Relationships between blood pressure and urinary sodium, potassium, calcium and magnesium in Bantu of Zaire.

: The relationships between blood pressure and 24-h urinary sodium, potassium, calcium and magnesium were investigated in adult men and women constituting a random sample of urban Bantu of Zaire. Blood pressure and the 24-h urinary sodium, potassium, calcium and magnesium averaged 124 +/- 20/72 +/- 14 mmHg, 87 +/- 51 mmol, 33 +/- 19 mmol, 828 +/- 91 mumol and 1.9 +/- 1.6 mmol, respectively. After adjusting for sex, age, body weight and pulse rate, systolic pressure was significantly and positively correlated with urinary sodium in all subjects and in women taken separately; it was also negatively correlated with urinary potassium, while diastolic pressure was weakly associated with urinary calcium. When instead of the 24-h urinary sodium and potassium the sodium: potassium ratio was considered as an independent variable in multiple regression analysis, it was correlated with both systolic and diastolic pressure. Our results indicate that age, body weight, pulse rate, sex and the sodium: potassium ratio contribute to the prediction of systolic and diastolic blood pressure, while urinary calcium was only associated with diastolic pressure.