Estimated Glomerular Filtration Rates Calculated by New and Old Equations in Children and Adolescents With Type 1 Diabetes—What to Do With the Results?

Abstract

Background: To apply and evaluate various equations for estimated glomerular filtration rates (eGFR) in a large paediatric type 1 diabetes population and compare the eGFR values with urinary creatinine clearances (UCC) in a subset of patients.Methods: Six eGFR formulae applicable for children and adolescents were used for calculation of eGFR values in 36,782 children/adolescents with type 1 diabetes. Via regression models, factors influencing eGFR values were identified. eGFR values were compared with measured UCC in 549 patients. Spearman correlation coefficients were given to assess the relation of eGFR and UCC values. Bland-Altman-Plots with corresponding linear regression were drawn to evaluate the agreement between eGFR and UCC.Results: eGFR values differed widely depending on the formula used, resulting in a percentage of pathological values <60 mL/min/1.73 m 2 up to 8%. Regression models showed age, sex, and duration of diabetes as influencing factors. Microalbuminuria was associated with significantly higher eGFR values for all formulae. In comparison of eGFR with UCC, the highest correlation coefficient was 0.33, the lowest 0.01. Bland-Altman-Plots demonstrated graphically a poor agreement between eGFR and UCC, regardless of the formula used. Conclusions: The broad range of eGFR values indicate that an ideal eGFR formula for children and adolescence with T1D is yet missing. The minimal agreement between measured UCC and eGFR values urges us to be careful in application and interpretation of eGFR values regardless of the formula used.

Creatinine-Based Formulae Poorly Match In The Classification of Hypofiltration Or Hyperfiltration In a General Population of Adolescents. A Retrospective Analysis of a Cross-Sectional Study

“…In line with former studies in healthy or T1D adolescents [13][14][15] , also in our study different pediatric formulae returned diverse mean eGFR values. Five out of six equations indicated sex differences in mean eGFR -but neither consistently regarding whether mean eGFR was higher in males or females, nor completely matching the sex differences reported by Boettcher et al for a large group of children and adolescents with T1D 15 .…”

“…In line with former studies in healthy or T1D adolescents [13][14][15] , also in our study different pediatric formulae returned diverse mean eGFR values. Five out of six equations indicated sex differences in mean eGFR -but neither consistently regarding whether mean eGFR was higher in males or females, nor completely matching the sex differences reported by Boettcher et al for a large group of children and adolescents with T1D 15 . The difference between the highest and the lowest mean eGFR in our study was similar to that reported for 12-to-17year-old US adolescents (43 mL/min/1.73 m 2 ) 14 but higher than the difference of about 16 mL/min/1.73 m 2 in males, and 20 mL/min/1.73 m 2 in females observed in 1-to-<18-year-old T1D patients 15 .…”

“…In our study, the LM equation gave the lowest eGFR among the six formulae throughout the whole range of creatinine values in both sexes, and thus the highest prevalence (>40%) of subjects with hypofiltration (eGFR <75 mL/min/1.73 m 2 ), followed by the Sch-L formula. This is in line with data on 1-to-<18-year-old males with T1D; while in females the Sch-L formula gave lower means compared with the LM equation 15 . As in the study of Boettcher et al 15 , the introduction of lean body mass component into the LM equation returned higher mean eGFR compared with the LM equation.…”

“…Currently, several equations derived from pediatric patients with renal disease or a general population of healthy subjects are available but none of them ideally reflects measured GFR 4,5 . Studies in the general population of children and adolescents, and pediatric patients with type 1 diabetes (T1D) comprehensively documented the disparities and errors between measured and estimated GFR and showed that different equations to estimate GFR return values in a broad range [13][14][15][16] . However, it remains unclear whether different formulae consistently categorize adolescents into the lower and upper tail of eGFR distribution.…”

Assessment of renal impairment using estimated glomerular filtration rate among type 2 diabetes mellitus patients in North-East Ethiopia: a cross-sectional study

“…Using serum creatinine alone is unreliable because its level is dependent on a number of factors that have nothing to do with a patient’s renal function. Instead an estimated glomerular filtration rate (eGFR) derived from prediction equations has been suggested as an important measure for assessing renal function [ 22 , 23 ].…”