Xavier Melo

Intima-Media Thickness in 11- to 13-Year-Old Children: Variation Attributed to Sedentary Behavior, Physical Activity, Cardiorespiratory Fitness, and Waist Circumference

BACKGROUND It is unclear how sedentary behavior (SED), physical activity (PA), and cardiorespiratory fitness (CRF) influence vascular structure in children of varying body size. This study examined whether associations between SED, PA, and CRF with intima-media thickness (IMT) added to that of abdominal fatness and IMT. Differences in physiological measures among waist circumference (WC) percentiles were tested. METHODS We assessed IMT of the carotid artery in 265 children aged 11 to 13 years (135 girls). Measures included IMT assessed with high-resolution ultrasonography, WC, body fat mass (BFM) from DXA, and CRF determined using a maximal cycle test. SED and PA were assessed by accelerometry. Association between IMT and CRF adjusted for PA variables, and body composition phenotypes were tested with multiple linear regression analysis. RESULTS CRF was related to IMT independently of moderate to vigorous PA (MVPA) and SED (P < .05). When WC was added to the model CRF was no longer associated with IMT (P > .05). Children in the higher WC group had increased mean values of BMI, BFM, WC, and IMT and lower MVPA and CRF (P < .05). CONCLUSION Full modeling of SED, MVPA, CRF, and WC revealed that regional adiposity appears to have the biggest role in arterial structure of children.

Independent Association of Muscular Strength and Carotid Intima-Media Thickness in Children

The aim of this cross-sectional study was to examine the influence of muscular strength on carotid intima-media thickness (cIMT) in children, controlling for the effect of cardiorespiratory fitness (CRF) and central adiposity and to examine if differences among muscular strength tertiles translate to physiological differences. We assessed cIMT of the common carotid artery in 366 children between 11-12 years of age (191 girls). Measures included cIMT assessed with high-resolution ultrasonography, a maximal handgrip strength test, body fat mass and lean mass from DXA and CRF determined using a maximal cycle ergometer test. Association between muscular strength and cIMT adjusted for CRF and central adiposity, as measured by trunk fat, was tested with multiple linear regression analysis. Differences in risk factors among muscular strength groups were tested with ANOVA. The Muscular Strength Index (MSI) was inversely associated with cIMT independently of CRF and central adiposity (p<0.05). The low MSI group had the highest values of cIMT, waist circumference and systolic blood pressure and the lowest CRF (p<0.05). There was an inverse and independent association between muscular strength and cIMT. Low muscular strength was associated with higher levels of cardiovascular disease risk factors in children.

The acute effect of maximal exercise on central and peripheral arterial stiffness indices and hemodynamics in children and adults

This 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.

Single and combined effects of body composition phenotypes on carotid intima‐media thickness

Central fatness might be a more sensitive predictor of atherosclerotic changes in children than are total body fat measures. However, it is unclear whether a total body fat measure coupled with an estimate of a more central pattern of fat accumulation predicts increased carotid intima‐media‐thickness (cIMT) better than either measure alone.

Finding the Best Waist Circumference Measurement Protocol in Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND Central fat accumulation is important in nonalcoholic fatty liver disease (NAFLD) etiology. It is unknown whether any commonly used waist circumference measurement protocol (WCmp), as a whole and central fat accumulation marker, is preferable for patients with NAFLD. The present study sought to find a preferable WCmp to be used in patients with NAFLD, based on 3-fold criteria. METHODS Body fat (BF) was assessed through dual-energy x-ray absorptiometry in 28 patients with NAFLD (19 men, 51 ± 13 years; 9 women, 47 ± 13 years). WC was measured with 4 types of WCmp: WC1, narrowest torso; WC2, just above iliac crest; WC3, middistance between iliac crest and last rib; WC4, at the umbilicus. RESULTS All WC measurements were highly correlated with central BF depots, including trunk BF (r = 0.78, r = 0.82, r = 0.82, r = 0.84 for WC1, WC2, WC3, and WC4, respectively), abdominal BF (r = 0.78, r = 0.78, r = 0.80, r = 0.72 for WC1, WC2, WC3, and WC4, respectively), and central abdominal BF (r = 0.76, r = 0.77, r = 0.78, r = 0.68 for WC1, WC2, WC3, and WC4, respectively), controlling for age, sex, and body mass index. There were no differences between the correlation coefficients obtained between all studied waist circumference measurements and each whole and central analyzed BF variable. CONCLUSIONS All studied WCmps seem suitable for use in patients with NAFLD, particularly as a central BF clinical assessment tool, though not interchangeably. Hence, biological and precision criteria alone did not sanction the superiority of any WCmp. Practical criteria may endorse WC measured at the iliac crest.

Waist-to-Hip Ratio Is Related to Body Fat Content and Distribution Regardless of the Waist Circumference Measurement Protocol in Nonalcoholic Fatty Liver Disease Patients

Central accumulation and distribution of body fat (BF) is an important cardiometabolic risk factor. Waist-to-hip ratio (WHR), commonly elevated in nonalcoholic fatty liver disease (NAFLD) patients, has been endorsed as a risk related marker of central BF content and distribution, but no standardized waist circumference measurement protocol (WCmp) has been proposed. We aimed to investigate whether using different WCmp affects the strength of association between WHR and BF content and distribution in NAFLD patients. BF was assessed with dual energy X-ray absorptiometry (DXA) in 28 NAFLD patients (19 males, 51 ± 13 years, and 9 females, 47 ± 13 years). Waist circumference (WC) was measured using four different WCmp (WC1: minimal waist; WC2: iliac crest; WC3: mid-distance between iliac crest and lowest rib; WC4: at the umbilicus) and WHR was calculated accordingly (WHR1, WHR2, WHR3 and WHR4, respectively). High WHR was found in up to 84.6% of subjects, depending on the WHR considered. With the exception of WHR1, all WHR correlated well with abdominal BF (r = .47 for WHR1; r = .59 for WHR2 and WHR3; r = .58 for WHR4) and BF distribution (r = .45 for WHR1; r = .56 for WHR2 and WHR3; r = .51 for WHR4), controlling for age, sex and body mass index (BMI). WHR2 and WHR3 diagnosed exactly the same prevalence of high WHR (76.9%). The present study confirms the strong relation between WHR and central BF, regardless of WCmp used, in NAFLD patients. WHR2 and WHR3 seemed preferable for use in clinical practice, interchangeably, for the diagnosis of high WHR in NAFLD patients.

A 5-Year Follow-Up of The Benefits of an Exercise Training Program in Liver Recipients Transplanted Due to Familial Amyloidotic Polyneuropathy

Background: Supervised (SE) and home-based exercise (HBE) training regimes are effective on reconditioning patients with familial amyloidotic polyneuropathy (FAP) after liver transplantation, but research of the long-term retention of the benefits attained in patients with FAP has not yet been conducted. Purpose: In this 5-year follow-up study, we aimed to determine whether the exercise training gains in body composition, physical activity, and function promoted by a 24-week SE or HBE training regimes are retained in patients with FAP who resume normal activity. Methodology: Sixteen liver-transplanted patients with FAP were reassessed for body composition (dual X-ray absorptiometry), physical activity (questionnaire), and function (handgrip strength and 6-minute walk test). Results: Total body fat increased with both exercise regimes during follow-up (P < .05; η2 = 0.432-0.625) as well as femoral neck bone density (P = .048; η2 = 0.119). However, gains in upper limbs muscle quality during follow-up (P < .001; η2 = 0.597) were only found in the SE group (P = .042; η2 = 0.245). Both exercise regimes showed retaining aptitudes in walking capacity (P < .05; η2 = 0.329-0.460) and muscle mass (P = .05; η2 = 0.245). Still, none could retain the physical activity levels. Conclusion: Long-term resumption of normal activity following a 24-week SE or HBE regime in patients with FAP resulted in loss of exercise induced increases in physical activity but counterweighted postoperative losses in bone mineral density and substantially retained the benefits in walking capacity, muscle mass, and quality, in particular, in the SE group.

Pulse pressure tracking from adolescence to young adulthood: contributions to vascular health

Abstract Purpose: We examined whether exposure to high PP in adolescence predicts carotid artery intima-media thickness (IMT) and stiffness indices at young adulthood. Methods: Seventy-nine participants had their brachial systolic (SBP) and diastolic blood (DBP) pressures taken at the age of 15–16 years and later at young adulthood (29–31 years). Carotid IMT, distensibility and stiffness index β were measured at young adulthood. Linear and logistical regression analysis were performed. Results: PP at adolescence and at young adulthood predicted vascular health independently of sex, body mass index, and mean arterial pressure, explaining up to 37% of the variance. When analyzing its single constituents, at adolescence DBP was more predictive of vascular health, whereas DBP and SBP were equally important at young adulthood. Adolescents with high PP were at risk for increased carotid IMT (OR: 4.04–4.09), even if PP decreased at young adulthood. Young adults with high PP were at risk for increased stiffness regardless of adolescence PP (OR: 4.64–7.35). Conclusion: PP at adolescence and young adulthood may be a better predictor of early pathological changes in carotid artery structure and stiffness. Whereas carotid IMT in young adults appears to be influenced by PP at adolescence, carotid stiffness depends primarily on current PP.

Energy expenditure during an exercise training session for cardiac patients

Increasing energy expenditure (EE) in cardiac patients remains a challenge. Exercise approaches in cardiac rehabilitation/secondary prevention programs (CR/SP) have consistently resulted in minimal weight loss, due in part to the low exercise-related EE. The purpose of this study was to measure the EE among patients participating in a routine exercise session of Phase III maintenance CR/SP, where a recreational activity was introduced. Twelve overweight/obese male patients with coronary artery disease (aged 62.6 ± 8.5 years) had their total EE measured during a combined aerobic (circuit workout (ACW) and recreational activity) and resistance training (RT) session using a portable gas analyzer. Subjects were instructed to exercise at 60%-70% of heart rate reserve. Activity EE was calculated from total EE and resting EE. The duration of the session was 75.3 ± 1.5 min, of which 59.7 ± 8.8 min were above moderate intensity (3-6 METs). Activity EE was 309 ± 76 kcal, concurring to a total EE of 457 ± 80 kcal (3.9 ± 0.8 METs-h). ACW, recreational activity, and RT fulfilled 34.4% ± 6.4%, 25.0% ± 5.3%, and 14.2% ± 2.7% of the activity EE, respectively. Absolute intensities (METs) were significantly different between the RT (3.9 ± 1.0) and the ACW (6.9 ± 1.8) and recreational activity (5.9 ± 0.8). In conclusion, a combined aerobic and resistance training following standard exercise prescription practices, coupled with a recreational activity, is an effective tool to promote exercise above moderate intensity in male coronary artery disease patients. Clinicians can adopt concepts from recreational activity to develop CR/SP sessions.

Linking cardiorespiratory fitness classification criteria to early subclinical atherosclerosis in children.

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.