A simple deep breathing test reveals altered cerebral autoregulation in type 2 diabetic patients

Aims/hypothesis: Patients with diabetes mellitus have an increased risk of stroke and other cerebrovascular complications. The purpose of this study was to evaluate the autoregulation of cerebral blood flow in diabetic patients using a simple method that could easily be applied to the clinical routine screening of diabetic patients. Methods: We studied ten patients with type 2 diabetes mellitus and 11 healthy volunteer control participants. Continuous and non-invasive measurements of blood pressure and cerebral blood flow velocity were performed during deep breathing at 0.1 Hz (six breaths per minute). Cerebral autoregulation was assessed from the phase shift angle between breathing-induced 0.1 Hz oscillations in mean blood pressure and cerebral blood flow velocity. Results: The controls and patients all showed positive phase shift angles between breathing-induced 0.1 Hz blood pressure and cerebral blood flow velocity oscillations. However, the phase shift angle was significantly reduced (p < 0.05) in the patients (48 ± 9°) compared with the controls (80 ± 12°). The gain between 0.1 Hz oscillations in blood pressure and cerebral blood flow velocity did not differ significantly between the patients and controls. Conclusions/interpretation: The reduced phase shift angle between oscillations in mean blood pressure and cerebral blood flow velocity during deep breathing suggests altered cerebral autoregulation in patients with diabetes and might contribute to an increased risk of cerebrovascular disorder

Partial pharmacologic blockade shows sympathetic connection between blood pressure and cerebral blood flow velocity fluctuations

Cerebral autoregulation (CA) dampens transfer of blood pressure (BP)-fluctuations onto cerebral blood flow velocity (CBFV). Thus, CBFV-oscillations precede BP-oscillations. The phase angle (PA) between sympathetically mediated low-frequency (LF: 0.03–0.15 Hz) BP- and CBFV-oscillations is a measure of CA quality. To evaluate whether PA depends on sympathetic modulation, we assessed PA-changes upon sympathetic stimulation with and without pharmacologic sympathetic blockade. In 10 healthy, young men, we monitored mean BP and CBFV before and during 120-second cold pressor stimulation (CPS) of one foot (0 °C ice-water). We calculated mean values, standard deviations and sympathetic LF-powers of all signals, and PAs between LF-BP- and LF–CBFV-oscillations. We repeated measurements after ingestion of the adrenoceptor-blocker carvedilol (25 mg). We compared parameters before and during CPS, without and after carvedilol (analysis of variance, post-hoc t-tests, significance: p < 0.05). Without carvedilol, CPS increased BP, CBFV, BP-LF- and CBFV-LF-powers, and shortened PA. Carvedilol decreased resting BP, CBFV, BP-LF- and CBFV-LF-powers, while PAs remained unchanged. During CPS, BPs, CBFVs, BP-LF- and CBFV-LF-powers were lower, while PAs were longer with than without carvedilol. With carvedilol, CPS no longer shortened resting PA. Sympathetic activation shortens PA. Partial adrenoceptor blockade abolishes this PA-shortening. Thus, PA-measurements provide a subtle marker of sympathetic influences on CA and might refine CA evaluation

Advanced Electrocardiographic Predictors of Sudden Death in Familial Dysautonomia

To identify accurate predictors for the risk of sudden death in patients with familial dysautonomia (FD). Ten-minute resting high-fidelity 12-lead ECGs were obtained from 14 FD patients and 14 age/gender-matched healthy subjects. Multiple conventional and advanced ECG parameters were studied for their ability to predict sudden death in FD over a subsequent 4.5-year period, including multiple indices of linear and non-linear heart rate variability (HRV); QT variability; waveform complexity; high frequency QRS; and derived Frank-lead parameters. Four of the 14 FD patients died suddenly during the follow-up period, usually with concomitant pulmonary disorder. The presence of low vagally-mediated HRV was the ECG finding most predictive of sudden death. Concomitant left ventricular hypertrophy and other ECG abnormalities such as increased QTc and JTc intervals, spatial QRS-T angles, T-wave complexity, and QT variability were also present in FD patients, suggesting that structural heart disease is fairly common in FD. Although excessive or unopposed cardiac vagal (relative to sympathetic) activity has been postulated as a contributor to sudden death in FD, the presence of low vagally-mediated HRV was paradoxically the best predictor of sudden death. However, we suggest that low vagally-mediated HRV be construed not as a direct cause of sudden death in FD, but rather as an effect of concurrent pathological processes, especially hypoxia due to pulmonary disorders and sleep apnea, that themselves increase the risk of sudden death in FD and simultaneously diminish HRV. We speculate that adenosine may play a role in sudden death in FD, possibly independently of vagal activity, and that adenosine inhibitors such as theophylline might therefore be useful as prophylaxis in this disorder

Sexual dysfunction among married couples living in Kumasi metropolis, Ghana

<p>Abstract</p> <p>Background</p> <p>Sexuality and its manifestation constitute some of the most complex of human behaviour and its disorders are encountered in community. Sexual dysfunction is more prevalent in women than in men. While studies examining sexual dysfunction among males and females in Ghana exist, there are no studies relating sexual problems in males and females as dyadic units. This study therefore investigated the prevalence and type of sexual disorders among married couples.</p> <p>Method</p> <p>The study participants consisted of married couples between the ages of 19 and 66 living in the province of Kumasi, Ghana. Socio-demographic information and Golombok-Rust Inventory of Sexual Satisfaction (GRISS) questionnaires were administered to 200 couples who consented to take part in the study. All 28 questions of the GRISS are answered on a five-point (Likert type) scale from "always", through "usually', "sometimes", and "hardly ever", to "never". Responses are summed up to give a total raw score ranging from 28-140. The total score and subscale scores are transformed using a standard nine point scale, with high scores indicating greater problems. Scores of five or more are considered to indicate SD. The study was conducted between July and September 2010.</p> <p>Results</p> <p>Out of a total of 200 married couples, 179 completed their questionnaires resulting in a response rate of 89.5%. The mean age of the participating couples as well as the mean duration of marriage was 34.8 ± 8.6 years and 7.8 ± 7.6 years respectively. The husbands (37.1 ± 8.6) were significantly older (p < 0.0001) than their corresponding wives (32.5 ± 7.9). After adjusting for age, 13-18 years of marriage life poses about 10 times significant risk of developing SD compared to 1-6 years of married life among the wives (OR: 10.8; CI: 1.1 - 49.1; p = 0.04). The total scores (6.0) as well as the percentage above the cut-off (59.2) obtained by the husbands compared to the total score (6.2) and the percentage above cut-off (61.5) obtained by the wives, indicates the likely presence of sexual dysfunction. The prevalence of impotence and premature ejaculation were 60.9% and 65.4% respectively from this study and the prevalence of vaginismus and anorgasmia were 69.3% and 74.9% respectively. The highest prevalence of SD subscales among the men was dissatisfaction with sexual act followed by infrequency, whereas the highest among the women was infrequency followed by anorgasmia. Dissatisfaction with sexual intercourse among men correlated positively with anorgasmia and wife's non-sensuality and infrequency of sex.</p> <p>Conclusion</p> <p>The prevalence of sexual dysfunction in married couples is comparable to prevalence rates in the general male and female population and is further worsened by duration of marriage. This could impact significantly on a couple's self-esteem and overall quality of life.</p

A simple deep breathing test reveals altered cerebral autoregulation in type 2 diabetic patients

Aims/hypothesis Patients with diabetes mellitus have an increased risk of stroke and other cerebrovascular complications. The purpose of this study was to evaluate the autoregulation of cerebral blood flow in diabetic patients using a simple method that could easily be applied to the clinical routine screening of diabetic patients.Methods We studied ten patients with type 2 diabetes mellitus and 11 healthy volunteer control participants. Continuous and non-invasive measurements of blood pressure and cerebral blood flow velocity were performed during deep breathing at 0.1 Hz (six breaths per minute). Cerebral autoregulation was assessed from the phase shift angle between breathing-induced 0.1 Hz oscillations in mean blood pressure and cerebral blood flow velocity.Results The controls and patients all showed positive phase shift angles between breathing-induced 0.1 Hz blood pressure and cerebral blood flow velocity oscillations. However, the phase shift angle was significantly reduced (p < 0.05) in the patients (48 ± 9°) compared with the controls (80 ± 12°). The gain between 0.1 Hz oscillations in blood pressure and cerebral blood flow velocity did not differ significantly between the patients and controls.Conclusions/interpretation The reduced phase shift angle between oscillations in mean blood pressure and cerebral blood flow velocity during deep breathing suggests altered cerebral autoregulation in patients with diabetes and might contribute to an increased risk of cerebrovascular disorders

Altered cerebral regulation in type 2 diabetic patients with cardiac autonomic neuropathy

Aims/hypothesis Assessment of cerebral regulation in diabetic patients is often problematic because of the presence of cardiac autonomic neuropathy. We evaluated the technique of oscillatory neck suction at 0.1 Hz to quantify cerebral regulation in diabetic patients and healthy control subjects.Subjects and methods In nine type 2 diabetic patients with cardiac autonomic neuropathy and 11 age-matched controls, we measured blood pressure and cerebral blood flow velocity responses to application of 0.1 Hz neck suction. We determined spectral powers and calculated the transfer function gain and phase shift between 0.1 Hz blood pressure and cerebral blood flow velocity oscillations as parameters of cerebral regulation.Results In the patients and control subjects, neck suction did not significantly influence mean values of the RR interval, blood pressure and cerebral blood flow velocity. The powers of 0.1 Hz blood pressure and cerebral blood flow velocity oscillations increased in the control subjects, but remained stable in the patients. Transfer function gain remained stable in both groups. Phase shift decreased in the patients, but remained stable in control subjects.Conclusions/interpretation The absence of an increase in the power of 0.1 Hz blood pressure and cerebral blood flow velocity oscillations confirmed autonomic neuropathy in the diabetic patients. Gain analysis did not show altered cerebral regulation. The decrease in phase shift in the patients indicates a more passive transmission of neck suction-induced blood pressure fluctuations onto the cerebrovascular circulation, i.e. altered cerebral regulation, in the patients, and is therefore suited to identifying subtle impairment of cerebral regulation in these patients

Effect of physical countermaneuvers on orthostatic hypotension in familial dysautonomia

Familial dysautonomia (FD) patients frequently experience debilitating orthostatic hypotension. Since physical countermaneuvers can increase blood pressure (BP) in other groups of patients with orthostatic hypotension, we evaluated the effectiveness of countermaneuvers in FD patients.In 17 FD patients (26.4 ± 12.4 years, eight female), we monitored heart rate (HR), blood pressure (BP), cardiac output (CO), total peripheral resistance (TPR) and calf volume while supine, during standing and during application of four countermaneuvers: bending forward, squatting, leg crossing, and abdominal compression using an inflatable belt. Countermaneuvers were initiated after standing up,when systolic BP had fallen by 40mmHg or diastolic BP by 30mmHg or presyncope had occurred.During active standing, blood pressure and TPR decreased, calf volume increased but CO remained stable.Mean BP increased significantly during bending forward (by 20.0 (17 – 28.5) mmHg; P = 0.005) (median (25th– 75th quartile)), squatting (by 50.8 (33.5 – 56) mmHg; P = 0.002), and abdominal compression (by 5.8 (–1 – 34.7) mmHg; P = 0.04) – but not during leg–crossing. Squatting and abdominal compression also induced a significant increase in CO (by 18.1 (–1.3 – 47.9) % during squatting (P = 0.02) and by 7.6 (0.4 – 19.6) % during abdominal compression (P=0.014)). HR did not change significantly during the countermaneuvers. TPR increased significantly only during squatting (by 37.2 (11.8 – 48.2) %; P = 0.01). However, orthopedic problems or ataxia prevented several patients from performing some of the countermaneuvers. Additionally, many patients required assistance with the maneuvers.Squatting, bending forward and abdominal compression can improve orthostatic BP in FD patients, which is achieved mainly by an increased cardiac output. Squatting has the greatest effect on orthostatic blood pressure in FD patients. Suitability and effectiveness of a specific countermaneuver depends on the orthopedic or neurological complications of each FD patient and must be individually tested before a therapeutic recommendation can be given

Dermal microdialysis provides evidence for hypersensitivity to noradrenaline in patients with familial dysautonomia

Objectives: To use the technique of dermal microdialysis to examine sensitivity of skin vessels to noradrenaline (NA) in patients with familial dysautonomia (FD) and in healthy controls. Methods: In 14 patients with FD and 12 healthy controls, plasma extravasation, local laser Doppler blood flow, and skin blanching were observed before, during, and after application of 10(-6) M NA through a microdialysis membrane, located intradermally in the skin of the lower leg. Results: Maximum local vasoconstriction measured by laser Doppler blood flow did not differ between patients with FD and controls. In contrast, patients with FD had an earlier onset of vasoconstriction (p = 0.02). Moreover, reaction to NA was more prominent and prolonged in FD, shown by a larger zone of skin blanching around the microdialysis membrane (p < 0.001) and delayed reduction of the protein content in the dialysate after termination of NA application (p = 0.03). Conclusion: These data support the hypothesis that peripheral blood vessels of patients with FD show a denervation hypersensitivity to catecholamines. This may be one mechanism contributing to the major hypertension that frequently occurs during "dysautonomic crises" in FD