Millen A.M.E., Libhaber C.D., Majane O.H.I., Libhaber E., Maseko M.J., Woodiwiss A.J., Norton G.R.
Cardiovascular Pathophysiology and Genomics Research Unit, School of Physiology, University of the Witwatersrand Medical School, 7 York Road, Parktown, Johannesburg, South Africa; Department of Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
Millen, A.M.E., Cardiovascular Pathophysiology and Genomics Research Unit, School of Physiology, University of the Witwatersrand Medical School, 7 York Road, Parktown, Johannesburg, South Africa; Libhaber, C.D., Department of Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Majane, O.H.I., Cardiovascular Pathophysiology and Genomics Research Unit, School of Physiology, University of the Witwatersrand Medical School, 7 York Road, Parktown, Johannesburg, South Africa; Libhaber, E., Department of Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Maseko, M.J., Cardiovascular Pathophysiology and Genomics Research Unit, School of Physiology, University of the Witwatersrand Medical School, 7 York Road, Parktown, Johannesburg, South Africa; Woodiwiss, A.J., Cardiovascular Pathophysiology and Genomics Research Unit, School of Physiology, University of the Witwatersrand Medical School, 7 York Road, Parktown, Johannesburg, South Africa; Norton, G.R., Cardiovascular Pathophysiology and Genomics Research Unit, School of Physiology, University of the Witwatersrand Medical School, 7 York Road, Parktown, Johannesburg, South Africa
Aim: To determine whether blood pressure (BP) or an excess adiposity, both frequently observed comorbidities that independently relate to left ventricular diastolic dysfunction (LVDD), have a greater impact on LVDD at a community level. Methods: We assessed the relative independent impact of an excess adiposity versus BP on indices of LVDD as determined from the ratios of early-to-late transmitral blood flow velocity (E/A) and E/the mean of lateral and septal wall myocardial tissue lengthening at the level of the mitral annulus (e'; (E/e') in 417 randomly recruited participants of a community-based study with a high prevalence of excess adiposity (43% obese and 25% morbidly obese). Results: In multivariate adjusted models, including adjustments for appropriate BP values (SBP for E/e' and DBP for E/A), waist circumference was independently associated with E/A (partial r = -0.12, P < 0.02) and E/e' (partial r = 0.15, P < 0.005). In contrast, BMI was independently associated with E/e' (partial r = 0.11, P < 0.05), but not E/A (partial r = -0.09, P = 0.08). In multivariate models, SBP had a greater impact on E/e' (standardized β-coefficient = 0.32 ± 0.05, P < 0.0001) than did waist circumference (standardized β-coefficient = 0.16-0.05, P < 0.005; P < 0.05 for comparison), whereas DBP had a similar impact on E/A (standardized β-coefficient = -0.10 ± 0.03, P < 0.005) as did waist circumference (standardized β-coefficient = -0.10 ± 0.04, P < 0.05). Importantly, whereas SBP was the main factor independently associated with an increased E/e' (≥10) (P < 0.0005), waist circumference was not independently associated with either a decreased E/A (≤0.75) (P = 0.82) or an increased E/e' (≥10; P = 0.15). Conclusion: In a community sample with a high prevalence of excess adiposity, BP exceeds obesity as the most important modifiable risk factor for LVDD. These data suggest that in communities with a high prevalence of obesity, if weight loss programmes fail to produce sustainable target body weights, rigorous BP management to lower than normal thresholds may be sufficient to prevent LVDD. Copyright © Lippincott Williams & Wilkins.