Figure 2.

Normograms of 24-hour urinary creatinine excretion (μmol/kg/24 hours). A) Men and B) Women. The dashed lines represent centiles curves of the 24-hour urinary creatinine excretion, according to age and sex, estimated for a BMI of 25 kg/m². Horizontal lines show the current reference values of 177 to 221 μmol/kg/24 hours in men and 133 to 177 μmol/kg/24 hours in women. BMI: body mass index; to convert creatinine from μmol to mg, divide by 8.84. C) Correction of centiles obtained in normograms A and B, according to BMI. Application example: estimating the percentile represented by a 24-hour urinary creatinine excretion of 200 μmol/kg/24 hours in a 40-year old man with BMI 35 kg/m²: in A, the intersection of age 40 years (on X axis) and urine creatinine 200 μmol/kg/24 hours (on Y axis) corresponds to the 50th percentile. In C, the intersection of BMI 35 kg/m² (on X axis) and the percentile 50 obtained from A (on Y axis) gives a percentile corrected for BMI of 75 (upper dashed line).