Prevalence and Determinants of Left Ventricular Geometric and Functional Abnormalities in Asymptomatic Hypertensive Adults at a Tertiary Hospital, South-Southern Nigeria

摘要

BACKGROUND: Hypertensive left ventricular hypertrophy (LVH) is a predictor of cardiovascular morbidity and mortality. Left ventricular geometric pattern further increases the cardiovascular disease burden among hypertensives. The aim of this study was to determine the prevalence, determinants, pattern of left ventricular geometry, and left ventricular (LV) functional status of hypertensives, pre-hypertensive, and normotensive Nigerians. METHOD: A cross-sectional comparative study conducted at the University of Port Harcourt Teaching Hospital, Rivers state, Nigeria. Clinical and trans-thoracic echocardiography was performed among recruited patients with normal blood pressure, pre-hypertension, and newly-diagnosed hypertension. Two socioeconomic indicators (education and occupation) were employed to estimate the effect of socioeconomic status (SES) on LV structure and geometry. RESULTS: A total of 218 subjects were studied, 121 newly-diagnosed hypertensives, 60 pre-hypertensives, and 37 normotensives. The mean age of the hypertensive patients was 51.32±13.1 years, the pre-hypertensives was 50.25±13.0 years, while the normotensives was 47.76±12.0 years. This study showed that individuals within the lower SES had higher blood pressure (BP) levels. Lower educational class was inversely associated with the presence of LVH and LV remodeling. This study also found that central obesity was more prevalent among the lower social classes than among the upper and middle class (p=0.020). Subjects with pre-hypertension had higher values of most echocardiographic parameters than those with normotension. The prevalence of concentric remodeling, eccentric hypertrophy and concentric hypertrophy were 28.8%, 5.85, and 34.6% in the pre-hypertension group, and 16.9%, 14.6%, and 65.2% in the hypertension group. Logistic regression analysis showed that only diastolic blood pressure (DBP) was an independent risk factor for concentric remodeling, concentric hypertrophy, and eccentric hypertrophy (OR=0.257, p=0.006). This study also showed that impaired LV diastolic dysfunction occurred earlier than systolic dysfunction with an associated greater atrial contribution to LV filling. CONCLUSION: In countries undergoing epidemiological transition, effects of socioeconomic status on blood pressure and other cardiovascular risk factor may require more than a casual assessment. Left ventricular geometrical changes exist in adults with pre-hypertension and hypertension in South-Southern Nigeria and may be influenced by social stratification. The geometric changes are strongest among the lower social classes and may be due to higher BP levels. There is a need to develop and test appropriate social interventions to correct social inequalities among the populations to reduce the impact of social factors on cardiovascular health.