Eve Unt

Aortic Stiffness and Vitamin D are Independent Markers of Aortic Calcification in Patients with Peripheral Arterial Disease and in Healthy Subjects

OBJECTIVE Arterial stiffness is a significant determinant of cardiovascular risk and is related to vascular calcification. Vitamin D may regulate arterial calcification and has been associated with cardiovascular survival benefits. However, data about the relationship between arterial stiffness, aortic calcification and vitamin D levels in patients with peripheral arterial disease (PAD) and in healthy subjects are limited. We examined the potential association between aortic calcification, arterial stiffness and vitamin D levels in patients with symptomatic PAD and in healthy individuals. METHODS We studied 78 men with PAD (aged 63 ± 7 years) and 74 healthy men (aged 61 ± 10 years). Aortic pulse wave velocity (aPWV) was determined by applanation tonometry using the Sphygmocor device. Aortic calcification score (ACS) was quantified by computed tomography. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using a radioimmune assay. RESULTS ACS (4.9(2.3-8.9) vs. 0.2(0.03-1.6) (cm³); p < 0.01), aPWV (9.8 ± 2.4 vs. 8.2 ± 1.6 (m s⁻¹; p < 0.01) and 25(OH)D (15.1 ± 5.4 vs. 19.0 ± 5.9 (ng ml⁻¹); p < 0.01) were different in the patients compared with the controls. In multivariate analysis, ACS was independently determined by 25(OH)D, aPWV, calcium and age in patients with PAD (R² = 0.49; p < 0.001) and by 25(OH)D, aPWV, cholesterol/high-density lipoprotein (HDL) and age in the control group (R² = 0.55; p < 0.001). Increased aPWV and lower levels of 25(OH)D were associated with decreased ankle-brachial pressure index (p = 0.03). CONCLUSION These results indicate that calcification of the aorta is independently associated with aortic stiffness and serum 25(OH)D level in patients with PAD and in healthy subjects. Aortic stiffness and abnormal vitamin D level may contribute to vascular calcification and are related to higher severity grade of atherosclerotic disease.

Association of Osteoprotegerin With Aortic Stiffness in Patients With Symptomatic Peripheral Artery Disease and in Healthy Subjects

BACKGROUND Arterial stiffening is an independent predictor for cardiovascular mortality. Preliminary studies have shown that arterial calcification may have an impact on increased vascular stiffness. However, there are limited data about the role of calcification inhibitor osteoprotegerin (OPG) as an independent predictor for arterial stiffness in patients with peripheral arterial disease (PAD) and in healthy subjects. The aim of this study was to evaluate the association between OPG and arterial stiffness parameters in patients with PAD and in healthy subjects. METHODS We studied 69 men with PAD (age 63 + or - 7 years) and 68 healthy subjects (age 54 + or - 8 years). Serum OPG and oxidized low-density lipoprotein (oxLDL) were measured using the enzyme-linked immunosorbent assay method. Radial and aortic pulse wave velocity (aPWV) and augmentation index (AIx) were determined by applanation tonometry. RESULTS The OPG (5.4 + or - 1.7 vs. 4.4 + or - 1.1 pmol/l; P < 0.001) and aPWV (10.1 + or - 2.5 vs. 7.6 + or - 1.6 m/s; P < 0.001) were different for the patients and for the controls. There was a linear relationship between OPG and aPWV in patients with PAD (R = 0.37; P = 0.003) and in healthy individuals (R = 0.40; P = 0.001). In multiple regression models after adjustment for potential confounders, OPG was independently associated with aPWV in the patients (R(2) = 0.47; P < 0.0001) and in the controls (R(2) = 0.44; P < 0.0001). The AIx or radial PWV was not correlated with OPG for either group. CONCLUSION The independent association between OPG and aPWV in patients with PAD and in controls suggests that the calcification inhibitor OPG may influence aortic stiffening in atherosclerosis and in clinically healthy subjects.

Effects of a synbiotic product on blood antioxidative activity in subjects colonized with Helicobacter pylori

Aim:  To evaluate the impact of the consumption of a synbiotic product on the antioxidative activity markers of blood in asymptomatic H. pylori‐colonized persons.

Homocysteine status in former top‐level male athletes: possible effect of physical activity and physical fitness

The importance of elevated homocysteine (Hcy) as a risk marker for cardiovascular disease is continously under debate. Lifestyle factors may increase the total Hcy (tHcy) level of the plasma, but there are no consistent findings relating to Hcy, physical activity, and cardiorespiratory fitness. Cross‐sectional measurement from an ongoing follow‐up study was performed on 77 former male athletes and 33 sedentary controls (age range 35–62 years). Lifestyle parameters (current physical activity patterns, smoking, etc.), anthropometric and blood pressure data, and data about tHcy, reduced, and oxidized glutathione (GSH, GSSG, respectively) in blood, lipoproteins, and maximal oxygen consumption (VO2max) were collected. Our study results showed that the subgroup of physically active ex‐athletes (n=52) had a significantly lower tHcy level and glutathione redox ratio (GSSG:GSH) in comparison with the subgroup of sedentary ex‐athletes (n=25). tHcy level was inversely related to cardiorespiratory fitness (VO2max/kg). Dietary and smoking habits were not significantly associated with the tHcy level in our study group. In conclusion, the research findings indicate that both current physical activity and cardiorespiratory fitness are significantly inversely associated with an elevated homocysteine level in middle‐aged former athletes.

Association between arterial elasticity, C-reactive protein and maximal oxygen consumption in well-trained cadets during three days extreme physical load: a pilot study

Regular aerobic training has beneficial effects on inflammatory pathways and on arterial elasticity, which are both important cardiovascular risk factors. The aim of the present study was to evaluate the effect of extreme physical load on arterial elasticity and inflammatory markers in well-trained healthy men who participated in a high-ranking combat course. Seven well-trained male cadets were examined during an international military combat course of 3.5 days duration. Small (C2) and large (C1) artery elasticity was assessed using diastolic pulse wave analysis. Inflammatory markers and arterial elasticity measurement were performed before and after the competition. The extreme prolonged physical load caused individually different responses in arterial elasticity, C-reactive protein (CRP) and creatine kinase in individual cadets. Maximal oxygen consumption (VO(2) max kg(-1)) correlated significantly with the change (Delta-difference between baseline and 24 h recovery period) of creatine kinase (r= -0.78; p=0.04) and DeltaC2 (r=0.78; p=0.04) and DeltaC1 (r=0.82; p=0.02). In multivariate analysis (R(2)=0.89, p=0.01) the DeltaC2 correlated strongly with VO(2) max kg(-1) (p=0.005) and with the DeltaCRP (p=0.03), whereas the DeltaC1 correlated only with VO(2) max kg(-1) and did not correlate significantly with the DeltaCRP. Changes in small arterial elasticity induced by extreme physical load were significantly related to VO(2) max kg(-1) and DeltaCRP, whereas the change of large artery elasticity was only associated with VO(2) max kg(-1). Our preliminary results indicate that acute exercise-induced inflammation may affect small artery elasticity. However, further, more extensive studies are needed in this area.

Heat acclimation decreases the growth hormone response to acute constant-load exercise in the heat

OBJECTIVE The major objective of this study was to elucidate the effect of heat acclimation on blood growth hormone (GH) response to moderate intensity exhausting exercise in the heat. In addition, the potential relationship between inter-individual differences in GH response to exercise and variability in exercise-induced sweat loss was investigated. DESIGN Twenty young men completed three exercise tests on a treadmill: H1 (walk at 60% VO₂peak until exhaustion at 42 °C), N (walk at 22 °C; duration equal to H1) and H2 (walk until exhaustion at 42 °C after a 10-day heat acclimation program). Core temperature (T(c)) was recorded continuously and venous blood samples were taken before, during and after each exercise test. Exercise-induced sweat production was calculated on the basis of body mass change taking into account water intake and the volume of blood samples drawn. RESULTS Lower pre-exercise T(c), lower rate of rise in T(c) during exercise, and prolonged time to exhaustion in H2 compared with H1 revealed that the subjects successfully achieved an acclimated state. Overall, serum GH level was higher in H1 compared with both N and H2 (p<0.001) but did not differ between the two latter trials (p>0.05). T(c) correlated with serum GH concentration (r=0.615, p<0.01). Analysis of the individual data revealed a group (n=9) possessing a threshold-like pattern of the relationship between T(c) and blood GH response, whereas a plateau-like pattern was evident in the rest of the subjects (n=11). Both sweat production (r=0.596; p<0.001) and the rate of sweat production (r=0.457; p<0.001) correlated with the growth hormone area under the curve. CONCLUSION Heat acclimation decreases the GH response to moderate intensity exhausting exercise in the heat. GH may have a modest stimulating effect on whole-body sweat production during exercise.

Dietary sodium citrate supplementation enhances rehydration and recovery from rapid body mass loss in trained wrestlers

This study assessed the effects of dietary sodium citrate supplementation during a 16 h recovery from 5% rapid body mass loss (RBML) on physiological functions, affective state, and performance in trained wrestlers. Sixteen wrestlers performed an upper body intermittent sprint performance (UBISP) test under three conditions: before RBML, after RBML, and after a 16 h recovery from RBML. During recovery, the subjects ate a prescribed diet supplemented with sodium citrate (600 mg·kg(-1); CIT group, N = 8) or placebo (PLC group, N = 8) and drank water ad libitum. RBML reduced (p < 0.05) UBISP mean power and increased urine specific gravity (USG). Reduction in mean power was associated with changes in plasma volume (PV) (r = 0.649, p = 0.006) and USG (r = -0.553, p = 0.026). During the 16 h recovery, increases in body mass (BM) and PV were greater (p < 0.05) in the CIT group than in the PLC group. BM gain was associated with water retention in the CIT group (r = 0.899, p = 0.002) but not in the PLC group (r = 0.335, p = 0.417). Blood pH, HCO(3)(-) concentration, and base excess increased (p < 0.05) only in the CIT group. Changes in UBISP, general negative affect, and general positive affect did not differ in the two groups. In conclusion, ingestion of sodium citrate increases blood buffering capacity and PV and stimulates BM regain during a 16 h recovery from RBML in trained wrestlers. However, sodium citrate does not improve UBISP nor does it have an impact on the affective state.

Effects of a long-term military mission on arterial stiffness, inflammation markers, and vitamin D level

vitamin D level Erik Salum ⁎, Mihkel Zilmer , Priit Kampus , Jaak Kals , Eve Unt , Martin Serg , Maksim Zagura , Mai Blöndal , Kersti Zilmer , Jaan Eha a,b a Department of Cardiology, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia b Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia c Department of Biochemistry, Centre of Excellence for Translational Medicine, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia d Department of Vascular Surgery, Tartu University Hospital, 8 Puusepa Street, Tartu 51014, Estonia e Institute of Exercise Biology and Physiotherapy, University of Tartu, 14a Ravila Street, Tartu 50411, Estonia f Department of Sports Medicine and Rehabilitation, University of Tartu, 5 Jakobi Street, Tartu 50090, Estonia

Impact of sodium citrate ingestion during recovery after dehydrating exercise on rehydration and subsequent 40-km cycling time-trial performance in the heat

The purpose of this study was to assess the impact of sodium citrate (CIT) ingestion (600 mg·kg-1) during recovery from dehydrating cycling exercise (DE) on subsequent 40-km cycling performance in a warm environment (32 °C). Twenty male nonheat-acclimated endurance athletes exercised in the heat until 4% body mass (BM) loss occurred. After 16 h recovery with consumption of water ad libitum and prescribed diet (evening meal 20 kcal·kg-1, breakfast 12 kcal·kg-1) supplemented in a double-blind, randomized, crossover manner with CIT or placebo (PLC), they performed 40-km time-trial (TT) on a cycle ergometer in a warm environment. During recovery greater increases in BM and plasma volume (PV) concomitant with greater water intake and retention occurred in the CIT trial compared with the PLC trial (p < 0.0001). During TT there was greater water intake and smaller BM loss in the CIT trial than in the PLC trial (p < 0.05) with no between-trial differences (p > 0.05) in sweat loss, PV decrement, ratings of perceived exertion, or TT time (CIT 68.10 ± 3.28 min, PLC 68.11 ± 2.87 min). At the end of TT blood lactate concentration was higher (7.58 ± 2.44 mmol·L-1 vs 5.58 ± 1.32 mmol·L-1; p = 0.0002) and rectal temperature lower (39.54 ± 0.50 °C vs 39.65 ± 0.52 °C; p = 0.033) in the CIT trial than in the PLC trial. Compared with pre-DE time point, PV had decreased to a lower level in the PLC trial than in the CIT trial (p = 0.0001). In conclusion, CIT enhances rehydration after exercise-induced dehydration but has no impact on subsequent 40-km cycling TT performance in a warm uncompensable environment.

Influence of Rhodiola rosea on the heat acclimation process in young healthy men

The adaptogen Rhodiola rosea (RR) may mitigate stress responses and have beneficial effects on endurance capacity (EC) and mental performance. Heat acclimation (HA) improves EC in the heat, but the potential impact of RR on the HA process is unknown. Therefore, our intent was to determine if RR has a positive impact on HA. Twenty male subjects (age, 22.5 ± 3.0 years) completed 2 EC tests involving walking (6 km·h-1) until volitional exhaustion in a climate chamber (air temperature, 42 °C; relative humidity, 18%) before (H1) and after (H2) an 8-day HA period. One group (SHR; n = 10) ingested standardised extract SHR-5 of RR (a single daily dose of 432 mg), while a second group (PLC; n = 10) administered a placebo prior to each HA session. Efficacy of HA was evaluated on the basis of changes that occurred from H1 to H2 in the time to exhaustion (TTE), exercise heart rate (HR), core and skin temperatures (Tc, Tsk), stress hormones, ratings of perceived exertion (RPE) and fatigue (RPF), and thermal sensation (TS). HA significantly increased TTE (133.1 ± 44.1 min in H1; 233.4 ± 59.8 min in H2; p < 0.0001) and decreased (p < 0.0001) HR, Tc, Tsk, stress hormones as well as RPE, RPF, and TS. However, the magnitude of all these changes was similar (p > 0.05) in the SHR and PLC groups. These results suggest that the use of RR during HA has no beneficial performance, physiological, or perceptual effects in young healthy males.