Reference serum creatinine levels determined by an enzymatic method in Japanese children: relationship to body length

Abstract

There have been no previous reports of the determination of reference serum Cr levels by enzymatic methods in Japanese children. Our formula will be applicable for screening of renal function in Japanese children.

Reference serum cystatin C levels in Japanese children

“…Factors such as renal transplantation, glucocorticoid use, and malignancy may affect serum cysC concentration independently of GFR [2][3][4][5][6]. Nevertheless, cysC concentration is regarded as more accurate than SCr levels for determining kidney function, because SCr level has shown a significant positive correlation with body length in children [1] and because low SCr concentrations have been reported in selected populations of children with low muscle mass. In contrast, cysC concentration was found not to vary by age, height, or sex [7][8][9].…”

“…CysC is produced at a constant rate in the body, freely filtered by the glomerulus, not secreted or reabsorbed by kidney tubules, and excreted only by the kidneys. We previously found a significant positive correlation between serum creatinine (SCr) concentration and body length in children aged 1-12 years, with body length (m) 9 0.30 yielding a value similar to reference SCr level [1]. Thus, normal SCr value is limited as a tool for estimating GFR in that it gradually increases with body length.…”

Measurements of serum cystatin C concentrations underestimate renal dysfunction in pediatric patients with chronic kidney disease

“…We previously observed a significant positive correlation between serum creatinine (Cr) concentration and body length in children aged 1-12 years, with body length (m) 9 0.30 yielding a value similar to the reference serum Cr concentration [1]. An equation for estimated GFR (eGFR) has been used to assess the relationships among body length, glomerular filtration rate (GFR), and serum Cr concentration, using the equation eGFR (ml/min/1.73 m 2 ) = j 9 body length (cm)/serum Cr value (mg/dl) [2], where the constant j was assumed to be unvaried in children aged 2-12 years.…”

“…We utilized two equations for eGFR [1][2][3][4]. In children aged 1-12 years, body length (m) 9 0.30 yielded a value similar to the reference serum Cr concentration measured enzymatically [1].…”

“…In children aged 1-12 years, body length (m) 9 0.30 yielded a value similar to the reference serum Cr concentration measured enzymatically [1]. Since the reciprocal of serum Cr correlated with GFR [2, 5, 6], we utilized an equation for eGFR derived from serum Cr Cr -GFR (%Þ ¼ ½0:30  body length (m)=serum Cr  100:…”