Validity of the modified shuttle walk test to assess cardiorespiratory fitness after exercise intervention in overweight/obese adults with primary hypertension

The study aimed to assess whether the Modified Shuttle Walk Test (MSWT) can detect changes in cardiorespiratory fitness (CRF) in overweight/obese people with hypertension (HTN) after an exercise intervention evaluating the equation presented in the previous research by Jurio-Iriarte et al. Participants (N= 248) performed a peak cardiorespiratory exercise test (CPET) and MSWT before and after 16-weeks of different types of aerobic exercise intervention. The formula of Jurio-Iriarte et al. was used to predict peak oxygen uptake (V?O_2peak). The correlation between measured and predicted V?O_2peak was strong (r= 0.76, P< 0.001) with a standard error of estimate (SEE) of 4.9 mL·kg^?1·min^?1; SEE%= 17%. The intraclass correlation coefficient indicates a moderate level of association and agreement (ICC= 0.69; 95% CI 0.34–0.82; P< 0.001) between the measured and predicted V?O_2peak. When analyzing obese participants alone (N= 128), MSWT equation was more accurate compared to the whole sample (ICC= 0.76; 95% CI 0.52–0.87). The relationship between the change of measured and predicted V?O_2peak at follow-up was weak (r= 0.42, P< 0.001) with a 31% SEE, and a low level of association and agreement (ICC= 0.31; 95% CI 0.06–0.49; P< 0.001). In conclusion, although MSWT does not accurately predict CRF in people with HTN after exercise intervention and questions its validity, the new equation may have practical application to estimate V?O_2peak for obese people with HTN when CPET is not available.

Abbreviations: AC: Attention Control; BM: Body Mass; BP: Blood Pressure; CI: Confidence Interval; CRF: Cardiorespiratory Fitness; CPET: Cardiopulmonary Exercise Test; HTN: Primary Hypertension; HR: Heart Rate; HV-HIIT: High-Volume and High-Intensity Interval Training; ICC: Intraclass Correlation Coefficient; LV-HIIT: Low-Volume and High-Intensity Interval Training; MICT: Moderate-intensity continuous training; MSWT: Modified Shuttle Walk Test; SD: Standard Deviation; SEE: Standard Error of Estimate; V?O_2peak: Peak Oxygen Uptake.     

Reduced acute vascular injury and atherosclerosis in hyperlipidemic mice transgenic for lysozyme

Hyperlipidemia promotes oxidant stress, inflammation, and atherogenesis in apolipoprotein E-deficient (ApoE((-/-))) mice. Mice transgenic for lysozyme (LZ-Tg) are resistant to acute and chronic oxidative stress and have decreased circulating levels of pro-oxidant advanced glycation end-products (AGEs). Herein we report that TIB-186 macrophages transduced with adenovirus-expressing human LZ (AdV-LZ) containing the AGE-binding domain facilitated AGE uptake and degradation and that AdV-LZ-transduced macrophages and peritoneal macrophages from LZ-Tg mice suppressed the AGE-triggered tumor necrosis factor-alpha response. We assessed atherosclerosis in LZ-Tg mice crossed with ApoE((-/-)) mice (LZ/ApoE((-/-))) and found increased serum LZ levels and decreased AGE and 8-isoprostanes levels, although hyperlipidemia remained similar to ApoE((-/-)) controls. Atherosclerotic plaques and neointimal lesions at the aortic root and descending aorta were markedly decreased (by 40% and 80%, respectively) in LZ/ApoE((-/-)) versus ApoE((-/-)) mice, as were inflammatory infiltrates. The arterial lesions following femoral artery injury in LZ/ApoE((-/-)) mice were suppressed (intimal to media ratio decreased by 50%), as were AGE deposits and vascular smooth muscle cell activation, compared to ApoE((-/-)) mice. Despite hyperlipidemia, development of atheroma and occlusive, inflammatory arterial neointimal lesions in response to injury was suppressed in LZ/ApoE((-/-)) mice. This effect may be due to the antioxidant properties of LZ, which is possibly linked to the AGE-binding domain region of the molecule.     

Effects of dilutional hyponatremia on brain organic osmolytes and water content in patients with cirrhosis

In advanced cirrhosis there is a reduction in the brain concentration of many organic osmolytes, particularly myo-inositol (MI). Hyponatremia could theoretically aggravate these changes as a result of hypo-osmolality of the extracellular fluid. The aim of this study was to determine the effects of hyponatremia on brain organic osmolytes and brain water content in cirrhosis. Brain organic osmolytes, measured by (1)H-magnetic resonance spectroscopy, and brain water content, as estimated by magnetization transfer ratio (MTR) and measurement of brain volume were determined in 14 patients with dilutional hyponatremia, 10 patients without hyponatremia, and eight healthy subjects. Patients with hyponatremia had remarkable lower levels of MI compared with values in nonhyponatremic patients and healthy subjects. Brain MI levels correlated directly with serum sodium and osmolality. Serum sodium was the only independent predictor of low brain MI levels. Serum sodium also correlated directly with other brain organic osmolytes, such as choline-containing compounds, creatine/phosphocreatine, and N-acetyl-aspartate. By contrast, brain glutamine/glutamate levels were higher in patients with cirrhosis compared with values in healthy subjects and correlated with plasma ammonia levels but not with serum sodium or osmolality. No significant differences were found in MTR values and cerebral volumes between patients with and without hyponatremia. In conclusion, dilutional hyponatremia in cirrhosis is associated with remarkable reductions in brain organic osmolytes that probably reflect compensatory osmoregulatory mechanisms against cell swelling triggered by a combination of high intracellular glutamine and low extracellular osmolality. These findings may be relevant to the pathogenesis of encephalopathy in hyponatremic patients.