Altered aortic properties in elderly orthostatic hypertension.

To investigate the impact of arterial properties on orthostatic blood pressure (BP) dysregulation in older hypertensives, orthostatic BP dysregulation, a common phenomenon in elderly hypertensives, is associated with target organ damage and falls. However, the mechanism of orthostatic BP dysregulation remains unclear. The pulse wave velocity (PWV), related arterial stiffness, and the augmentation index (AI), a measure of arterial wave reflection, were measured in 365 older hypertensives. We classified the study patients into an orthostatic hypertension (OHT) group with orthostatic increase of systolic BP (SBP) of > or = 220 mmHg (n = 27) and an orthostatic normotension (ONT) group with an orthostatic increase of SBP of < 20 mmHg and orthostatic SBP decrease of < 20 mmHg (n = 338). Orthostatic AI was significantly greater in the OHT group than in the ONT group (OHT: 6.5 +/- 12% vs. ONT: -5.6 +/- 12%, p < 0.001), while supine AI and supine and orthostatic pulse rate were comparable between the two groups. There was no significant difference in the PWV between the OHT and ONT groups. Orthostatic hypertension was affected by altered aortic properties and associated with augmented wave reflection of arterial pressure.     

Vascular stiffness in chronic renal failure patients treated by hemodialysis

Cardiovascular disease is a major cause of morbidity in patients with end-stage renal failure. Arterial stiffness measured by pulse wave velocity (PWV) is an independent risk factor for morbidity in end stage renal failure patients. The aim of our study was to evaluate the arterial stiffness in patients with chronic renal failure. In 20 chronic renal failure patients treated by hemodialysis (HD) we assessed the PWV of the carotic artery as well as artery diameter and distensibility, systolic pressure (SBP), diastolic pressure (DBP), pulse pressure (PP), and basal biochemical parameters and compared them with the values determined in 20 healthy controls of comparable age. PWV and PP are significantly (p < 0.001, p < 0.05) higher and distensibility of the carotic artery was significantly lower (p < 0.001) compared to a control group SBP and DBP were < 140/90 mmHg in HD patients (high normotensive range) but were significantly (p < 0.05) higher than in a control group. In HD patients PP was correlated with arterial distensibility r = -0.600 (p < 0.005), and systolic artery rice r = -0.408 (p < 0.05). SBP was correlated with PP r = 0.689 (p < 0.0007) and with arterial distensibility r = -0.476 (p < 0.03), arterial diameter to systolic artery rice r = -0.463 (p < 0.03), systolic artery rice to arterial distensibility r = 0.885 (p < 0.00001), intima media to arterial distensibility r = 0.815 (p < 0.00001), intima media to arterial compliance r = 0.893 (p < 0.00001). Our results suggest that not only established hypertension but also high normotensive pressure could cause arterial stiffness absened in chronic renal failure patients.     

Serum testosterone levels and arterial blood pressure in the elderly.

The aim of this study was to evaluate the relationship between serum testosterone levels and arterial blood pressure (BP) in the elderly. We studied 356 non-diabetic, non-smoking, non-obese men aged 60 to 80 years and untreated for hypertension. All subjects were evaluated in the morning after an overnight fast. Evaluation included measurements of the following: BP (by mercury sphygmomanometer, Korotkoff I and V), body weight, height and free testosterone (T) plasma levels (by radioimmunoassay). According to the BP values, the subjects were classified as normotensives (NT; n=112; SBP/DBP<140/90 mmHg), systolic and diastolic hypertensives (HT; n=127; SBP/DBP>140/90 mmHg), and isolated systolic hypertensives (ISH; n=117; SBP>140 mmHg and DBP<90 mmHg). T values decreased with increasing age in all 3 groups and was significantly lower in HT (-15%) and ISH men (-21%) than in NT men (p<0.05). In each group, the T levels showed a highly significant negative correlation with BMI (p<0.001). A significant negative correlation was also found between T levels and SBP in NT (r=-0.35, p<0.001), ISH (r=-0.67, p<0.001), and HT (r=-0.19, p<0.05) men, whereas a negative correlation with DBP was observed only in the NT men (r=-0.19, p<0.05). Adjusting for the BMI confirmed a significant difference in plasma T levels between ISH and NT men, but not between HT and NT men. Multiple regression analysis employing BP as a dependent variable confirmed a strong relationship between T levels and SBP in all 3 groups, whereas a significant relationship between T levels and DBP was found only in NT men. In conclusion, although further studies are needed to clarify the relationship between plasma T levels and BP, our findings suggest that in elderly men with ISH, the reduced plasma levels of testosterone might contribute to the increased arterial stiffness typical of these subjects.     

Effect of estrogen and progestin replacement on arterial stiffness indices in postmenopausal women

Our objectives were to investigate whether long-term estrogen replacement therapy (ERT) is associated with a reduction in age-associated increases in arterial stiffness and blood pressure (BP), and whether the addition of progestin modifies the effects of estrogen. ERT has been found to have beneficial effects on cardiovascular risk. There are few data, however, delineating the effects of ERT on BP and arterial stiffness, and their age-associated changes. BP and aorto-femoral pulse wave velocity (PWV) were measured in 134 postmenopausal volunteers, aged 51 to 90 years, from the Baltimore Longitudinal Study of Aging, screened to exclude clinical and occult cardiovascular disease, and classified as ERT non-users (N=57) or ERT users (N=77). The latter group was further substratified according to the use of estrogen alone (N=32) or a combination of estrogen and progestins (N=45). ERT users showed similar body habitus, physical activity, and plasma lipids compared to non-ERT users. ERT was associated with an average 9.8 mmHg lower systolic BP (p<0.001), and a 6.3 mmHg lower pulse pressure (p<0.01) than in non-users. Multiple regression analysis showed that ERT was an independent predictor of lower SBP and PP (p<0.05). By analysis of covariance, ERT predicted a reduced age-associated increase in SBP, PP, and PWV (p<0.05). When systolic BP was >130 mmHg, the combination of ERT and progestins predicted a higher PWV than ERT alone. In conclusion, ERT in postmenopausal women can beneficially affect the vascular system, by reducing BP and the age-associated increase in arterial stiffness. The addition of progestins to ERT may reduce these beneficial effects.     

Selective angiotensin receptor antagonism with valsartan decreases arterial stiffness independently of blood pressure lowering in hypertensive patients.

Angiotensin II plays a key role in the development of vascular disease. We examined the long-term effects of selective angiotensin II receptor (ATR) blockade with valsartan on arterial wall stiffness. Brachial to ankle pulse wave velocity (baPWV) was measured in 28 women and 25 men with hypertension (mean age: 62+/-2 years). The measurements were repeated after 24 weeks of treatment with valsartan, 40 to 160 mg/day, with (n=10) or without (n=36) concomitant statin therapy. By multiple regression analysis, baseline baPWV was correlated with age (p<0.001), systolic blood pressure (SBP, p<0.0001), body mass index (p=0.018), and pulse pressure (p=0.005), but not with total cholesterol (p=0.446). Valsartan lowered mean SBP and diastolic blood pressure (DBP) from 155+/-3 to 140+/-3 mmHg and from 90+/-2 to 82+/-2 mmHg, respectively, and mean baPWV from 1,853+/-49 to 1,682+/-52 cm/s. Lowering of baPWV was not influenced by statin therapy. An overlap analysis was performed to separate the effect of angiotensin II receptor blockade from that of blood pressure (BP) lowering. The decrease in the baPWV value of 1,794+/-46 cm/s before valsartan (n=39) vs. 1,663+/-45 cm/s during valsartan (p=0.048, n=31) at a similar mean SBP level (149+/-2 vs. 146+/-3 mmHg, p=0.304) confirmed that ATR blockade had a beneficial effect independent of BP lowering. SBP strongly influences baPWV. However, the decrease in baPWV with valsartan was independent of BP lowering. Statins had no synergistic effect on baPWV. Lowering of baPWV may account for the therapeutic benefit conferred by valsartan independent of its BP-lowering effect.     

Effects of obesity and smoking on mental stress-induced blood pressure and augmentation index responses in normotensive young males: the J-SHIPP study

Exaggerated blood pressure (BP) response to mental stress has been known to be a prognostic factor for cardiovascular disease. It has been argued that such unusual vascular reactivity to mental stress may arise from insulin resistance. To examine the vascular responses to mental stress, we evaluated the stress-related changes in BP and the augmentation index (AI), an index of arterial stiffness, in normotensive young males. Changes in late systolic BP (SBP2) representing central aortic pressure were also examined. Subjects were 86 males (21+/-2 years), 13 of whom were classified as obese (>or=25 kg/m(2)). AI was obtained from the radial arterial waveform as a ratio of the height of the late systolic peak to that of the first peak. Blood pressure and AI measurements were taken before, during and after a simple mental arithmetic test (MAT) lasting 3 min. Systolic BP (baseline 125+/-13, during MAT 133+/-13, post-MAT 124+/-11 mmHg; p<0.001) and heart rate (74+/-12, 81+/-13, 74+/-11 beats/min; p<0.001) were significantly increased during the MAT, whereas AI showed a slight reduction. In a separate analysis, the opposite response was observed between obese subjects showing increased AI (54+/-11, 56+/-13, 52+/-11%) and non-obese subjects who showed reduced AI (54+/-12, 51+/-12, 53+/-12%; p=0.032). The responses in SBP and SBP2 (obese 103+/-14, 117+/-12, 104+/-12; non-obese 98+/-13, 104+/-12, 97+/-12 mmHg; p=0.007) were also larger in the obese subjects. Stress-related transient increases in arterial stiffness may be involved in the exaggerated responses in aortic pressure in obese subjects.     

The relationship between pulse wave velocity and indexes of collagen synthesis in hypertensive patients, according to the level of systolic blood pressure

Vascular stiffening, a process responsible for the development of isolated systolic hypertension, depends on dysregulation of collagen-elastine production and arrangement, yet it is not known whether the effect is uniform throughout wide blood pressure (BP) range. To check whether arterial stiffness is similarly related to increased fibrotic remodelling, in patients with systolic blood pressure (SBP) above and below 160 mmHg. Consecutive peri- and postmenopausal female outpatients treated for hypertension and free from other disorders interfering with fibrotic processes, had their BP, pulse wave velocity (PWV), and collagen (N-terminal procollagen type III propeptide (PIIINP); C-terminal procollagen type I propeptide-(PICP)) measured. The average age of 100 women was 71.8+/-10.5 years, BP was 145/83+/-25/15 mmHg, pulse pressure 63+/-17 mmHg, and mean blood pressure (MBP) 104+/-17 mmHg. PWV was 12.9+/-3.6 m/s and was significantly higher among 30 patients with SBP of > or =160 mmHg. PIIINP averaged 4.6+/-1.6 ng/ml and PICP 142.2+/-47.0 ng/ml. In the low SBP (<160 mmHg) group there was no relationship between PWV and collagen concentrations. However, in the > or =160 mmHg group there was significant correlation between PWV and PIIINP concentration. The relationship held significant after adjustment for age, and BP components. Our result can help explaining the results of recent intervention trials where older patients tended to benefit more from potentially antifibrotic drugs (ACE-I), whereas those with compliant arteries tend to benefit from diuretics.     

Arterial blood pressure and arterial stiffness in adolescents are related to gestational age

BACKGROUND: Recent studies show that low birth weight (LBW) infants are at risk of increased arterial blood pressure (BP) in adulthood. Previous work from our centre and others suggests that arterial stiffness (AS) is increased in such patients. However, the respective roles of preterm birth and of intrauterine growth restriction (IUGR) are unclear. AIM: To characterize AS and BP in adolescents who were: born at term with an appropriate birth weight for gestational age (GA) (group 1, n=41); born preterm with an appropriate birth weight for GA (group 2, n=25); born at term and small for GA (group 3, n=24). PATIENTS AND METHODS: Systemic BP was measured with an automated oscillometric device. AS was assessed by measuring pulse wave velocity (PWV) between carotid and radial arteries. RESULTS: 90 adolescents were studied at a mean (SD) age of 13.9 (1.2) years. Subjects from group 2 were born with a 33.6 (1.5) GA. Systolic BP, mean BP, and PWV were significantly increased in group 2 subjects in comparison to both group 1 (123 +/- 11 vs. 117 +/- 11 mmHg, p = 0.04; 88 +/- 7 vs. 83 +/- 7 mmHg, p = 0.03; 7.7 +/- 1.0 vs. 7.0 +/- 0.9 m/s, p = 0.02 respectively) and to group 3 (114 +/- 15 mmHg, p = 0.03: 79 +/- 8 mmHg, p = 0.001; 6.8 +/- 0.9 m/s, p = 0.005 respectively) subjects. Systolic BP, mean BP, and PWV were similar in group 1 and group 3 subjects. CONCLUSION: BP and AS are increased during adolescence in subjects born with a LBW due to preterm birth, while they are not altered in subjects when LBW is related to IUGR. It may be speculated that such changes predispose to long term hypertension and that preterm birth is involved in the early programming of arterial diseases in adulthood.     

Blood pressure and heart rate of students undergoing a medical licensing examination

AIMS: To assess the effect of a real life mental stress situation on blood pressure (BP) and heart rate (HR) in students undergoing a medical licensing examination. METHOD: Prospective observational study of 121 medical students taking the final licensing exam. BP and HR were taken before and after the exam. Additionally, BP was measured by ambulatory BP monitoring device and HR was recorded continuously by an HR monitor belt in 25 students throughout the examination. MAJOR FINDINGS: Diastolic BP (DBP) increased from 81 +/- 10 mmHg before the exam to 86 +/- 9 mmHg (p = 0.008) during the exam and to 88 +/- 11 mmHg, (p = 0.007) 15 min after the exam. Systolic BP (SBP) did not increase significantly during (from 131 +/- 14 before the exam to 136 +/- 18 mmHg) and after the exam (135 +/- 16 mmHg). HR decreased during (to 100 +/- 18 beats/min, p < 0.001), and after the exam (to 95 +/- 19 beats/min, p < 0.001) compared to values before the exam (114 +/- 19 beats/min). SBP was higher in male students compared to female students before (138 +/- 10 vs 125 +/- 18 mmHg) and after (126 +/- 18 vs 115 +/- 17 mmHg) the exam (p < 0.01). CONCLUSION: Only DBP increased during medical licensing examination, albeit within a small range. SBP did not change significantly and HR decreased during the exam. Male students showed a higher SBP compared to female students.     

Selected climatic variables and blood pressure in Central European patients with chronic renal failure on haemodialysis treatment

BACKGROUND/AIMS;Higher blood pressure (BP) in winter has been documented in healthy and hypertensive adults. It may potentially contribute to the observed excess winter cardiovascular mortality in the general population. The aim of the study was to assess whether BP varies similarly among patients with chronic renal failure on haemodialysis treatment, who present an increased risk of cardiovascular death. METHODS: We retrospectively analysed values of pre-dialysis BP and parameters of fluid retention--pre-dialysis body weight and inter-dialytic weight gain measured in 49 patients (23 male, 26 female; aged 46.0+/-13.5 years) from 1995 to 1998. For each patient we calculated deviations of monthly mean values of systolic BP, diastolic BP, pre-dialysis body weight and inter-dialytic weight gain from the lowest monthly means of these parameters in a given year. Monthly means of these deviations for the whole study group (dSBP, dDBP, dBW, dWG, respectively) were subsequently computed. Monthly means of air temperature (T), air relative humidity (H) and atmospheric pressure (AP) were provided by the local Institute of Meteorology. The Wilcoxon paired test was applied to compare mean values of BPs and parameters of fluid retention of every patient in three warmest and three coldest months of each year. Spearman rank correlation analysis was employed to evaluate relationships between dSBP, dDBP and climatic variables, dBW or dWG. RESULTS: Systolic BP was higher in summer than in winter (146.6+/-20.5 vs 143.4+/-18.9 mmHg; p<0.00001). Diastolic BP was also higher in summer than in winter (82.6+/-8.5 vs 79.6+/-7.3 mmHg; p<10(-9)). Pre-dialysis body weight and inter-dialytic weight gain did not differ between summer and winter (66.0+/-13.2 vs 66.0+/-13.2 kg; p=0.98 and 2.27+/-0.6 vs 2.29+/-0.5 kg; p=0.53). There was a positive correlation between dSBP and T (RS=0.424, p<0.003), as well as dDBP and T (RS=0.591, p<0.00001) and an inverse correlation between dSBP and H (RS=-0.372, p<0.01), as well as dDBP and H (RS=-0.408, p<0.004). There were no significant associations between BPs and AP, dBW or dWG. CONCLUSIONS: In haemodialysed patients from southern Poland, BP is higher in summer than in winter. Changes in BP are related to seasonal changes in climatic variables--air temperature and air relative humidity. Seasonal variation in BP is not associated with variation in fluid retention. Possible alteration of cardiovascular reactivity to changes in climatic environment in haemodialysed chronic renal failure patients may be one of the potential explanations of these observations.     

The relationship between pulse wave velocity and pulse pressure in Chinese patients with essential hypertension.

Aortic pulse wave velocity (PWV) is a significant and independent predictor of cardiovascular disease in hypertensive subjects and in patients with end-stage renal disease, but there have been few studies on PWV in Chinese patients with essential hypertension. In this cross-sectional study, we investigated 3,156 consecutive patients (mean age: 53.7 +/- 11.58 years) of the Hypertension Division of Ruijin Hospital in Shanghai. Together with sphygmomanometric blood pressure measurements, aortic PWV was measured using a validated automatic device. PWV in patients with pulse pressure (PP) > or = 60 mmHg was significantly greater than that in patients with PP < 60 mmHg (p < 0.01). PP and PWV were positively related to age (PP: r = 0.396, p = 0.001; PWV: r = 0.531, p = 0.001). After adjustment by age and heart rate, PWV was still closely related to PP (r = 0.249, p = 0.001). At any given systolic blood pressure (SBP), PWV significantly decreased with the increase of diastolic blood pressure (DBP), whereas at any given DBP there was a significant increase of PWV with the increase of SBP. In conclusion, PWV was the major determinant of PP, and was highest in Chinese patients with isolated systolic hypertension, followed by those with systolic and diastolic hypertension, isolated diastolic hypertension, and normal blood pressure.     

Summer-winter variation in 24 h ambulatory blood pressure

OBJECTIVE: To examine possible seasonal differences in circadian blood pressure patterns and the specific contribution of indoor temperature. METHOD: Twenty-four-hour ambulatory systolic blood pressure (SBP) and diastolic blood pressure (DBP) were monitored once in summer and once in winter in 101 healthy subjects aged 28-63 years. Subjects were interviewed concerning health-related habits, and measurements of environmental and occupational conditions were obtained. RESULTS: After controlling for possible confounders, mean SBP during work was significantly higher in winter than in summer by 3.4 mmHg. Both in winter and in summer, the highest values were recorded during work. The daily SBP circadian amplitude was higher in winter, reflected by higher mean SBP during the day and lower mean SBP at night. All of the daytime DBP measurements were higher in winter than in summer, but at night there were no seasonal differences. The blood pressure showed an independent association with season and with environmental temperature (SBP) beta = 3.98 mmHg and -1.14 mmHg/ degrees C, respectively; DBP beta =4.39 mmHg and -0.58 mmHg/ degrees C, respectively).CONCLUSION: In healthy men, the daily amplitude of ambulatory blood pressure varies physiologically by season with the highest values being obtained during work time in the winter months. If these results can be extrapolated to hypertensives then it might be necessary to tailor drug therapy to these variations. The daily average or clinical measurements may lead to an underestimation of the extent of the seasonal variation in blood pressure. The season of the year must be controlled for in clinical and epidemiological studies comparing blood pressure levels and amplitudes between groups or between baseline and follow-up study.     

Blood pressure measurements by the Keito machine. Evaluation versus office blood pressure by physicians

BACKGROUND: The Keito machine offers automatic measurements of blood pressure (BP), height and weight on insertion of coins and has been introduced in pharmacies. DESIGN: Cross-sectional study comparing automatic BP measurements by the Keito machine to office BP measurements by physicians. METHODS: Patients scheduled for pre-catheterisation screening participated in the study. Their BP was first measured using the Keito machine, then by physicians. Office BP was recorded as the last of three consecutive BP measurements recorded with one-min intervals after a five-min rest in the sitting position. In a sub-study BP was measured simultaneously during the Keito measurement by a physician. RESULTS: In 390 consecutive patients average BP was significantly lower with the Keito machine compared to office BP measurements made by the physicians (136/75+/-19/8 mmHg versus 141/79+/-21/10 mmHg, both p<0.001). The correlation coefficient (r) was 0.56 (p<0.001) for systolic BP (SBP) and 0.53 (p<0.001) for diastolic BP (DBP). Bland-Altman analysis showed a mean difference (+/-2 SD) for SBP and DBP of -5 (+/-37) and -4 (+/-17) mmHg, respectively. When defining hypertension (HT) as office SBP> or =140 and/or DBP> or =90 mmHg, the Keito method diagnosed 83% of the systolic and 62% of the diastolic hypertensive population correctly. The classification of systolic and diastolic normotensive was correct in 61% and 86%, respectively. CONCLUSION: Agreement between office and Keito BP is poor. The Keito machine underestimates SBP on average by 5 mmHg and DBP by 4 mmHg, which may be of significance for diagnosing HT and starting anti-hypertensive therapy. However, the difference can be much larger in individual patients. Therefore, the Keito machine cannot be recommended for medical screening of HT or as a replacement for follow-up by physicians.     

Significant association of C-reactive protein with arterial stiffness in treated non-diabetic hypertensive patients

C-reactive protein (CRP) has been known to be associated with vascular inflammation and hypertension. Pulse wave velocity (PWV) increases according to the degree of the arterial stiffness in hypertension patients. Therefore, PWV may be correlated with CRP levels in treated hypertensive patients, irrespective of medication. We sought to determine whether there is a correlation between hsCRP and arterial stiffness in non-diabetic treated hypertensive patients, independent of cardiovascular risk factor. This study consisted of 424 non-diabetic patients at least 45-years-old who were being treated for hypertension. At the time of enrollment, the patients underwent a baseline laboratory assessment of C-reactive protein levels and pulse wave velocity (PWV). Heart to femoral PWV (hfPWV) and brachial to ankle PWV (baPWV) were used as a marker of arterial stiffness. Subjects were categorized according to tertiles of hsCRP level [Group 1: first tertile (0.20-0.46 mg/L), Group 2: second tertile (0.47-1.15 mg/L), Group 3: third tertile (1.17-9.71 mg/L)]. Group 1 consisted of 141 patients (mean age 58+/-8 years), Group 2 had 142 patients (mean age 60+/-9 years) and Group 3 had 141 patients (mean age 61+/-8 years). The hfPWV and baPWV increased significantly along with the hsCRP level. Group 1, Group 2 and Group 3 demonstrated hfPWV and baPWV of 965+/-199 and 1438+/-246, 975+/-174 and 1487+/-258 and 1043+/-215 and 1566+/-252 cm/s, respectively (p<0.01). The hfPWV also showed a strong correlation with baPWV (r=0.698, p<0.001). The hsCRP level was independently associated with arterial stiffness (hfPWV: R(2)=0.273, p<0.001; baPWV: R(2)=0.284, p=0.001) after controlling for age, body mass index, systolic blood pressure (BP), heart rate, gender, HDL-cholesterol, triglyceride, glucose level and medications. In conclusion, hsCRP was associated with arterial stiffness, independent of age, systolic BP, gender, heart rate, glucose, lipid profiles and medications in treated hypertension. Therefore, hsCRP could be a useful marker of arterial stiffness in treated hypertension patients and a possible target for arterial inflammation in hypertension.     

Rosiglitazone reduces office and diastolic ambulatory blood pressure following 1-year treatment in non-diabetic subjects with insulin resistance

OBJECTIVE: Rosiglitazone (RSG) has been reported to reduce blood pressure (BP) in patients with type-2 diabetes, but similar effects in non-diabetic people with insulin resistance is less clear. Our aim was to test the long-term BP-lowering effects of RSG compared with placebo. METHODS: We recruited participants for BP evaluation of RSG treatment from a larger intervention trial. Office BP was recorded in 355 non-diabetic subjects with insulin resistance randomized to receive either RSG or placebo for 52 weeks. Ambulatory BP monitoring (ABPM; Spacelab 90207) was performed in a subgroup of 24 subjects (RSG: n = 11; placebo n = 13). RESULTS: After 1 year, the office BP decreased by -3.1 mmHg systolic (p<0.05) and -3.8 mmHg diastolic (p<0.001) in the RSG group versus placebo. In patients treated with RSG, at 1 year there was a trend for a reduction from baseline for mean 24-h diastolic BP (DBP), daytime DBP and night-time DBP (-4.39, -5.26 and -2.93 mmHg, respectively). However, only daytime DBP was significantly lower in the RSG group compared with control (adjusted mean difference: -4.41 mmHg, p = 0.007). There was also a non-significant trend for a reduction in mean 24-h systolic BP (SBP), daytime SBP and night-time SBP (-2.70, -2.51 and -3.35 mmHg, respectively). CONCLUSIONS: RSG treatment for 1 year was associated with a small but significant decrease in diastolic 24-h ambulatory diastolic BP, and both systolic and diastolic office BPs in non-diabetic people with insulin resistance.     

Exercise blood pressure changes between seasons

BACKGROUND: Blood pressure (casual and daytime) is higher in winter than it is in summer, and this factor might be partly responsible for the higher cardiovascular mortality in winter. OBJECTIVE: To determine in a prospective study whether there is also a seasonal variation in exercise blood pressure. METHODS: We evaluated the pretest, exercise (five-step treadmill test) and recovery values of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate of 94 healthy men, aged 20-65 years, during the summer and winter. RESULTS: SBP and DBP values were higher in winter than they were in summer during the resting period immediately before exercise (P = 0.003 and P = 0.07, respectively), and during recovery (both P < 0.0001). Exercise SBP and heart rate values were similar in the two seasons, although exercise DBP was higher in winter than it was in summer (P < 0.0001). The increase in DBP from pretest to stage 3 was 6.5 mmHg in summer and 10.4 mmHg in winter (P = 0.002). After we had controlled for possible confounders, the increase in DBP during exercise was found to be independently associated with season of the year and resting DBP. CONCLUSIONS: Exercise DBP varies according to season whereas exercise SBP does not. Our results suggest that, since measures of the response of blood pressure to exercise testing are frequently used in blood pressure and hypertension research as well as in clinical practice, the seasonal influences should be taken into account.     

Validity of pulse pressure and augmentation index as surrogate measures of arterial stiffness during beta-adrenergic stimulation

OBJECTIVE: Increased arterial stiffness is a determinant of cardiovascular mortality. Pulse wave velocity (PWV) is a direct measure of arterial stiffness. Aortic augmentation index (AI) and pulse pressure (PP) are surrogate measures of arterial stiffness. Both PWV, AI and PP increase with cardiovascular risk factors. The aim of this study was to test the validity of AI and PP as surrogate measures of arterial stiffness compared with PWV, during beta-adrenergic stimulation with Isoprenaline (Iso). DESIGN AND METHODS: A total of 41 healthy volunteers entered a randomized, double-blind, placebo-controlled, cross-over study. In random order, subjects were given intravenous infusion in equal volume of Iso 8 microg/kg per min (dissolved in glucose 5%) and placebo (glucose 5%). A wash-out period of 25 min was observed between the infusions. Measurements included blood pressure (BP), heart rate (HR), PWV, and AI. PWV were determined using complior (Complior, Artech-Medical, Paris, France). AI and aortic PP were obtained from pulse wave analysis of radial applanation tonometry, using transfer function (SphygmoCor Windows software). RESULTS: Baseline AI increased (P < 0.05) with aging, a lower height and a larger diastolic BP (DBP). Iso increased (P < 0.0001) HR, brachial SBP, brachial and aortic PP as compared with placebo. In contrast, Iso decreased (P < 0.05) AI, brachial DBP, peripheral PWV, but not aortic PWV. Decrease of AI induced by Iso was not related to PWV. In stepwise multiple regression changes in HR, brachial SBP and DBP were independent determinants of AI response to Iso (r = 0.78, P < 0.0001). CONCLUSIONS: Our findings show that AI and PP fail as surrogate measures of arterial stiffness during beta-adrenergic stimulation.     

Ambulatory arterial stiffness index or pulse pressure: which correlates better with arterial stiffness in resistant hypertension?

The ambulatory arterial stiffness index (AASI) is a recently proposed index derived from 24-h ambulatory blood pressure monitoring (ABPM) for the evaluation of arterial stiffness. In this cross-sectional study we investigated whether AASI reflects arterial stiffness in patients with resistant hypertension by comparing AASI and ambulatory pulse pressure (PP) with aortic pulse wave velocity (PWV), a measure of arterial stiffness, in 391 resistant hypertensives. Clinical, laboratory and echocardiographic variables, 24-h ABPM and aortic PWV (measured using the Complior device) were obtained. AASI was calculated as 1--the regression slope of 24-h diastolic on systolic blood pressure (BP). Statistical analysis involved single and multiple linear regressions to assess the correlations between the two ABPM variables and PWV, both unadjusted and adjusted for potential confounders (age, gender, body height, presence of diabetes, 24-h mean arterial pressure [MAP], heart rate, and nocturnal BP reduction). Ambulatory PP and aortic PWV were independently associated with age, gender, presence of diabetes, and 24-h MAP, whereas AASI was associated with age, diabetes, and nocturnal diastolic BP reduction. PP showed stronger unadjusted (r=0.39, p<0.001) and adjusted (r=0.22, p<0.001) correlations with aortic PWV than AASI (r=0.12, p=0.032 and r= -0.04, p=0.47, respectively). In the analysis of subgroups stratified by gender, age, presence of atherosclerotic diseases and diabetes, dipping pattern, and ambulatory BP control, the superiority of PP over AASI was apparent in all subgroups. In conclusion, 24-h ambulatory PP was better correlated to arterial stiffness, as evaluated by aortic PWV, than the novel AASI, in patients with resistant hypertension.     

Effect of 4 weeks of aerobic or resistance exercise training on arterial stiffness, blood flow and blood pressure in pre- and stage-1 hypertensives

The benefits of aerobic exercise (AE) training on blood pressure (BP) and arterial stiffness are well established, but the effects of resistance training are less well delineated. The purpose of this study was to determine the impact of resistance vs aerobic training on haemodynamics and arterial stiffness. Thirty pre- or stage-1 essential hypertensives (20 men and 10 women), not on any medications, were recruited (age: 48.2 +/- 1.3 years) and randomly assigned to 4 weeks of either resistance (RE) or AE training. Before and after training, BP, arterial stiffness (pulse wave velocity (PWV)) and vasodilatory capacity (VC) were measured. Resting systolic BP (SBP) decreased following both training modes (SBP: RE, pre 136 +/- 2.9 vs. post 132 +/- 3.4; AE, pre 141 +/- 3.8 vs. post 136 +/- 3.4 mm Hg, P = 0.005; diastolic BP: RE, pre 78 +/- 1.3 vs post 74 +/- 1.6; AE, pre 80 +/- 1.6 vs. post 77 +/- 1.7 mm Hg, P = 0.001). Central PWV increased (P = 0.0001) following RE (11 +/- 0.9-12.7 +/- 0.9 ms(-1)) but decreased after AE (12.1 +/- 0.8-11.1 +/- 0.8 m s(-1). Peripheral PWV also increased (P = 0.013) following RE (RE, pre 11.5 +/- 0.8 vs. post 12.5 +/- 0.7 ms(-1)) and decreased after AE (AE, pre 12.6 +/- 0.8 vs post 11.6 +/- 0.7 m s(-1)). The VC area under the curve (VC(AUC)) increased more with RE than that with AE (RE, pre 76 +/- 8.0 vs. post 131.1 +/- 11.6; AE, pre 82.7 +/- 8.0 vs. post 110.1 +/- 11.6 ml per min per s per 100 ml, P = 0.001). Further, peak VC (VCpeak) increased more following resistance training compared to aerobic training (RE, pre 17 +/- 1.9 vs. post 25.8 +/- 2.1; AE, pre 19.2 +/- 8.4 vs post 22.9 +/- 8.4 ml per min per s per 100 ml, P = 0.005). Although both RE and AE training decreased BP, the change in pressure may be due to different mechanisms.     

Effect of acute and long-term aerobic exercise on arterial stiffness in the elderly.

Arterial stiffness is an important factor for cardiovascular performance and a predictor of cardiovascular risk. We evaluated the effects of both acute and long-term aerobic exercise on arterial stiffness in community-dwelling healthy elderly subjects. In addition, we evaluated the relationship between the effects of long-term exercise and those of acute exercise. The study subjects were participants in the Shimanami Health Promoting Program study (J-SHIPP), which was designed to investigate factors relating to cardiovascular disease, dementia, and death (67+/-6 years). They performed mild-to-moderate aerobic exercise lasting for 30 min twice a week for 6 months. Arterial stiffness was assessed before and after the first 30-min acute exercise (n=99) and long-term 6-month aerobic training (n=40). The radial arterial augmentation index (AI) obtained from the radial pulse waveform by the tonometry method was used as a parameter of arterial stiffness. Both systolic blood pressure (SBP) and diastolic blood pressure (DBP) were significantly decreased after 30-min of aerobic exercise, however no significant change in AI was observed. On the other hand, there were significant decreases in AI (from 87 to 84%, p<0.01), SBP (from 136 to 129 mmHg, p<0.01), and DBP (from 75 to 70 mmHg, p<0.01) after the 6-month exercise period. Long-term exercise-induced changes in AI were significantly and inversely correlated with the pre-exercise AI (r=-0.40, p<0.01). In addition, AI changes after the 6-month exercise period were significantly related to those observed after first 30-min exercise (r=0.48, p<0.01). These findings indicate that apparently healthy and sedentary elderly subjects with higher AI may benefit from mild-to-moderate aerobic exercise to improve arterial stiffness.