The Association between Body Composition Measurements and Surgical Complications after Living Kidney Donation

Obesity is considered a risk factor for peri-and postoperative complications. Little is known about this risk in overweight living kidney donors. The aim of this study was to assess if anthropometric body measures and/or surgical determinants are associated with an increased incidence of peri-and postoperative complications after nephrectomy. We included 776 living kidney donors who donated between 2008 and 2018 at the University Medical Center Groningen. Prenephrectomy measures of body composition were body mass index (BMI), body surface area (BSA), waist circumference, weight, and waist–hip ratio. Incidence and severity of peri-and postoperative complications were assessed using the Comprehensive Complication Index. Mean donor age was 53 ± 11 years; 382 (49%) were male, and mean BMI at donor screening was 26.2 ± 3.41 kg/m2. In total, 77 donors (10%) experienced peri-and postoperative complications following donor nephrectomy. Male sex was significantly associated with fewer surgical complications (OR 0.59, 0.37–0.96 95%CI, p = 0.03) in binomial logistic regression analyses. Older age (OR: 1.03, 1.01–1.05 95%CI, p = 0.02) and a longer duration of surgery (OR: 1.01, 1.00–1.01 95%CI, p = 0.02) were significantly associated with more surgical complications in binomial logistic regression analyses. Multinomial logistic regression analyses did not identify any prenephrectomy measure of body composition associated with a higher risk of surgical complications. This study shows that higher prenephrectomy BMI and other anthropometric measures of body composition are not significantly associated with peri-and postoperative complications following living donor nephrectomy.</p

Fat-Free Mass Derived From Bioimpedance Spectroscopy and Computed Tomography are in Good Agreement in Patients With Chronic Kidney Disease

Objective: Malnutrition is highly prevalent in patients with kidney failure. Since body weight does not reflect body composition, other methods are needed to determine muscle mass, often estimated by fat-free mass (FFM). Bioimpedance spectroscopy (BIS) is frequently used for monitoring body composition in patients with kidney failure. Unfortunately, BIS-derived lean tissue mass (LTMBIS) is not suitable for comparison with FFM cutoff values for the diagnosis of malnutrition, or for calculating dietary protein requirements. Hypothetically, FFM could be derived from BIS (FFMBIS). This study aims to compare FFMBIS and LTMBIS with computed tomography (CT) derived FFM (FFMCT). Secondarily, we aimed to explore the impact of different methods on calculated protein requirements. Methods: CT scans of 60 patients with kidney failure stages 4-5 were analyzed at the L3 level for muscle cross-sectional area, which was converted to FFMCT. Spearman rank correlation coefficient and 95% limits of agreement were calculated to compare FFMBIS and LTMBIS with FFMCT. Protein requirements were determined based on FFMCT, FFMBIS, and adjusted body weight. Deviations over 10% were considered clinically relevant. Results: FFMCT correlated most strongly with FFMBIS (r = 0.78, P &lt; .001), in males (r = 0.72, P &lt; .001) and in females (r = 0.60, P &lt; .001). A mean difference of −0.54 kg was found between FFMBIS and FFMCT (limits of agreement: −14.88 to 13.7 kg, P = .544). Between LTMBIS and FFMCT a mean difference of −12.2 kg was apparent (limits of agreement: −28.7 to 4.2 kg, P &lt; .001). Using FFMCT as a reference, FFMBIS best predicted protein requirements. The mean difference between protein requirements according to FFMBIS and FFMCT was −0.7 ± 9.9 g in males and −0.9 ± 10.9 g in females. Conclusion: FFMBIS correlates well with FFMCT at a group level, but shows large variation within individuals. As expected, large clinically relevant differences were observed in calculated protein requirements.</p

Aorto-Iliac Artery Calcification and Graft Outcomes in Kidney Transplant Recipients

While the association of vascular calcification with inferior patient outcomes in kidney transplant recipients is well-established, the association with graft outcomes has received less at-tention. With this dual-centre cohort study, we aimed to determine the clinical impact of recipient pre-transplant aorto-iliac calcification, measured on non-contrast enhanced computed tomography (CT)-imaging within three years prior to transplantation (2005–2018). We included 547 patients (61.4% male, age 60 (interquartile range 51–68) years), with a median follow-up of 3.1 (1.4–5.2) years after transplantation. The aorto-iliac calcification score (CaScore) was inversely associated with one-year estimated-glomerular filtration rate (eGFR) in univariate linear regression analysis (standard β −3.3 (95% CI −5.1 to −1.5, p < 0.0001), but not after adjustment for potential confounders, including donor and recipient age (p = 0.077). In multivariable Cox regression analyses, a high CaScore was associated with overall graft failure (p = 0.004) and death with a functioning graft (p = 0.002), but not with death-censored graft failure and graft function decline. This study demonstrated that pre-transplant aorto-iliac calcification is associated with one-year eGFR in univariate, but not in multivariable linear regression analyses. Moreover, this study underlines that transplantation in patients with a high CaScore does not result in earlier transplant function decline or worse death censored graft survival, although ongoing efforts for the prevention of death with a functioning graft remain essential