Low vegetable consumption doubles the odds of stroke among people with hypertension: Findings from the SIREN Study in West Africa.

BACKGROUND

While hypertension is a primary risk factor for higher stroke risk, adequate vegetable consumption has been linked with a lower odds of stroke. However, it is unclear whether low/inadequate vegetable consumption could aggravate the odds of stroke among people with hypertension. This study assessed the interaction of low vegetable consumption and hypertension with stroke among West Africans.

METHODS

In this case-control study, 3684 stroke cases (aged ⩾ 18 years) matched for age ±5 years, sex, and ethnicity, with 3684 healthy controls were recruited across multiple sites in Nigeria and Ghana. Hypertension was defined using standard guidelines, and vegetable consumption was assessed with a food frequency questionnaire. Multivariable-adjusted conditional logistic regression and interaction models were used to estimate the odds ratios (OR) with a 95% confidence interval (CI) of stroke and the synergistic interaction of both low vegetable consumption (< 6 servings per week) and hypertension. The attributable proportion (AP), relative excess risk due to interaction (RERI), and synergy index (SI) were estimated at a two-sided P < 0.05.

RESULTS

Overall, the mean age was 59.0 ± 14.9 years, and 45.8% (3376) were female. Among stroke cases, the prevalence of low vegetable consumption and hypertension was 68.1% (2508) and 95.9% (3480), respectively. The multivariable-adjusted odds of stroke, given low vegetable consumption with hypertension, were OR = 25.66 (95% CI = 16.65, 39.54) with an RERI of 13.40 (95% CI = 7.21, 19.59), AP of 0.52 (95% CI = 0.44, 0.60), SI of 2.19 (95% CI = 1.82, 2.63), and a multiplicative interaction of about 50%; 1.51 (95% CI = 0.91, 2.49).

CONCLUSION

The odds of stroke double with low vegetable consumption among people with hypertension in this population.