Cardiac Autonomic Adjustments During Baroreflex Test in Obese and Non-Obese Preadolescents

Abstract Background: Recent studies have shown changes in cardiac autonomic control of obese preadolescents. Objective: To assess the heart rate responses and cardiac autonomic modulation of obese preadolescents during constant expiratory effort. Methods: This study assessed 10 obese and 10 non-obese preadolescents aged 9 to 12 years. The body mass index of the obese group was between the 95th and 97th percentiles of the CDC National Center for Health Statistics growth charts, while that of the non-obese group, between the 5th and 85th percentiles. Initially, they underwent anthropometric and clinical assessment, and their maximum expiratory pressures were obtained. Then, the preadolescents underwent a constant expiratory effort of 70% of their maximum expiratory pressure for 20 seconds, with heart rate measurement 5 minutes before, during and 5 minutes after it. Heart rate variability (HRV) and heart rate values were analyzed by use of a software. Results: The HRV did not differ when compared before and after the constant expiratory effort intra- and intergroup. The heart rate values differed (p < 0.05) during the effort, being the total variation in non-obese preadolescents of 18.5 ± 1.5 bpm, and in obese, of 12.2 ± 1.3 bpm. Conclusion: The cardiac autonomic modulation did not differ between the groups when comparing before and after the constant expiratory effort. However, the obese group showed lower cardiovascular response to baroreceptor stimuli during the effort, suggesting lower autonomic baroreflex sensitivity.

Correlation of Insulin Resistance with Anthropometric Measures and Blood Pressure in Adolescents

Abstract Background: Blood pressure is directly related to body mass index, and individuals with increased waist circumference have higher risk of developing hypertension, insulin resistance, and other metabolic changes, since adolescence. Objective: to evaluate the correlation of blood pressure with insulin resistance, waist circumference and body mass index in adolescents. Methods: Cross-section study on a representative sample of adolescent students. One group of adolescents with altered blood pressure detected by casual blood pressure and/or home blood pressure monitoring (blood pressure > 90th percentile) and one group of normotensive adolescents were studied. Body mass index, waist circumference were measured, and fasting glucose and plasma insulin levels were determined, using the HOMA-IR index to identify insulin resistance. Results: A total of 162 adolescents (35 with normal blood pressure and 127 with altered blood pressure) were studied; 61% (n = 99) of them were boys and the mean age was 14.9 ± 1.62 years. Thirty-eight (23.5%) adolescents had altered HOMA-IR. The group with altered blood pressure had higher values of waist circumference, body mass index and HOMA-IR (p<0.05). Waist circumference was higher among boys in both groups (p<0.05) and girls with altered blood pressure had higher HOMA-IR than boys (p<0.05). There was a significant moderate correlation between body mass index and HOMA-IR in the group with altered blood pressure (ρ = 0.394; p < 0.001), and such correlation was stronger than in the normotensive group. There was also a significant moderate correlation between waist circumference and HOMA-IR in both groups (ρ = 0.345; p < 0.05). Logistic regression showed that HOMA-IR was as predictor of altered blood pressure (odds ratio - OR = 2.0; p = 0.001). Conclusion: There was a significant association of insulin resistance with blood pressure and the impact of insulin resistance on blood pressure since childhood. The correlation and association between markers of cardiovascular diseases was more pronounced in adolescents with altered blood pressure, suggesting that primary prevention strategies for cardiovascular risk factors should be early implemented in childhood and adolescence.

Assessment of Intima-Media Thickness in Healthy Children Aged 1 to 15 Years

Abstract Background: Carotid intima-media thickness (CIMT) has been shown to be increased in children and adolescents with traditional cardiovascular risk factors such as obesity, hypertension, and chronic kidney disease, compared with those of healthy children. Objective: To assess the influence of sex, age and body mass index (BMI) on the CIMT in healthy children and adolescents aged 1 to 15 years. Methods: A total of 280 healthy children and adolescents (males, n=175; mean age, 7.49±3.57 years; mean BMI, 17.94±4.1 kg/m2) were screened for CIMT assessment. They were divided into 3 groups according to age: GI, 1 to 5 years [n=93 (33.2%); males, 57; mean BMI, 16±3 kg/m2]; GII, 6 to 10 years [n=127 (45.4%); males, 78; mean BMI, 17.9±3.7 kg/m2], and GIII, 11 to 15 years [n=60 (21.4%); males, 40; mean BMI, 20.9±4.5 kg/m2]. Results: There was no significant difference in CIMT values between male and female children and adolescents (0.43±0.06 mm vs. 0.42±0.05 mm, respectively; p=0.243). CIMT correlated with BMI neither in the total population nor in the 3 age groups according to Pearson correlation coefficient. Subjects aged 11 to 15 years had the highest CIMT values (GI vs. GII, p=0.615; GI vs. GIII, p=0.02; GII vs. GIII, p=0.004). Conclusions: CIMT is constant in healthy children younger than 10 years, regardless of sex or BMI. CIMT increases after the age of 10 years.

Early Markers of Atherosclerotic Disease in Individuals with Excess Weight and Dyslipidemia

Abstract Background: Excessive weight is a cardiovascular risk factor since it generates a chronic inflammatory process that aggravates the endothelial function. Objective: To evaluate the endothelial function in individuals with excess weight and mild dyslipidemia using brachial artery flow-mediated dilation (BAFMD), and the association of endothelial function with anthropometric and biochemical variables. Methods: Cross-sectional study that included 74 individuals and evaluated anthropometric variables (body mass index [BMI], waist-hip ratio [WHR], waist circumference [AC], and percentage of body fat [PBF]), biochemical (blood glucose, insulinemia, ultrasensitive C-reactive protein, fibrinogen, total cholesterol, HDL-cholesterol, triglycerides, and LDL-cholesterol) and endothelial function (BAFMD, evaluated by ultrasound). The statistical analysis was performed with SPSS, version 16.0. To study the association between the variables, we used chi-square, Student's t and Mann-Whitney tests, and Pearson's correlation. Logistic regression analyzed the independent influence of the factors. Values of p < 0.05 were considered significant. Results: The participants had a mean age of 50.8 years, and 57% were female. BMI, WC, WHR, and PBF showed no significant association with BAFMD. The male gender (p = 0.02) and higher serum levels of fibrinogen (p = 0.02) were significantly and independently associated with a BAFMD below 8%. Conclusions: In individuals with excess weight and mild untreated dyslipidemia, male gender and higher levels of fibrinogen were independently associated with worse BAFMD.

Acute Effects of Exercise on Blood Pressure: A Meta-Analytic Investigation

Abstract Hypertension affects 25% of the world's population and is considered a risk factor for cardiovascular disorders and other diseases. The aim of this study was to examine the evidence regarding the acute effect of exercise on blood pressure (BP) using meta-analytic measures. Sixty-five studies were compared using effect sizes (ES), and heterogeneity and Z tests to determine whether the ES were different from zero. The mean corrected global ES for exercise conditions were -0.56 (-4.80 mmHg) for systolic BP (sBP) and -0.44 (-3.19 mmHg) for diastolic BP (dBP; z ≠ 0 for all; p < 0.05). The reduction in BP was significant regardless of the participant's initial BP level, gender, physical activity level, antihypertensive drug intake, type of BP measurement, time of day in which the BP was measured, type of exercise performed, and exercise training program (p < 0.05 for all). ANOVA tests revealed that BP reductions were greater if participants were males, not receiving antihypertensive medication, physically active, and if the exercise performed was jogging. A significant inverse correlation was found between age and BP ES, body mass index (BMI) and sBP ES, duration of the exercise's session and sBP ES, and between the number of sets performed in the resistance exercise program and sBP ES (p < 0.05). Regardless of the characteristics of the participants and exercise, there was a reduction in BP in the hours following an exercise session. However, the hypotensive effect was greater when the exercise was performed as a preventive strategy in those physically active and without antihypertensive medication.

Geschlechterspezifischer Zusammenhang zwischen Adipositas und der Aktivität des autonomen Nervensystems

Magdeburg, Univ., Med. Fak., Diss., 2015

Changes of overweight and obesity in the adult Swiss population according to educational level, from 1992 to 2007.

In many high income developed countries, obesity is inversely associated with educational level. In some countries, a widening gap of obesity between educational groups has been reported. The aim of this study was to assess trends in body mass index (BMI) and in prevalence of overweight and obesity and their association with educational level in the adult Swiss population. Four cross-sectional National health interview surveys conducted in 1992/93 (n = 14,521), 1997 (n = 12,474), 2002 (n = 18,908) and 2007 (n = 17,879) using representative samples of the Swiss population (age range 18-102 years). BMI was derived from self-reported data. Overweight was defined as BMI > or = 25 and <30 kg/m(2), and obesity as BMI > or = 30 kg/m(2). Mean (+/- standard deviation) BMI increased from 24.7 +/- 3.6 in 1992/3 to 25.4 +/- 3.6 kg/m2 in 2007 in men and 22.8 +/- 3.8 to 23.7 +/- 4.3 kg/m(2) in women. Between 1992/3 and 2007, the prevalence of overweight + obesity increased from 40.4% to 49.5% in men and from 22.3% to 31.3% in women, while the prevalence of obesity increased from 6.3% to 9.4% in men and from 4.9% to 8.5% in women. The rate of increase in the prevalence of obesity was greater between 1992/3 and 2002 (men: +0.26%/year; women: +0.31%/year) than between 2002 and 2007 (men: +0.10%/year; women: +0.10%/year). A sizable fraction (approximately 25%) of the increasing mean BMI was due to increasing age of the participants over time. The increase was larger in low than high education strata of the population. BMI was strongly associated with low educational level among women and this gradient remained fairly constant over time. A weaker similar gradient by educational level was apparent in men, but it tended to increase over time. In Switzerland, overweight and obesity increased between 1992 and 2007 and was associated with low education status in both men and women. A trend towards a stabilization of mean BMI levels was noted in most age categories since 2002. The increase in the prevalence of obesity was larger in low education strata of the population. These findings suggest that obesity preventive measures should be targeted according to educational level in Switzerland.

Impact of preoperative risk factors on morbidity after esophagectomy: is there room for improvement?

BACKGROUND: Despite progress in multidisciplinary treatment of esophageal cancer, oncologic esophagectomy is still the cornerstone of therapeutic strategies. Several scoring systems are used to predict postoperative morbidity, but in most cases they identify nonmodifiable parameters. The aim of this study was to identify potentially modifiable risk factors associated with complications after oncologic esophagectomy. METHODS: All consecutive patients with complete data sets undergoing oncologic esophagectomy in our department during 2001-2011 were included in this study. As potentially modifiable risk factors we assessed nutritional status depicted by body mass index (BMI) and preoperative serum albumin levels, excessive alcohol consumption, and active smoking. Postoperative complications were graded according to a validated 5-grade system. Univariate and multivariate analyses were used to identify preoperative risk factors associated with the occurrence and severity of complications. RESULTS: Our series included 93 patients. Overall morbidity rate was 81 % (n = 75), with 56 % (n = 52) minor complications and 18 % (n = 17) major complications. Active smoking and excessive alcohol consumption were associated with the occurrence of severe complications, whereas BMI and low preoperative albumin levels were not. The simultaneous presence of two or more of these risk factors significantly increased the risk of postoperative complications. CONCLUSIONS: A combination of malnutrition, active smoking and alcohol consumption were found to have a negative impact on postoperative morbidity rates. Therefore, preoperative smoking and alcohol cessation counseling and monitoring and improving the nutritional status are strongly recommended.

Resting metabolic rate and protein turnover in apparently healthy elderly Gambian men.

Body composition, resting energy expenditure (REE), and whole body protein metabolism were studied in 26 young and 28 elderly Gambian men matched for body mass index during the dry season in a rural village in The Gambia. REE was measured by indirect calorimetry (hood system) in the fasting state and after five successive meals. Rates of whole body nitrogen flux, protein synthesis, and protein breakdown were determined in the fed state from the level of isotopic enrichment of urinary ammonia over a period of 12 h after a single oral dose of [15N]glycine. Expressed in absolute value, REE was significantly lower in the elderly compared with the young group (3.21 +/- 0.07 vs. 4.04 +/- 0.07 kJ/min, P < 0.001) and when adjusted to body weight (3.29 +/- 0.05 vs. 3.96 +/- 0.05 kJ/min, P < 0.0001) and fat-free mass (FFM; 3.38 +/- 0.01 vs. 3.87 +/- 0.01 kJ/min, P < 0.0001). The rate of protein synthesis averaged 207 +/- 13 g protein/day in the elderly and 230 +/- 13 g protein/day in the young group, whereas protein breakdown averaged 184 +/- 13 g protein/day in the elderly and 203 +/- 13 g protein/day in the young group (nonsignificant). When values were adjusted for body weight or FFM, they did not reveal any difference between the two groups. It is concluded that the reduced REE adjusted for body composition observed in elderly Gambian men is not explained by a decrease in protein turnover.

Rare genomic structural variants in complex disease: lessons from the replication of associations with obesity.

The limited ability of common variants to account for the genetic contribution to complex disease has prompted searches for rare variants of large effect, to partly explain the 'missing heritability'. Analyses of genome-wide genotyping data have identified genomic structural variants (GSVs) as a source of such rare causal variants. Recent studies have reported multiple GSV loci associated with risk of obesity. We attempted to replicate these associations by similar analysis of two familial-obesity case-control cohorts and a population cohort, and detected GSVs at 11 out of 18 loci, at frequencies similar to those previously reported. Based on their reported frequencies and effect sizes (OR≥25), we had sufficient statistical power to detect the large majority (80%) of genuine associations at these loci. However, only one obesity association was replicated. Deletion of a 220 kb region on chromosome 16p11.2 has a carrier population frequency of 2×10(-4) (95% confidence interval [9.6×10(-5)-3.1×10(-4)]); accounts overall for 0.5% [0.19%-0.82%] of severe childhood obesity cases (P = 3.8×10(-10); odds ratio = 25.0 [9.9-60.6]); and results in a mean body mass index (BMI) increase of 5.8 kg.m(-2) [1.8-10.3] in adults from the general population. We also attempted replication using BMI as a quantitative trait in our population cohort; associations with BMI at or near nominal significance were detected at two further loci near KIF2B and within FOXP2, but these did not survive correction for multiple testing. These findings emphasise several issues of importance when conducting rare GSV association, including the need for careful cohort selection and replication strategy, accurate GSV identification, and appropriate correction for multiple testing and/or control of false discovery rate. Moreover, they highlight the potential difficulty in replicating rare CNV associations across different populations. Nevertheless, we show that such studies are potentially valuable for the identification of variants making an appreciable contribution to complex disease.

Creation of an Age-Adjusted, Dual-Energy X-ray Absorptiometry-Derived Trabecular Bone Score Curve for the Lumbar Spine in Non-Hispanic US White Women.

The trabecular bone score (TBS, Med-Imaps, Pessac, France) is an index of bone microarchitecture texture extracted from anteroposterior dual-energy X-ray absorptiometry images of the spine. Previous studies have documented the ability of TBS of the spine to differentiate between women with and without fractures among age- and areal bone mineral density (aBMD)-matched controls, as well as to predict future fractures. In this cross-sectional analysis of data collected from 3 geographically dispersed facilities in the United States, we investigated age-related changes in the microarchitecture of lumbar vertebrae as assessed by TBS in a cohort of non-Hispanic US white American women. All subjects were 30 yr of age and older and had an L1-L4aBMDZ-score within ±2 SD of the population mean. Individuals were excluded if they had fractures, were on any osteoporosis treatment, or had any illness that would be expected to impact bone metabolism. All data were extracted from Prodigy dual-energy X-ray absorptiometry devices (GE-Lunar, Madison, WI). Cross-calibrations between the 3 participating centers were performed for TBS and aBMD. aBMD and TBS were evaluated for spine L1-L4 but also for all other possible vertebral combinations. To validate the cohort, a comparison between the aBMD normative data of our cohort and US non-Hispanic white Lunar data provided by the manufacturer was performed. A database of 619 non-Hispanic US white women, ages 30-90 yr, was created. aBMD normative data obtained from this cohort were not statistically different from the non-Hispanic US white Lunar normative data provided by the manufacturer (p = 0.30). This outcome thereby indirectly validates our cohort. TBS values at L1-L4 were weakly inversely correlated with body mass index (r = -0.17) and weight (r = -0.16) and not correlated with height. TBS values for all lumbar vertebral combinations decreased significantly with age. There was a linear decrease of 16.0% (-2.47 T-score) in TBS at L1-L4 between 45 and 90 yr of age (vs. -2.34 for aBMD). Microarchitectural loss rate increased after age 65 by 50% (-0.004 to -0.006). Similar results were obtained for other combinations of lumbar vertebra. TBS, an index of bone microarchitectural texture, decreases with advancing age in non-Hispanic US white women. Little change in TBS is observed between ages 30 and 45. Thereafter, a progressive decrease is observed with advancing age. The changes we observed in these American women are similar to that previously reported for a French population of white women (r(2) > 0.99). This reference database will facilitate the use of TBS to assess bone microarchitectural deterioration in clinical practice.

Elevated blood pressure prevalence in children did not follow the increase in overweight: results from a school-based study in a rapidly developing country, 1998-2006

Background: Blood pressure (BP) is strongly associated with body weight and there is concern that the pediatric overweight epidemic could lead to an increase in children's mean BP. Objectives: We analyzed BP trends from 1998 to 2006 among children of the Seychelles, a rapidly developing middle-income country in Africa. Methods: Serial school-based surveys of weight, height and BP were conducted yearly between 1998-2006 among all students of the country in four school grades (kindergarten, 4th, 7th and 10th years of compulsory school). We used the CDC criteria to define "overweight" (BMI _95th sex-, and age-specific percentile) and the NHBPEP criteria for "elevated BP" (BP _95th sex-, age-, and height specific percentile). Methods for height, weight, and BP measurements were identical over the study period. The trends in mean BMI and mean systolic/diastolic BP were assessed with linear regression. Results: 27,703 children aged 4-18 years (participation rate: 79%) contributed 43,927 observations on weight, height, and BP. The prevalence of overweight increased from 5.1% in 1998-2000 to 8.1% in 2004-2006 among boys, and from 6.1% to 9.1% among girls, respectively. The prevalence of elevated BP was 8.4% in 1998-2000 and 6.9% in 2004-2006 among boys; 9.8% and 7.8% among girls, respectively. Over the 9-years study period, age-adjusted body mass index (BMI) increased by 0.078 kg/m2/year in boys and by 0.083 kg/m2/year in girls (both sexes, P_0.001). Age- and height-adjusted systolic BP decreased by -0.37 mmHg/year in boys and by -0.34 mmHg/year in girls (both sexes, P_0.001). Diastolic BP did not change in boys (-0.02 mmHg/year, P: 0.40) and slightly increased in girls (0.07 mmHg/year, P: 0.003). These trend estimates were altered modestly upon further adjustment for BMI or if analyses were based on median rather than mean values. Conclusion: Although body weight increased markedly between 1998 and 2006 in this population, systolic BP decreased and diastolic BP changed only marginally. This suggests that population increases in body weight are not necessarily associated with corresponding rises in BP in children.

Videolaryngoscopy improves intubation condition in morbidly obese patients

Résumé : Contexte clinique et objectifs: l'intubation oro-trachéale peut être plus difficile chez les patients obèses morbides (index de masse corporelle BMI > 35 kg/m2) que chez les patients non-obèses. Récemment, de nouveaux instruments permettant une intubation assistée au moyen d'une caméra ont été développés. Notre expérience pratique avec la vidéolaryngoscopie nous a conduit à l'hypothèse que celle-ci pourrait améliorer la vision laryngoscopique chez cette population spécifique et de ce fait faciliter l'intubation. Le but de cette étude était donc d'évaluer le bénéfice du vidéolaryngoscope sur le grade de laryngoscopie chez le patient obèse morbide. Résultats : le grade laryngoscopique fut abaissé de manière significative avec le vidéolaryngoscope comparé à la vision directe avec un laryngoscope standard. Lorsque le grade laryngoscopique était plus grand que 1 à la laryngoscopie directe, il fut dans la grande majorité des cas (93% des patients) abaissé avec le vidéolaryngoscope. Chez les 7 % restant, le grade laryngoscopique resta identique. Conclusions : chez le patient obèse morbide, l'utilisation du vidéolaryngoscope améliore de manière significative la visualisation du larynx et de ce fait facilite l'intubation. Une application systématique de ce procédé pourrait donc permettre de réduire l'incidence d'une intubation difficile ainsi que ses conséquences chez cette population de patients. Summary : Background and objective: Tracheal intubation may be more difficult in morbidly obese patients (body mass index >35 kgM-2) than in the non-obese. Recently, new video-assisted intubation devices have been developed. After some experience with videolaryngoscopy, we hypothesized that it could improve the laryngoscopic view in this specific population and therefore facilitate intubation. The aim of this study was to assess the benefit of a videolaryngoscope on the grade of laryngoscopy in morbid obesity. Methods: We studied 80 morbidly obese patients undergoing bariatric surgery. They were randomly assigned to one of two groups. One group was intubated with the help of the videolaryngoscope and in the control group the screen of the videolaryngoscope was hidden to the intubating anaesthesiologist. The primary end-point of the study was to assess in both groups the Cormack and Lehane direct and indirect grades of laryngoscopy. The duration of intubation, the number of attempts needed as well as the minimal SPO2 reached during the intubation process were measured. Results: Grade of laryngoscopy was significantly lower with the videolaryngoscope compared with the direct vision (P < 0.001). When the grade of laryngoscopy was higher than one with the direct laryngoscopy (n = 30), it was lower in 28 cases with the videolaryngoscope and remained the same only in two cases (P < 0.001). The minimal SPO2 reached during the intubation was higher with the videolaryngoscope but it did not reach statistical significance. Conclusions: In morbidly obese patients, the use of the videolaryngoscope significantly improves the visualization of the larynx and thereby facilitates intubation.

Age, smoking and overweight contribute to the development of intestinal metaplasia of the cardia.

AIM: To assess the role of Helicobacter pylori (H. pylori), gastroesophageal reflux disease (GERD), age, smoking and body weight on the development of intestinal metaplasia of the gastric cardia (IMC).¦METHODS: Two hundred and seventeen patients scheduled for esophagogastroduodenoscopy were enrolled in this study. Endoscopic biopsies from the esophagus, gastroesophageal junction and stomach were evaluated for inflammation, the presence of H. pylori and intestinal metaplasia. The correlation of these factors with the presence of IMC was assessed using logistic regression.¦RESULTS: IMC was observed in 42% of the patients. Patient age, smoking habit and body mass index (BMI) were found as potential contributors to IMC. The risk of developing IMC can be predicted in theory by combining these factors according to the following formula: Risk of IMC = a + s - 2B where a = 2,...6 decade of age, s = 0 for non-smokers or ex-smokers, 1 for < 10 cigarettes/d, 2 for > 10 cigarettes/d and B = 0 for BMI < 25 kg/m² (BMI < 27 kg/m² in females), 1 for BMI > 25 kg/m² (BMI > 27 kg/m² in females). Among potential factors associated with IMC, H. pylori had borderline significance (P = 0.07), while GERD showed no significance.¦CONCLUSION: Age, smoking and BMI are potential factors associated with IMC, while H. pylori and GERD show no significant association. IMC can be predicted in theory by logistic regression analysis.