The University of Maine DigitalCommons@UMaine Maine-Syracuse Longitudinal Papers Maine-Syracuse Longitudinal Study 2011 Norms and reference values for pulse wave velocity: One size does not fit all Merrill F. Elias University of Maine, [email protected] Gregory A. Dore University of Maine Adam Davey Temple University Walter P. Abhayaratna Amanda L. Goodell University of Maine See next page for additional authors Follow this and additional works at: https://digitalcommons.library.umaine.edu/ longitudinal_papers Repository Citation Elias, Merrill F.; Dore, Gregory A.; Davey, Adam; Abhayaratna, Walter P.; Goodell, Amanda L.; and Robbins, Michael A., "Norms and reference values for pulse wave velocity: One size does not fit all" (2011). Maine-Syracuse Longitudinal Papers. 63. https://digitalcommons.library.umaine.edu/longitudinal_papers/63 This Article is brought to you for free and open access by DigitalCommons@UMaine. It has been accepted for inclusion in Maine-Syracuse Longitudinal Papers by an authorized administrator of DigitalCommons@UMaine. For more information, please contact [email protected]. Authors Merrill F. Elias, Gregory A. Dore, Adam Davey, Walter P. Abhayaratna, Amanda L. Goodell, and Michael A. Robbins This article is available at DigitalCommons@UMaine: https://digitalcommons.library.umaine.edu/longitudinal_papers/63 The Journal of Bioscience and Medicine 1, 4 (2011) | Artcle Norms and reference values for pulse wave velocity: one size does not ft all Merrill F. Elias1,2,*, Gregory A. Dore2, Adam Davey3, Walter P. Abhayaratna4, Amanda L. Goodell2, Michael A. Robbins1,2 1. Graduate School of Biomedical Sciences, University of Maine, USA. 2. Department of Psychology, University of Maine, USA. 3. Department of Public Health, Temple University, USA. 4. College of Medicine, Biology and Environment, Australian Natonal University, Canberra, Australia. *Corresponding Author: Merrill F. Elias ([email protected]) Received: 05 June 2011, Accepted: 19 July 2011, Published: 31 July 2011 ABSTRACT: Carotd-femoral pulse wave velocity (PWV) is a gold standard non-invasive marker of arterial stfness, but its clinical utli- ty has been limited due to the need for normatve and reference group data for specifc measurement devices. Our community-based sample (N = 502) ranged in age from 40 to 93 years afer exclusion of individuals with a history of acute stroke, probable dementa, and diabetes. PWV was assessed with the SphygmoCor® system. Means, medians, SD and 95th percentle values were presented in ten-year age groups for normotensive and hypertensive partcipants. From among multple cardiovascular risk factors, a parsimoni- ous regression equaton for predictng PWV was developed. Results were compared with the Reference Values for Arterial Stfness Collaboraton (RVASC) study featuring mathematcally standardized reference values for an aggregate of clinic sites and measure- ment devices. As in the RVASC study, a systematc rise in PWV with age was observed with a more pronounced rise for hypertensive individuals, but our specifc point estmates of PWV difered from theirs. Our regression models accounted for 48 percent of the vari- ance in PWV using variables routnely available to practcing physicians: age, hypertension status, height, weight, heart rate, mean arterial pressure, creatnine, and glucose. It is important to make available PWV norms and reference group data for specifc meas- urement devices. Development of reference group data for smaller samples is feasible and predicton equatons for PWV can be de- veloped from diagnostc informaton readily available to the practcing physician. KEYWORDS: pulse wave velocity, norms, reference values, risk factors, atherosclerosis arotd-femoral pulse wave velocity (PWV) is a gold jects were classifed as follows: optmal, normal, high normal, standard non-invasive marker of arterial stfness and grade I, and grade II/III hypertensive blood pressure (BP) catego- is itself a predictor of cardiovascular morbidity and ries by age decades, including two additonal groups not by decade mortality *1-11+. The clinical utlity of PWV has been but above 70 and below 30 years of age. Results for fve PWV restrictedC by limited normatve and reference group data, a situa- measuring systems were combined, necessitatng the merging of ton exacerbated by diferences in PWV measurement methods fndings from centers using diferent algorithms and diferent est- across studies *1-14+. The contnuing need for normatve and refer- mates of path length. Consequently, mathematcal adjustments ence values for specifc devices has been emphasized in studies designed to equate transit tme and path length estmates across comparing PWV measuring devices and meta-analyses *12-14+. studies were required. The RVASC (20) investgators cauton read- There are norms and reference group data for study partcipants in ers that “Even afer full adjustment, diferences between algorithm good health by age and by combined hypertensive-diabetc status and path length were blunted, but not totally abolished.” Moreo- *12-19+, but to our knowledge, none exists for hypertensive (HT) ver, they point out that there was a strong data collecton center and normotensive (NT) classifcatons by decades or HT and NT efect that was not accounted for by their standardizaton proce- groups, except for the Reference Values for Arterial Stfness Col- dures. laboraton (RVASC) study *20+. In the RVASC study, PWV data were gathered from 13 centers across eight European countries. Sub- www.jbscience.org DOI: 10.5780/jbm2011.4 | Page 1 Artcle Merrill F. Elias et al.| Pulse wave velocity Thus, our goals were: frst, provide normatve and reference ant-diabetc agents, or by a fastng glucose level ≥ 7 mmol/l. MAP group data based on a single algorithm (intersectng tangent) em- was calculated as diastolic BP+1/3 (systolic BP – diastolic BP). The ployed in a single widely used system (SphygmoCor®); second, to demographic and cardiovascular morbidity characteristcs of the compare our fndings with those of the RVASC study in so far as sample are presented in Table 1 . possible, e.g. we present data for persons 80 to 93 years of age Procedure rather than combining groups above 70 years of age; and third, to determine a parsimonious regression model for predictng PWV The University of Maine approved this investgaton and in- beyond age, hypertension, and necessary control variables such as formed consent for data collecton was obtained from all partci- height and weight, heart rate and mean arterial pressure (MAP). pants. Partcipants were admited to the study center on the day Previous studies have explored relatons between cardiovascular of the study, followed by medical history interview and then PWV risk factors other than hypertension and age that predict PWV *6- measurements. 8+. Here, we are concerned with the best predicton possible from the fewest variables beyond essental controls. Blood Pressure (BP) and Pulse Wave Assessment METHODS Brachial artery pressures were measured using a Critkon Di- namap ProCare 100 (oscillometric method) instrument. All precau- Partcipants tons, training and procedures in BP measurement recommended by the Commitee Report: Blood Pressure Publicaton Guidelines The PWV data were obtained from a community-based sample were observed *26+. of 626 partcipants (61% women; 14% African American) ranging in age from 24 to 93 years (mean age 64.3). They were partcipants in Following 10 minutes of supine rest, 15 consecutve automated PWV studies conducted for the frst tme in the seventh wave brachial BP measurements were taken at 1 minute intervals, 5 (repeated serial data collecton) of the Maine Syracuse Longitudi- supine, 5 standing, and 5 sitng. The resultng 15 measurements nal Study (MSLS), which was initated in 1975. Recruitment proce- were averaged and used for analyses outlined below. Afer an dures have been described previously *21-23+. Subjects were re- additonal 10 minutes rest, fve supine brachial artery BP measure- cruited from the Syracuse, New York community and the surround- ments were obtained, averaged and used for calibraton of the ing area by means of mult-media advertsement for partcipaton SphygmoCor® device *27+. This procedure permited us to maintain in a study of cogniton and BP, and admited to the study unless the BP measurement protocol that has been used since the since they were diagnosed as psychotc or alcoholic, or were receiving the beginning of the MSLS study and to obtain additonal supine treatment for these diseases. Upon diagnosis of hypertension at measurements for device calibraton purposes. any wave, individuals were referred to their physician for treat- PWV was assessed noninvasively using the SphygmoCor® sys- ment and 88.6 percent were treated at wave 7. tem. Electrocardiogram-gated carotd and femoral waveforms Carotd-femoral PWV (m/s) was measured for the frst tme at were recorded using applanaton tonometry. Carotd-femoral path the seventh (fnal) wave (2006-2009) of the MSLS and cardiovascu- length was measured as the diference between the surface dis- lar disease (CVD) risk factor covariates from that wave were em- tances joining (1) the suprasternal notch, the umbilicus and the ployed. Thus the present data analysis is cross-sectonal. In an femoral pulse and (2) the suprasternal notch and the carotd pulse. inital analysis of the 626 partcipants for whom PWV data were Carotd-femoral transit tme was estmated in 8-10 sequental fem- obtained, subjects were excluded in the following sequence: (1)