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This study investigates 24-h blood pressure (BP) and heart rate (HR) values in clinically healthy subjects adapted to living in Antarctica, as compared to their coeval subjects living in their home country. Its aim is to detect how cardiovascular rhythms behave in those environmental conditions and occupational cues. The 24-h BP and HR values were measured via a noninvasive ambulatory monitor, and statistically analyzed via conventional and chronobiological procedures. The normotensive subjects living in Antarctica were seen to show significant changes in the daily mean level of systolic BP (increase) and HR (decrease) as compared to their controls. In addition, they were seen to show the BP and HR circadian rhythms to be perfectly synchronized to the 24-h cycle, despite the permanent solar light, as an effect imposed by the routines of their local lifestyle. The observed changes reflect a tonic modulation of the BP and HR circadian rhythms which allows the cardiovascular apparatus to adapt itself without imposing an extra load on its function.

Essential hypertensive patients with a history of recent TIA syndrome were investigated by ambulatory blood pressure monitoring (ABPM). The aim of this trial was to verify the presence of false normotensive patients in order to optimize the secondary prevention of hypertensive cerebrovascular damage (ischemic or hemorrhagic stroke). This study was carried out on 51 patients (26 M and 25 F, mean age = 58 +/- 14 yrs) and 225 clinically healthy control subjects (113 M and 112 F, mean age = 55 +/- 12 yrs), who underwent an ABPM. The BP time series were analyzed by chronobiometric procedures. The comparison of the individual BP within-day values to the reference limit revealed a highly significant proportion of these patients (90%) whose hypertension was not well controlled. Their BP series showed supranormal values ranging from 39% to 56% of all the readings, with a pressure excess ranging from 8.35 h to 11.34 h. The high incidence of not adequately treated patients with a history of recent TIA syndrome confirms that their hypertension should be controlled by means of the ABPM. These results suggest that the chronomodulation of the antihypertensive treatment might be the better management of BP regimen in these patients for the secondary prevention of cerebrovascular damage.

This study was performed in order to define who are the "non-dippers", knowing that their present definition does not imply any explanation about the mechanisms. The investigation was performed on 34 heart transplanted patients, 28 males (mean age 52 +/- 11 years) and 6 women (mean age 35 +/- 14 years), knowing that the "non-dippers" were described as the hypertensives who are devoid of the expected nocturnal fall in blood pressure (BP). The "non-dipping" phenomenon was investigated by exploring the BP 24-h pattern via ambulatory non-invasive BP monitoring, and by applying the rhythmometric analysis for quantifying the BP circadian rhythm. The study provided evidence that the "non-dippers" can be found among the hypertensives as well as the normotensives, suggesting that high BP is not a necessary condition for the "non-dipping" phenomenon, and vice versa. Both the normotensive and hypertensive "non-dippers" were seen to show stereotypic changes in BP circadian rhythm. There are normotensive and hypertensive "non-dippers" with or without the BP circadian rhythm. The "rhythmic non-dippers" show a BP circadian rhythm which is inverted in phase or demodulated in amplitude. The "non-dippers" are, thus, a heterogeneous category.

The 14-year follow-up of a female patient with Liddle's syndrome (LS), a rare disease characterized by hypertension, hypokalemic alkalosis, and negligible aldosterone secretion due to renin suppression, is described. The disease was diagnosed at the age of 10 months (youngest identification). The patient was repeatedly investigated during follow-up for plasma renin activity (PRA), plasma aldosterone concentration (PA), serum sodium and potassium (K) concentration, blood pressure (BP), somatic anthropometry, and mental development. Noteworthy results included: persistent low circulating K, PRA, and PA and high BP, coinciding with unauthorized withdrawal of the triamterene therapy. These findings are in keeping with the hypothesis that LS results from a pathogenetic disorder which is not correctable with age. The triamterene therapy was effective in correcting the endocrine and metabolic disorders as well as arterial hypertension, but did not prevent a deficit in mental and physical development. However, the information derived from this study allows further clarification of the clinical picture of the disease.

The present study investigates the blood pressure (BP) 24 h pattern in 25 subjects who were found to show some incipient signs of hypertensive retinopathy, although they were diagnosed as normotensive by means of casual sphygmomanometry. BP was controlled by means of non invasive ambulatory monitoring. A comparable number of normotensive subjects without fundoscopic signs of hypertensive retinopathy was investigated as a control group. BP times series were analyzed by means of conventional and rhythmometric biometry. The biometric estimates suggest that the subjects with incipient hypertensive retinopathy show a significantly higher level of daily systolic BP even though their BP values remain below the reference limits. This finding suggests that the hypertensive retinopathy may exist in a non-zero stage characterizable as minimal change tensive retinopathy. This retinal picture occurs in subjects who show a pre-hypertensive stage in their BP 24 h pattern.

The study investigates how the human body composition (BC) changes as a function of the day-night cycle. The BC was investigated using bioelectrical impedance analysis (BIA) of 10 clinically healthy subjects (CHS), monitored in supine position (readings at 2-h intervals), avoiding mealtimes, dietary abuses, and bladder and intestinal retention. Time series data were analyzed for their temporal characteristics and circadian rhythm (CR). All the variables of BC (lean body mass, fat body mass, body cell mass, total body water, intracellular and extracellular body water, sodium and potassium exchangeable pool) showed a within-day variability with nighttime crests. Such an oscillatory synchronism corroborates the hypothesis that the rest time plays a fundamental role, via its anabolic effects, in conferring the nocturnal phase to the CR of the human BC.

This study is aimed at investigating the relationship between cardiac hypertrophy and blood pressure (BP) 24-h pattern in 34 heart transplanted patients (HTP), 9 out of them (26%) being considered as normotensives, the other ones (74%) being regarded as hypertensives under adequate treatment, via casual sphygmomanometry. The study is an attempt to explain the occurrence of at least one sign of hypertrophic cardiopathy in 20 cases (59%), hypothesizing the presence of false normotensives among the putative normotensives and presumably-cured hypertensives. The ambulatory BP monitoring was able to identify 7 hypertensives (78%) among the putative normotensives, and 17 not well-cured subjects (68%) among the presumably cured hypertensives. At least one sign of cardiac hypertrophy was found in 5 (50%) of the 10 true normotensives, who were all non-dipper, and in 15 (63%) of the 24 hypertensives. The 9 hypertensives without cardiac hypertrophy (37%) had developed hypertension very recently. These findings stress the role of the ambulatory BP monitoring as a diagnostic tool during the follow-up of HTP, in order to identify the false normotensives as well as the not well-treated hypertensives. This role can contribute to optimize the prophylaxis of hypertensive damage for the transplanted heart.

This investigation was performed in 34 heart transplanted patients (HTP), 28 males and 6 females, mean age 49 +/- 13 years. The aim of the study was to detect hypertension in HTP by casual sphygmomanometry and non-invasive ambulatory blood pressure monitoring (ABPM). The evaluation of ABPM demonstrated that 71% out of the HTP was hypertensive because of some elevated blood pressure values scattered during the hours of the day and/or of the night. These hypertensives were found within the groups of normotensives as well as of hypertensives considered to be correctly treated. Fifty percent hypertensive HTP did not show the physiologic nocturnal decrease in blood pressure (non-dippers); 25% out of the non-dipper hypertensives showed absence of the blood pressure circadian rhythm, demonstrating that their hypertension was prevalently nocturnal and could not be detected by casual sphygmomanometry-The ABPM is recommended in clinical follow-up of HTP for a correct diagnosis of hypertension, which frequently complicates heart transplantation, and with the aim of avoiding hypertensive damage of the transplanted organ. The ABPM is useful for adjusting the antihypertensive therapy, in order to restore the blood pressure circadian rhythm.