Browsing by Author "Fernhall, Bo"
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- Body composition and body fat distribution are related to cardiac autonomic control in non-alcoholic fatty liver disease patientsPublication . Pimenta, Nuno; Santa-Clara, Helena; Cortez-Pinto, Helena; Silva-Nunes, José; Rosado, Maria da Lapa; Sousa, Pedro J.; Calé, Rita; Melo, Xavier; Sardinha, Luís B.; Fernhall, BoBACKGROUND/OBJECTIVES: Heart rate recovery (HRR), a cardiac autonomic control marker, was shown to be related to body composition (BC), yet this was not tested in non-alcoholic fatty liver disease (NAFLD) patients. The aim of this study was to determine if, and to what extent, markers of BC and body fat (BF) distribution are related to cardiac autonomic control in NAFLD patients. SUBJECTS/METHODS: BC was assessed with dual-energy X-ray absorptiometry in 28 NAFLD patients (19 men, 51±13 years, and 9 women, 47±13 years). BF depots ratios were calculated to assess BF distribution. Subjects’ HRR was recorded 1 (HRR1) and 2 min (HRR2) immediately after a maximum graded exercise test. RESULTS: BC and BF distribution were related to HRR; particularly weight, trunk BF and trunk BF-to-appendicular BF ratio showed a negative relation with HRR1 (r 1⁄4 0.613, r 1⁄4 0.597 and r 1⁄4 0.547, respectively, Po0.01) and HRR2 (r 1⁄4 0.484, r 1⁄4 0.446, Po0.05, and r 1⁄4 0.590, Po0.01, respectively). Age seems to be related to both HRR1 and HRR2 except when controlled for BF distribution. The preferred model in multiple regression should include trunk BF-to-appendicular BF ratio and BF to predict HRR1 (r2 1⁄4 0.549; Po0.05), and trunk BF-to-appendicular BF ratio alone to predict HRR2 (r2 1⁄4 0.430; Po0.001). CONCLUSIONS: BC and BF distribution were related to HRR in NAFLD patients. Trunk BF-to-appendicular BF ratio was the best independent predictor of HRR and therefore may be best related to cardiovascular increased risk, and possibly act as a mediator in age-related cardiac autonomic control variation.
- Body fat responses to a 1-year combined exercise training program in male coronary artery disease patientsPublication . Pimenta, Nuno; Santa-Clara, Helena; Sardinha, Luís B.; Fernhall, BoObjective: To analyze the body fat (BF) content and distribution modifications in coronary artery disease (CAD) patients in response to a 1-year combined aerobic and resistance exercise training (CET) program. Design and Methods: We followed two groups of CAD male patients for 12 months. One group consisted of 17 subjects (57 6 12 years) who engaged in a CET program (CET group) and the other was a age-matched control group of 10 subjects (58 6 11 years). BF content and distribution were measured through dual energy X-ray absorptiometry (DXA) at baseline and follow-up. Results: We found no differences on body mass and BMI between baseline and end of follow-up in both groups but, in CET group, we found significant reductions in all analyzed BF depots, including total BF (21.60 6 6.00 vs. 20.32 6 5.89 kg, P < 0.01), % total BF (27.8 6 5.5 vs. 26.4 6 5.4%, P < 0.05), trunk fat (12.54 6 3.99 vs. 11.77 6 4.01 kg, P < 0.05), % trunk fat (31.1 6 6.9 and 29.2 6 7.1%, P < 0.05), appendicular fat (8.22 6 2.08 vs. 7.72 6 2.037 kg, P < 0.01), % appendicular fat (25.7 6 4.9 and 24.5 6 4.9%, P < 0.05), and abdominal fat (2.95 6 1.06 vs. 2.75 6 1.10 kg, P < 0.05). Control group showed significant increase in appendicular fat (7.63 6 1.92 vs. 8.10 6 2.12 kg, P < 0.05). Conclusions: These results confirm the positive effect of CET on body composition of CAD patients, despite no changes in body mass or BMI. In this study, we observed no alterations on BF distribution meaning similar rate of fat loss in all analyzed BF depots. These results also alert for the limitations of BMI for tracking body composition changes.
- Linking cardiorespiratory fitness classification criteria to early subclinical atherosclerosis in childrenPublication . Melo, Xavier; Santa-Clara, Helena; Santos, Diana; Pimenta, Nuno M.; Minderico, Cláudia S.; Fernhall, Bo; Sardinha, Luís B.It is unclear if cardiorespiratory fitness (CRF) can be used as a screening tool for premature changes in carotid intima-media thickness (cIMT) in paediatric populations. The purpose of this cross-sectional study was 3-fold: (i) to determine if CRF can be used to screen increased cIMT; (ii) to determine an optimal CRF cut-off to predict increased cIMT; and (iii) to evaluate its ability to predict increased cIMT among children in comparison with existent CRF cut-offs. cIMT was assessed with high-resolution ultrasonography and CRF was determined using a maximal cycle test. Receiver operating characteristic analyses were conducted in boys (n = 211) and girls (n = 202) aged 11-12 years to define the optimal sex-specific CRF cut-off to classify increased cIMT (≥75th percentile). Logistic regression was used to examine the association between the CRF cut-offs with the risk of having an increased cIMT. The optimal CRF cut-offs to predict increased cIMT were 45.81 and 34.46 mL·kg(-1)·min(-1) for boys and girls, respectively. The odds-ratios for having increased cIMT among children who were unfit was up to 2.8 times the odds among those who were fit (95% confidence interval: 1.40-5.53). Considering current CRF cut-offs, only those suggested by Adegboye et al. 2011. (Br. J. Sports Med. 45(9): 722-728) and Boddy et al. 2012 (PLoS One, 7(9): e45755) were significant in predicting increased cIMT. In conclusion, CRF cut-offs (boys: ≤ 45.8; girls: ≤ 34.5 mL·kg(-1)·min(-1)) are associated with thickening of the arterial wall in 11- to 12-year-old children. Low CRF is an important cardiovascular risk factor in children and our data highlight the importance of obtaining an adequate CRF.
- The acute effect of maximal exercise on central and peripheral arterial stiffness indices and hemodynamics in children and adultsPublication . Melo, Xavier; Fernhall, Bo; Santos, Diana; Pinto, Rita; Pimenta, Nuno; Sardinha, Luis; Santa-Clara, HelenaThis study compared the effects of a bout of maximal running exercise on arterial stiffness in children and adults. Right carotid blood pressure and artery stiffness indices measured by pulse wave velocity (PWV), compliance and distensibility coefficients, stiffness index α and β (echo-tracking), contralateral carotid blood pressure, and upper and lower limb and central/aortic PWV (applanation tonometry) were taken at rest and 10 min after a bout of maximal treadmill running in 34 children (7.38 ± 0.38 years) and 45 young adults (25.22 ± 0.91 years) having similar aerobic potential. Two-by-two repeated measures analysis of variance and analysis of covariance were used to detect differences with exercise between groups. Carotid pulse pressure (PP; η(2) = 0.394) increased more in adults after exercise (p < 0.05). Compliance (η(2) = 0.385) decreased in particular in adults and in those with high changes in distending pressure, similarly to stiffness index α and β. Carotid PWV increased more in adults and was related to local changes in PP but not mean arterial pressure (MAP). Stiffness in the lower limbs decreased (η(2) = 0.115) but apparently only in those with small MAP changes (η(2) = 0.111). No significant exercise or group interaction effects were found when variables were adjusted to height. An acute bout of maximal exercise can alter arterial stiffness and hemodynamics in the carotid artery and within the active muscle beds. Arterial stiffness and hemodynamic response to metabolic demands during exercise in children simply reflect their smaller body size and may not indicate a particular physiological difference compared with adults.