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Biomedical subjects

Luigi Tubani

Publications and source records attributed to Luigi Tubani.

5 recordsLinked to original sources
PubMed2006

Circadian rhythm of the autonomic nervous system in insulin resistant subjects with normoglycemia, impaired fasting glycemia, impaired glucose tolerance, type 2 diabetes mellitus.

BACKGROUND: In 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. METHODS: Eighty 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. RESULTS: The total SDNN showed statistically significant reduction in all four groups with insulin resistant subjects (IR) when compared to the control group (p <0,001). During night LF normalized units (n.u.) were found to be higher in all four groups including IR subjects than in the control group (all p < 0,001) and subjects with normal glucose regulation (NGR), with impaired fasting glycemia (IFG) and with impaired glucose tolerance (IGT) were found to have higher LF n.u. than those in the type 2 diabetes mellitus group. The linear regression model demonstrated direct association between LF values and the homeostasis model assessment-index (HOMA-I), in the insulin resistant group (r = 0,715, p <0,0001). CONCLUSION: The 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.

Adult↗
PubMedDate not supplied

Heart rate variability in cluster headache.

Eight patients with cluster headache were studied by evaluating the heart rate variability on the basis of 24-hour ECG monitoring performed during attacks (critic periods) to demonstrate if any imbalance of the autonomic nervous system was present and to determine its temporal correlation, if any, with the attack. The same monitoring allowed us to compare the patients' data during headache-free periods (intercritic periods) with those of normal controls. Our investigation demonstrated a severe sympathovagal imbalance during spontaneous attacks: the parasympathetic drive is at once increased at the onset with a mild reduction of the sympathetic drive, and all these modifications slowly disappear at the end of each attack. Comparison of the average low-frequency and high-frequency values during intercritic periods showed a significant reduction in the low-frequency values in patients, even when the low-frequency/high-frequency ratio was normal. This is highly suggestive of the presence of an autonomic nervous system dysfunction.

Adult↗
PubMedDate not supplied

Alterations of the sympathovagal balance evaluated by heart rate variability in a rare case of adult Still's disease.

We present a rare case of adult Still's disease with cardiac involvement (myocarditis and coronary arteritis). The autonomic nervous system function was evaluated by heart rate variability (HRV) analysis performed by 24-hour electrocardiographic recording during the acute phase of the disease and the remission (after 1 month and 1 year). The HRV parameters were studied in the time (standard deviation of all NN intervals-total power - SDNN, square root of the mean of the sum of the squares of the differences between adjacent NN - RMS-SD and HRV index) and frequency domains (low frequency, high frequency, and low frequency/high frequency). The results of the analysis of the HRV highlight that in the acute phase of the disease with cardiac involvement the autonomic nervous system is globally altered, with modifications of the sympathovagal balance, due to impairment of the parasympathetic component. This trend tends to persist in the short period (1 month), but seems to resolve completely within 1 year. An altered sympathovagal balance should be considered as a possible marker of vasculitis-related ischemia.

Adult↗