Ethnic and Sex Differences in Salt Sensitivity amongst Normotensive Young Adult Nigerians: Implications for Hypertension Prevention

Abstract

BACKGROUND: High dietary salt intake is a well-established modifiable risk factor for hypertension and cardiovascular disease. Salt sensitivity - a blood pressure (BP) phenotype defined by exaggerated BP response to salt loading, remains underrecognised in normotensive populations despite its strong link to adverse cardiovascular outcomes. The burden and determinants of salt sensitivity amongst young Nigerians remain poorly understood. AIMS: This study aimed to identify demographic and behavioural risk factors associated with salt sensitivity, explore potential ethnic and sex-related differences and determine the independent predictors of salt-sensitive (SS) BP response amongst normotensive young adult Nigerians. SUBJECTS AND METHODS: An interviewer-administered questionnaire was used to collect demographic and behavioural data. Participants underwent a 5-day salt-loading protocol. BP, serum and urinary electrolytes were assessed before and after salt-loading. Data were analysed using appropriate statistical tools and P values set at P < 0.05. RESULTS: Among the participants, 24% were SS. The prevalence of salt sensitivity was higher in Igbos (47.8%) compared to Yorubas (20.5%). SS individuals had significantly lower baseline systolic, diastolic and MA P values and reduced urinary sodium concentrations pre-salt loading, particularly among females. There were no statistically significant associations between salt sensitivity and body mass index, sleep duration or residential location ( P > 0.05). CONCLUSIONS: Salt sensitivity is common amongst normotensive young adult Nigerians, with clear ethnic and sex-related differences. The observed subclinical BP alterations and reduced sodium excretion suggest early renal or vascular dysregulation in SS individuals. These findings underscore the need for early identification and targeted prevention strategies to reduce future hypertension risk in this population.