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Biomedical subjects

Gianfranco Parati

Publications and source records attributed to Gianfranco Parati.

At least 37 records · Page 2Linked to original sources
PubMed2006

The impact of the degree of obesity on the discrepancies between office and ambulatory blood pressure values in youth.

OBJECTIVES: Obesity is an increasingly frequent problem among children and adolescents, and may lead to blood pressure (BP) increase. The aim of the present study was to assess the prevalence of hypertension, white-coat and masked hypertension in obese adolescents making systematic use of both office BP and 24-h ambulatory BP measurement. The impact of different degrees of obesity on BP and heart rate variability was also investigated. METHODS: Office and ambulatory BP were obtained in 285 overweight and obese Caucasian adolescents (11-18 years old) and in 180 age- and sex-matched controls. The extent of obesity was quantified using body mass index z score. RESULTS: A significant positive relationship between body mass index z score and both office and ambulatory systolic BP was found after adjusting for age and height in both boys and girls. Obese youths had not only higher BP levels, but also higher BP variability compared with controls. Among obese youths, 20.8% had abnormal BP conditions, 6.6% were white-coat hypertensives, 9.2% were masked hypertensives and 5% were sustained hypertensives. CONCLUSIONS: The prevalence of these abnormal BP conditions, which can be identified thanks to ambulatory BP monitoring, further emphasizes the usefulness of this diagnostic tool in obese youths.

Adolescent↗
PubMed2006

Assessment of the autonomic control of heart rate variability in healthy and spinal-cord injured subjects: contribution of different complexity-based estimators.

We investigated how complexity-based estimators of heart rate variability can detect changes in cardiovascular autonomic drive with respect to traditional measures of variability. This was done by analyzing healthy subjects and paraplegic patients with different autonomic impairment due to low (vascular impairment only) or high (cardiac and vascular impairment) spinal cord injury, during progressive autonomic activations. While traditional techniques only quantified the effects of the autonomic activation, not distinguishing the effects of the lesion level, some recently proposed complexity estimators could also reveal the pathologic alterations in the autonomic control of heart rate. These estimators included the detrended fluctuation analysis coefficient (sensitive to both low and high autonomic lesions), sample entropy (sensitive to low-level lesions) and the largest Lyapunov exponent (sensitive to high-level lesions). Thus complexity-based methods provide information on the autonomic function from the heart rate dynamics that cannot be obtained by traditional techniques. This finding supports the combined use of both complexity-based and traditional methods to investigate the autonomic cardiovascular control from a more comprehensive perspective.

Adult↗
PubMed2006

Autonomic cardiac modulation in obstructive sleep apnea: effect of an oral jaw-positioning appliance.

BACKGROUND: Patients with obstructive sleep apnea (OSA) are characterized by deranged cardiovascular variability, a well-established marker of cardiovascular risk. While long-term treatment with continuous positive airway pressure leads to a significant improvement of cardiovascular variability, little is known of the possibility of achieving the same results with other therapeutic approaches. The aim of our study was to investigate the responses of autonomic indexes of neural cardiac control to another type of OSA treatment based on an oral jaw-positioning appliance. METHODS: In 10 otherwise healthy subjects with OSA (OSA+) and in 10 subjects without OSA (OSA-) we measured heart rate, BP, and indices of autonomic cardiac regulation derived from time-domain and spectral analysis of R-R interval (RRI), before and after 3 months of treatment with the oral device. High-frequency (HF) power of RRI was taken as an index of parasympathetic cardiac modulation, and the ratio between low-frequency (LF) and HF RRI powers as an indirect marker of the balance between sympathetic and parasympathetic cardiac modulation. RESULTS: At baseline, in comparison with OSA- subjects, OSA+ subjects displayed a significantly lower RRI variance (p < 0.02) and reduced HF RRI powers (p < 0.001). After 3 months of treatment with the oral device, the OSA+ group showed a marked reduction in apnea-hypopnea index (p < 0.001), a lengthening in RRI and a significant increase in its variance (p < 0,02), an increased HF RRI power (from 134 +/- 26 to 502 +/- 48 ms2, p < 0.001), and a reduction in LF/HF RRI power ratio (from 3.11 +/- 0.8 to 1.5 +/- 0.5). As a result of these changes, after the 3-month treatment there were no more significant differences between the two groups in these parameters. In both OSA+ and OSA- groups, body weight, heart rate, and BP did not change over time. CONCLUSIONS: Three months of treatment with a specific oral jaw-positioning appliance improves cardiac autonomic modulation in otherwise healthy patients with OSA of mild degree.

Adult↗
PubMed2006

Influence of sympathetic vascular regulation on heart-rate scaling structure: spinal cord lesion as a model of progressively impaired autonomic control.

Estimation of self-similarity is a promising tool for quantifying alterations in cardiovascular dynamics. To evaluate the as yet unexplored influence of sympathetic vascular regulation on the scaling exponent, namely on the parameter characterizing self-similarity, we studied patients with a spinal cord injury as a model of progressively impaired vascular control. We considered 24 able-bodied subjects (AB) and 23 paraplegics with increasing lesion levels: between T(12) and L(4) (n=7); T(5) and T(11) (n=9); and C(6) and T(4) (n=7). We recorded the heart rate in three conditions characterized by increasing sympathetic activation: supine (SUP), sitting (SIT) and exercise (EXE). We calculated the scaling exponent by detrended fluctuation analysis (H(DFA)). Sympathetic activation had different effects on H(DFA), depending on the lesion level. H(DFA) tended to decrease in AB from SUP (0.85+0.02; mean+SEM) and SIT (0.84+0.02) to EXE (0.79+0.02). It remained constant in the T(12)-L(4) group (0.92+0.04, 0.94+0.05 and 0.94+0.04, respectively), while it increased significantly in the T(5)-T(11) group (0.88+0.07, 0.94+0.05, 1.00+0.08) and increased even more in the C(6)-T(4) group (0.83+0.07, 0.91+0.05, 1.06+0.06). Results suggest that heart-rate self-similarity depends on vascular sympathetic control, because it is altered by spinal-cord lesions, even when cardiac neural control is intact.

Autonomic Nervous System↗
PubMed2006

Zofenopril plus hydrochlorothiazide: Combination therapy for the treatment of mild to moderate hypertension.

Achieving target blood pressure (BP) levels in clinical practice is one of the main challenges for physicians in the management of patients with hypertension. It is now recognised that the majority of patients will require at least two antihypertensive drugs to achieve optimal BP control; the use of combination therapy as first-line treatment is also increasing as BP goals of antihypertensive therapy become more ambitious. The fixed combination of zofenopril/hydrochlorothiazide (HCTZ) 30/12.5 mg/day is approved in Italy, France, Switzerland and Greece for the management of mild to moderate hypertension. In clinical trials comparing zofenopril/HCTZ with each agent administered as monotherapy, combination therapy was more effective in normalising BP. This effect was particularly evident in one trial in which patients who were nonresponsive to zofenopril monotherapy were studied. In addition, in clinical trials to date, combination therapy provided sustained and consistent BP control over the entire 24-hour dose interval. Despite the greater efficacy of zofenopril/HCTZ 30/12.5 mg/day, when directly compared with each agent administered as monotherapy, there were no significant differences in the nature, severity or incidence of treatment-related adverse events; headache, dizziness, cough and polyuria were most frequently reported. Notably, in one study, fewer patients discontinued treatment with combination therapy than with zofenopril monotherapy due to adverse events. In conclusion, zofenopril/HCTZ 30/12.5 mg/day provides more optimal BP control in a larger proportion of patients than would be achievable with monotherapy, while maintaining the tolerability profile observed with each individual agent, and thereby potentially enhancing patient compliance. The efficacy and safety profiles of this combination shown in clinical trials to date indicate that it will be a useful addition to currently available therapy for patients who have mild to moderate hypertension that is not adequately controlled by monotherapy, as well as for patients who require more rapid, intensive BP control.

Adolescent↗
PubMed2006

HEARTFAID: A knowledge based platform of services for supporting medical-clinical management of heart failure within elderly population.

HEARTFAID is a research and development project aimed at devising, developing and validating an innovative knowledge based platform of services, able to improve early diagnosis and to make more effective the medical-clinical management of heart diseases within elderly population. Chronic Heart Failure is one of the most remarkable health problems for prevalence and morbidity, especially in the developed western countries, with a strong impact in terms of social and economic effects. All these aspects are typically emphasized within the elderly population, with very frequent hospital admissions and a significant increase of medical costs. Recent studies and experiences have demonstrated that accurate heart failure management programs, based on a suitable integration of inpatient and outpatient clinical procedures, might prevent and reduce hospital admissions, improving clinical status and reducing costs. HEARTFAID aims at defining efficient and effective health care delivery organization and management models for the "optimal" management of the care in the field of cardiovascular diseases. The HEARTFAID innovative computerized system will improve the processes of diagnosis, prognosis and therapy provision, providing the following services: * electronic health record for easy and ubiquitous access to heterogeneous patients data;* integrated services for healthcare professionals, including patient telemonitoring, signal and image processing, alert and alarm system;* clinical decision support in the heart failure domain, based on pattern recognition in historical data, knowledge discovery analysis and inferences on patients' clinical data.The formalization of the pre-existing clinical knowledge and the discovery of new elicited knowledge represent the core of the HEARTFAID platform.

Aged↗
PubMed2005

Weather-related changes in 24-hour blood pressure profile: effects of age and implications for hypertension management.

A downward titration of antihypertensive drug regimens in summertime is often performed on the basis of seasonal variations of clinic blood pressure (BP). However, little is known about the actual interaction between outdoor air temperature and the effects of antihypertensive treatment on ambulatory BP. The combined effects of aging, treatment, and daily mean temperature on clinic and ambulatory BP were investigated in 6404 subjects referred to our units between October 1999 and December 2003. Office and mean 24-hour systolic BP, as well as morning pressure surge, were significantly lower in hot (>90th percentiles of air temperature; 136+/-19, 130+/-14, and 33.3+/-16.1 mm Hg; P<0.05 for all), and higher in cold (<10th percentiles) days (141+/-12, 133+/-11, and 37.3+/-9.5 mm Hg; at least P<0.05 for all) when compared with intermediate days (138+/-18, 132+/-14, and 35.3+/-15.4 mm Hg). At regression analysis, 24-hour and daytime systolic pressure were inversely related to temperature (P<0.01 for all). Conversely, nighttime systolic pressure was positively related to temperature (P<0.02), with hot days being associated with higher nighttime pressure. Air temperature was identified as an independent predictor of nighttime systolic pressure increase in the group of elderly treated hypertensive subjects only. No significant relationship was found between air temperature and heart rate. Our results show for the first time that hot weather is associated with an increase in systolic pressure at night in treated elderly hypertensive subjects. This may be because of a nocturnal BP escape from the effects of a lighter summertime drug regimen and may have important implications for seasonal modulation of antihypertensive treatment.

Aged↗
PubMed2005

Effects of salt sensitivity on neural cardiovascular regulation in essential hypertension.

Salt-sensitive hypertensive subjects, as defined by conventional categorical classification, exhibit alterations of autonomic cardiovascular control. The aim of our study was to explore whether, in hypertensive subjects, the degree of autonomic dysfunction and the level of salt sensitivity are correlated even when the latter is only mildly elevated and displays under-threshold values. Salt sensitivity of 34 essential hypertensive subjects was assessed on a continuous basis by the salt sensitivity index after low- and high-sodium diet. Beat-by-beat finger blood pressure was recorded after each diet period. Autonomic cardiovascular control was evaluated by spectral analysis of blood pressure and pulse interval and by assessment of spontaneous baroreflex sensitivity (sequence technique). Salt sensitivity and baroreflex sensitivity showed a negative relationship during low and high sodium intake, starting from low values of the salt sensitivity index. All spectral indexes of pulse interval, except the ratio between low- and high-frequency powers, were inversely related to salt sensitivity index after high sodium intake. In subjects with lower salt sensitivity, baroreflex sensitivity and pulse interval power in the high-frequency band were higher after high sodium intake than after low sodium intake. In contrast, subjects with a higher salt sensitivity index showed lower values of baroreflex sensitivity and pulse interval power in the high-frequency band, uninfluenced by salt intake. Our results provide the first demonstration of an impairment of parasympathetic cardiac control in parallel with the increase in the degree of salt sensitivity, also in subjects who were not ranked as salt-sensitive by the conventional categorical classification.

Autonomic Nervous System↗
PubMed2005

Impact of chronic psychosocial stress on autonomic cardiovascular regulation in otherwise healthy subjects.

Elevated psychosocial stress might favor the occurrence of cardiovascular disease; however, mechanisms are incompletely understood. We hypothesized that patients (n=126; 44+/-1 years of age) referred to an internal medicine clinic because of symptoms related to chronic psychosocial stress would demonstrate signs of autonomic dysregulation compared with controls (n=132; 42+/-1 years of age). We used autoregressive spectral analysis of RR interval variability to obtain indirect markers of sympathetic and of vagal (respectively, low-frequency and high-frequency components, both expressed in normalized units) oscillatory modulation of sinoatrial node, as well as of sympathetic vasomotor regulation (low-frequency component of systolic arterial pressure variability) and of cardiac baroreflex sensitivity (alpha-index). Higher values of systolic and diastolic arterial pressure (respectively, 124+/-1 versus 117+/-1 mm Hg and 80+/-1 versus 75+/-1 mm Hg; both P<0.001), altered markers of autonomic regulation (increased normalized low-frequency and reduced high-frequency component of RR variability, P<0.005; increased-low frequency component of systolic arterial pressure variability, P<0.002), and reduced baroreflex sensitivity (19.3+/-1.4 versus 23.0+/-2.0 ms/mm Hg; P<0.05) were observed in patients compared with controls. Autonomic responses to active standing were also blunted in stressed patients. Autonomic markers were significantly correlated to stress perception score and were capable of discriminating between controls and patients with a high degree of accuracy. Chronic real-life stress in humans appears associated to increased arterial pressure and to impaired autonomic regulation of cardiovascular functions. The combination of sympathetic predominance, vagal withdrawal, and blunted baroreflex sensitivity might represent a treatable mechanistic link between psychosocial factors and future incidence of hypertension.

Adult↗
PubMed2005

The interleukin-6 -174 G>C promoter polymorphism is associated with a higher risk of death after an acute coronary syndrome in male elderly patients.

BACKGROUND: Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) are key mediators of inflammation and their increased plasma levels are associated with acute coronary syndrome (ACS). Polymorphisms in the promoter region of IL-6 (-174 G>C) and TNF-alpha (-308 G>A) demonstrated to affect gene expression were analyzed to test their predictive power for cardiovascular death over one year follow-up in elderly male ACS patients. METHODS: We assessed the IL-6 -174 G>C polymorphism and TNF-alpha -308 G>A polymorphism in 139 consecutive elderly male patients affected by an ACS, such as ST-Elevation (STEMI), No ST-Elevation (NSTEMI) Myocardial Infarction and Unstable Angina. The presence of well known risk factors for Coronary Heart Diseases (CHD) were also assessed in all ACS patients. Survival rate was assessed after one year follow-up. RESULTS: We found that IL-6 -174 G>C polymorphism is an independent predictor of cardiovascular death after an ACS in male patients. In particular ACS patients carrying the IL-6 -174 C- (GG) genotypes showed a marked increase in one year follow-up mortality rate (HR=3.89, 95% CI 1.71-8.86, p=0.001). Moreover CRP serum levels > or = 5.5 mg/dl (HR= 3.79, 95% CI 1.71-8.42, p=0.001), a history of CHD (HR=2.96, 95% CI 1.22-7.20, p=0.016) and the absence of statins treatment (HR=3.27, 95% CI 1.17-9.18, p=0.021), significantly increased one year risk of death in male ACS patients. CONCLUSIONS: These data suggest that IL-6 -174 G>C polymorphism can be added to other clinical markers in order to identify a subgroup of elderly ACS male patients at higher risk of death.

Acute Disease↗
PubMed2005

Diabetic neuropathy is a more important determinant of baroreflex sensitivity than carotid elasticity in type 2 diabetes.

The object of this study was to evaluate the contribution of carotid distensibilty on baroreflex sensitivity in patients with type 2 diabetes mellitus with at least 2 additional cardiovascular risk factors. Carotid distensibility was measured bilaterally at the common carotid artery in 79 consecutive diabetic patients and 60 matched subjects without diabetes. Spontaneous baroreflex sensitivity assessment was obtained using time and frequency methods. Baroreflex sensitivity was lower in diabetic subjects as compared with nondiabetic control subjects (5.25+/-2.80 ms/mm Hg versus 7.55+/-3.79 ms/mm Hg; P<0.01, respectively). Contrary to nondiabetic subjects, diabetic subjects showed no significant correlation between carotid distensibility and baroreflex sensitivity (r2=0.08, P=0.04 and r2=0.04, P=0.13, respectively). In diabetic subjects, baroreflex sensitivity was significantly lower in subjects with peripheral neuropathy than in those with preserved vibration sensation (4.1+/-0.5 versus 6.1+/-0.4 ms/mm Hg, respectively; P=0.005). Age in nondiabetic subjects, diabetes duration, systolic blood pressure, peripheral or sensitive neuropathy, and carotid distensibility were introduced in a stepwise multivariate analysis to identify the determinants of baroreflex sensitivity. In diabetic patients, neuropathy is a more sensitive determinant of baroreflex sensitivity than the reduced carotid distensibility (stepwise analysis; F ratio=5.1, P=0.028 versus F ratio=1.9, P=0.16, respectively). In diabetic subjects with 2 additional cardiovascular risk factors, spontaneous baroreflex sensitivity is not related to carotid distensibility. Diabetic subjects represent a particular population within the spectrum of cardiovascular risk situations because of the marked neuropathy associated with their metabolic disorder. Therefore, neuropathy is a more significant determinant of baroreflex sensitivity than carotid artery elasticity in patients with type 2 diabetes.

Adult↗
PubMed2005

Prevalence of home blood pressure measurement among selected hypertensive patients: results of a multicenter survey from six hospital outpatient hypertension clinics in Italy.

AIM: The purpose of this study was to evaluate the prevalence of home blood pressure (BP) measurement, the type of devices and accuracy in a large sample of hypertensive patients referred to hospital outpatient hypertension clinics. METHODS: Eight hundred and fifty-five consecutive treated hypertensive patients who attended six specialized centers during a period of 4 months were included. They underwent the following procedures: (i) detailed medical interview by a structured questionnaire; (ii) physical examination; (iii) standard 12-lead electrocardiogram; (iv) BP measurements taken by a validated mercury sphygmomanometer and patient's devices. RESULTS: A total of 640 (74.7%) of 855 patients were regularly performing home BP measurement. These patients were on average younger than those not practising it (58 vs 60 years, p<0.01); men were more numerous than women (58 vs 44%, p=0.03) and had higher educational level. Electronic arm-cuff instruments were the most frequently used devices (58%) followed by wrist devices (19%) and mercury or aneroid sphygmomanometers (23%). Significant correlations were found between BPs measured by validated mercury sphygmomanometers and patients' devices [r=0.85, p<0.0001 for systolic BP (SBP) and r=0.78, p<0.0001 for diastolic BP (DBP)]. Differences 5 mmHg in SBP or DBP were found in 50 and 60% of patients, respectively. CONCLUSIONS: Our findings indicate that: (i) home BP measurement is performed by a majority of treated hypertensives seen in specialized centers; (ii) male gender, age and educational level seem to influence the adoption of home BP monitoring; (iii) electronic arm-cuff devices are the most used instruments; (iv) a notable fraction of patient's devices do not meet the accuracy criteria recommended by US Association for the Advancement of Medical Instrumentation.

Aged↗