Leandro Sanesi

Effects of gravity-induced upper-limb blood pressure changes on wave transmission and arterial radial waveform.

Background: Local blood pressure (BP) changes induced by arm tilting may influence pressure wave transmission and reflection. We investigated the effects of upper-limb tilting on radial augmentation index (rAIx) and related central measures [aortic augmentation index (aAIx)]. Methods: In 45 volunteers (age 49 ± 19 years), supine brachial BP and radial artery waveforms were obtained by applanation tonometry with the dominant arm stretched and gently supported in three different positions: at the heart level, with the BP cuff 15 cm above heart level (approximately +30°), and 15 cm below heart level (−30°). Results: Brachial SBP/DBP was 120/68 ± 17/8 mmHg. Mean arterial pressure changed predictably with arm tilting (99 ± 12 mmHg at −30°, 88 ± 10 mmHg at 0°, 77 ± 11 mmHg at +30°, all P < 0.001). rAIx decreased at −30° (69 ± 22%), and increased at +30° (93 ± 20%) compared with 0° (82 ± 20%, all P less than 0.001). Changes in rAIx (value at +30° minus value at −30°) showed an inverse relationship with age (r = −0.32, P = 0.03). Heart rate, BP and rAIx did not change in the contralateral arm, which was held at the heart level during the examination. aAIx followed the same pattern as rAIx (123 ± 27% at −30°, 144 ± 33% at +30°, 136 ± 31% at 0°, all P less than 0.001); changes in rAIx and aAIx were strongly related each other (r = 0.82, P < 0.001). Conclusion: Acute gravitational upper-limb BP changes generate opposite, profound changes in rAIx, and major artifactual changes in aAIx. These findings provide a rationale for recommending to keep the upper limb at the heart level during radial waveform assessment.

2B.09: ARTERIAL STIFFNESS AND DISEASE-RELATED ORGAN DAMAGE IN SYSTEMIC LUPUS ERYTHEMATOSUS.

Objective: Increased arterial stiffness has been reported in subjects with systemic lupus erythematosus (SLE) compared with healthy controls, and this association is partially reverted by immunosuppressive treatment. In SLE, indexes of organ damage are related to a poor clinical status and worse prognosis independently from the activity of the disease. Data are controversial about the association between organ damage and arterial stiffness in SLE. Design and method: 40 subjects with positive history of SLE (mean age 45 ± 12 years, 90% women) and a median disease duration of 12 years (IQR 5–19), underwent assessment of carotid-femoral pulse wave velocity (cf-PWV) by means of applanation tonometry (SphygmoCor). A comprehensive clinical, metabolic and immunological assessment was performed. Irreversible organ damage, not related to active inflammation, was assessed through the Systemic Lupus International Collaborating Clinics (SLICC) damage index. The relationship between cf-PWV and SLICC index was investigated with univariate and multivariate models. Results: Mean blood pressure was 128/75 ± 16/10 mmHg. 9 subjects (23%) were on anti-hypertensive treatment, 4 (10%) had had previous cardiovascular events, 17 (42%) subjects were treated with steroids, 29 (71%) with hydroxychloroquine and 15 (37%) with other immunosuppressants. Median SLICC index was 2 (IQR 1–3) and average cf-PWV was 7.5 ± 1.9 m/s. cf-PWV significantly increased across SLICC damage index categories (F = 3.141, p < 0.019). The association between cf-PVW and SLICC index persisted after adjustment for age, sex, mean arterial pressure, height, heart rate, disease duration, anti-hypertensive treatment, number of drugs for SLE therapy, C-reactive protein and previous cardiovascular events (p = 0.031). Conclusions: In a cohort of subjects with SLE under active treatment, SLICC damage index had a significant independent association with cf-PWV. Further studies are needed to explore the role of arterial stiffness as a predictor of disease-related organ damage in SLE.

[OP.5C.03] DETERMINANTS OF CENTRAL AND PERIPHERAL PULSE PRESSURE IN A POPULATION OF HEALTHY ADOLESCENTS. THE MACISTE STUDY

Objective: There is paucity of data about central blood pressure (BP) and vascular phenotypes in young individuals. The identification of the main determinants of central BP parameters and the BP amplification phenomenon may help in defining the clinical relevance of BP patterns in adolescence. We aimed at evaluating the anthropometric and hemodynamic factors associated with central pulse pressure (cPP), peripheral pulse pressure (pPP) and central-to-peripheral PP amplification (PPamp) in a population of healthy adolescents. Design and method: We studied 459 subjects (boys 57%, mean age 16.8 ± 1.5y, SBP/DBP 124/67 ± 11/7 mmHg) attending the Liceo Donatelli High School in Terni, Italy. pPP was measured by validated oscillometry. cPP was estimated from radial applanation tonometry (SphygmoCor GTF) calibrated to brachial MAP/DBP. PPamp was expressed as pPP/cPP. Indexed left ventricular mass (iLVM = LVM/BSA) and stroke index (SI = stroke volume/BSA) were derived from 2D-echocardiography (Teicholzs formula, Devereux correction). Carotid-femoral (cf-PWV) and carotid-radial (cr-PWV) pulse wave velocities were measured by applanation tonometry (SphygmoCor). PWV ratio was expressed as cf-PWV/cr-PWV. cPP, pPP and PPamp were introduced as dependent variables in three separate stepwise multivariate regression models. Age, male sex, BSA, heart rate (HR), MAP, stroke index (SI:stroke volume/BSA) and cf-PWV were included in each model as independent factors. Results: average cPP was 36 ± 7 mmHg, PPamp 1.57 ± 0.13. cPP was positively associated with male sex, BSA, MAP, SI, and negatively with HR. The above variables explained 47% of the cPP variance. pPP was positively associated with male sex, BSA and SI (44% of pPP variance explained). PPamp was positively associated with age, HR and cf-PWV (17% of PPamp variance explained). Results did not change when BMI and height replaced BSA, iLVM replaced SI, and cr-PWV or PWV ratio replaced cf-PWV. Figure. No caption available. Conclusions: Anthopometric and hemodynamic factors differently impact on cPP, pPP and PPamp. HR and MAP are significantly related to cPP, but not to pPP. HR, cf-PWV and age are all positively related to PPamp. These results could help in better elucidate the clinical relevance of some BP patterns frequently observed in adolescence, such as isolated systolic hypertension and spurious hypertension.

[PP.04.02] SODIUM CONSUMPTION, CENTRAL AND PERIPHERAL BLOOD PRESSURE, AND FOOD HABITS IN A POPULATION OF HEALTHY ADOLESCENTS. THE MACISTE STUDY

Objective: There is a clear relationship between sodium intake and peripheral blood pressure (BP), both in adults and in adolescents. Less is known on the relationship between sodium consumption and central BP and the main dietary sources of daily sodium intake in adolescence. We aimed at evaluating sodium intake and its links with central and peripheral BP in a population of Italian adolescents. Design and method: 401 healthy adolescents aged 17 ± 1 years (58% boys, average brachial/central BP: 124/67 ± 11/7 mmHg, and 105/69 ± 9/8 mmHg), attending the Liceo Donatelli High School, Terni, Italy, were evaluated. Daily sodium intake was estimated from a single fasting second-void urine by a previously-validated formula (Tanaka). Main sources of daily sodium intake were investigated by a self-administered food frequency questionnaire (Project Big-Life). Central BP was estimated by radial and brachial applanation tonometries, and calibrated to brachial MAP/DBP (SphygmoCor). Results: 24-h estimated urinary sodium (24-hUNa) was 135 ± 30 mmol/d (3.116 g/d), and was higher in boys than in girls (139 ± 30 vs 130 ± 31 mmol/d, p = 0.004). 89% of the population showed excess sodium intake according to international guidelines. 24-hUNa was directly correlated to brachial and central SBP (&rgr; = 0.14 and &rgr; = 0.15, both p < 0.01), to brachial and central PP (&rgr; = 0.19 and &rgr; = 0.24, both p < 0.01), and to central-to-peripheral PP amplification (&rgr; = −0.13, p < 0.01), but not to central-to-peripheral SBP amplification (&rgr; = −0.01, p = 0.85). In a fully-adjusted multivariate regression model, 24-hUNa (&bgr;=0.10, p = 0.04) was independently related to central-to-peripheral PP amplification, but not to other measures of both peripheral and central BP. In a factorial analysis, the main daily dietary sources of sodium were bread, biscuits, and salt added to foods (41% of the total estimated sodium intake). Conclusions: Current salt intake is unnecessarily high in Italian adolescents. Sodium intake has a direct relationship with both central and peripheral SBP and PP, and shows an independent association with central-to-peripheral PP amplification. The adverse effects of an excess of sodium intake are more pronounced in central than in peripheral PP. Interventions aiming at reducing sodium intake may ultimately have a favorable impact on the cardiovascular health among adolescents through a reduction of central PP.

[OP.6A.02] IDEAL CARDIOVASCULAR HEALTH IS INVERSELY ASSOCIATED WITH INCREASED CAROTID-FEMORAL PULSE WAVE VELOCITY IN ITALIAN ADOLESCENTS. THE MACISTE STUDY

Objective: Ideal cardiovascular health (ICH) among adolescents is defined as the optimal levels of three CV risk factors (SBP/DBP < 90°percentile, fasting glucose <100 mg/dL, total cholesterol <170 mg/dL) and four behaviours (body mass index (BMI) <85°percentile, not smoking, presence of >=4 healthy components in diet, moderate or vigorous physical activity at least 1 h/day). We investigated the burden of ICH among Italian adolescents, and its association with arterial stiffness (carotid-femoral pulse wave velocity, cfPWV). Design and method: 307 healthy subjects (mean age 17 ± 2 years, 55% men) attending the Liceo Dontatelli High School, Terni, Italy, were evaluated. Physical activity, dietary and smoking habits were assessed through self-reported questionnaires. Sodium consumption was estimated by single-void second fasting urine samples. Smoking status was confirmed by exhaled carbon-oxyde (pico-smokerlyzer). CfPWV was evaluated by arterial tonometry (SphygmoCor, subtracted distance). For each ICH metric, a score of 2 was also assigned if levels were ideal, 1 if intermediate, and 0 if poor. Results: No one had all 7 ICH metrics; the majority of subjects (76%) had 4 or more ICH metrics; 17 subjects had 6 out of 7 ICH metrics, while 6 subjects had 1 out of 7. Ideal glycemic values were mostly common (99%), while ideal dietary habits the least common (7%). An inverse linear trend in cfPWV was observed over the number of ICH (p for linear trend <0.01, figure). The inverse association between ICH and cf-PWV was observed in females (p < 0.01), but not in men (p = 0.20). When subjects were grouped in tertiles according to ICH score, after adjustment for age and sex, subjects in the lower tertile, compared to upper tertile, showed higher values of cf-PWV (5.1 ± 1.3 m/s vs 4.6 ± 1.8 m/s, p < 0.01), which remained significant after further adjustment for mean BP, height, serum cholesterol, serum glucose, smoking habits, and physical activity (p = 0.02). Conclusions: ICH is relatively uncommon among Italian adolescents, and is inversely related to cf-PWV in females. The potential adverse effects of CV risk factors and unhealthy behaviours on arterial stiffness, an early marker of vascular damage, begins to develop at an early stage of lifespan. Figure. No caption available.

8A.05: AGE-DEPENDENT ASSOCIATION OF 24-HOUR PERIPHERAL OR CENTRAL PULSE PRESSURE WITH STROKE VOLUME.

Objective: Pulse pressure (PP) is a complex physiologic trait affected by many variables, including left ventricular contractility (reflected by stroke volume), arterial stiffness, and central-to-brachial amplification. The impact of age on the relationship between stroke volume and central or brachial PP has not been investigated. Design and method: 3765 adult subjects with untreated essential hypertension (men 56%, age 50 ± 12 years) underwent 24-hour ambulatory BP monitoring (SpaceLabs) and 2D-guided M-mode echocardiography. In a subset of 982 subjects in whom central PP was measured by applying a transfer function to radial pulse wave (SphygmoCor), we also estimated central office (or 24 h) PP by regression equations based on office (or 24 h) PP and mean arterial pressure, heart rate, age, height and sex (R2 = 0.92 between estimated and measured central PP). The same equations were then applied to the original population to obtain estimated central PP. Results: Stroke volume had a significant direct association with both brachial and central 24 h PP up to the age of 39 years (Figure). The above relationship weakened with age and became mostly non-significant after the age of 40 (all r < 0.10). Similar, although weaker, trends were observed for office PP (both brachial and central). Figure. No caption available. Conclusions: 24-h PP has a strong direct association with left ventricular stroke volume in the young only, and might more exclusively depend on arterial stiffness later in life. Since the above relationship was also observed with estimated central PP, it may not depend on PP amplification. The ’young’ and ’old’ pathophysiological patterns of PP may help to explain the increasingly adverse prognostic value of PP observed with advancing age.