Higher 24-hour urinary sodium was associated with a 3.14 mm Hg higher systolic and 0.14 mm Hg higher diastolic blood pressure per 100 mmol increase after adjustment for body mass index.
Observational
Yes
Does body mass index modify the association of urinary sodium and potassium with blood pressure?
BMI partially confounds the relationship between sodium intake and blood pressure, but a significant independent association between sodium, potassium, and blood pressure persists regardless of BMI.
Mean Difference: 3.14
This report further examines the relation of body mass index (BMI) to associations of 24-hour urinary sodium, potassium, and sodium-potassium ratio with blood pressure in INTERSALT, a 52-center international study of electrolytes and blood pressure. Analyses without adjustment for BMI indicated average systolic pressure greater by 6.00 mm Hg per 100 mmol higher sodium and diastolic by 2.52 mm Hg. With adjustment for BMI, these values were reduced to 3.14 and 0.14 mm Hg, respectively. For the sodium-potassium ratio, blood pressure associations were stronger when not adjusted for BMI, and for potassium, adjustment generally had little effect. To explore possible interactions of these variables with BMI in relation to blood pressure, the 52 centers were divided into two groups of 26 based on whether the center median for BMI was less than or greater than or equal to 24.5 kg/m2, and individuals within each of the 52 centers were classified into lower- or higher-BMI groups based on individual BMI less than or greater than or equal to 24.1 kg/m2. Sodium and the sodium-potassium ratio were positively and significantly and potassium inversely and significantly related to systolic pressure in all four of these subgroups, and the sodium-potassium ratio and potassium were related to diastolic pressure in two and three subgroups, respectively. Electrolyte-blood pressure associations did not differ significantly between the two subgroups of centers or between the two subgroups based on individuals.(ABSTRACT TRUNCATED AT 250 WORDS)
Dyer et al. (Wed,) conducted a observational in Blood pressure. 24-hour urinary sodium, potassium, and sodium-potassium ratio was evaluated on Systolic and diastolic blood pressure (MD 3.14 mm Hg (systolic) and 0.14 mm Hg (diastolic) per 100 mmol higher sodium). Higher 24-hour urinary sodium was associated with a 3.14 mm Hg higher systolic and 0.14 mm Hg higher diastolic blood pressure per 100 mmol increase after adjustment for body mass index.