The association between sodium and potassium on differences in renin and aldosterone levels among ghanaian populations in rural ghana, urban ghana and amsterdam

Objective: To identify if differences in dietary, and serum, sodium and potassium levels are associated with differences in aldosterone, renin and the aldosterone-renin ratio. Secondly, to assess the contribution of confounders, and site-specific factors. Design and method: A multi-site analytical cross-sectional study using baseline data from the RODAM (Research on Obesity and Diabetes among African Migrants). Adult Ghanaians (aged over 25 years) were recruited across rural Ghana, urban Ghana and Amsterdam, the Netherlands. Both food questionnaires and renin and aldosterone measurements occurred in a subset of the baseline RODAM population: rural Ghana (n=193), urban Ghana (n=199) and Amsterdam (n= 69). Dietary behaviour was collected by a RODAM-specific Food Propensity Questionnaire (FPQ) which assessed the usual intake of 134 food items over the preceding 12 months. Three outcomes were investigated: aldosterone (pg/mL), renin (pg/mL) and the ARR, aldosterone-renin ratio (pg/mL/pg/mL). Results: Sodium intake was highest in urban Ghana (2.9g/day) and Amsterdam (2.8g/day), followed by rural Ghana (2.5g/day). Potassium intake was highest in rural Ghana (4.8g/day) and Amsterdam (4.7g/day), followed by urban Ghana (3.9g/day). Sites had similar renin levels; however, differences in aldosterone, led to a median ARR of 13.2, 12.2 and 22.0 pg/mL/pg/mL in rural, urban Ghana and Amsterdam respectively. Generalised linear models both with and without covariates, revealed no significant associations between dietary or serum sodium and potassium levels with either aldosterone, renin nor ARR. Associations were more pronounced in subgroup analyses among participants not taking blood pressure medication, although they remained weak or non-significant. Conclusions: Unlike previous research, no clear association between salt and hormone levels was found. However, bias from missingness, a possible healthy volunteer effect and medication use may have masked results. The findings may suggest that increased medication usage could benefit these populations in reducing blood pressure-related issues. These findings encourage the development of further longitudinal and intervention studies in people of African descent, to investigate the interaction of specific medications on dietary intake and renin, aldosterone levels.