Dietary assessment and prevention of hypertension in Nigeria

Background: This PhD developed validated, culturally-appropriate dietary screening tools for hypertension for clinicians to assess dietary intake and offer personalised dietary advice to patients to improve hypertension prevention and long-term cardiovascular health in Nigeria.
Methods: The PhD used a mixed-method design with quantitative and qualitative assessment strategies to evaluate epidemiological and clinical evidence and patients’ and healthcare professionals’ feedback on the dietary screening tools.
Findings: Study one found that a high intake of salt, red meat, dietary fats, junk foods, and alcohol was associated with increased odds of hypertension by 17-76%, whereas a high fruit and vegetable intake reduced the odds of hypertension by 20% in West Africa. This evidence supported the development of the Nigerian dietary screening tool (NiDST). In study two, most (≥ 94%) patients and healthcare professionals reported clarity, ease of use, culturally-appropriate, and relevance of the (NiDST) with high adherence (88%), short completion time (< 8 minutes) and promising feasibility of integration in clinical practice (>83%). In addition, the NiDST demonstrated good agreement with 24-hour dietary recall, confirming its validity and reliability. Building on this, study three simplified the NiDST to create the Nigerian diet risk score (NiDRS). Each unit increase in the NiDRS was associated with a 2-fold increase in the odds of hypertension (OR: 2.04, 95%CI: 1.16, 3.58, p=0.013). Moreover, the NiDRS demonstrated a strong predictive accuracy (AUC) of 92% in correctly identifying individuals at high risk of hypertension. In addition, atherogenic lipids, c-reactive protein, and homocysteine mediated the relationship between the NiDRS and mean arterial blood pressure by 47-71%. Collectively, these refined tools have a high adherence rate (92%), short completion time (< 5 minutes) and improved patient-clinician engagement and communication on dietary discussion, as affirmed by all patients and clinicians in study four.
Conclusion: This PhD delivers the 25-item NiDST and 11-item NiDRS for hypertension, to quickly identify individuals at risk of hypertension. Along with dietary counselling and behavioural changes, these tools have the potential to improve poor dietary habits, reduce hypertension prevalence, and improve overall cardiovascular health in Nigeria.