The rise in serum creatinine shortly after kidney donation is correlated with skeletal muscle mass as measured by CT image analysis
L.C. van Laar, A. Nurmohamed, A. van der Werf, J.W. van der Heijden
Thursday 15 march 2018
12:45 - 12:55h
at Willem Burger Zaal
Categories: Clinical, Session (parallel)
Parallel session: Parallel session 3: Clinical
Background
Sometimes serum creatinine rises to unexpected high levels shortly after donor nephrectomy, despite of a good preoperative renal function (estimated GFR and calculation in the 24 hour urine collection). Stabilization of renal function is expected to be attained 1 month after nephrectomy. The question arises whether this rise in serum creatinine is associated with a reduced renal reserve capacity, or that it is just a reflection of muscle mass. The goal of the current research is to investigate the correlation between skeletal muscle mass and the difference of serum creatinine before- and after kidney donation(∆creatinine).
Methods
All potential donors of both VU University Medical Center and Academic Medical Center in Amsterdam underwent a non-contrast CT scan between 2006 and 2014. A single CT slice of the third lumbar vertebra(L3) was used to assess skeletal muscle area(SMA cm2) which is correlated with total skeletal muscle mass. Serum creatinine(µmol/L) levels were measured before-, 1 day- and 3 months after kidney donation.
Results
Due to missing data three subgroups were made for analysis. Of the 689 donors, 399 were included for the subgroup analyses of eGFR equations before donation, 119 were included for the subgroup analyses with serum creatinine levels 1 day after donation and 275 were included for the subgroup analysis of serum creatinine 3 months after donation. Mean rise of serum creatinine 1 day after donation was 45.1±19.9 μmol/L. After correction for age, sex and baseline creatinine levels, the increase of creatinine(∆creatinine) 1 day after donation was positively correlated with SMA(P-value=0.024). Moreover, donors with high SMA had a higher rise in serum creatinine 1 day after donation in comparison to low- and intermediate SMA. The mean rise of serum creatinine 3 months after donation was 38.0±11.1 μmol/L. After correction for age, sex and baseline creatinine levels, ∆creatinine 3 months after donation was no longer correlated with SMA(p-value=0.089).
Conclusions
A bigger rise in serum creatinine 1 day after donation is associated with more skeletal muscle mass. This association disappears after 3 months, which suggests that an unexpected high rise of serum creatinine shortly after donation is likely to be a reflection of large skeletal muscle mass and not of a decreased renal reserve capacity.
