limb support) were registered using GAITRite® system. Discriminant analysis was conducted after PCA with stepwise procedures to determine hierarchy between components (CPs) in terms of relative importance to discriminate groups. The most discriminant CPs were interpreted using a biplot graph. PCA resulted in 4 components which explained 99.6% of data variance. Discriminant analysis indicated that only components 1 (CP1, rhythm dimension) and 3 (CP3, balance dimension) were statistically significant between groups. CP1 had higher contribution of speed, cadency and time of support variables and CP3 of base of support and double limb support variables. Elderly women with diabetes tend to maintain a smaller gait rhythm with slower speed and cadency and a higher time on the support phase when compared to non- diabetic women. The attempt to maintain gait stability was associated to an increase of the base of support. Biplot graph showed that gait speed is the variable that most contributed to discriminate diabetic form non-diabetic elderly women. On study II the objective was to verify the impact of DM2 time of diagnosis on spatiotemporal gait parameters and functional capacity of elderly women. 82 elderly with DM2 participated in the study, divided in two groups: (1) 49 elderly (71.3 ± 4.8 years) with less than 10 years of diagnosis and (2) 33 elderly (70 ± 4.5 years) with 10 or more years of DM2 time of diagnosis. Spatiotemporal gait parameters were assessed by GAITRite® system and functionality using the following tests: 5 times sit to stand test (STS-5x) and Timed Up and Go. Results showed that only gait speed (122.9 cm/s vs 112.3 cm/s, p=0.001) and step length (62.4 cm vs 59.2 cm, p=0.006) were statistically different among the groups. In relation to functional tests TUG and STS-5x, there were no statistically significant differences between the groups of diabetic elderly with less than ten years of diagnosis and those with ten or more years of diagnosis. The objective of study III was to verify the effect of an aerobic exercise program on functional capacity and plasmatic concentrations of inflammatory markers on DM2 elderly women. 29 elderly with DM2 and mean age of 70.5 ± 3.9 were enrolled in the study. The aerobic program was conducted three times a week during ten weeks as suggested by the American College of Sports Medicine. Functional capacity was assessed by TUG, usual gait speed in 10 meters (GS 10M), handgrip strength (HGS) and Unipodal support test (UST). The analysis of plasmatic concentrations of inflammatory markers was conducted using ELISA (enzyme-linked immunosorbent assay) method, through DuoSet ELISA (R&D Systems, Minnesota, MN) kit for soluble receptors of tumour necrosis factor alpha (sTNFR1 e sTNFR2) and high sensibility kits for IL-6 and interleukin10 (IL-10). After intervention, elderly with DM2 reduced time of execution of TUG in 1.3 ± 1.2s (p < 0.001) and STS-5x in 1.8 ± 2.6s (p < 0.001). Besides, increases in GS10M of 0.14 ± 0.2 m/s ( p = 0.001) and in HGS of 2.2 ± 3.3 kgf ( p = 0.001) were observed. There were no significant differences on UST and on the inflammatory markers assessed between baseline and post intervention. These findings suggest that, speed is the parameter that best discriminate diabetic elderly gait and duration of disease impacts spatiotemporal gait parameters of elderly with DM2. Furthermore, aerobic training had a positive effect on functional capacity of elderly with DM2.