Prevention of leg cramps by using compression stockings or magnesium supplements in the 50-84 age group : study protocol for a randomised controlled trial

Background: Leg cramps are painful sensations of tightening in the muscles of the legs that commonly appear during the night and are often associated with secondary insomnia. They are common especially in older age. There is no evidence that any method of prevention of nocturnal leg cramps is both safe and effective. There are no previous trials concerning cramp prevention by using compression stockings. The objective of this study is to assess in a prospective randomised controlled trial whether leg cramps can be prevented by the daily use of knee-length compression stockings or magnesium supplements. Methods: The study will be set in Finland, and 50-84-year-old volunteers will be recruited through Google Ads, the Finnish health library website and Finnish primary health care centres. The participants must have a minimum of two episodes of leg cramps per week for the past 4 weeks to be included in the study. The participants (n = 225) will be allocated to three equal groups: the compression stocking arm, the magnesium supplement arm and the placebo arm. The participants will go through 4 weeks of follow-up without intervention and then another 4 weeks of follow-up with the assigned intervention. The material for the study will be collected through electronic questionnaires. Discussion: This protocol describes a study that compares compression stockings, magnesium supplements and placebo for the prevention of leg cramps. The results of this study can significantly improve knowledge on the methods of preventing leg cramps.Peer reviewe

Ambulatory daytime blood pressure versus tonometric blood pressure measurements in the laboratory : effect of posture

Objective To compare blood pressure (BP) in tonometric radial artery recordings during passive head-up tilt with ambulatory recordings and evaluate possible laboratory cutoff values for hypertension. Methods Laboratory BP and ambulatory BP were recorded in normotensive (n=69), unmedicated hypertensive (n=190), and medicated hypertensive (n=151) subjects. Results Mean age was 50.2 years, BMI 27.7kg/m2, ambulatory daytime BP 139/87mmHg, and 276 were male (65%). As supine-to-upright changes in SBP ranged from -52 to +30mmHg, and in DBP from -21 to +32mmHg, the mean values of BP supine and upright measurements were compared with ambulatory BP. The mean(supine+upright) systolic laboratory BP was corresponding to ambulatory level (difference +1mmHg), while mean(supine+upright) DBP was 4mmHg lower (P<0.05) than ambulatory value. Correlograms indicated that laboratory 136/82mmHg corresponded to ambulatory 135/85mmHg. When compared with ambulatory 135/85mmHg, the sensitivity and specificity of laboratory 136/82mmHg to define hypertension were 71.5% and 77.3% for SBP, and 71.7% and 72.8%, for DBP, respectively. The laboratory cutoff 136/82mmHg classified 311/410 subjects similarly to ambulatory BP as normotensive or hypertensive, 68 were hypertensive only in ambulatory, while 31 were hypertensive only in laboratory measurements. Conclusion BP responses to upright posture were variable. When compared with ambulatory BP, mean(supine+upright) laboratory cutoff 136/82mmHg classified 76% of subjects similarly as normotensive or hypertensive. In the remaining 24% the discordant results may be attributed to white-coat or masked hypertension, or higher physical activity during out-of-office recordings.Peer reviewe

Resting heart rate predicts cardiac autonomic modulation during passive head-up tilt in subjects without cardiovascular diseases

Background Resting heart rate (HR) and its variability (HRV) reflects the cardiac sympathovagal balance that is stimulated by head-up tilting. HRV is influenced by the level of HR, but how much HRV offers additional information about cardiac autonomic tone than HR alone remains unresolved. We examined the relation of resting HR with HRV during head-up tilt. Methods. Hemodynamics of 569 subjects without known cardiovascular diseases and medications with direct cardiovascular effects were recorded using whole-body impedance cardiography, radial pulse wave analysis, and electrocardiography-based HRV analysis during passive head-up tilt. Results. Higher low frequency to the high-frequency ratio (LF/HF) of HRV (reflecting sympathovagal balance) was associated with higher HR in supine (p < .05, both linear regression analysis and variance analysis comparing HR tertiles) and upright postures (p < .001, linear regression analysis). The association of HR with HRV during tilt-testing remained significant when the HR dependence of HRV was mathematically weakened by dividing the HRV power spectra with the fourth power of the average RR-interval. Conclusion. Higher resting HR is related to higher LF/HF both supine and upright, reflecting elevated sympathetic influence on cardiac autonomic modulation. Lower resting HR is associated with lower resting LF/HF, while the differences in LF/HF between the HR tertiles were minor during head-up tilt, suggesting a greater change in cardiac sympathovagal balance in response to upright posture in those with lowest resting HR. Altogether, resting HR well predicts HRV levels during head-up tilt.Trial registration: Clinicaltrialsregister.eu 2006-002065-39, first registered 5 May 2006. ClinicalTrials.gov NCT01742702, first registered 5 December 2012.publishedVersionPeer reviewe

The characteristics of elevated blood pressure in abdominal obesity correspond to primary hypertension : a cross-sectional study

Background: Obesity-related hypertension and the associated metabolic abnormalities are considered as a distinct hypertensive phenotype. Here we examined how abdominal fat content, as judged by waist:height ratio, influenced blood pressure and hemodynamic profile in normotensive subjects and never-treated hypertensive patients. Methods: The 541 participants (20–72 years) underwent physical examination and laboratory analyses and were divided into age and sex-adjusted quartiles of waist:height ratio. Supine hemodynamics were recorded using whole-body impedance cardiography, combined with analyses of radial tonometric pulse wave form and heart rate variability. Results: Mean waist:height ratios in the quartiles were 0.46, 0.51, 0.55 and 0.62. Radial and aortic blood pressure, systemic vascular resistance, pulse wave velocity, markers of glucose and lipid metabolism, leptin levels and C-reactive protein were higher in quartile 4 when compared with quartiles 1 and 2 (p < 0.05 for all). Cardiac index was lower in quartile 4 versus quartile 1, while no differences were seen in heart rate variability, augmentation index, plasma renin activity, and aldosterone concentration between the quartiles. Linear regression analyses showed independent associations of abdominal obesity with higher aortic systolic and diastolic blood pressure, systemic vascular resistance, and pulse wave velocity (p < 0.05 for waist:height ratio in all regression models). Conclusion: Higher waist:height ratio was associated with elevated blood pressure, systemic vascular resistance, and arterial stiffness, but not with alterations in cardiac sympathovagal modulation or activation of the circulating renin-angiotensin-aldosterone system. Although obesity-related elevation of blood pressure has distinct phenotypic features, these results suggest that its main characteristics correspond those of primary hypertension. Trial registration: ClinicalTrails.gov NCT01742702 (date of registration 5th December 2012).publishedVersionPeer reviewe

Patient-tailored design for selective co-inhibition of leukemic cell subpopulations

The extensive drug resistance requires rational approaches to design personalized combinatorial treatments that exploit patient-specific therapeutic vulnerabilities to selectively target disease-driving cell subpopulations. To solve the combinatorial explosion challenge, we implemented an effective machine learning approach that prioritizes patient-customized drug combinations with a desired synergy-efficacy-toxicity balance by combining single-cell RNA sequencing with ex vivo single-agent testing in scarce patient-derived primary cells. When applied to two diagnostic and two refractory acute myeloid leukemia (AML) patient cases, each with a different genetic background, we accurately predicted patient-specific combinations that not only resulted in synergistic cancer cell co-inhibition but also were capable of targeting specific AML cell subpopulations that emerge in differing stages of disease pathogenesis or treatment regimens. Our functional precision oncology approach provides an unbiased means for systematic identification of personalized combinatorial regimens that selectively co-inhibit leukemic cells while avoiding inhibition of nonmalignant cells, thereby increasing their likelihood for clinical translation.Peer reviewe

Individual changes of central blood pressure in response to upright posture : different hemodynamic phenotypes

OBJECTIVES: Most studies about upright regulation of blood pressure have focused on orthostatic hypotension despite the diverse hemodynamic changes induced by orthostatic challenge. We investigated the effect of passive head-up tilt on aortic blood pressure. METHODS: Noninvasive peripheral and central hemodynamics in 613 volunteers without cardiovascular morbidities or medications were examined using pulse wave analysis, whole-body impedance cardiography and heart rate variability analysis. RESULTS: In all participants, mean aortic SBP decreased by -4 (-5 to -3) mmHg [mean (95% confidence intervals)] and DBP increased by 6 (5--6) mmHg in response to upright posture. When divided into tertiles according to the supine-to-upright change in aortic SBP, two tertiles presented with a decrease [-15 (-14 to -16) and -4 (-3 to -4) mmHg, respectively] whereas one tertile presented with an increase [+7 (7-- 8) mmHg] in aortic SBP. There were no major differences in demographic characteristics between the tertiles. In regression analysis, the strongest explanatory factors for upright changes in aortic SBP were the supine values of, and upright changes in systemic vascular resistance and cardiac output, and supine aortic SBP. CONCLUSION: In participants without cardiovascular disease, the changes in central SBP during orthostatic challenge are not uniform. One-third presented with higher upright than supine aortic SBP with underlying differences in the regulation of systemic vascular resistance and cardiac output. These findings emphasize that resting blood pressure measurements give only limited information about the blood pressure status.publishedVersionPeer reviewe

Voluntary liquorice ingestion increases blood pressure via increased volume load, elevated peripheral arterial resistance, and decreased aortic compliance

Abstract We investigated the haemodynamic effects of two-week liquorice exposure (glycyrrhizin dose 290–370 mg/day) in 22 healthy volunteers during orthostatic challenge. Haemodynamics were recorded during passive 10-minute head-up tilt using radial pulse wave analysis, whole-body impedance cardiography, and spectral analysis of heart rate variability. Thirty age-matched healthy subjects served as controls. Liquorice ingestion elevated radial systolic (p < 0.001) and diastolic (p = 0.018) blood pressure and systemic vascular resistance (p = 0.037). During orthostatic challenge, heart rate increased less after the liquorice versus control diet (p = 0.003) and low frequency power of heart rate variability decreased within the liquorice group (p = 0.034). Liquorice intake increased central pulse pressure (p < 0.001) and augmentation index (p = 0.002) supine and upright, but in the upright position the elevation of augmentation index was accentuated (p = 0.007). Liquorice diet also increased extracellular fluid volume (p = 0.024) and aortic to popliteal pulse wave velocity (p = 0.027), and aortic characteristic impedance in the upright position (p = 0.002). To conclude, in addition to increased extracellular fluid volume and large arterial stiffness, two weeks of liquorice ingestion elevated systemic vascular resistance and augmentation index. Measurements performed at rest may underestimate the haemodynamic effects of liquorice ingestion, as enhanced central wave reflection and reduced chronotropic response were especially observed in the upright position

Plasma uric acid is related to large arterial stiffness but not to other hemodynamic variables : a study in 606 normotensive and never-medicated hypertensive subjects

BACKGROUND: Elevated level of plasma uric acid (PUA) has been associated with cardiovascular disease, but whether uric acid is an independent risk factor or merely a marker remains controversial. METHODS: We investigated in a cross-sectional setting the association of PUA with hemodynamics in 606 normotensive and never-medicated hypertensive subjects (295 men, 311 women, age range 19-73 years) without cardiovascular disease or gout. In all except 15 individuals, PUA was within the normal range. Supine hemodynamics were recorded using whole-body impedance cardiography and radial tonometric pulse wave analysis. RESULTS: The mean concentrations of PUA in age, sex and body mass index adjusted quartiles were 234, 278, 314, and 373 µmol/l, respectively. The highest PUA quartile presented with higher aortic to popliteal pulse wave velocity (PWV) than the lowest quartile (8.7 vs. 8.2 m/s, p = 0.026) in analyses additionally adjusted for plasma concentrations of C-reactive protein, low density lipoprotein cholesterol, triglycerides, and mean aortic blood pressure. No differences in radial and aortic blood pressure, wave reflections, heart rate, cardiac output, and systemic vascular resistance were observed between the quartiles. In linear regression analysis, PUA was an independent explanatory factor for PWV (β = 0.168, p < 0.001, R2 of the model 0.591), but not for systolic or diastolic blood pressure. When the regression analysis was performed separately for men and women, PUA was an independent predictor of PWV in both sexes. CONCLUSIONS: PUA concentration was independently and directly associated with large arterial stiffness in individuals without cardiovascular disease and PUA levels predominantly within the normal range. Trial registration ClinicalTrials.gov NCT01742702.publishedVersionPeer reviewe