Impending hyperglycemia in normoglycemic renal transplant recipients--an experimental predictive surrogate

Comparing Glycaemic Benefits of Active Versus Passive Lifestyle Intervention in Kidney Allograft Recipients: A Randomized Controlled Trial

BACKGROUND

New-onset diabetes is common after kidney transplantation, but the benefit of lifestyle intervention to improve glucose metabolism posttransplantation is unproven.

METHODS

We conducted a single-center, randomized controlled trial involving 130 nondiabetic kidney transplant recipients with stable function between 3 and 24 months post-transplantation. Participants were randomly assigned in a 1:1 ratio to receive active intervention (lifestyle advice delivered by renal dietitians using behavior change techniques) versus passive intervention (leaflet advice alone). Primary outcome was 6-month change in insulin secretion, insulin sensitivity, and disposition index. Secondary outcomes included patient-reported outcomes, cardiometabolic parameters, clinical outcomes, and safety endpoints.

RESULTS

Between August 17, 2015 and December 18, 2017, 130 individuals were recruited, of whom 103 completed the study (drop-out rate 20.8%). Active versus passive intervention was not associated with any change in glucose metabolism: insulin secretion (mean difference, -446; 95% confidence interval [CI], -3184 to 2292; P = 0.748), insulin sensitivity (mean difference, -0.45; 95% CI, -1.34 to 0.44; P = 0.319), or disposition index (mean difference, -940; 95% CI, -5655 to 3775; P = 0.693). Clinically, active versus passive lifestyle intervention resulted in reduced incidence of posttransplantation diabetes (7.6% versus 15.6%, respectively, P = 0.123), reduction in fat mass (mean difference, -1.537 kg; 95% CI, -2.947 to -0.127; P = 0.033), and improvement in weight (mean difference, -2.47 kg; 95% CI, -4.01 to -0.92; P = 0.002). No serious adverse events were noted.

CONCLUSIONS

Active lifestyle intervention led by renal dietitians did not improve surrogate markers of glucose metabolism. Further investigation is warranted to determine if clinical outcomes can be improved using this methodology.

Comparing glycaemic benefits of Active Versus passive lifestyle Intervention in kidney Allograft Recipients (CAVIAR): study protocol for a randomised controlled trial

Background

Lifestyle modification is widely recommended to kidney allograft recipients post transplantation due to the cardiometabolic risks associated with immunosuppression including new-onset diabetes, weight gain and cardiovascular events. However, we have no actual evidence that undertaking lifestyle modification protects from any adverse outcomes post transplantation. The aim of this study is to compare whether a more proactive versus passive interventional approach to modify lifestyle is associated with superior outcomes post kidney transplantation.

Methods/design

We designed this prospective, single-centre, open-label, randomised controlled study to compare the efficacy of active versus passive lifestyle intervention for kidney allograft recipients early post transplantation. A total of 130 eligible patients, who are stable, nondiabetic and between 3 and 24 months post kidney transplantation, will be recruited. Randomisation is being undertaken by random block permutations into passive (n = 65, leaflet guidance only) versus active lifestyle modification (n = 65, supervised intervention) over a 6-month period. Supervised intervention is being facilitated by two dietitians during the 6-month intervention period to provide continuous lifestyle intervention guidance, support and encouragement. Both dietitians are accredited with behavioural intervention skills and will utilise motivational aids to support study recruits randomised to active intervention. The primary outcome is change in abnormal glucose metabolism parameters after 6 months of comparing active versus passive lifestyle intervention. Secondary outcomes include changes in a wide array of cardiometabolic parameters, kidney allograft function and patient-reported outcome measures. Long-term tracking of patients via data linkage to electronic patient records and national registries will facilitate long-term comparison of outcomes after active versus passive lifestyle intervention beyond the 6-month intervention period.

Discussion

This is the first randomised controlled study to investigate the benefits of active versus passive lifestyle intervention in kidney allograft recipients for the prevention of abnormal cardiometabolic outcomes. In addition, this is the first example of utilising behaviour therapy intervention post kidney transplantation to achieve clinically beneficial outcomes, which has potential implications on many spheres of post-transplant care.

Trial registration

This study was registered with the Clinical Trials Registry on 27 August 2014 (ClinicalTrials.org Identifier: NCT02233491).

Preventing and managing hyperglycemia in kidney transplant patients

PURPOSE OF REVIEW

New onset diabetes after kidney transplantation (NODAT) remains a common complication after transplantation and is associated with significant morbidity and mortality. The review will examine recent advances in our knowledge of this metabolic disorder and speculate upon future development.

RECENT FINDINGS

Research continues to broaden the horizon of existing and emerging risk factors that contribute to development of NODAT. Attempts to use this knowledge to develop quantitative risk scoring composites have been made, utilizing either pretransplant or 1-year posttransplantation variables, with variable success. Reassuringly a number of clinical trials have been published, or are currently in progress, that utilize pharmacological intervention for both prevention and management of NODAT. These are both in the form of differential immunosuppressant regimens or use of antiglycemic agents. Upcoming results will prove crucial in developing a genuine evidence-base for NODAT management.

SUMMARY

Rather than simple translation of data from the general to kidney transplant population, clinicians must appreciate that NODAT constitutes a distinct metabolic entity with unique pathophysiology. As such targeted strategies to prevent and manage NODAT require focused investigation to deal with this common complication.

Early basal insulin therapy decreases new-onset diabetes after renal transplantation

No effective interventions to reduce risk for new-onset diabetes after transplantation (NODAT), a condition associated with postoperative hyperglycemia and reduced patient and graft survival, have been established. In this 1-year, proof-of-concept clinical trial, we randomly assigned 50 renal transplant recipients to immediate-postoperative isophane insulin for evening blood glucose ≥140 mg/dl (treatment group) or short-acting insulin and/or oral antidiabetic agents for blood glucose ≥180-250 mg/dl (standard-of-care control group). We included only patients without a history of diabetes who received tacrolimus. By the third postoperative evening, all patients in the treatment group had blood glucose ≥140 mg/dl and were subsequently treated with basal insulin; during the first 3 weeks after transplantation, the mean ± SD daily insulin dosage was 17±11 IU/d. Among controls, 23 (92%) of 25 had blood glucose ≥200 mg/dl and 18 (72%) of 25 received standard-of-care antihyperglycemic treatment. Asymptomatic hypoglycemia occurred five times in the treatment group and once in the control group. Throughout follow-up, the treatment group had 73% lower odds of NODAT (odds ratio, 0.27) than the control group, and hemoglobin A1c was on average 0.38% lower in the treatment group than the control group. Twelve months after transplantation, all patients in the treatment group were insulin-independent, whereas 7 (28%) of 25 controls required antidiabetic agents. The groups did not differ for insulin sensitivity, but the treatment group showed better β-cell function throughout the 1-year follow-up. In conclusion, this study suggests regimens that include basal insulin significantly reduce the odds for NODAT after renal transplantation, presumably via insulin-mediated protection of β cells.

Is adiponectin a marker of preclinical atherosclerosis in kidney transplantation?

The aim of this study was to analyze the relationship between pre-transplant adiponectin (pre-ADP), abnormalities in glucose homeostasis (AGH) at three months post-transplantation, and preclinical atherosclerosis in non-diabetic patients prior to kidney transplantation (KT).

METHODS

We carried out a multicenter study in 157 non-diabetic KT patients (66.5% men; age: 50±13 yr). Pre-ADP levels were analyzed using radioimmunoassay. Carotid ultrasound was performed to determine carotid intima-media thickness (c-IMT). Oral glucose tolerance test was carried out to classify patients according ADA criteria.

RESULTS

Of the patients, 52.8% had AGH. Median pre-ADP was 19.5 (14-27) μg/mL. An inverse correlation was found between ADP and HOMA index (r=-0.432; p<0.001). Median c-IMT was 0.6 (0.48-0.71) mm. Significant inverse correlation existed between ADP and c-IMT on both sides (p<0.05). Patients with c-IMT >0.6 mm had more AGH (p=0.012) and lower ADP levels (p=0.02). We performed a logistic regression analysis using preclinical atherosclerosis (c-IMT ≥0.6 mm) as dependent variable and sex, age, BMI, ADP, AGH, and HOMA index as independent variables of altered c-IMT. Age, pre-ADP, and AGH were independent risk factors for elevated c-IMT.

CONCLUSIONS

Patients with AGH have a greater presence of preclinical atherosclerosis. ADP has an inverse relationship with AGH and is an independent marker of preclinical atherosclerosis.