Evaluation of vertebral muscle measurements in renal donors and the relationship with developed sarcopenia and other complications during follow-up

Due to the limited availability of cadaveric organ procurement in our country, living kidney donors are generally preferred. The computed tomography (CT) examinations performed on donor candidates include not only renal anatomy but also muscle and fat tissues. This study evaluates the relationships between the measurements from the donors' CT scans and adverse outcomes such as glomerular filtration rate (GFR) hypertension (HT), diabetes (DM), albuminuria and sarcopenia during follow-up. The CT scans measured total muscle areas from T10 to L5, psoas major muscle areas from L3-L4 and visceral (VAT) and subcutaneous (SAT) fat tissue areas from L3-L4. A total of 107 donors, including 67 women, with a mean age of 55 ± 9.7 years and a median follow-up duration of 5.4 years were included in the study. It was found that 18 (16.8%) donors had a GFR below 60 and 17 donors (15.9%) had albuminuria. Thirty-two donors (29.9%) were classified as having chronic kidney disease (CKD) based on GFR <60 or albuminuria. Sarcopenia was found in 24 donors during the evaluation. Regression analyses indicated that independent of age, the increase in the muscle area/Body Mass Index (SMA/BMI) indices calculated from T12, L1, L4, L5, and L4 psoas major muscle areas reduced the risk of sarcopenia. CKD was associated with visceral (VAT) and total fat tissue measurements from L3 and L4, independent of age and sex. The greatest risk increase was noted in VAT/BMI indices, where a unit increase in VAT/BMI raised the likelihood of developing CKD by 1.3 times at L3 and 1.4 times at L4 (p=0.016 and p=0.015). When examining the relationships with adverse outcomes, VAT, SAT, and total fat tissue measurements from L3 and L4 levels were associated with the presence of adverse outcomes, independent of donor age and sex. Visceral fat at the L3-L4 levels in donors is linked to CKD and adverse outcomes BMI is inadequate for assessing body composition, highlighting the need for further investigation into the role of CT-measured visceral fat in determining donor risks.