Dietary patterns associated with hypertension among stroke-free indigenous Africans: insights from the Stroke Investigative Research and Educational Network study

Abstract

Background: The dietary factors associated with the high burden of hypertension among indigenous Africans remain poorly understood. We assessed the relationship between dietary patterns and hypertension among indigenous Africans.

Method: In this study, 1550 participants with hypertension matched (for age: ± 5 years, sex and ethnicity) with 1550 participants without hypertension were identified from the stroke-free population in the Stroke Investigative Research and Educational Network study in Ghana and Nigeria. Food consumption was assessed using a food frequency questionnaire, and dietary information was summarized using principal component analysis to identify seven dietary patterns. Conditional logistic regression was applied to compute the odds ratio (OR) and 95% confidence interval (CI) for the risk of hypertension by tertiles of dietary patterns adjusting for age, education, income, smoking, alcohol use, physical inactivity, family history of cardiovascular diseases, obesity and salt intake at a two-sided P less than 0.05.

Results: Multivariable-adjusted OR [95% confidence interval (CI)] for risk of hypertension by second and third tertiles [using the lowest (first) tertile as reference] of dietary patterns were 0.62 (0.48-0.80), 0.70 (0.54-0.90) for whole grains and fruit drinks; 0.87 (0.68-1.12), 0.83 (0.64-1.08) for fruits; 0.85 (0.65-1.10), 0.97 (0.75-1.26) for vegetables, legumes and potatoes; 0.78 (0.60-1.00), 0.84 (0.65-1.08) for fried foods and sweetened drinks; 1.13 (0.88-1.45), 0.80 (0.62-1.03) for poultry product and organ meat; 1.11 (0.86-1.43), 0.88 (0.68-1.14) for red meat; and 1.14 (0.88-1.48), 1.09 (0.84-1.43) for processed foods ( P < 0.05).

Conclusion: A higher adherence to dietary consumption of whole grains and fruits was inversely associated with low odds of hypertension in this population.

Figure 1:

Adjusted odds ratio and 95% confidence interval of hypertension by tertile distribution of each dietary pattern in a conditional logistic regression model among sstroke-free controls in the SIREN study The first tertile in each dietary pattern represented the lowest level of adherence and was used as a reference for the second and third tertiles. The model was adjusted for age (years, continuous), highest education completed (none/primary vs secondary), monthly income (<$100 vs $100), ever smoked (no vs yes), current alcohol use (no vs yes), physical inactivity (no vs yes), family history of cardiovascular diseases (no vs yes), BMI (< 25kg/m² vs ≥25kg/m²) and salt intake (no vs yes).

Figure 2:

Restricted cubic splines for the association between factor scores of whole grain and fruit drinks patterns and the odds of hypertension among participants. Green lines denote the odds ratio (OR), and grey shades represent the 95% confidence intervals. Knots were positioned at the 5th (as reference), 25th, 50th, and 75th percentiles of the factor scores of the whole grain patterns. The model was adjusted for age (years, continuous), highest education completed (none/primary vs secondary), monthly income (<$100 vs $100), ever smoked (no vs yes), current alcohol use (no vs yes), physical inactivity (no vs yes), family history of cardiovascular diseases (no vs yes), BMI (< 25kg/m² vs ≥25kg/m²) and salt intake (no vs yes).