Practice Patterns in the Acceptance of Medically Complex Living Kidney Donors with Obesity, Hypertension, Family History of Kidney Disease, or Donor-Recipient Age Discrepancy

Background To assess the practice patterns of the acceptance of medically complex living kidney donors (MCLKDs). Methods We distributed a survey to nephrologists and transplant surgeons (TS) across the world through major international transplant societies. The survey contained questions regarding obesity, abnormal blood glucose profile, mild hypertension, donor-recipient age discrepancy, or family history of kidney disease of unknown etiology. Results In total, 239 respondents from 29 countries (42% were nephrologists and 58% were TS).Most respondents would allow donations from obese donors, especially if they intended to lose weight but would be cautious if these donors had abnormal blood glucose or family history of diabetes mellitus. In hypertensive donors, future pregnancy plans mattered in decisions regarding the acceptance of female donors. Most respondents would allow young donors but would be more cautious if they had a future risk of hypertension or a family history of kidney disease of unknown etiology. They would also allow donations from an older person if prolonged waiting time was anticipated. We found multiple areas of consensus of practice among the diverse members of international transplant societies, with some interesting variations among nephrologists and TS. Conclusions This survey highlights the practice patterns of the acceptance of MCLKDs among the international community. In the absence of clear guidelines, this survey provides additional information to counsel kidney donors with these conditions.

Negative perception of aging is associated with frailty transitions within a cohort of sexual minority men

Background and Objectives Older people have increased risk of developing frailty, an age-related clinical syndrome associated with worse health outcomes. This study examined the effect of self-perception of aging (i.e., age discrepancy - individuals feel younger/older than their chronological age, and aging satisfaction) on frailty transitions. Research Design and Methods We use longitudinal data from 549 HIV-/499 HIV+ sexual minority men (SMM) aged 50 years or older enrolled in the Multicenter AIDS Cohort Study (MACS). To test the association of self-perception of aging on transitions between states of frailty (non-frail/frail), defined using Fried Frailty Phenotype, a multinomial modeling was used. Results With remaining non-frail as the referent group, participants reporting low aging satisfaction (vs moderate aging satisfaction) had increased odds of transitioning from Non-Frail to Frail (OR: 2.72; 95% CI:1.56-4.74), Frail to Non-Frail (OR: 3.40; 95% CI: 1.62-7.12) or remaining frail (Frail to Frail) (OR: 6.64; 95% CI: 3.88-11.38). Participants reporting older subjective age (vs no age discrepancy) had increased odds of transitioning from Non-Frail to Frail (OR: 2.50; 95% CI: 1.11-5.64), Frail to Non-Frail (OR: 4.47; 95% CI: 1.85-10.81) or remaining frail (Frail to Frail) (OR: 5.68; 95% CI: 3.06-10.56). High aging satisfaction and younger subjective age were not statistically associated with frailty transitions. Discussion and Implications Our findings show that negative self-perception of aging (i.e., older subjective age and low aging satisfaction) is associated with frailty transitions (non-frail to frail, frail to non-frail, frail to frail) when compared to remaining non-frail. Translational significance Frailty is associated with increased risk of adverse health outcomes and poor quality of life. Independent of HIV-status, negative self-perception of aging (i.e., low aging satisfaction and older subjective age) is associated with frailty transitions among a cohort of sexual minority men aged 50 years or older. Given functional limitations are a core component of the definition of frailty, promoting efforts that would mitigate the impact of negative self-perceptions of aging on functional limitations is important. The impact of this individual level factor will intersect with other dyadic, community and structural factors, all of which foster healthy aging.

Undernutrition and Pubertal Timing in Female Survivors of Medulloblastoma and Other Embryonal Tumors

Context Children with brain tumors may have pubertal onset at an inappropriately young chronologic age. Hypothalamic-pituitary irradiation ≥18Gy has been found to be a risk factor; age at irradiation is associated with pubertal timing. However, the underlying mechanisms are unknown. Objective To determine the impact of body mass index (BMI) and catch-up growth on pubertal timing in females treated for medulloblastoma and other embryonal tumors. Design, Setting, and Patients Retrospective cohort analysis of 90 female patients treated for medulloblastoma and other embryonal tumors at Dana-Farber Cancer Institute/Boston Children’s Hospital from 1996 to 2016. Eighteen individuals met inclusion criteria, with a mean ± SD follow-up period of 11.9 ± 3.4 years. Main Outcome Measures Multiple linear regression models for age at pubertal onset and bone age discrepancy from chronologic age at pubertal onset assessed the joint influences of age at irradiation, hypothalamic irradiation dose, undernutrition duration, BMI standard deviation score (SDS) at pubertal onset, and catch-up BMI SDS. Results The mean ± SD age of pubertal onset was 9.2 ± 1.3 years and hypothalamic radiation dose was 31.9 ± 9.9 Gy. There was a direct relationship between age at irradiation and age at pubertal onset (β = 0.323 ± 0.144 [standard error] year per year; P = 0.04) that was significantly attenuated after adjusting for BMI SDS at pubertal onset (P = 0.5) and catch-up BMI SDS (P = 0.08), suggesting that BMI is a mediator. Conclusions Both absolute and catch-up BMI SDS at pubertal onset are significant mediators of pubertal timing and bone age discrepancy in pediatric medulloblastoma and other embryonal tumors, and thus, are targetable risk factors to optimize pubertal timing.

P1716MULTI-NATIONAL SURVEY AMONG NEPHROLOGISTS & TRANSPLANT SURGEONS ABOUT THE SUITABILITY & ACCEPTANCE OF MARGINAL LIVE KIDNEY DONORS REGARDING AGE DISCREPANCY

Background and Aims Living donor kidney transplantation is the best option for patients on dialysis. There are no guidelines or generally accepted consensus about the acceptable kidney donor age and what is the acceptable donor-recipient age discrepancy. Method This is a cross sectional survey of nephrologists and transplant surgeons about acceptable age of living kidney donors. The survey was sent to participants in different countries and through AST and ERA/EDTA. Results 122 respondents from 22 countries answered 4 questions related to donor age. Most respondents (N=86, 70%) would allow an 18-years old man to donate to his older sibling. However, this percentage would fall to (N=69, 57%) if the donor was an 18-years old woman (P=0.02), reflecting the impact of childbearing period as a major criterion in considering kidney donation. On the opposite side, up to 20% of respondents will decline a very young donor regardless of the gender of the donor. The acceptance rate of a very young donor drops to only 37% if the recipient is 75-year-old (versus 70% in case of younger recipient, P = 0.004). In case of old donor( > 65 years old) old to an 18 year old recipient with expected prolonged waiting time for deceased donor, ( N= 80, 65%) will advise to find an alternative donor but will allow the donation if no alternative donor is available. Conclusion The majority of the nephrologists and transplant surgeons will allow a very young donor to donate to a sibling especially if the donor is a male. However up to 20% will decline this donation regardless of the gender of the donor. The transplant community is divided about allowing a very young donor to donate to a very old recipient. However, the majority will accept > 65 years old donor to donate to an 18 years old recipient with expected prolonged waiting time for deceased donor.

Homing in on Polaris: A 7 M⊙ first-overtone Cepheid entering the instability strip for the first time

A recently presented HST/FGS parallax measurement of the Polaris system has been interpreted as evidence for the Cepheid Polaris Aa to be pulsating in the second overtone. An age discrepancy between components A and B has been noted and discussed in terms of a stellar merger. Here I show that the new parallax of Polaris is consistent with a simpler interpretation of Polaris as a 7 M⊙, first-overtone, classical Cepheid near the hot boundary of the first instability strip crossing. This picture is anchored to rates of period change, the period-luminosity relation, the location in color-magnitude space, the interferometrically determined radius, spectroscopic N/C and N/O enhancements, and a dynamical mass measurement. The detailed agreement between models and data corroborates the physical association between the Cepheid and its visual companion as well as the accuracy of the HST parallax. The age discrepancy between components A and B is confirmed and requires further analysis, for example to investigate the possibility of stellar mergers in an evaporating birth cluster of which the Polaris triple system would be the remaining core.

U/Th and 14C Crossdating of Parietal Calcite Deposits: Application to Nerja Cave (Andalusia, Spain) and Future Perspectives

Abstract14C and U/Th methods were used to date three thin carbonate layers deposited on decorated walls of Nerja Cave (Malaga, southern Spain) in order to constrain the age of the parietal non-figurative marks situated under these carbonate layers. Modern formations were also dated to estimate the detritic contribution for the U/Th method and the dead carbon proportion for 14C dating. We sampled two locations with ocher painting marks. In one case (mark 1), the good agreement between the ages obtained by the two methods suggests that the sample was not subjected to post-deposition alteration and that the results are reliable. In the other case (mark 2), the age discrepancy between the two methods reached 30,000 yr, indicating that geochemical alteration had affected the sample and that one or both results were inaccurate. The ages for mark 1 indicate that this type of non-figurative representation is older than 25,000 cal BP and that it can be associated with the oldest attested Paleolithic occupation of Nerja Cave.