Evaluating modifiable hypertension risk in Nigerian adults-The Nigerian diet risk score

Abstract

Aims: Our study aimed to derive and validate a diet risk score for clinical use in Nigeria to screen for hypertension risk and evaluate its association against a panel of cardiovascular biomarkers.

Methods: The Nigerian dietary screening tool was used to collect dietary intake data from 151 participants visiting the River State University Teaching Hospital, Port Harcourt, Nigeria, for routine medical care. Blood samples were collected from a subsample (n = 94) for biomarker assessment. Multiple logistic regression was used to derive the Nigerian diet risk score for hypertension. Internal validation of the Nigerian diet risk score for hypertension was performed using measures of discrimination and calibration. Mediation analysis was used to evaluate the biomarker-mediated effects of the diet risk score for hypertension on hypertension. All statistical analyses were performed in R.

Results: Each one-point increment in Nigerian diet risk score (on a scale of 0 to 30) was associated with a twofold increase in odds of hypertension (odds ratio: 2.04, 95% confidence interval [CI]: 1.16, 3.58, p = 0.01), with the highest score associated with >18-fold increased odds of hypertension, compared to lowest Nigerian diet risk score for hypertension. The score demonstrated good discrimination (area under the curve: 0.92, 95% CI: 0.80, 1.00) with a high sensitivity (0.85) and specificity (0.94). Additionally, mediation analysis suggested that the association between Nigerian diet risk score for hypertension and blood pressure is partly explained by shared biological pathways that mediate cholesterol, triglycerides, LDL-C, CRP and homocysteine levels.

Conclusion: The resulting Nigerian diet risk score for hypertension is a valuable tool for clinicians to identify individuals at risk of hypertension, and will advance community efforts in the prevention and management of hypertension in Nigeria.

Keywords: biomarkers; clinical practice; diet risk score; hypertension; mediation analysis.

FIGURE 1

Participant selection flowchart through completion of the FFQ (the Nigerian dietary screening tool; NiDST) and biomarkers estimation. CRP, C‐reactive protein; NiDRS, Nigerian diet risk score; HCY, homocysteine, blood lipids (such as triglyceride, total cholesterol, low‐density lipoprotein, high‐density lipoproteins, very low‐density lipoprotein) and electrolytes (such as sodium, potassium, calcium, and magnesium).

FIGURE 2

Food group intake among adults with and without hypertension in Nigeria. Radar plot showcasing the skewed dietary intake patterns of hypertensive individuals (red) towards foods commonly considered unhealthy (black), compared to non‐hypertensive (green) individuals with a more balanced diet of healthy (white) and unhealthy (black) foods.

FIGURE 3

A comparison of foods and their weights in the NiDRS and INTERHEART score. The Nigerian dietary risk score (NiDRS) considered 11 food groups (light grey), which are all positively associated with hypertension, while INTERHEART considers five primary food groups (black), which include negatively and positively associated foods.

FIGURE 4

Receiver‐operating characteristic curves for the Nigerian dietary risk score (NiDRS) in the validation data set. (a) risk score; (b) risk score category; AUC, area under curve.

FIGURE 5

Decision curve analysis of NiDRS for prediction of hypertension risk. Green line represents the strategy of no dietary screening with the Nigerian diet risk score (NiDRS). Red line represents the strategy of screening all patients with NiDRS. Blue line represents the strategy of using the NiDRS multivariable prediction model.

FIGURE 6

Path diagram of the mediation linear regression model. Path a: direct effects of Nigerian diet risk score (NiDRS) on biomarkers; Path b: direct effect of biomarkers on mean arterial pressure (MAP); Path c: direct effects of NiDRS on MAP.