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Aim Autonomic dysfunction (AD) is an early feature of systemic sclerosis (SSc). A regular endothelial function is a prerequisite for normal response of the myocardial blood flow (MBF) to cold pressure test (CPT). The aim of the study was to evaluate the relation between MBF and AD at rest and after CPT in asymptomatic SSc patients. Methods Twenty SSc patients and 10 age-, sex- and body mass index-matched healthy controls underwent cardiac magnetic resonance at rest and after CPT. All subjects underwent 24 hours ambulatory 3-channel electrocardiogram Holter to evaluate AD by heart rate variability. Results We did not observe any significant difference in MBF (mL/g/min) at rest and after CPT between SSc patients and healthy controls. Delta of MBF (difference between MBF after CPT and rest MBF) was lower (P = 0.039) in SSc patients than healthy controls (0.28 [0.04-0.40] vs 0.33 [0.24-0.54]). The low frequency/high frequency (LF/HF) was higher (P = 0.002) in SSc patients than healthy controls (3 [1.7-6] vs 1.8 [1.1-2.8]). The high frequencies (HF), modulated mainly by paraympathetic system, was lower (P = 0.003) in SSc patients than healthy controls (30 [16-42] vs 36.5 [24-44]). Sympathetic hyperactivity, due to reduction of parasympathetic activity (HF), is present in SSc patients. A negative correlation was observed between Delta of MBF and LF/HF (r = -0.572, P = 0.0031). Conclusion AD, characterized by sympathovagal imbalance due to a reduced parasympathetic tone with high LF/HF ratio, could be responsible for the reduced myocardial vasodilatory response after CPT.

Background The QT interval reflects the duration of the intracellular action potential. Little is known on the interval QT duration in non diabetic insulin-resistant subjects. Objective The aims of the current study were to evaluate the QTc interval in three groups of non diabetic insulin-resistant subjects and the possible correlation between QTc and the autonomic nervous system's activity. Design 90 subjects were divided in subjects with impaired fasting glycaemia (IFG) and, by the results of OGTT, according to the criteria of ADA, in subjects with normal glucose regulation (NGR) and impaired glucose tolerance (IGT). Insulin resistance was evaluated by the homeostasis model assessment-index (HOMA-I). Heart rate variability and Qtc were calculated. Results QTc interval is correlated with SDNN, LF n.u. and LF/HF. Conclusion We have observed that the QTc interval is prolonged in insulin-resistant subjects with associated impaired glucose metabolism, while no difference was reported between insulin-resistant and non insulin-resistant subjects with normal glucose regulation. We hypothesize that hyperglycaemia could play a major role than hyperinsulinemia on the QTc prolongation.

Systemic sclerosis (SSc) is an autoimmune disease characterized byendothelial dysfunction and fibrosis of the skin and internal organs [1].Cardiac involvement in the course of SSc could be primary or sec-ondary to pulmonary arterial hypertension and kidney pathology. Pri-mary cardiac involvement may manifest as myocardial involvement,arrhythmias,fibrosisoftheconductionsystem,pacemakerandintracar-diac defibrillator implantation, sudden death and autonomic dysfunc-tion [2,3].Amongtheabnormalities in SSc,QTc intervalprolongation hasbeenreportedandassociatedwithanti-RNApolymeraseIIIantibodies,longerdisease duration, and greater disease severity [4].Accordingly,theaimofthestudyistoassessQTcprolongationinSScand evaluate correlations with clinical variables and complications ofthe disease.The protocol is in accordance with the Declaration of Helsinki andwas approved by the Ethics Committee at our Institution. Twenty Cau-casian subjects fulfilling the American Rheumatism Association (ARA)criteria for classification and diagnosis of SSc [5] and twenty healthysubjectswereexaminedbeforeinclusioninthestudy.All examined pa-tientsunderwentclinicalevaluation,ambulatory24-hourECGmonitor-ing, transthoracic echocardiogram.Scleroderma patients with coronary artery disease, congestiveheartfailure, left ventricular dysfunction, significant valvular abnormalitiesand arrhythmias were not included in the study.Patients with pulmonary function abnormalities were not includedeither. Patients with diabetes mellitus, renal failure, hepatic or thyroiddysfunction, and anemia were excluded.Patients were not takingβ-blockers, antiarrhythmic drugs,ACE-inhibitors or angiotensin receptor antagonists. QTc interval,assessed by 24-hour Holter ECG recording, was defined as prolongedwhen N440 ms [6].Nailfold videocapillaroscopy (NVC) was performed by an opticalprobe, equipped with magnification 200× contact lens and connectedto image analysis software (Pinnacle Studio Version 8). The identifiedpatterns were classified as early, active or late [7]. Skin thickening wasassessed by a modified Rodnan total skin score (mRSS) [8]. In all pa-tientswemeasuredtheDiseaseActivityIndex(DAI)andDiseaseSever-ity Scale (DSS) [9].Thedatawereexpressedasmedianandrange.Multivariateanalysiswas applied for the estimation of relationship of QTc with disease vari-ables. The Mann–Whitney U-test or Kruskal–Wallis were used to testdifferences between two individual study groups. Spearman's rankorder correlation coefficient (r) was used to test for an association be-tweennumericalvariables.p-Valuesb0.05wereconsideredsignificant.Commercial software (SPSS version 20.0) was used for statisticalanalysis.Twentysclerodermapatientswereenrolledinthecurrentstudy.Theepidemiological and clinical features of SSc are shown in Table 1.ThemedianvalueofQTcissignificantly(pb0.0001)increasedinSScpatients than healthy controls [447 (414–566) vs 386 (342–447)].The medianvalueof QTc is significantly (p b 0.01) different in threecapillaroscopicgroups:early425(421 –454),active437(416–467),late471 (445–566).ThemedianvalueofQTcissignificantly(pb 0.05)augmentedin SScpatients with digital ulcers than in SSc patients without digital ulcers[459(422–566)vs436(416–454)].Apositivecorrelation (p b0.05)ex-ists between QTc and mRSS (r = 0.53).NocorrelationswerefoundbetweenQTcanddiseasesubset,diseaseduration, Disease Activity Index, and Disease Severity Scale.Amongthe causes of suddencardiacdeath in SScpatients,ventricu-lar late potentials, autonomic dysfunction, pro-arrhythmogenic drugsand increased QT dispersion were found.

Systemic sclerosis (SSc) is a systemic disease of connective tissue,characterized by endothelial dysfunction and fibrosis of the skin andvisceral organs [1]. Autonomic dysfunction (AD) is a feature of SSc,starting early in the disease and possibly preceding the developmentof fibrosis [2].Several manifestations of renal involvement occur in SSc and wehave recently demonstrated that renal resistive index (RI) correlateswith glomerular filtration rate (GFR), digital microvascular damage [3]and in monitoring scleroderma renal crisis [4].Accordingly, the aim of the study is to assess intrarenal arterialstiffness by Doppler ultrasound and examine the correlation with ADusing heart rate variability (HRV) analysis.The protocol is in accordance with the Declaration of Helsinki andwas approved by the Ethics Committee at our Institution. NineteenCaucasian subjects fulfilling the American Rheumatism Association(ARA) criteria for classification and diagnosis of SSc [5] and nineteenhealthysubjectswereexaminedbeforeinclusioninthestudy.Allexam-ined patients underwent clinical evaluation, 24-h Holter monitoring,electrocardiography (ECG) and transthoracic echocardiogram.Scleroderma patients with coronary artery disease, congestiveheartfailure, left ventricular dysfunction, significant valvular abnormalitiesand arrhythmias were not included in the study.Patients with pulmonary function abnormalities were not includedeither. Patients with diabetes mellitus, renal failure, hepatic or thyroiddysfunction and anaemia were excluded.Patients were not taking β-blockers, antiarrhythmic drugs, ACE-inhibitors or angiotensin receptor antagonists. GFR was calculatedwith CKD-EPI equation [6].Autonomic nervous activity was evaluated by heart rate variability(HRV) analysis during 24-hour ECG recording. Autonomic nervousactivity was analyzed following the recommendations of the TaskForce of the European Society of Cardiology and the North AmericanSociety of Pacing and Electrophysiology [7]. Total power in the fre-quency range (0–0.40 Hz) was divided into low frequency (LF:0.04–0.15 Hz, modulated mainly by sympathetic system) and highfrequency (HF: 0.15–0.40 Hz, modulated by parasympathetic system).The power of LF and HF components was considered in normalizedunits (nu). LF/HF rate is sympathovagal balance. Artificial data andarrhythmic were excluded. Data analyses were performed with soft-ware Del Mar Avionics Accuplus 363, Irvine California, USA.Renal Doppler ultrasound was performed using a Toshiba AplioUltrasound System SSA-790 (Tokyo, Japan) equipped with convex 3.5-MHz probe. RI was calculated as (peak systolic frequency shift −minimum diastolic frequency shift) / peak systolic frequency shift.All the ultrasound examinations were performed by same blindedphysician in order to reduce variability in the assessment managementof the study.Thedatawereexpressedasmedianandrange.Multivariateanalysiswas applied for the estimation of relationship of HRV variables withrenal Doppler indices or disease variables. The Mann–Whitney U-testor Kruskal–Wallis was used to test differences between two individualstudy groups. Spearman's rank order correlation coefficient (r) wasused to test for an association between numerical variables. p-Valuesb0,05 were considered significant. Commercially software (SPSSversion 20.0) was used for statistical analysis.Nineteen scleroderma patients were enrolled in the current study.Median age of 45 years (range 23–58) and a median SSc duration of6,5 years (range 2–25) were investigated in the Clinical ImmunologyUnit-Scleroderma Center. Six patients had limited cutaneous SSc and

Primary antiphospholipid syndrome is associated with an increased risk of vascular throm bosis. The authors describe a young patient without any risk factor for coronary artery disease who was admitted to the hospital because of a transient cerebral ischemic attack. Standard EKG showed signs of a previous silent inferior wall myocardial infarction, confirmed by echocar diography, technetium-99 scintigraphy, and left ventricular angiography. Coronary arteries appeared normal at angiography. Blood tests showed the presence of antiphospholipid anti bodies and lupus anticoagulant. Since there is evidence that these antibodies are associated with an increased risk of microvascular thrombosis, the authors conclude that this silent myocardial infarction could be caused by a cardiac microvascular disease accompanying the antiphospholipid syndrome.

Following the introduction of tolcapone, a potent, reversible Catechol-O-methyltransferase (COMT) inhibitor, it has been possible to optimise the management of Parkinson's disease (PD) patients in chronic Levodopa (L-dopa) therapy. The interaction between tolcapone and the endogenous metabolism of catecholamines points to a possible influence on autonomic cardiovascular function.Cardiovascular reflexes have been analysed in a group of seven PD patients (four males, three females; mean age 69.7years, mean disease duration 14.1years) by means of the heart rate variability (HRV) method using a continuous 24-h ECG (ECGD), before and after six months of treatment with tolcapone (in addition to L-dopa).We have observed no statistically significant differences in HRV parameters, nor any changes in the incidence of hyperkinetic and hypokinetic arrhythmias, which suggest that autonomic cardiovascular function in PD patients is not influenced by six months of treatment with tolcapone.

Autonomic nervous system activity is involved in body weight regulation. We assessed whether the body mass index (BMI) is related to the autonomic nervous system activity as assessed by heart rate variability (HRV). Twenty-five adult normotensive, euglycemic healthy males (M) and females (F) were studied (M/F=13/12). BMI was assessed in each individual. HRV was assessed and the domains of low frequencies (LF, index of the sympathetic modulation) and high frequencies (HF, index of the parasympathetic modulation) were measured. Data were statistically analyzed and are presented as mean+/-s.d. Mean BMI did not correlate with either HF or LF. It inversely related to HF (r=-0.50, P0.01), whereas its relationship with LF was marginally significant (r=-0.39, P=0.05). The HF in individuals with BMI20 kg/m(2) was significantly higher from those measured in the remaining subjects (P0.05). The results support the role of parasympathetic activity in influencing BMI through likely modulation of body weight.

Background: Meditation in its various forms is a traditional exercise with a potential benefit on well-being and health. On a psychosomatic level these exercises seem to improve the salutogenetic potential in man.Especially the cardiorespiratory interaction seems to play an important role since most meditation techniques make use of special low frequency breathing patterns regardless of whether they result from a deliberate guidance of breathing or other mechanisms, for example, the recitation of specific verse. During the different exercises of Zen meditation the depth and the duration of each respiratory cycle is determined only by the process of breathing. Respiratory manoeuvres during Zazen meditation may produce HR variability changes similar to those produces during biofeedback.Recognition that the respiratory sinus arrhythmia (RSA) was mediated by efferent vagal activity acting on the sinus node led investigators to attempt to quantify the fluctuations in R-R intervals that were related to breathing. Materials and Methods: Nine Zen practitioners with five years of experience took part in the study. Autonomic nervous system function was evaluated by heart rate variability (HRV) analysis during 24-hours ECG recording during zen meditation and at rest. Results: The data of this small observational study confirm that ZaZen breathing falls within the range of low frequency HR spectral bands. Our data suggest that the modification of HR spectral power remained also in normal day when the subject have a normal breathing. Conclusion: We suggest that the changes in the breathing rate might modify the chemoreflex and the continuous practice in slow breathing can reduce chemoreflex. This change in the automonic control of respiration can be permanent with a resetting of endogenous circulatory rhythms.

The cardiac autonomic function was evaluated in 23 patients with Systemic Lupus Erythe matosus (SLE) without clinical expression of dysautonomia and in 14 healthy volunteer subjects as a control group, by analysis of Heart Rate Variability (HRV) from 24 h ambula tory electrocardiography. All the patients were taking corticosteroids and 10 of them also Ciclosporin A (CsA). The following parameters of HRV were performed: Time domain: standard deviation of the RR intervals average (SDNN) and percentage of RR adjacent intervals differing from each other more than 50 msec (pNN50). Frequency domain: low frequencies (LF) and high frequencies (HF). Significant lower values were detected in SLE patients vs controls: SDNN = 69.40 vs 127.72; pNN50 = 16.44 vs 25.95; LF = 8.34 vs 34.97; HF = 3.21 vs 12.18. The incidence of autonomic dysfunction in our SLE population evaluated by considering intervals of nor mality is approximately 78% for SDNN; 17% for pNN50; 91% for LF and, finally, 56% for HF. The analysis of HRV may be a valuable technique in the study of the incidence of dysautonomia for these patients.

Background Aim of the study was to assess QTc interval by a 24-hour ECG recording in a group of HIV-infected individuals with a basal prolonged QTc. The risk factors associated with QTc prolongation and the indices of cardiovascular autonomic control were also evaluated. Methods A case–control study was performed using as cases 32 HIV-infected patients with prolonged (>440 msec) QTc interval as assessed by Holter ECG, and as controls 64 HIV-infected subjects with normal QTc interval. Autonomic function was evaluated by heart rate variability analysis during 24-hour recording. Results Duration of HIV disease was significantly longer among cases than among controls (p=0.04). Waist/hip ratio was also higher among cases than among controls (p=0.05). Frequency domain analysis showed the absence of physiologic decrease of low frequency (LF) in the night period in both cases and controls. The LF night in cases showed a statistically significant reduction when compared with controls (p=0.007). Conclusions In our study group, QTc interval prolongation was associated with a longer duration of HIV infection and with a greater waist/hip ratio. HIV patients with QTc interval prolongation and with a longer duration of HIV infection were more likely to have an impairment of parasympathetic and sympathetic cardiac component.

We observe, in patients with type 2 diabetes of recent onset, the activity of the autonomic nervous system and glucose metabolic impairment. The data indicate the hyperactivity of the sympathetic and minimal changes in glucose values. The role played by glycemia appeared to be less important than that represented by insulin resistance.

There is little information on the long-term effect of liver transplantation (LT) on cardiac autonomic dysfunction in cirrhotic patients. We compared cardiac autonomic function before and in the long-term after LT. In a transversal study, we investigated 30 cirrhotics awaiting LT, 15 clinically stable patients 2-6 years after LT and 27 healthy controls. Seven cirrhotic patients were studied before LT, and 6, 12 and 33 months after LT, in a prospective fashion. Cardiac autonomic function was measured by heart rate variability (HRV) analysis during 24-h electrocardiogram recording. In the transversal study, patients with cirrhosis as compared to healthy controls had significantly reduced standard deviation of normal-to-normal RR intervals (SDNN) (p

To the Editor: We have read with great interest the article by Ryan et al.1 We agree with the authors that the NZBWF1 strain may be an important model to study the effects of obesity and insulin resistance on systemic lupus erythematosus (SLE)–associated hypertension. The authors have observed that this hypertensive mouse model of …

To the Editor: We have read with interest the article by MJ Chen et al1 on the relationship between androgen levels and blood pressure in young women with polycystic ovary syndrome (PCOS). The authors have observed that characteristic hyperandrogenemia in young …

Sleep is one of the most important factors contributing to health. Although same studies examining the relationship between sleep duration and mortality, has not been fully discussed. We consecutively studied two hundred and fifty Caucasian subjects, normoweight, who were referred for ambulatory blood pressure monitoring (APM). Quality of sleep was evaluated through the Pittsburgh Sleep Quality Index (PSQI). PSQI assessed subjective sleep quality of the past 4 weeks and was administered during the personal interview. A global PSQI > or =5 has a diagnostic sensitivity of 89.6 and specificity of 86.5 in distinguishing "poor sleepers"(PSQI > or =5) from "good sleepers" (PSQI

BackgroundIn type 2 diabetes mellitus both insulin resistance and hyperglycemia are considered responsible for autonomic dysfunction. The relation between the autonomic activity, impaired fasting glycemia and impaired glucose tolerance is, however, unclear. The purpose of this study was to evaluate and compare the circadian autonomic activity expressed as heart rate variability (HRV) measured by 24-hours ECG recording in insulin resistant subjects (IR) with characteristics as follow: IR subjects with normal oral glucose tolerance test results, IR subjects with impaired fasting glucose, IR subjects with impaired glucose tolerance and subjects with type 2 diabetes mellitus.MethodsEighty Caucasian insulin resistant subjects (IR) and twenty five control subjects were recruited for the study. IR subjects were divided into four groups according to the outcoming results of oral glucose tests (OGTTs): IR subjects with normal glucose regulation (NGR), IR subjects with impaired fasting glycemia (IFG), IR subjects with impaired glucose tolerance (IGT) and subjects with type 2 diabetes mellitus (DM). Autonomic nervous activity was studied by 24-hours ECG recording. Heart rate variability analysis was performed in time and frequency domains: SDNN, RMS-SD, low frequency (LF) and high frequency (HF) were calculated.ResultsThe total SDNN showed statistically significant reduction in all four groups with insulin resistant subjects (IR) when compared to the control group (p ConclusionThe results of our study suggest that insulin resistance might cause global autonomic dysfunction which increases along with worsening glucose metabolic impairment. The analysis of sympathetic and parasympathetic components and the sympathovagal balance demonstrated an association between insulin resistance and sympathetic over-activity, especially during night. The results indicated that the sympathetic over-activity is directly correlated to the grade of insulin resistance calculated according to the HOMA-I. Since increased sympathetic activity is related to major cardiovascular accidents, early diagnosis of all insulin resistant patients should be contemplated.

In patients with systemic lupus erythematosus, involvement of the cardiovascular system is the third leading cause of death. However, although autopsy studies have demonstrated a high incidence of abnormalities in both the myocardium and coronary vessels, clinical manifestations have been reported in only a small percentage of cases. The aim of this study was to evaluate myocardial perfusion in asymptomatic lupus patients using technetium-99m sestamibi single-photon emission tomography (SPET). Twenty-eight patients without overt cardiac involvement and risk factors were studied with 99mTc-sestamibi SPET at rest and after dipyridamole infusion. Perfusion abnormalities were detected in 18 cases: six had persistent defects, three had reversible defects, seven had both persistent and reversible defects, and two showed rest defects which normalized on dipyridamole images (”reverse redistribution pattern”). Coronary angiography was performed in eight patients with positive 99mTc-sestamibi SPET, and showed normal epicardial vessels in all the cases. These results indicate that 99mTc-sestamibi SPET reveals a high prevalence (18 out of 28 patients in this study, i.e. 64%) of myocardial perfusion abnormalities in asymptomatic lupus patients, probably due to the primary immunological damage of this autoimmune disease. In conclusion, rest/dipyridamole 99mTc-sestamibi SPET can be a useful non-invasive method to identify subclinical myocardial involvement in systemic lupus erythematosus, and patients potentially at risk of later cardiac events.

The objective of this paper was to investigate the incidence of myocardial perfusion defects in patients with systemic lupus erythematosus (SLE) associated with dysauto nomic alterations. Twenty patients without any sign or symptoms of heart disease, selected from a larger population of patients with SLE, underwent technetium-99m sestamibi (Tc-99m MIBI) single photon emission computed tomography (SPECT), at rest and after dipyridamole infusion; they also underwent heart rate variability (HRV) exam ination by a 24 hour ambulatory electrocardiography, analyzing in the time domain the standard deviation of the R-R intervals average (SDNN) and the percentage of R-R adjacent intervals differing from each other more than 50 msec (pNN50); in the frequency domain the low (LF) and high frequencies (HF) were analyzed. Twenty healthy volunteers served as control group for heart rate variability. At MIBI-SPECT examina- tion, the scan was found abnormal in 15 patients and normal in five: three patients demonstrated reversible defects in the anteroseptal region, four had irreversible defects in a region (two in the anteroseptal region and two in the lateral region), two had rest defects in two different regions (lateral and inferior, lateral and anteroseptal) that improved during dipyridamole scan, and six had both reversible and irreversible defects: four in a single segment (three anteroseptal and one lateral, and two in two different regions, particularly anteroseptal and lateral, lateral and inferior). All 20 patients showed significantly lower HRV parameters in comparison with the control group, except for pNN50, which indicates decreased physiologic periodic fluctuations of the autonomic nervous system. In six patients who underwent coronary angiography, the epicardial vessels were found completely normal. In view of the high incidence of myocardial hypoperfusion in patients with HRV alterations, the authors hypothesize that autonomic dysfunction may be associated with microvascular disease or metabolic alteration. They also believe that MIBI scintigraphy is a suitable technique in detecting myocardial damage in SLE patients free of clinical manifestation.

Objectives - To evaluate the autonomic dysfunction in Parkinson's disease patients by means of a 24-h heart rate variability (HRV) method. Material and methods - Thirteen patients with a diagnosis of Parkinson's disease were compared with 13 age-matched healthy persons (control group). The 13 patients had a mean age of 70.5 years, and mean disease duration of 10.9 years. The autonomic function was evaluated by HRV analysis using a continuous 24-h ECG. The parameters of SDNN (standard deviation of the normal-to-normal intervals between adjacent QRS complexes), of LF (power in low frequency) and of HF (power in high frequency) were studied during the following 3 periods: 24 h, night and day. Results - The data show a statistically significant difference between groups for SDNN and LF in all the periods, while for HF parameters the difference is statistically significant only in the night period. Conclusion - The use of the 24-h HRV method can provide more accurate and reproducible data than other conventional cardiovascular tests.

Sir,We present a 35-year-old malepatient with 10 years’ history ofepisodic cluster headache (3–4attacks per day, previously treatedwith methysergide, lithium and oxy-gen without significant benefit).Therapy with verapamil 240 mg/dayreduced the frequency of attacks (2–3per day). After increasing the dose ofverapamil to 360 mg/day the patientpresented hypotension (75/40 mmHg)and serious bradycardia (HR 32/min),which required the implant of a tem-porary ventricular non-sequentialpacemaker. Once the critical periodhad passed, the blood pressure nor-malised; after the electrophysiologystudy found normal results, it waspossible to remove the pacemaker.Before starting verapamil therapy,cardiac examination and 24-h ECGrecording were normal.In the last 7 years, we have beenobserving four patients treated withverapamil for episodic clusterheadache that have referred hypoten-sion and serious bradycardia. Thepatients have not presented any con-traindication to prophylactic therapywith verapamil. Verapamil is a calci-um channel blocker and its commonadverse effects include constipation,dizziness, nausea, bradycardia andhypotension. It is widely used as afirst-line prophylactic drug for clusterheadache at doses starting at 360 mg[1, 2]. Patients with cluster headachepresent an increase in sympathetictone before the attack of a headache.This “sympathetic storm” could causeshort but hazardous periods ofarrhythmia [3]. On the contrary, aparasympathetic overactivity withconsequent bradycardia is presentduring the attack [4, 5]. Verapamiltherapy prevents episodic clusterheadache but it requires a strict con-trol of blood pressure and heart rate,because an overlap between theeffects of verapamil and the effects ofthe parasympathetic overactivitycharacterising the attack of clusterheadache that could cause serioushypotension and bradycardia can beverified [6].

We read with interest the article by Colussi et al. (1) on the relationship between insulin resistance, hyperinsulinemia, and aldosterone levels in hypertensive patients. The authors observed that the homeostasis model assessment index is correlated with plasma aldosterone. They conclude that in patients with hypertension, this relationship …

The aim of the present study was to evaluate, by heart rate variability (HRV) with 24-hours ECG Holter (HRV), the circadian autonomic activity in offspring of type 2 diabetic subjects and the relation with insulin-resistance. METHODS: 50 Caucasian offsprings of type 2 diabetic subjects were divided in two groups: insulin-resistant offsprings (IR) and non insulin-resistant offsprings (NIR). Autonomic nervous activity was studied by HRV. Time domain and spectral analysis (low frequency, LF, and high frequency, HF, provide markers of sympathetic and parasympathetic modulation when assessed in normalized units) were evaluated. RESULTS. Time domain showed a reduction of total SDNN in IR (p < 0.001) and NIR (p 0.047) versus controls. Spectral analysis showed a total and night LF higher in IR and NIR than in control group (all p < 0.001). CONCLUSION. In frequency domain, the analysis of sympathetic (LF) and parasympathetic (HF) component evidenced an association between the offspring of type 2 diabetic subjects and a sympathetic overactivity. A global reduction and alteration of circadian rhythm of autonomic activity are present in offspring of type 2 diabetic patients with and without insulin resistance. The data of our study suggested that an autonomic impairment is associated with the familiarity for type 2 diabetes independently to insulin resistance and that an impairment of autonomic system activity could precede the insulin resistance.