Impact of body mass index on urinary solutes in Egyptian adolescents

Background High body mass index constitutes a risk for nephrolithiasis in the context of metabolic syndrome. The majority of these renal stones are either composed of Urate or Calcium Oxalate. We aimed to evaluate the ratios of urinary Calcium and Uric Acid to urinary Creatinine as an early alarming pathological sign in overweight and obese adolescents. Ninety adolescents of both sexes participated in the study. Anthropometric measures were fulfilled, and calculation of body mass index and waist to height ratio were assessed. Urinary Calcium and urinary Uric Acid to Creatinine ratios were estimated in an early morning spot urine sample. Results Males and females had comparable values for solutes/Creatinine ratios. A highly significant negative correlation was detected between urinary Urate/Creatinine ratio and age of the child ( P -value 0.001). Adolescents with higher body mass index had higher urinary Calcium/Creatinine and higher urinary Urate/Creatinine ratios but P-values were insignificant in our research. Conclusion At the age range of 10 to 18 years, the sex of the adolescent has an equivocal effect on urinary concentration of both Calcium and Uric Acid. Urinary solutes/Creatinine ratio decrease significantly by age in adolescence. Overweight and obesity tend to be risk factors for higher urinary solutes ‘concentration.