Federico Pieruzzi

Results of blood pressure screening in a population of school-aged children in the province of Milan: role of overweight.

Objectives To study the prevalence of high blood pressure (BP) in an Italian paediatric population, and to verify whether in this population elevated BP values are associated with overweight (OW). Study design Children (1206 males, 1210 females) from the lower-grade public schools (ages 6–11 years) were studied. Body weight, height and BP were measured in each child. Elevated BP was defined if resting systolic and/or diastolic BP values equalled or exceeded the 95th percentile according to gender, age and height, based on the US normative BP tables. Overweight children were identified using four different methods: (1) the classification based on the relative body weight; (2) the French references by Rolland-Cachera et al. (Am J Clin Nutr 1982; 36:178–184); (3) the International Obesity Task Force charts; and (4) the Italian charts defined by Cacciari et al. (Eur J Clin Nutr 2002; 56:171–180). Results The prevalence of high BP in our population was 4.2% and was significantly higher in females (65/1210 = 5.4%) than in males (37/1206 = 3.1%), P = 0.005. The different methods used to define OW provide different estimates of OW prevalence (from 17.0 to 38.6%). The percentage of high BP subjects was significantly higher in OW than in normal-weight children regardless of the method used for the definition of the weight class (P < 0.0001), in both genders. In addition, for each age range, absolute systolic and diastolic BP values were higher in OW as compared to normal-weight children both in males and in females (P < 0.0001). Conclusions Our study indicates the importance of performing BP screenings in the paediatric population, and to promote interventions that may reduce the prevalence of OW in children.

Maternal perception of excess weight in children: a survey conducted by paediatricians in the province of Milan.

OBJECTIVEnTo establish whether maternal perception of a childs body weight (BW) and food intake is related to the level of maternal education.nnnSTUDY DESIGNnHeight and BW of 569 mother/child couples were measured, and mothers received a questionnaire regarding their perception of their own weight and their childs BW and food intake.nnnRESULTSnTwenty-nine percent of mothers and 35% of children were overweight or obese. Only 10% of the mothers underestimated their own weight, while 37% overestimated it. In contrast, 28% of mothers underestimated their childs BW, while 9% overestimated it. Higher maternal instruction level was significantly associated to a lower weight class in both mothers and children, and to a correct perception of the childs weight. Fifty-seven per cent of the mothers who perceived their child to be overweight or obese were not concerned. Forty-four per cent of the mothers with overweight or obese children believed that their child was eating correctly.nnnCONCLUSIONSnA better understanding of how mothers perceive the problem of excess weight in their children is relevant to the success of preventive interventions in childhood obesity.

Usefulness of waist circumference for the identification of childhood hypertension.

Objective To investigate the ability of BMI and waist circumference, single and combined, in identifying children who are at risk of hypertension and in influencing absolute blood pressure values. Methods The body weight, height, waist circumference and blood pressure of 4177 5–11-year-old school children [2005 (48%) girls] were collected. Elevated blood pressure was defined if either systolic or diastolic blood pressure values or both were more than the 95th percentile according to sex, age and height (US normative blood pressure tables). Overweight and obese children were defined according to International Obesity Task Force BMI cut-offs. Results The prevalence of hypertension was 4.1% and increased together with weight class: 1.4% (n = 42/3076) in normal weight, 7.1% (n = 59/827) in overweight and 25% (n = 69/274) in obese (P < 0.001). Only BMI and waist circumference showed a remarkable ability to discriminate hypertensive children (areas under receiver operating characteristic curves, 0.84 and 0.76, respectively). The multivariate analysis showed that z-scores for both BMI and waist circumference were significantly related to the risk of hypertension with odds ratios of 3.59 (95% confidence interval, 2.55, 5.06) and 1.20 (95% confidence interval, 1.04, 1.39), respectively, after adjusting for sex and age. When the weight class was included in the multivariate analysis, waist circumference retained its ability to identify hypertensive children only in the obese class (odds ratio, 1.44; 95% confidence interval, 1.21, 1.72; P < 0.01). When considering blood pressure as a continuous variable, both weight class and waist circumference showed a significant effect on systolic and diastolic blood pressure absolute values (P < 0.01). The effect of waist circumference on blood pressure values was maintained even when corrected for BMI. Conclusion High blood pressure is strongly associated with excess weight. Waist circumference improves the ability of BMI to identify hypertension in obese children. Waist circumference is related to absolute blood pressure values in all weight classes.

QT interval prolongation and decreased heart rate variability in cirrhotic patients: relevance of hepatic venous pressure gradient and serum calcium

A prolongation of QT interval has been shown in patients with cirrhosis and it is considered as part of the definition of the so-called cirrhotic cardiomyopathy. The aim of the present study was to assess the determinants of QT interval prolongation in cirrhotic patients. Forty-eight male patients with different stages of liver disease were divided into three subgroups according to the Child-Pugh classification. All patients underwent a 24-h ECG Holter recording. The 24-h mean of QT intervals corrected for heart rate (termed QTc) and the slope of the regression line QT/RR were calculated. HRV (heart rate variability), plasma calcium and potassium concentration and HVPG (hepatic venous pressure gradient) were measured. QTc was progressively prolonged from Child A to Child C patients (P=0.001). A significant correlation between QTc and HVPG was found (P=0.003). Patients with alcohol-related cirrhosis presented QTc prolongation more frequently than patients with post-viral cirrhosis (P<0.001). The QT/RR slope was steeper in subjects with alcoholic aetiology as compared with viral aetiology (P=0.02), suggesting that these patients have a further QTc prolongation when heart rate decreases. The plasma calcium concentration was inversely correlated with QTc (P<0.001). The presence of severe portal hypertension was associated with decreased HRV (P<0.001). Cirrhotic patients with a more severe disease, especially of alcoholic aetiology, who have greater HVPG and lower calcium plasma levels, have an altered ventricular repolarization and a reduced vagal activity to the heart, which may predispose to life-threatening arrhythmias.

Analysis of Heart Period and Arterial Pressure Variability in Childhood Hypertension: Key Role of Baroreflex Impairment

In adults, initial stages of hypertension are associated with elevated sympathetic drive and significant alterations in indirect autonomic markers. There is growing evidence that children in the highest-pressure percentiles will be more likely to develop hypertension in adulthood, although mechanisms are not understood. We assessed whether computer analysis of RR interval and arterial blood pressure variability could detect early autonomic alterations in childhood hypertension, as assessed by noninvasive time and frequency domain measures of baroreflex regulation. We studied 75 children, subdivided in 3 subgroups of similar age (9.7±0.2 years): control subjects, prehypertensive children (ie, children with arterial pressure values >90th and <95th percentile for age, gender, and height), and children in the hypertensive range (ie, >95th percentile; systolic arterial pressure: 97±3/57±2, 121±5/70±1, and 128±2/80±2 mm Hg, respectively). We observed that hypertensive children demonstrate a significant impairment of the baroreflex as compared with control subjects (index α: 20±2 and 40±4 ms/mm Hg; spontaneous baroreflex slope: 20±2 and 37±5; ms/mm Hg; P <0.05 in both cases) and reduced RR variance. A similar baroreflex impairment is also observed in children whose arterial pressure falls short of this limit, ie, in the prehypertensive range. In conclusion, hypertensive children display a marked baroreflex impairment. A similar baroreflex impairment is also observed in the prehypertensive state. Baroreflex assessment could furnish additional information in the clinical assessment of pediatric hypertension.

Renal afferents signaling diuretic activity in the cat.

Mechanoreceptors and chemoreceptors have been identified inside the kidney, but their functional role is still largely unclear. The aim of this study was to investigate whether changes in urine output could modify the discharge rate of renal afferent fibers. Experiments were performed in anesthetized cats in which afferent renal nerve activity (ARNA) was recorded by standard electrophysiological techniques from a centrally cut renal nerve. Arterial pressure, renal blood flow velocity, urine flow rate, and renal pelvic pressure were also measured. Three diuretic maneuvers were tested in the same cat: intravenous administration of physiological saline (8 to 13 mL/min for 2 minutes), furosemide (1 mg/kg), and atrial natriuretic peptide (ANP, 1 microgram/kg). The three maneuvers increased urine flow rate and pelvic pressure, respectively, 137.0 +/- 20.6% and 136.8 +/- 21.1% (saline), 148.6 +/- 31.7% and 139.6 +/- 43.5% (furosemide), and 75.9 +/- 7.9% and 62.1 +/- 21.2% (ANP) at the time of the maximum response. Arterial pressure slightly increased after saline, did not change after furosemide, and slightly decreased after ANP. Renal blood flow increased after saline and did not change after furosemide and ANP. The three maneuvers increased ARNA by 98.4 +/- 15.2% (saline), 270.7 +/- 100.8% (furosemide), and 59.6 +/- 23.4% (ANP). Changes in ARNA significantly correlate with changes in both pelvic pressure and urine flow rate. Our data demonstrate that increments in urine flow rate increase the firing rate of renal afferent fibers and suggest that (1) pelvic pressure is the major determinant of the neural response, and (2) this increased afferent discharge is due to activation of renal mechanoreceptors.

Blood pressure responses to renal denervation precede and are independent of the sympathetic and baroreflex effects.

It is still largely unknown whether the neuroadrenergic responses to renal denervation (RD) are involved in its blood pressure (BP)–lowering effects and represent predictors of the BP responses to RD. In 15 treated true resistant hypertensives, we measured before and 15 days, 1, 3, and 6 months after RD clinic, ambulatory and beat-to-beat BP. Measurements included muscle sympathetic nerve traffic (MSNA), spontaneous baroreflex–MSNA sensitivity, and various humoral and metabolic variables. Twelve treated hypertensives served as controls. BP, which was unaffected 15 days after RD, showed a significant decrease during the remaining follow-up period. MSNA and baroreflex did not change at 15-day and 1-month follow-up and showed, respectively, a decrease and a specular increase at 3 and 6 months after RD. No relationship, however, was detected between baseline MSNA and baroreflex, MSNA changes and BP changes. At the 6-month follow-up, the MSNA reduction was similar for magnitude in patients displaying a BP reduction greater or lower the median value. Similarly, the BP reduction detected 6 months after RD was similar in patients displaying a MSNA reduction greater or lower median value. No significant BP and MSNA changes were detected in the control group. Thus, the BP reduction associated with RD seems to precede the MSNA changes and not to display a temporal, qualitative, and quantitative relationship with the MSNA and baroreflex effects. Given the small sample size of the present study further investigations are warranted to confirm the present findings.

A case series of chronic haemodialysis patients: mortality, sudden death, and QT interval

AIMSnA high prevalence of prolonged QT interval duration has been observed among haemodialysis (HD) patients. The aim of this cases series was to describe the association of various risk factors with total mortality and sudden cardiac death (SCD) in this population.nnnMETHODS AND RESULTSnOne hundred and twenty-two patients undergoing HD, [median: age 71.3 years [interquartile ratio (IQR) 62.9-76.6], HD duration 3.0 years (IQR 1.3-7.8) and 64.8% male], of which 37.7% with ischaemic cardiac disease, 41.8% with dilated cardiomyopathy (DC), 84.4% with hypertension, and 27.1% with diabetes, were studied. Median left ventricular ejection fraction (LVEF) was 60.0% (IQR 52-64) and left ventricular mass index (LVMI) was 147.3 g/m(2) (IQR 128.0-179.9). QT interval duration corrected for heart rate (QTc) was measured by electrocardiogram Holter recording and considered prolonged when longer than 450 ms in men and 460 ms in women. Forty-four patients (36.0%) had a prolonged QTc. Female gender (P < 0.001) and DC (P = 0.018) were associated with a longer QTc, while LVEF (P = 0.012) was inversely related. During the study period (median follow-up 3.9 years), 51 patients died (41.8%), of whom 12 died for SCD. In multivariate analysis age at recruitment [HR = 1.07, 95% confidence interval (CI): 1.03-1.11, P < 0.001], prolonged QTc (HR = 2.16, 95% CI: 1.20-3.91, P = 0.011) and presence of DC (HR = 3.75, 95% CI: 1.01-7.00, P < 0.001) were independently associated with total mortality, while only a prolonged QTc (HR = 8.33, 95% CI: 1.71-40.48, P = 0.009) and increasing LVMI (HR = 1.01, 95% CI: 1.00-1.02, P = 0.022) were associated with SCD.nnnCONCLUSIONSnIn a case series of HD patients, QTc was associated with total mortality and SCD. Further studies to test this hypothesis in a larger population are necessary.

Insulin resistance, prehypertension, hypertension and blood pressure values in paediatric age

Objective: The aim of the present study was to evaluate whether insulin resistance [as measured by Homeostasis Model Assessment (HOMA) index] has an effect on prehypertension and hypertension risk in children after acknowledging the role of BMI and waist-to-height ratio. Methods: We studied a sample of 377 children 10.5u200a±u200a2.3 years old who had a first diagnosis of hypertension or family history of cardiovascular disease. In this sample all weight classes were represented. The HOMA index was standardized by a linear regression model including BMI, waist-to-height ratio and pubertal status. Results: The role of BMI and waist-to-height ratio on the risk of prehypertension and hypertension was confirmed by univariate logistic regression models, odds ratio of 1.59 [95% confidence interval (CI)u200a=u200a1.27–2.00] for BMI, and 1.56 (95% CIu200a=u200a1.06–2.31) for waist-to-height ratio (>50 vs. ⩽50%). When standardized HOMA index was added to BMI or waist-to-height ratio in a multivariate model, it gave a significant independent contribution to explain the risk of prehypertension and hypertension. Odds ratio was 1.23 (95% CIu200a=u200a1.01–1.51) in the model with BMI, and 1.23 (95% CIu200a=u200a1.01–1.50) in the model with waist-to-height ratio. The role of HOMA index was confirmed when continuous values of systolic and diastolic blood pressure (standardized by age, sex and height) were analysed, instead of hypertension category. Conclusions: These results strongly support the hypothesis that in children, insulin resistance plays a role on hypertension independently from obesity, fat distribution and puberty across weight classes.

The role of blood pressure, body weight and fat distribution on left ventricular mass, diastolic function and cardiac geometry in children.

Background: Hypertension and obesity in childhood are related to early cardiac damage, as left ventricular hypertrophy. Few studies have analyzed the independent effects of hypertension and weight excess on diastolic function and left ventricular geometry. Objective: We studied the effects of weight, waist circumference (as an index of fat distribution) and blood pressure on left ventricular mass index, the risk of left ventricular hypertrophy, diastolic function and left ventricular geometry in 526 children (237 girls, age range 6–15 years). Methods: Children were divided into normotensive, prehypertensive and hypertensive (US Nomograms) groups, and into normal-weight, overweight, and obese (International Obesity Task Force classification) groups. Left ventricular mass index, diastolic function and left ventricular geometry were assessed. Results: SBP z-scores and blood pressure categories significantly influenced cardiac mass (Pu200a<u200a0.001 and Pu200a=u200a0.02, respectively) and the prevalence of left ventricular hypertrophy (Pu200a<u200a0.001 and Pu200a<u200a0.05, respectively). Obesity, BMI, and waist circumference z-scores were significantly associated with an increment in E/Em ratio (Pu200a<u200a0.001, Pu200a<u200a0.01, and Pu200a<u200a0.01, respectively). Increasing blood pressure values and the presence of prehypertension (Pu200a<u200a0.05) and hypertension (Pu200a<u200a0.003), but not weight excess, were associated with concentric cardiac remodeling. In contrast, concentric hypertrophy was associated with hypertension (Pu200a<u200a0.01), obesity (Pu200a<u200a0.001), and increasing waist circumference (Pu200a<u200a001). Conclusions: Blood pressure values and hypertension are independently associated with an increase of cardiac mass and the presence of cardiac hypertrophy. Obesity and waist circumference, but not hypertension, are associated with a worsening of diastolic function, whereas only hypertensive children show high prevalence of concentric remodeling. Blood pressure and body weight and fat distribution have an independent and different impact on left ventricular structure and function in children.