Bone and mineral metabolism and fibroblast growth factor 23 levels after kidney donation.

Living kidney donation offers a unique setting to study changes in phosphate and vitamin D homeostasis attributable to mild isolated decreases in estimated glomerular filtration rate (eGFR). Cross-sectional study. 198 living kidney donors and 98 nondonor controls from 9 transplant centers across 3 countries. For donors, median time after donation was 5.3 years. At assessment, donors had a lower eGFR than controls (73 vs 98 mL/min/1.73 m(2)). Living kidney donation (mildly decreased eGFR). Biochemical markers of chronic kidney disease-mineral and bone disorder. Serum creatinine, total serum calcium, serum and urine inorganic phosphate, plasma intact parathyroid hormone, serum calcidiol and calcitriol, renal fractional excretion of inorganic phosphate, and intact serum fibroblast growth factor 23 (FGF-23). Serum FGF-23 levels were significantly higher in donors (38.1 vs 29.7 pg/mL; P < 0.001). For every 10-mL/min/1.73 m(2) decrease in eGFR, FGF-23 level was higher by 3.2 (95% CI, 2.0-4.4) pg/mL. Compared with controls, donors showed higher renal tubular fractional excretion of inorganic phosphate (17.8% vs 12.3%; P < 0.001), lower serum phosphate (0.97 vs 1.02 mmol/L; P = 0.03), and lower serum calcitriol values (63 vs 77 pmol/L; P < 0.001). Serum calcium levels were not significantly different between the 2 groups. Plasma intact parathyroid hormone levels were significantly higher in donors (5.7 vs 5.0 pmol/L; P = 0.03), but were not correlated with FGF-23 or calcitriol levels. Enrollment of a small proportion of past donors at participating centers; assessment of only postdonation values; unable to assess seasonal variation or other temporal patterns in biochemical markers; assessment of kidney function was based on eGFR, not measured GFR. The FGF-23 pathway may be activated in living kidney donors who show early biochemical changes compatible with chronic kidney disease-mineral and bone disorder. Whether these changes influence bone mineral density and fracture rates warrants consideration.

Young A ，Hodsman AB ，Boudville N ，Geddes C ，Gill J ，Goltzman D ，Jassal SV ，Klarenbach S ，Knoll G ，Muirhead N ，Prasad GV ，Treleaven D ，Garg AX ，Donor Nephrectomy Outcomes Research (DONOR) Network ... -  《-》

Fracture risk in living kidney donors: a matched cohort study.

Chronic kidney disease increases the risk of bone fragility fractures (osteoporotic fractures). Living kidney donors lose 50% of their renal mass and show changes in calcium homeostasis. We studied whether living kidney donation increases the risk of fragility fracture. Retrospective matched-cohort study. We reviewed the medical charts of all 2,015 adults in Ontario, Canada, who donated a kidney between 1992 and 2009 (surgeries performed across 5 transplant programs). We linked this information to health care databases and randomly selected 20,150 matched nondonors from the healthiest portion of the general population. Median age was 43 (95% CI, 24-50) years at study enrollment. Donors and nondonors were then followed up for a median of 6.6 years and a maximum of 17.7 years. Living donor nephrectomy. The primary outcome was lower- and upper-extremity fragility fractures. Individuals who reached 66 years or older in follow-up had bisphosphonate prescriptions recorded. The rate of fragility fracture was no higher in donors compared with nondonors (16.4 vs 18.7 events/10,000 person-years; rate ratio, 0.88; 95% CI, 0.58-1.32). Results were similar in multiple additional analyses. There was little difference in the proportion of older adults in follow-up who received a bisphosphonate prescription (17.1% vs 15.2%; P = 0.4). These are interim results. Ongoing surveillance of this and other donor cohorts is warranted to be sure an association does not manifest with longer follow-up. To date, there is no evidence of increased fragility fracture risk in living kidney donors. Our results meet an information need and are reassuring for the safety of the practice.

Garg AX ，Pouget J ，Young A ，Huang A ，Boudville N ，Hodsman A ，Adachi JD ，Leslie WD ，Cadarette SM ，Lok CE ，Monroy-Cuadros M ，Prasad GV ，Thomas SM ，Naylor K ，Treleavan D ，Donor Nephrectomy Outcomes Research (DONOR) Network ... -  《-》

Serum level of fibroblast growth factor 23 in maintenance renal transplant patients.

Sánchez Fructuoso AI ，Maestro ML ，Pérez-Flores I ，Valero R ，Rafael S ，Veganzones S ，Calvo N ，De la Orden V ，De la Flor JC ，Valga F ，Vidaurreta M ，Fernández-Pérez C ，Barrientos A ... -  《-》

Long-term outcomes of living kidney donors over the past 28 years in a single center in Taiwan.

The chronic shortage of kidneys for transplantation has increased the number of living donations, but demand remains high, which has created a long waiting list of end-stage kidney disease patients. Donors with decreased renal mass may suffer a higher risk of developing proteinuria, hypertension (HTN), and chronic renal disease (CKD) during long-term follow-up. We retrospectively retrieved medical data of living kidney donors at our hospital over the past 28 years. There were 45 male and 60 female donors with a mean donation age of 46.34 ± 12.47 years (range = 20-70y). The mean follow-up duration was 4.67 ± 4.78 years. The serum creatinine (Cr) at donation was 0.93 ± 0.22 mg/dL, while the latest Cr was 1.26 ± 0.45 mg/dL (P < .001). The mean age at follow-up was 50.95 ± 14.57 years. At last follow-up, eight subjects (7.6%) displayed HTN requiring treatment, 10 (9.5%), proteinuria and 55.4%, an estimated glomerular filtration rate (eGFR) of less than 60 mL/min, including one with diabetic nephropathy at 10 years after donation who required long-term hemodialysis. Although gender did not correlate with occurrence of HTN, proteinuria, and CKD, the occurrence of CKD was associated with age at donation (P < .001, odds ratio [OR] = 1.076), and age at follow-up (P < .001, OR = 1.071). HTN donors were older (P = .036, OR = 1.057) with longer follow-up durations (P = .007, OR = 1.166) and had higher Cr values at donation (P = .044, OR = 94.4). Donors with proteinuria were not related to gender, follow-up duration, initial Cr, warm ischemic time, or duration of admission. eGFR was indeed worse after donation (P = .002). Our results indicated a significant proportion of living donors may develop CKD upon long-term follow-up. The factors affecting donor risk of CKD were baseline renal function, older age, and duration after kidney donation.

Tsai SF ，Shu KH ，Ho HC ，Wu MJ ，Cheng CH ，Lian JD ，Wen MC ，Su CK ，Yu TM ，Chuang YW ，Huang ST ，Chen CH ... -  《-》

Post-nephrectomy development of renal function in living kidney donors: a cross-sectional retrospective study.

Fehrman-Ekholm I ，Kvarnström N ，Söfteland JM ，Lennerling A ，Rizell M ，Odén A ，Simonsson T ... -  《-》