RESUMO
BACKGROUND: Low muscle quality index (MQI) is a potential risk of developing functional impairments in older people. However, considering that individuals with Down syndrome (DS) present with a faster decline in biological aging, an investigation on MQI in individuals with DS is necessary. The aims of this present cross-sectional study were to compare (1) MQI between adolescents with and without DS and (2) evaluate laboratory versus field-based estimates of MQI. METHODS: Fifty-six adolescents were recruited and separated into two groups: DS (n = 30, 13 boys and 17 girls; age: 12.38 ± 3.07 years) and a control (non-DS; n = 26, 9 boys and 17 girls; age: 12.46 ± 2.88 years). Laboratory MQI was derived from the ratio of grip strength to arm muscle mass (in kg) measured by dual-energy X-ray absorptiometry (DXA). Field-based MQI was quantified from the ratio of hand grip strength (HGS) to body mass index (BMI). For statistical analyses, a two-way ANOVA was conducted for group comparisons, and a Pearson correlation was used to test the association between field MQI and laboratory MQI. RESULTS: Adolescents with DS displayed lower field (P = 0.001), laboratory MQI estimates (P = 0.001) and HGS (P = 0.001) as compared non-DS. Also, there was a strong correlation effect between field MQI and laboratory MQI estimates (P < 0.001, R = 0.81). CONCLUSION: Adolescents with DS have lower field and laboratory MQI compared with adolescents without DS. Simpler field MQI might be used in daily clinical practice, with special attention to those with DS.
Assuntos
Síndrome de Down , Força da Mão , Masculino , Feminino , Humanos , Adolescente , Idoso , Criança , Força da Mão/fisiologia , Estudos Transversais , Absorciometria de Fóton , Índice de Massa Corporal , Músculos , Composição Corporal/fisiologia , Força Muscular/fisiologiaRESUMO
The purpose of the present study was to correlate the acute and chronic decrease in blood pressure (BP) following resistance training (RT). 13 normotensive women (18-49 years) completed an acute whole body RT session with 3 sets of 10 repetitions at 60% 1RM and then 8 weeks of RT as follows: 3/week, 3 sets of 8-12 repetitions maximum. Systolic (SBP) and diastolic BP (DBP) were measured up to 60 min and 24 h following RT (acute and chronic). The greatest acute decrease of SBP (108.5±7.0 mmHg) and DBP (71.5±6.4 mmHg) values over the 60-min period were reduced compared to pre-exercise (117.3±11.7 and 79.3±8.2 mmHg, respectively; p<0.05). The chronic effect on resting BP was observed only for those presenting acute post-exercise hypotension (PEH). The change in both SBP and DBP following acute RT was correlated with the chronic change in resting SBP and DBP (r>0.5; p≤0.05). The change in 24 h BP after acute RT was correlated with the chronic reduction in SBP (r=0.74) and DBP (r=0.80). The magnitude of PEH is a promising candidate for the prediction of individual BP-related training efficacy.