[Identification of "presumptive risk" of hypertension crises with fractal interpolation of the 24-hour arterial pressure. III: study of normotensive subjects]. / Individuazione del "rischio presuntivo" di crisi ipertensive mediante interpolazione frattalica della pressione arteriosa di 24 ore. III: studio in soggetti normotesi.

PURPOSE: The present study is devoted to identify the normotensive subjects who are at a "presumptive risk" (PR) for hypertensive crisis, by applying the "fractal interpolation" (FI) to blood pressure 24-h pattern. MATERIALS AND METHODS: The investigation was performed on 109 ascertained cases of normotension, who underwent a non-invasive ambulatory monitoring of their 24-h blood pressure, by applying the FI to their daily mean arterial pressure. RESULTS: The study showed that the PR for hypertensive crisis can be found in 12% out of the investigated normotensives. The proportion of such a risk is not significantly higher in non-dippers as compared to dippers. Vice versa, the prevalence of cases with a PR for hypertensive crisis was found to be significantly increased in normotensives who were deprived by a significant blood pressure circadian rhythm as compared to those who showed the blood pressure circadian rhythm to be preserved. Furthermore, the cases "at risk" were found to show a different spectrum for the harmonic formants which compose the complex harmonic structure of the blood pressure 24-h variability. CONCLUSIONS: The PR for hypertensive crisis in normotensives seems to be increased by the loss of the blood pressure circadian rhythm, due to a change in the harmonic structure which confers the 24-h periodicity to the hemodynamic variable. This means that the abrogation of the blood pressure circadian rhythm in conditions of normotension promotes an adjunctive disorder for which the PR for hypertensive crisis is augmented.

[Determination of the "presumptive risk" of hypertensive crisis with fractal interpolation of 24-hour arterial pressure. II: study with secondary hypertensive patients]. / Individuazione del "rischio presuntivo" di crisi ipertensive mediante interpolazione frattalica della pressione arteriosa di 24 ore. II: Studio in ipertesi secondari.

PURPOSE: The present study applies the "fractal interpolation" (FI) to 24-h blood pressure nonivasively and ambulatorily monitored over a day-night period in secondary hypertensives. The purpose is the evaluation of the prevalence for a "presumptive risk" (PR) of hypertensive crisis. MATERIALS AND METHODS: The study was carried out in 108 cases of secondary hypertension, who were non-invasively and ambulatorily monitored for their 24-h blood pressure values. The FI was applied to the time-qualified values of the mean arterial pressure. RESULTS: The PR of hypertensive crisis was found in 11% of the investigated secondary hypertensive patients. Such a risk shows a not significant prevalence in dippers as compared to non-dippers, and in those who showed a significant blood pressure circadian rhythm as compared to those who showed the blood pressure circadian rhythm to be abolished. Additionally, a not significant difference was found between the cases "at risk" and "not at risk" as far as the spectrum of harmonic formants of the 24-h blood pressure pattern is concerned. CONCLUSIONS: The PR of hypertensive crisis is not associated with the dipping/non-dipping phenomenon as well as the circadian rhythmicity of blood pressure. Its occurrence in secondary hypertensives is essentially related to the disorder that is detectable in blood pressure non-linear variability. Therefore, such a risk may be caused by neurovegetative mechanisms which notoriously confer a non-linear chaotic variability to 24-h blood pressure pattern.

[Individualization of the "presumptive risk" of hypertensive crisis using fractals interpolation of the 24-hour arterial pressure. Study of patients with essential hypertension]. / Individuazione del "rischio presuntivo" di crisi ipertensive mediante interpolazione frattalica della pressione arteriosa di 24 ore. I: Studio in ipertesi essenziali.

PURPOSE: The present study applies the "fractal interpolation" (FI) to blood pressure that was nonivasively and ambulatorily monitored over a day-night period in essential hypertensives. The purpose is the identification of cases who are at a "presumptive risk" (PR) for hypertensive crisis. MATERIALS AND METHODS: The investigation was performed on 380 ascertained cases of essential hypertension, who underwent a non-invasive ambulatory monitoring of 24-h blood pressure. The FI was applied to the ambulatory mean arterial pressure. RESULTS: The FI showed that the PR of hypertensive crisis can be found in 14% of the investigated essential hypertensive patients. Such a risk is not significantly higher in dippers as compared to non-dippers, and in those who showed a significant blood pressure circadian rhythm as compared to those who showed the blood pressure circadian rhythm to be abolished. Furthermore, no significant difference was found between the cases "at risk" and "not at risk" as far as the spectrum of harmonic formants of the 24-h blood pressure pattern is concerned. CONCLUSIONS: The PR of hypertensive crisis is not correlated to the dipping/nondipping condition, circadian rhythmicity and complex harmonic structure of 24-h blood pressure pattern. Its occurrence depends essentially from the disorder that is detectable in 24-h blood pressure pattern. Therefore, such a PR in essential hypertensives may be attributed to the mechanisms, likely neurovegetative, which confer a non-linear chaotic variability to 24-h blood pressure values.

Is melatonin circadian rhythm a physiological feature associated with healthy longevity? A study of long-living subjects and their progeny.

The study investigates the circadian rhythm (CR) of urinary 6-sulphatoxy-melatonin (aMT6s) in long-living (longevous) subjects and their progeny. The aim is to detect whether or not the melatonin CR is a physiological feature associated with healthy longevity. The aMT6s CR was investigated in 10 longevous subjects, 8 of their children and 9 of their grandchildren, all in good health. Control data were obtained respectively from 13 adult subjects and 9 young subjects, in good health, but characterized by a negative family history for longevity. All the subjects were born and living in the same city. The study was performed in the summer of 1996. The aMT6s CR was found to persist in longevous subjects, being characterized by a lower mesor and amplitude. The aMT6s CR was found not to show properties consistently different in children and grandchildren as compared respectively to their adult and young controls. Because of its preservation in longevous subjects, it can be argued that the melatonin CR is a physiological feature associated with healthy longevity. Because of the comparability of aMT6s CR in children and grandchildren, with respect to their controls without a positive family history of longevity, it can be argued that the melatonin CR is not a marker that can be used for an earlier identification of the candidates for longevity.

Age-related trend for blood pressure circadian rhythm in normotensive healthy subjects: estimates provided by the clinospectror method.

The present study investigates how blood pressure (BP) circadian rhythm (CR) changes in its rhythmic properties as a function of chronological age in normotensive healthy subjects (NHS). The age-related trend for BP CR was investigated via the Clinospectror method, a periodic-linear analysis of regression for rhythmic parameters. The study was performed on 437 NHS (219 males and 218 females, ranging in age from 1 year to 102 years), who were monitored in their 24-h BP via a noninvasive automated recorder. An age-related trend was detected for the three properties of BP CR, i.e., mesor (M), amplitude (A) and acrophase (cent). Such a trend was positive for M and A, and negative for cent. According to the clinospectrometric formula, the BP CR can be classified as a "dianaclinous rhythm", i.e., a rhythm which increases in its oscillatory level and extent with advancing years. The documented age-related trend for the rhythmic properties suggests that the biological clock which regulates the BP CR in human beings undergoes a resetting of its mechanisms of tonic, amplitude and phasic modulation as a function of chronological age. The readjustment of the pressure clock may be regarded as one of the physiological features which characterize the aging process in human beings.

Hunger sensation in Graves' disease before and after pharmacological therapy.

PURPOSE: Hunger sensation (HS) provides information about the need of eating in order to counterbalance the energy expenditure (EE). HS was, thus, investigated in patients affected by Graves' disease (PAGD), a clinical condition characterized by excessive EE. MATERIALS AND METHODS: Ten newly diagnosed PAGD were investigated before and after therapy. Thirty clinically healthy subjects (CHS) were investigated as controls. The investigated subjects were asked to provide the 24-h profile of their HS by subjectively self-rating (from 1 to 10 hunger units) their orectic perception (OP) at regular intervals of 30 minutes (orexigram). The orexigrams were investigated via the conventional descriptive statistics as well as the Single-Cosinor method. RESULTS: PAGD were found to show a very consistent increase of their HS (hyperorexia), whose day-night variability was, still, the expression of a circadian rhythm, characterized by an elevation in its oscillatory level and extent. Interestingly, the pre-treatment hyperorexia was seen to show a normalization (eurexia) after pharmacological therapy. CONCLUSIONS: According to these results, it can be affirmed that hyperorexia is a clinical sign of Graves' disease, which is obtained via mechanisms of tonic and amplitude modulation of the HS circadian rhythm. Because of the eurexia after remission, it can be argued that the hyperorexia is a theleological response really aimed at increasing food intake in order to counterbalance the excessive EE which characterizes the thyrotoxicosis.

Anxiety, depression, hunger and body composition: III. Their relationships in obese patients.

The present paper explores the relationships between anxiety, depression, hunger sensation and body composition in obese patients (OP). The aim is to detect whether or not there are abnormalities in these relationships in OP as compared to clinically healthy subjects (CHS). The study was performed on 22 CHS (2 M, 20 W; mean age = 24 +/- 2 years; mean body mass index = 21 +/- 2 kg/m2) and 48 OP (4 M, 44 W; mean age = 40 +/- 17 years; mean body mass index = 32 +/- 7 kg/m2). Anxiety and depression were found to be correlated, negatively, with the relative lean body mass, and, positively, with the fat body mass in OP but not in CHS. These findings corroborate the idea that anxiety and depression can reach an abnormal expression when obesity shows its worst loss in lean body mass and its highest expansion in adipocyte mass. As hunger sensation was found not to correlate with either anxiety or depression in OP, the opinion is expressed that the impairment of anxio-depressive integrity is a corollary of obesity rather than a primary affective disorder leading to obesity via an enhanced food intake.

Daily hunger sensation and body compartments: II. Their relationships in obese patients.

Hunger sensation (HS) is a signal whose levels change during the 24-h day. The daily mean level of HS was correlated with the human body compartments, as investigated by bioelectrical impedance analysis, to detect the relationship between the orectic perception and both the free fat mass (FFM) and the fat body mass (FBM) in 22 clinically healthy subjects (CHS) (2 M, 20 W, BMI: 18.5-24.0 kg/m2) and 48 obese patients (OP) (4 M, 44 W, BMI: 25.2-54.7 kg/m2). In CHS, the daily mean level of HS correlated positively with the FFM and negatively with the FBM. These correlations were not present in OP. This lack of relationships between HS and the body compartments where energy is maximally consumed (i.e., the FFM) and maximally stored (i.e., the FBM) indicates that the orectic response to energy expenditure and the orectic inhibition to fat accumulation are feedback mechanisms which are impaired in obesity.

[The concept of "preclinical arterial hypertension" - in light of non-invasive, ambulatory blood pressure monitoring]. / Il concetto di "pre-ipertensione arteriosa" alla luce del monitoraggio ambulatorio non-invasivo della pressione arteriosa.

In clinical medicine it is possible to find subjects who show initial signs of hypertensive damage being normotensive at the "casual" sphygmomanometry. In order to verify whether or not these subjects are "true normotensives", it was applied the noninvasive ambulatory monitoring of blood pressure (BP). Five studies were performed: I. Normotensives with initial hypertensive retinopathy; II. normotensives with initial hypertensive cardiohypertrophy; III. Normotensives with initial hypertensive cardiohypertrophy of the transplanted heart; IV. Normotensive pregnant women with altered uterine blood flow; V. Normotensive pregnant women with intrauterine growth retardation. From all the studies, it was possible to derive that the subjects were all true normotensive. However, they were characterized by BP values on average higher than those of their controls, but below the reference limits given by WHO. Because of the relative elevation of BP, it was possible to argue that there exists a BP regimen which is potentially dangerous for the target organs, even though there is no evidence of manifest arterial hypertension. Such a hemodynamic condition causing hypertensive cardiovascular damage was defined "arterial pre-hypertension".

Who are the non-dippers? A better definition via the blood pressure circadian rhythm.

OBJECTIVE: The non-dipping phenomenon (NDP) can be better interpreted when considering that blood pressure (BP) shows a within-day variability which is the expression of a circadian rhythm (CR). PATIENTS AND METHODS: The NDP was investigated at the light of the BP CR by analysing the ambulatory BP monitoring of 298 essential hypertensive patients (EHP), 84 secondary hypertensive patients (SHP), as well as 93 normotensive subjects (NS). According to the rhythmometric validation, the investigated subjects were defined "rhythmic" (R) or "non-rhythmic" (NR). RESULTS: The non-dippers (ND) were found among not only the EHP (14%) and SHP (27%) but also the NS (16%). The percentages of R ND were 9%, 4% and 20%, respectively in EHP, SHP and NS. The R ND were characterized by a nocturnal phase-shift (100% in NS), associated with an amplitude increase (50% in EHP) or a mesor increase (50% in EHP; 100% in SHP) in BP CR. The NR ND were characterized by an amplitude almost negligible (100% in NS) associated with a mesor increase (100% in EHP; 100% in SHP). CONCLUSIONS: The detection of a NDP associated with a rhythmicity suggests that the criterion with which the ND are identified cannot be used for making inferences on the BP CR in HP or NS. The rhythmic characteristics in ND suggest that the rhythmometric analysis is fundamental for identifying the abnormal time structure of BP 24-h values in the presence of the NDP.

Hunger sensation: a chronobiometric approach to its within-day and intra-day recursivity in anorexia nervosa restricting type.

Hunger sensation (HS) is a perception with a daily (circadian) and within-day (ultradian) recursive pattern. In human beings, circadian repeatability was investigated by means of the Single Cosinor method, while the ultradian recursivity was investigated by means of the spectral analysis, both applied to the 24-h HS profile (orexigram). Orexigrams were provided by each subject investigated, who self-rated her subjective orectic stimulus (OS) (from 1 to 10 hunger units) every half hour. The study was performed in 19 female patients aged 13-52 newly diagnosed as in the first episode of Anorexia Nervosa Restricting Type, with a BMI below 18.7. The control group consisted of 10 clinically healthy women aged 21 to 52 years with a BMI from 23 to 25. Two types of orexigrams were found. The first was characterized by a low profile with negligible ultradian variability, in which the HS circadian rhythm (CR) was still detectable, but the power spectrum (PS) was composed of unusual ultradian components associated with a very diminished amplitude for the circadian harmonics. The second was characterized by an almost regular profile, in which the ultradian variability was clearly detectable, the CR regularly fluctuated, and the PS was almost regularly composed. These findings indicate that anorectic patients (AP) can be recognized by their orexigram as "hyporectic", or "eurectic". Therefore, the term "anorexia" seems to be appropriate for AP who exhibit the first type of orexigram (anorectic aphagia nervosa), whereas the second identifying those who could be defined as suffering from "eurectic aphagia nervosa".

Daily hunger sensation and body composition: I. Their relationships in clinically healthy subjects.

The human hunger sensation (HS) is a perceptive signal characterized by day-night variability (DNV). This pattern was investigated with respect to its relations with the body compartments in 22 clinically healthy subjects (CHS, 11 males and 11 females, mean age: 24 +/- 2.5 years, mean BMI: 21 +/- 1.7). The DNV was investigated by means of conventional descriptive statistics and the single cosinor method (SCM). Both procedures were applied to the orexigram, i.e., the 24-h profile of the orectic stimulus (OS) provided by each subject, who self-rated his/her HS (from 1 to 10 hunger units) every half hour. Body composition was investigated by Bioelectrical Impedance Analysis (BIA) on the day when the orexigrams were compiled. It was found that the daily HS level correlates positively with the Free Fat Body Mass (FFBM) and negatively with the Fat Body Mass (FBM). These opposite relations indicate that HS is stimulated by the needs of the FFBM, and inhibited by expansion of the FBM, and provide further evidence of the existence of an "adipostat" anorectic mechanism.

The chaotic component of human heart rate variability shows a circadian periodicity as documented by the correlation dimension of the time-qualified sinusal R-R intervals.

OBJECTIVE: This study investigates the hypothesis that the nonlinear component of human heart rate (HR) variability might show a periodic structure over the 24-h span. Such a postulate could explain how the chaotic component might coexist with the deterministic periodic variability of instantaneous HR in beat per minute. MATERIALS AND METHODS: The sinusal R-R intervals (sRRi) of the Holter EKG of 10 clinically healthy subjects (5 M, 5 F, 23-30 years) were analyzed per each hour of the day-night span according to two methods for the nonlinear chaotic variability, i.e., the correlation dimension method, and the linear periodic variability, i.e., periodic regression analysis. RESULTS: The hourly-qualified correlation integrals were found to show a significant circadian rhythm, with an acrophase located during the night in coincidence with the longest duration of the sRRi and the lowest rate of cardiac pulse. CONCLUSIONS: The rhythmic structure of the chaotic component of the human HR variability let us to think that a deterministic periodic chaos of fractal type regulates the nonlinear cardiac dynamics. Such a periodic structure allows the chaos to be compatible with the deterministic linear periodicity of circadian type which characterizes the within-day variability of human HR.

[Tyrosinosis. A difficult diagnosis of late infancy]. / Tirosinosi. Una diagnosi difficile nella seconda infanzia.

The Authors report an unusual case of tyrosinosis in which neonatal metabolic screenings were not performed and the diagnosis was made only at 4 years of age. The diet induced an improvement of cirrhosis but did not influence renal tubular damage. The authors stress the diagnostic differential elements against other cirrhogenic metabolic diseases and emphasize the prospectives of liver transplantation.