Functional health and well-being, arterial stiffness and vascular dysfunction in healthy adults

Current goals of healthcare delivery extend beyond treating and preventing disease outcomes to improvement in the quality of life. Clinicians routinely utilize patients' subjective reports of functional well-being and physical capacity to evaluate cardiopulmonary fitness, screen for illness-related impact on daily activities and to ascertain effectiveness of therapy. Similarly, standardized questionnaires assessing self-perceived physical and functional health are employed as clinical end-points and are also used to compare effectiveness of diagnostic and therapeutic modalities [1]. While there is no established gold standard for assessment of perceived health and well-being, the Short Form-36 version 2 Health Survey (SF-36) performs reliably in several clinical settings and across many patient populations [2]. The SF-36 allows for separate assessment of physical and mental health functioning, summarized by the physical (PCS) and mental (MCS) component summary scores, respectively. The internal consistency of SF-36 has been validated to represent an accurate portrayal of a responder's quality of life, as well as the clinician's interpretation of patients' health [3]. The SF-36 predicts morbidity and mortality in the general population, and lower PCS scores forecast dismal outcomes in patients with cardiovascular disease (CVD) [3]. However, its utility as a predictor of subclinical vascular disease has not been investigated previously [4]. Measures of arterial wall thickness and stiffness are powerful predictors of both future incidence of hypertension in asymptomatic individuals, as well as adverse outcomes in at-risk patient populations [5]. We examined the relationship between the physical (PCS) and mental (MCS) component summary scores of the SF-36 and subclinical vascular disease in subjects free of cardiovascular disease, with the hypothesis that low scores will be associated with vascular disease and dysfunction. We examined PCS and MCS scores in 609 University employees without overt CVD (Table 1), who underwent comprehensive evaluation of vascular structure and function, including carotid artery intima-media thickness (IMT) and arterial stiffness measured as PWV, central augmentation index (AIX), and subendocardial viability ratio (SEVR). The PCS score correlated negatively with age (r =−0.09, p = 0.027), body mass index (BMI; r = −0.28, p b 0.001) and the Framingham Risk Score (FRS; r = −0.12, p = 0.003), indicating higher scores in younger, leaner subjects with lower risk factor burden. PCS scores were also lower in women, African Americans, and in subjects with diabetes, hypertension, hyperlipidemia or smoking (Table 2). Lower PCS scores were associated with worse arterial stiffness, indicated by higher PWV and AIX, and lower SEVR (r = −0.14, −0.15 and 0.2, respectively; p ≤ 0.001 for all); as well as increased carotid IMT (r = −0.18, p ≤ 0.001) (Fig. 1). Following adjustment for FRS, BMI and race, the PCS, but not the MCS score remained independently associated with PWV (β = −0.13, p b 0.001), AIX (β = −0.1, p = 0.008), SEVR (β = 0.22, p b 0.001) and IMT (β = −0.12, p = 0.001). Each 5-point incrementin the PCS score is associated with 0.1 m/s and 0.01 mm change in PWV and IMT, respectively. Three questions in the SF-36 had significant univariate associations with all vascular measures; including IMT, PWV, AIX and SEVR (p-ANOVA b 0.03 for all questions). These were whether the subject's “health” status limits common daily activities such as: 1 — vigorous activities; 2 — bending, kneeling, or stooping and 3 — walking more than 1 mile. In conclusion, poor self-reported physical and functional health measured with the PCS score is associated with arterial stiffness and vascular dysfunction, irrespective of concomitant risk burden in this large multiethnic population with a relatively low risk factor