Reference Values for Plasma Electrolytes and Urea in Nigerian Children and Adolescents Residing in Abeokuta and its Environs

Abstract

Reference values for plasma electrolytes and urea have been defined for Nigerian children and adolescents residing in Abeokuta and its environs, a location in southern Nigeria, by estimating plasma sodium, potassium bicarbonate and urea concentrations in a reference population.
The study group comprised three hundred and eighteen [318] healthy children aged 1-12 years, randomly selected from the crèche and primary schools, and two hundred and thirty seven [237] healthy adolescents aged 13-19years, also randomly selected from secondary schools and tertiary educational institutions. The adolescents group had 125 males and 112 females.
Plasma sodium and potassium levels were measured by standard flame photometry, bicarbonate level was measured by Van Slyke titration method and urea estimation was by Berthelot reaction. Statistical analysis of acquired reference values was in accordance with the IFCC recommendations.
The mean values and reference intervals in mmoI/L, of the measured parameters in children [total study group] are as follows: sodium 130±5.5, 119-141; potassium 3.7 ± 0.6, 2.5-4.9; bicarbonate 23 ±2.0, 19-27; urea 4.5 ±1.2, 2.2-6.8. The corresponding values in adolescents [total study group] are as follows: sodium 131 ± 4.8, 122-140; potassium 3.7±0.6; 2.5-4-9; bicarbonate 23±2.0, 19-27; urea 4.7±1.2, 2.4-7.0. The mean plasma sodium and urea levels are significantly higher in adolescents than in children [p<0.05 and p0.001 respectively]. The mean plasma potassium and urea values are significantly higher in male children than in females [p<0.001 and p<0.05 respectively] and also in male adolescents than in females [p<0.001 and p<0.001 respectively].
The reference values reported in this study are generally lower than those reported in Caucasian, and also differ in some respect from findings in earlier studies conducted at different locations in Nigeria. The difference could be due to dietary, geographical and other environmental factors that are known to influence the plasma concentration of the measured parameters.


NQJHM Vol. 14 (1) 2004: pp. 26-30