scholarly journals Vasoconstriction Response to Mental Stress in Sickle Cell Disease: The Role of the Cardiac and Vascular Baroreflexes

2021 ◽  
Vol 12 ◽  
Author(s):  
Wanwara Thuptimdang ◽  
Payal Shah ◽  
Maha Khaleel ◽  
John Sunwoo ◽  
Saranya Veluswamy ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Mental Stress ◽  
Baroreflex Sensitivity ◽  
Autonomic Function ◽  
Baseline Period ◽  
Cell Disease ◽  
Cold Pain ◽  
Arterial Blood

Recent studies have shown that individuals with sickle cell disease (SCD) exhibit greater vasoconstriction responses to physical autonomic stressors, such as heat pain and cold pain than normal individuals, but this is not the case for mental stress (MTS). We sought to determine whether this anomalous finding for MTS is related to inter-group differences in baseline cardiac and vascular autonomic function. Fifteen subjects with SCD and 15 healthy volunteers participated in three MTS tasks: N-back, Stroop, and pain anticipation (PA). R–R interval (RRI), arterial blood pressure and finger photoplethysmogram (PPG) were continuously monitored before and during these MTS tasks. The magnitude of vasoconstriction was quantified using change in PPG amplitude (PPGa) from the baseline period. To represent basal autonomic function, we assessed both cardiac and vascular arms of the baroreflex during the baseline period. Cardiac baroreflex sensitivity (BRSc) was estimated by applying both the “sequence” and “spectral” techniques to beat-to-beat measurements of systolic blood pressure and RRIs. The vascular baroreflex sensitivity (BRSv) was quantified using the same approaches, modified for application to beat-to-beat diastolic blood pressure and PPGa measurements. Baseline BRSc was not different between SCD and non-SCD subjects, was not correlated with BRSv, and was not associated with the vasoconstriction responses to MTS tasks. BRSv in both groups was correlated with mean PPGa, and since both baseline PPGa and BRSv were lower in SCD, these results suggested that the SCD subjects were in a basal state of higher sympathetically mediated vascular tone. In both groups, baseline BRSv was positively correlated with the vasoconstriction responses to N-back, Stroop, and PA. After adjusting for differences in BRSv within and between groups, we found no difference in the vasoconstriction responses to all three mental tasks between SCD and non-SCD subjects. The implications of these findings are significant in subjects with SCD since vasoconstriction reduces microvascular flow and prolongs capillary transit time, increasing the likelihood for vaso-occlusive crisis (VOC) to be triggered by exposure to stressful events.

scholarly journals Normal Non-HDL Cholesterol, Low Total Cholesterol, and HDL Cholesterol Levels in Sickle Cell Disease Patients in the Steady State: A Case-Control Study of Tema Metropolis

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Richard K. D. Ephraim ◽  
Patrick Adu ◽  
Edem Ake ◽  
Hope Agbodzakey ◽  
Prince Adoba ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Steady State ◽  
Sickle Cell Disease ◽  
Total Cholesterol ◽  
Sickle Cell ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Lipoprotein Cholesterol ◽  
Cell Disease ◽  
Cross Sectional

Background.Abnormal lipid homeostasis in sickle cell disease (SCD) is characterized by defects in plasma and erythrocyte lipids and may increase the risk of cardiovascular disease. This study assessed the lipid profile and non-HDL cholesterol level of SCD patients.Methods.A hospital-based cross-sectional study was conducted in 50 SCD patients, in the steady state, aged 8–28 years, attending the SCD clinic, and 50 healthy volunteers between the ages of 8–38 years. Serum lipids were determined by enzymatic methods and non-HDL cholesterol calculated by this formula: non-HDL-C = TC-HDL-C.Results.Total cholesterol (TC) (p=0.001) and high-density lipoprotein cholesterol (HDL-C) (p<0.0001) were significantly decreased in cases compared to controls. The levels of non-HDL-C, low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) were similar among the participants. The levels of decrease in TC and HDL were associated with whether a patient was SCD-SS or SCD-SC. Systolic blood pressure and diastolic blood pressure were each significantly associated with increased VLDL [SBP,p=0.01, OR: 0.74 (CI: 0.6–0.93); DBP,p=0.023, OR: 1.45 (CI: 1.05–2.0)].Conclusion.Dyslipidemia is common among participants in this study. It was more pronounced in the SCD-SS than in SCD-SC. This dyslipidemia was associated with high VLDL as well as increased SBP and DBP.

scholarly journals Comparison of pulse oximetry and earlobe blood gas with CO-oximetry in children with sickle cell disease: a retrospective review

2020 ◽  
Vol 4 (1) ◽  
pp. e000690
Author(s):  
Michele Arigliani ◽  
Sean Zheng ◽  
Gary Ruiz ◽  
Subarna Chakravorty ◽  
Cara J Bossley ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Oxygen Saturation ◽  
Pulse Oximetry ◽  
Sickle Cell ◽  
Blood Gas ◽  
Cell Disease ◽  
Arterial Blood ◽  
Ambulatory Patients ◽  
The Difference ◽  
Age Range

ObjectivesTo investigate the agreement between pulse oximetry (SpO2) and oxygen saturation (SaO2) measured by CO-oximetry on arterialised earlobe blood gas (EBG) in children and adolescents with sickle cell disease (SCD).Design and settingWe retrospectively reviewed 39 simultaneous and paired SaO2 EBG and SpO2 measurements from 33 ambulatory patients with SCD (32 subjects with Haemoglobin SS and one with Haemoglobin Sß+, 52% male, mean±SD age 11.0±3.6, age range 5–18). Measurements were performed between 2012 and 2015 when participants were asymptomatic. Hypoxaemia was defined as SaO2 ≤93%. A Bland-Altman analysis was performed to assess the accuracy of SpO2 as compared with EBG SaO2.ResultsThe mean±SD SpO2 and SaO2 values in the same patients were, respectively, 93.6%±3.7% and 94.3%±2.9%. The bias SpO2–SaO2 was −0.7% (95% limits of agreement from −5.4% to 4.1%) and precision was 2.5%. In 9/39 (23%) cases, the difference in SpO2–SaO2 was greater than the expected error range ±2%, with SaO2 more often underestimated by SpO2 (6/9), especially at SpO2values ≤93%. Thirteen participants (33%) were hypoxaemic. The sensitivity of SpO2 for hypoxaemia was 100%, specificity 85% and positive predictive value 76%.ConclusionsPulse oximetry was inaccurate in almost a quarter of measurements in ambulatory paediatric patients with SCD, especially at SpO2values ≤93%. In these cases, oxygen saturation can be confirmed through EBG CO-oximetry, which is easier to perform and less painful than traditional arterial blood sampling.

Mechanisms of vascular instability in a transgenic mouse model of sickle cell disease

2000 ◽  
Vol 279 (6) ◽  
pp. R1949-R1955 ◽  
Author(s):  
K. A. Nath ◽  
V. Shah ◽  
J. J. Haggard ◽  
A. J. Croatt ◽  
L. A. Smith ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Lipid Peroxidation ◽  
Sickle Cell Disease ◽  
Mouse Model ◽  
Systolic Blood Pressure ◽  
Transgenic Mouse ◽  
Sickle Cell ◽  
Transgenic Mouse Model ◽  
Cell Disease

We investigated a transgenic mouse model of sickle cell disease, homozygous for deletion of mouse β-globin and containing transgenes for human βSand βS-antillesglobins linked to the transgene for human α-globin. In these mice, basal cGMP production in aortic rings is increased, whereas relaxation to an endothelium-dependent vasodilator, A-23187, is impaired. In contrast, aortic expression of endothelial nitric oxide synthase (NOS) is unaltered in sickle mice, whereas expression of inducible NOS is not detected in either group; plasma nitrate/nitrite concentrations and NOS activity are similar in both groups. Increased cGMP may reflect the stimulatory effect of peroxides (an activator of guanylate cyclase), because lipid peroxidation is increased in aortae and in plasma in sickle mice. Despite increased vascular cGMP levels in sickle mice, conscious systolic blood pressure is comparable to that of aged-matched controls; sickle mice, however, evince a greater rise in systolic blood pressure in response to nitro-l-arginine methyl ester, an inhibitor of NOS. Systemic concentrations of the vasoconstrictive oxidative product 8-isoprostane are increased in sickle mice. We conclude that vascular responses are altered in this transgenic sickle mouse and are accompanied by increased lipid peroxidation and production of cGMP; we suggest that oxidant-inducible vasoconstrictor systems such as isoprostanes may oppose nitric oxide-dependent and nitric oxide-independent mechanisms of vasodilatation in this transgenic sickle mouse. Destabilization of the vasoactive balance in the sickle vasculature by clinically relevant states may predispose to vasoocclusive disease.

scholarly journals The Malaria-High Blood Pressure Hypothesis: Revisited

2020 ◽  
Vol 33 (8) ◽  
pp. 695-702
Author(s):  
Chukwuemeka R Nwokocha ◽  
Enitome E Bafor ◽  
Olutayo I Ajayi ◽  
Anthony B Ebeigbe
Keyword(s):  
Blood Pressure ◽  
Endothelial Dysfunction ◽  
Sickle Cell Disease ◽  
High Blood Pressure ◽  
Sickle Cell ◽  
Malaria Infection ◽  
Vascular Reactivity ◽  
Gestational Hypertension ◽  
Adult Life ◽  
Cell Disease

Abstract Malaria etiologies with pathophysiological similarities to hypertension currently constitute a major subject of research. The malaria-high blood pressure hypothesis is strongly supported by observations of the increasing incidence of hypertension in malaria-endemic, low- and middle-income countries with poor socioeconomic conditions, particularly in sub-Saharan African countries. Malnutrition and low birth weight with persistent symptomatic malaria presentations in pregnancy correlate strongly with the development of preeclampsia, gestational hypertension and subsequent hypertension in adult life. Evidence suggest that the link between malaria infection and high blood pressure involves interactions between malaria parasites and erythrocytes, the inflammatory process, effects of the infection during pregnancy; effects on renal and vascular functions as well as effects in sickle cell disease. Possible mechanisms which provide justification for the malaria-high blood pressure hypothesis include the following: endothelial dysfunction (reduced nitric oxide (NO) levels), impaired release of local neurotransmitters and cytokines, decrease in vascular smooth muscle cell viability and/or alterations in cellular calcium signaling leading to enhanced vascular reactivity, remodeling, and cardiomyopathies, deranged homeostasis through dehydration, elevated intracellular mediators and proinflammatory cytokine responses, possible genetic regulations, activation of the renin–angiotensin–aldosterone system mechanisms and renal derangements, severe anemia and hemolysis, renal failure, and end organ damage. Two key mediators of the malaria-high blood pressure association are: endothelial dysfunction (reduced NO) and increased angiotensin-converting enzyme activity/angiotensin II levels. Sickle cell disease is associated with protection against malaria infection and reduced blood pressure. In this review, we present the state of knowledge about the malaria-blood pressure hypothesis and suggest insights for future studies.

Arterial Hypoxemia Syndrome in Sickle Cell Disease.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3801-3801
Author(s):  
Patricia Adams-Graves ◽  
M. Muthiah ◽  
G. Presbury ◽  
G. Somes ◽  
K. Lamar
Keyword(s):  
Mechanical Ventilation ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Normal Lung ◽  
Acute Chest Syndrome ◽  
Cell Disease ◽  
X Ray ◽  
Arterial Hypoxemia ◽  
Arterial Blood ◽  
Chest X Ray

Abstract Acute chest syndrome (ACS) is the most common cause of death during hospitalization of adults with sickle cell disease (SCD). ACS includes symptoms referable to the chest and a new infiltrate on chest X-ray. Adults over age 20 years have more symptoms of the disease and are at increased risk of early death compared to children. ACS may be the presenting diagnosis for a patient with SCD, but equally as often, develops while the patient has a painful vascular occlusive crisis. Notably, 35% of SCD patients have a normal lung exam upon presentation to the hospital. Previous research studies indicate that nearly three-fourths of SCD patients who die present during painful crises in an extremity, and about 50% conclusively by autopsy died of massive fat embolism syndrome (FES). Unfortunately, definitive diagnostic tests with rapid turn-around for FES and other acute vascular occlusive lung events do not exist. Earlier identification of the danger that this event may be evolving can be life saving. Clinicians who adhere to the strict definition of ACS may prematurely dismiss the likelihood of a subsequent fatal event. This alarming rate of adverse events may represent a “pre-chest syndrome” prodromal phase of ACS. Arterial hypoxemia syndrome (AHS) or pre-chest syndrome is defined as any sign or symptom referable to the chest, an oxygen saturation (Sp02) of &lt;94% by direct pulse oximeter or a Pa02 &lt;80% by arterial blood gas on room air plus a clear chest X-ray with or without fever. AHS may be a warning sign of an ultimately fatal event if earlier interventions are not done in a timely manner. A secondary data analysis was performed utilizing 500 health records of SCD patients from 1960 to 2004. Prior to 2003, we averaged 2 to 3 ICU admissions per month for ACS with about 20% requiring mechanical ventilation. This study sought to gain insight on 45 years of experience in the treatment of SCD, particularly “pre-chest syndrome.” The primary aims of the study were to devise treatment protocols to reduce ICU admissions and the need for mechanical ventilation in SCD patients presenting with AHS. Retrospective analysis suggests that earlier blood exchanges for patients with SCD may substantially reduce ICU admissions and the need for mechanical ventilation in patients presenting with AHS, compared with patients receiving standard supportive care. Examination of computerized hospital records of 437 sickle cell hospital admissions from January 2003 to March 2005 revealed 3 ICU and 2 step-down unit admissions. During this time period, there were 101 chest syndrome occurrences, of which 2 died. Both patients required mechanical ventilation and underwent red cell apheresis to reduce hemoglobin S to &lt;30%. One patient was admitted due to major trauma from a motor vehicle accident. Death was due to multi-organ failure. The medical condition of the second patient improved. This patient was discharged home in stable condition but died, unexpectedly, 48 hours at home of a massive pulmonary embolus. A protocol has been developed to prospectively evaluate our aims.

Enalapril Therapy Prevents Cardiac Remodelling of Sickle Cell Disease Patients.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3792-3792
Author(s):  
Sara T. Saad ◽  
Carmen S. Passos Lima ◽  
Osvaldo M. Ueti ◽  
Adriana A. Ueti ◽  
Kleber G. Franchini ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Ace Inhibitors ◽  
Aortic Root ◽  
Fetal Hemoglobin ◽  
Treated Group ◽  
Left Ventricular ◽  
Cell Disease

Abstract Angiotensin-converting enzyme (ACE) inhibitors are capable of decreasing cardiac remodelling in patients with cardiac dysfunction, however their effects on sickle cell disease (SCD) are unknown. Thus, this study aimed to investigate the cardiac effects of enalapril on SCD patients. Thirteen adult patients with sickle cell disease (SCD) and microalbuminuria (3M/10F); 11 sickle cell anemia patients (SCA), 1 Sβ thalassemia patient (Sβ) and 1 patient with hemoglobin SC (SC) were treated with enalapril. Thirteen other SCD patients (4M/9F) without microalbuminuria, matched according to age, diagnosis (11 SCA, 1 Sβ and 1 SC), and levels of hemoglobin, hematocrit and fetal hemoglobin, did not receive enalapril and were followed up as the control group in the same period of study. In the treated group, enalapril (5mg) was administered to 9 SCD patients during the entire study period. One patient did not complete follow-up, and higher doses (7.5mg to 20mg) were administered to 3 patients who developed systolic BP over 120 mmHg during the study period. Median age (28.5 vs 29.0; P= 0.580), baseline values of hemoglobin (8.5 vs 8.4g/dL, P= 0.600), hematocrit (25.0 vs 23.5%, P= 0.500), fetal hemoglobin (4.4 vs 4.1%, P=0.720) and mean blood pressure (MBP; 80 vs 93mmHg, P= 0.13) were similar in treated and untreated patients Echocardiograms were performed before the study entry and once a year in patients and controls. Comparisons of groups were performed at the beginning of the study and after 36 months of follow-up using the Wilcoxon-signed rank test and Spearman coefficient. At 36 months of follow-up, MBP was lower than the baseline value (93 mmHg vs 87 mmHg, P= 0.018) in the treated group. Significant increases in left ventricular mass (192 vs 231g, P= 0.005), posterior left ventricular wall thickness in end-diastole (8.5 vs 10.0mm, P= 0.013), left ventricular mass index (114.4 vs 131g/m2, P= 0.043), interventricular septal wall thickness in end-diastole (9.0 vs 9.5mm, P= 0.036) and aortic root dimension (28 vs 32mm, P= 0.009) values were seen in untreated, but not in enalapril treated patients. No major changes were seen in left ventricular ejection fraction, left ventricular systolic diameter, left ventricular diastolic dimension and left atrial diameter, in both groups, along the observational period. No significant correlation was detected between the data here presented. At the end of the study, no symptoms or signals related to cardiac failure were found in any of the enrolled patients. These results indicate a trend toward cardiac and aortic root remodeling in untreated SCD patients and suggest that long-term treatment with ACE inhibitors has beneficial effects on the cardiac remodeling of SCD patients and could be indicated for adult patients, if an increase in baseline blood pressure occurs.

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