Orthostatic blood pressure response, carotid intima-media thickness, and plasma fibrinogen in older nondiabetic adults.

OBJECTIVE

Although recent studies have indicated that both orthostatic hypotension and orthostatic hypertension (OHTN) independently predict cardiovascular events, the underlying mechanisms are still debatable.

METHODS

A total of 700 nondiabetic adults (43% men, age 64 years) were examined by orthostatic blood pressure (BP) test, carotid artery ultrasonography, and biochemical tests including plasma fibrinogen and lipid profile. Multivariate-adjusted logistic regression was applied to assess association of intima-media thickness (IMT) and P-fibrinogen with orthostatic hypotension and OHTN. In addition, distribution of IMT and P-fibrinogen across quintiles of orthostatic systolic BP (SBP) response was analyzed.

RESULTS

Orthostatic hypotension and OHTN were found in 40 (5.7%) and 45 (6.4%) study participants, respectively. Both IMT [odds ratio (OR), 95% confidence interval (CI) per one-SD increment: 1.27, 1.01-1.60; P = 0.04] and P-fibrinogen (OR 1.44, 1.07-1.93; P = 0.02) were associated with orthostatic hypotension in a crude model. After adjustment relationship between orthostatic hypotension and IMT was slightly attenuated (OR 1.26, 0.96-1.65; P = 0.09) but was substantially unchanged in regard to P-fibrinogen (OR 1.45, 1.06-1.99; P = 0.02). In contrast, OHTN showed no association with either IMT or P-fibrinogen (adjusted OR 1.09, 0.78-1.52; P = 0.61, and 0.97, 0.70-1.34; P = 0.84, respectively). Distribution of IMT across quintiles of orthostatic SBP response was U-shaped, whereas that of fibrinogen was more linear but none of borderline quintiles (with pronounced hypertensive or hypotensive response) significantly differed from the middle quintiles in a fully adjusted model.

CONCLUSION

In older nondiabetic adults only orthostatic hypotension seems to independently correlate with increased carotid atherosclerosis and systemic inflammation.