Echocardiographic Assessment of the Left Ventricle in Young Prehypertensive Nigerians

Abstract

Background: Prehypertension is associated with an increased risk of cardiovascular morbidity and mortality. This risk could partly be explained by the early compromise in left ventricular (LV) structure and function. This study investigated the LV geometry and function in young black prehypertensive subjects. Methods and results: This cross-sectional descriptive study was conducted at the Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria. Echocardiography-derived LV geometry and function were assessed using standardized methods. Prehypertensive subjects had higher mean systolic blood pressure (BP) (130.78 ± 3.57 mmHg vs 111.42 ± 3.54 mmHg, P <0.001), diastolic BP (79.32 ± 4.13 mmHg vs 66.39 ± 4.42 mmHg, P <0.001), body mass index (BMI) (26.24 ± 3.45 kg/m 2 vs 22.20 ± 2.21 kg/m 2 , P <0.001), waist circumference (WC) (86.93 ± 8.73 cm vs 76.73 ± 6.66 cm, P <0.001), fasting blood glucose (FBG) (93.84 ± 7.28 mg/dl vs 90.08 ± 6.26 mg/dl, P <0.001), and dyslipidemia (21.5% vs 6%. P <0.001) compared to normotensive subjects. LV mass index (LVMI) was greater in prehypertensive subjects compared to normotensive subjects {male (106.84 ± 12.34 g/m 2 vs 76.07 ± 10.25 g/m 2 , P <0.001); female (92.06 ± 8.80 g/m 2 vs 66.53 ± 7.21 g/m 2 , P <0.001)}, with abnormal LV geometry recorded in 17.5%. Linear regression analysis showed that waist circumference, systolic BP, serum creatinine level, and urea level were determinants of LVMI. The prevalence of LV diastolic dysfunction was higher in prehypertensive subjects than in normotensive subjects (14.5% vs. 0.5%, P <0.001), with systolic BP {odds ratio (OR) 0.928, confidence interval (CI) 0.834 - 0.969; P =0.016)} and diastolic BP (OR 0.832, CI 0.722 - 0.958; P =0.011) being independent predictors. Conclusion: This study showed that prehypertension in young Black subjects was associated with altered LV geometry and impaired diastolic function, and these changes demonstrated linear progression with increasing systolic BP.