Relation of Age to Left Ventricular Structure, Function, and Systemic Hemodynamics in Normotensive and Hypertensive Employed Adults.
Academic Article
Overview
abstract
To determine the effect of age on left ventricular status and systemic hemodynamics, we evaluated by echocardiogram older (age at or above 60 years, n equals 148) and younger (age is less than 60 years, n equals 472) employed adults. Using World Health Organization criteria, the population was divided into the following blood pressure strata: normotensive (n equals 142), borderline hypertensive (n equals 194), and sustained hypertensive (n equals 284). Older subjects were compared to younger subjects in each blood pressure stratum. Older subjects with borderline hypertension and sustained hypertension had a higher systolic blood pressure and wider pulse pressure than younger individuals. Older subjects with borderline hypertension had higher left ventricular mass index (106.7Â+/-28.7 vs 93.9Â+/-22.4, P equals 0.03), and greater wall thicknesses and relative wall thicknesses than younger subjects. Older borderline hypertensive patients had greater left ventricular wall thicknesses and mass, but closely resembled both age groups of sustained hypertensive patients in this regard. Older and younger individuals with borderline hypertension had similar mean cardiac outputs, stroke volumes, and peripheral resistances. In contrast, older patients with sustained hypertension had a lower stroke volume, stroke volume index, cardiac output, cardiac index, and fractional shortening, and a higher total peripheral resistance than their younger counterparts. There were no significant relations between age and any echocardiographic measurement in normotensive subjects. Borderline hypertensive individuals exhibited weak relationships between age and left ventricular wall thicknesses (r equals 0.17; 23) and left ventricular internal dimensions (r equals -0.19 and -0.21). Very weak negative relationships were identified between age and cardiac output for both hypertensive groups. In conclusion, increasing age had relatively little effect on cardiac status in either normotensive or sustained hypertensive employed adults, but was associated with greater left ventricular hypertrophy among individuals with borderline hypertension according to the World Health Organization classification. These results are consistent with the independent value of age and left ventricular mass as predictors of hypertensive complications, but also suggest that under some circumstances, greater age or longer exposure to hypertension may magnify the target-organ effects at a given degree of blood pressure elevation.
