Dietary Modification for Blood Pressure Control in Hypertension Patients in Bindura District, Zimbabwe

Abstract

About a third of the hypertensive patients reviewed at Shashi Hospital in 2019 had uncontrolled hypertension, prompting an investigation of the dietary modifications associated with this observation. The dietary components of interest in this study were the DASH diet plan, alcohol, salt and coffee consumption using the Health Belief Model as a theoretical framework. This was a retrospective 1:1 case-control study on 270 consenting adult respondents randomly selected from eligible hypertensive patients on treatment being attended at the Hospital. A structured interviewer administered questionnaire based on the World Health Organisation STEPS survey was employed to gather information from the respondents after Blood Pressure and anthropometric measurements were taken. Uncontrolled hypertension was more common in males than in females [OR 1.3, 95% CI 0.8; 2.1, p-value 0.38] and in those below 60 years of age who comprised 69.6% of the cases [OR 2.0, 95% CI 1.2; 3.2, p-value 0.009]. Earning a salary below the Poverty datum line was associated with increased odds of uncontrolled hypertension [OR 3.4, 95% CI 1.5; 7.9, p-value 0.003]. Although attaining basic education and being formally employed raised odds of uncontrolled hypertension this was not statistically significant [OR 1.4, 95% CI 0.9; 2.4, p-value 0.17 and OR 1.08, 95% CI 0.7; 1.8, p-value 0.75 respectively]. Those who were not on a prescribed diet for hypertension had four times the odds of having uncontrolled hypertension than those who were on diet control [OR 4.1, 95% CI 2.5; 6.9, p-value <0.001]. Having a BMI above 30kg/m2 raised the odds of uncontrolled hypertension by more than 4 times [AOR 4.4, 95% CI 2.3; 8.3, p-value <0.001]. Those who did not have fruits or vegetables as part of their diet had higher odds of uncontrolled hypertension than those who did [OR 3.2, 95% CI 1.6; 6.4, and p-value < 0.001 and OR 1.3, 95% CI 0.3; 4.8, p-value 0.74 respectively]. Both High salt intake and Consuming fast-foods were significantly associated with higher odds of uncontrolled hypertension [OR 3.2, 95% CI 1.8; 5, 6, p-value < 0.001 and OR 2.6, 95% CI 1.5; 4.58, p-value < 0.001 respectively]. Consumption of coffee and alcohol slightly raised odds of uncontrolled BP although this was not statistically significant [OR 1.5, 95% CI 0.8; 2.9, p-value 0.23 and OR 1.9, 95% CI 0.9; 4.0, p-value 0.07 respectively]. After logistic regression the risk factors independently associated with uncontrolled hypertension were Not having fruits as part of the diet [AOR 2.6, 95% CI 1.1; 5.9, p-value 0.03], High salt intake [AOR 2.0, 95% CI 1.1; 4, p-value 0.03] and Consuming fast-foods [AOR 2.4, 95% 1.2; 4.5, p-value 0.01]. The study shows that there is a challenge of uncontrolled hypertension in the population under study. Interventions recommended include prescribing diet modification as part of standard clinical practise, ensuring the healthy diet is assessable and affordable and measure to ensure healthy eating practices in the populations. These interventions are multidimensional with activities at the individual, health delivery system and policy levels to ensure adherence to diet modification.