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Peripheral endothelium-dependent flow-mediated vasodilatation is associated with left ventricular mass in older
Jidong Sung1, Pamela Ouyang, Anita C Bacher
1Johns Hopkins University School of Medicine, Baltimore, Md, USA.
Insights
Increased left ventricular (LV) mass is linked to poorer endothelial function, measured by flow-mediated dilation (FMD), in older adults with mild hypertension. This suggests a connection between heart structure and blood vessel health.
Area of Science:
- Cardiology
- Vascular Biology
- Hypertension Research
Background:
- Increased left ventricular (LV) mass is a known cardiovascular disease risk factor.
- Previous research linked higher LV mass to reduced coronary flow reserve.
- The relationship between LV mass and peripheral endothelial function (flow-mediated dilation, FMD) was less understood.
Purpose of the Study:
- To investigate the association between left ventricular mass and flow-mediated dilation (FMD) in peripheral arteries.
- To explore this relationship in elderly individuals with untreated mild hypertension.
Main Methods:
- Sixty-two healthy, hypertensive subjects aged 55-75 years were studied.
- Left ventricular mass was assessed using magnetic resonance imaging and indexed.
- Flow-mediated dilation (FMD) of the brachial artery was measured using high-resolution ultrasound during reactive hyperemia.
Main Results:
- LV mass index was correlated with lean body mass, diastolic blood pressure, and FMD.
- In multivariate analysis, lean body mass explained 44% of LV mass variance.
- Flow-mediated dilation (FMD) independently explained an additional 6% of LV mass variance (P <.05).
Conclusions:
- Impaired brachial artery FMD was independently associated with LV mass in elderly hypertensive subjects without LV hypertrophy.
- Body size influences LV mass, but endothelial function also plays a role.
- The role of mild hypertension as a common mechanism requires further investigation.
Background:
Increased left ventricular (LV) mass is associated with greater cardiovascular disease risk. Recent studies have also shown an association of increased LV mass with attenuated endothelium-dependent coronary flow reserve. Less is known about the association between LV mass and endothelium-dependent flow-mediated dilatation (FMD) in peripheral arteries, a noninvasive measure of endothelial function.
Methods:
Sixty-two subjects with untreated mild hypertension, aged 55 to 75 years and otherwise healthy, were examined. Resting blood pressure was obtained by the average of 4 to 5 visits, each at least 1 week apart. LV mass was determined from magnetic resonance imaging and was indexed by body surface area, height and height(2.7). Body composition was assessed with dual energy x-ray absorptiometry. FMD was measured as the percent change of brachial artery diameter during reactive hyperemia by use of high-resolution ultrasound.
Results:
Median LV mass index was 63 g/m2 (interquartile range, 58-73). In bivariate analysis, LV mass was correlated to lean body mass (r = 0.63, P <.001), diastolic blood pressure (r = 0.35, P <.01), and FMD (r = -0.27, P <.05). In multivariate analysis, 44% of the variance in log-LV mass was explained by lean body mass. An additional 6% of the variance was explained by FMD (P <.05). For each 1% point decrease in FMD, LV mass increased by 1.1%.
Conclusions:
In addition to the expected influences of body size, impairment of brachial artery FMD was independently related to LV mass in elderly subjects with mild hypertension who did not yet have LV hypertrophy. Whether mild hypertension is the common mechanism linking LV mass and endothelial function has yet to be determined.