Renal Disease in Metabolic Syndrome: the Hidden Role of Intrarenal Ischemia.

Introduction: The pathogenesis of renal disease in obesity and metabolic syndrome (MS) is mostly unknown. This is in part because of the limited information about renal morphological changes in these conditions. We evaluated renal histology in subjects with MS and those without MS, who are participants in the European Nephrectomy Biobank (ENBiBA) project. Methods: MS was defined with at least 3 of the following criteria: (i) body mass index (BMI) ≥27 kg/m2; (ii) prediabetes: fasting glucose of 100-125 mg/dl or HbA1c >5.7%; (iii) systolic or diastolic blood pressure >140/90 mm Hg or the use of medications; and (iv) triglycerides >150 mg/dl or high-density lipoprotein cholesterol <40 (in men) or 50 mg/dl (in women). The absence of these criteria defined patients without MS. Exclusion criteria were diabetes or known causes of renal disease. Results: A total of 157 cases were evaluated: 49 without and 108 with MS. Those with MS were older (54 ± 16 vs. 66 ± 11, P < 0.0001), had more prevalent chronic kidney disease (CKD, estimated glomerular filtration rate [eGFR] <60 ml/min): 24% (23%) versus 4% (8%) (P = 0.02), and had higher albumin-to-creatinine ratio (10 [4-68] vs. 4.45 [0-27], P = 0.05) than those without MS. Global sclerosis (3% [1-7] vs. 7% [3-13], P < 0.0001), nodular sclerosis, mesangial expansion, glomerulomegaly; moderate + severe hyalinosis, and arteriosclerosis were more frequent in those with MS than in those without (88 [82] vs. 29 [59]; 83 [77] vs. 30 [61]; P < 0.05). These vascular changes were independent of differences in age. Conclusion: In MS, ischemic renal disease may play a role in renal disease. In addition, some patients may develop lesions compatible with diabetic nephropathy such as increased mesangial expansion and nodular sclerosis. Further analyses are needed to study the consequences of the pandemic of obesity on renal health.

Preliminary Clinical Experience of Molnupiravir to Prevent Progression of COVID-19 in Kidney Transplant Recipients.

BACKGROUND: Recently, different therapeutic lines have been tried in the initial stage of the disease of COVID-19, including remdesivir and molnupiravir. There is scarce evidence on the efficacy and safety of molnupiravir in kidney transplant recipients (KTRs). METHODS: ingle-center prospective cohort study' all adult KTRs diagnosed with COVID-19 and treated with molnupiravir or remdesivir from January to April 2022 were included. RESULTS: Nine KTRs with SARS-CoV-2 (Omicron variant) infection and mild symptoms received molnupiravir in an outpatient basis and were compared with a cohort of similar patients treated with remdesivir (n = 7). Three patients in the molnupiravir cohort were in the early posttransplant period and received a basiliximab (n = 2) or antithymocite globulin-based induction (n = 1). One of the patients had been treated with methylprednisolone bolus and antithymocite globulin for an episode of acute rejection in the previous months. They were all vaccinated with mRNA vaccines' and all but 1 had serological response. Only one of the patients experienced clinical worsening despite molnupiravir treatment and developed pneumonia requiring hospital admission. None of the patients suffered adverse effects attributed to molnupiravir' and no adjustment of tacrolimus dose was needed. None of the patients treated with remdesivir progressed in COVID-19 severity. CONCLUSIONS: Our study suggests that KTRs with SARS-CoV-2 infection under treatment with molnupiravir have a good clinical evolution with a probable lower risk for hospitalization and no adverse effects. At the renal level, molnupiravir was well tolerated, with no evidence of nephrotoxicity secondary to the drug nor interactions with the immunosuppressive therapy.

High intrapatient variability of tacrolimus exposure associated with poorer outcomes in liver transplantation.

Tacrolimus (TAC) is a dose-dependent immunosuppressor with considerable intrapatient variability (IPV) in its pharmacokinetics. The aim of this work is to ascertain the association between TAC IPV at 6 months after liver transplantation (LT) and patient outcome. This single-center cohort study retrospectively analyzed adult patients who underwent transplantation from 2015 to 2019 who survived the first 6 months with a functioning graft. The primary end point was the patient's probability of death and the secondary outcome was the loss of renal function between month 6 and the last follow-up. TAC IPV was estimated by calculating the coefficient of variation (CV) of the dose-corrected concentration (C0 /D) between the third and sixth months post-LT. Of the 140 patients who underwent LT included in the study, the low-variability group (C0 /D CV < 27%) comprised 105 patients and the high-variability group (C0 /D CV ≥ 27%) 35 patients. One-, 3-, and 5-year patient survival rates were 100%, 82%, and 72% in the high-variability group versus 100%, 97%, and 93% in the low-variability group, respectively (p = 0.005). Moreover, significant impaired renal function was observed in the high-variability group at 1 year (69 ± 16 ml/min/1.73 m2 vs. 78 ± 16 ml/min/1.73 m2 , p = 0.004) and at 2 years post-LT (69 ± 17 ml/min/1.73 m2 vs. 77 ± 15 ml/min/1.73 m2 , p = 0.03). High C0 /D CV 3-6 months remained independently associated with worse survival (hazard ratio = 3.57, 95% CI = 1.32-9.67, p = 0.012) and loss of renal function (odds ratio = 3.47, 95% CI = 1.30-9.20, p = 0.01). Therefore, high IPV between the third and sixth months appears to be an early and independent predictor of patients with poorer liver transplant outcomes.

The Role of Vascular Lesions in Diabetes Across a Spectrum of Clinical Kidney Disease.

INTRODUCTION: The clinical-histologic correlation in diabetic nephropathy is not completely known. METHODS: We analyzed nephrectomy specimens from 90 patients with diabetes and diverse degrees of proteinuria and glomerular filtration rate (GFR). RESULTS: Thirty-six (40%) subjects had normoalbuminuria, 33 (37%) microalbuminuria, and 21 (23%) non-nephrotic proteinuria. Mean estimated GFR (eGFR) was 65±23 (40% <60 ml/min per 1.73 m2). About 170 glomeruli per patient were analyzed, and all samples included vascular tissue. Six subjects (7%) were classified in diabetic nephropathy class I, 61 (68%) in class II-a, 13 (14%) in class II-b, 9 (10%) class III, and 1 (1%) in class IV. Eighty percent to 90% of those with normoalbuminuria or microalbuminuria were classified in class II-a or II-b and <10% in class III; 52% of those with proteinuria were in class II-a, 15% in class II-b, and 19% in class III. Nodular sclerosis (57%) and mesangial expansion (15%) were more frequent in cases with proteinuria than in normoalbuminuria (28% and 8%; P = 0.028 and 0.017). About 20% to 30% of all cases, regardless the level of albuminuria or proteinuria or the histologic class had tubular atrophy, interstitial fibrosis, or inflammation in >10% to 20% of the sample. Moderate hyalinosis and arteriolar sclerosis were observed in 80% to 100% of cases with normoalbuminuria, microalbuminuria, proteinuria, as well as in class I, II, or III. CONCLUSIONS: Weak correspondence between analytical parameters and kidney histology was found. Thus, disease may progress undetected from the early clinical stages of the disease. Finally, vascular damage was a very common finding, which highlights the role of ischemic intrarenal disease in diabetes.

Clinical evolution of post-transplant diabetes mellitus.

BACKGROUND: The long-term clinical evolution of prediabetes and post-transplant diabetes mellitus (PTDM) is unknown. METHODS: We analysed, in this cohort study, the reversibility, stability and progression of PTDM and prediabetes in 672 patients using repeated oral glucose tolerance tests (OGTTs) for ≤5 years. RESULTS: Most patients were on tacrolimus, steroids and mycophenolate. About half developed either PTDM or prediabetes. The incidence of PTDM was 32% and bimodal: early PTDM (≤3 months) and late PTDM. Early PTDM reverted in 31%; late PTDM developed in patients with post-transplant prediabetes. The use of OGTTs was necessary to detect around half of PTDM. Pretransplant obesity was a major risk factor for early PTDM, for its persistence and for late PTDM {odds ratio [OR] 1.18 [95% confidence interval (CI) 1.09-1.28]}. At 3 months, higher HbA1c promoted [OR 2.37 (95% CI 1.38-4.06)], while insulin sensitivity protected against [OR 0.64 (95% CI 0.48-0.86)] late PTDM. At 3 months, 28% had prediabetes; of these, 36% remained stable, 43% normalized and 21% developed late PTDM. Pretransplant obesity [OR 1.20 (95% CI 1.04-1.39)] and higher HbA1c [OR 3.80 (95% CI 1.45-9.94)] at 3 months promoted while insulin sensitivity protected against [OR 0.57 (95% CI 0.34-0.95)] evolution from prediabetes to late PTDM. Immunosuppressive levels or acute rejection did not influence PTDM. Most (84%) of the patients with normal tests at 3 months remained stable without evolving into PTDM; 14% developed prediabetes. CONCLUSIONS: PTDM and prediabetes are very common in renal transplantation. Classic metabolic factors like obesity, prediabetes and insulin resistance promote the evolution of PTDM and prediabetes. Patients with normal glucose metabolism rarely develop PTDM. OGTT is necessary to detect PTDM and prediabetes and thus should be included in clinical practice.

Hyperinsulinemia and hyperfiltration in renal transplantation.

BACKGROUND: Insulin-resistance hyperinsulinemia is a novel risk factor for renal disease in the general population. Glomerular hyperfiltration has been proposed as an early consequence of hyperinsulinemia. METHODS: In this multicenter cohort study, we analyzed 202 patients without diabetes before or after renal transplantation during the first posttransplant year. Insulin was measured at 3 and 12 months. The majority of patients (91%) were on calcineurin inhibitors. Patients were classified as with persistent normo or hyperinsulinemia when situated below or above the median value of insulin (3 months: 9 muU/mL; 12 months: 8.74 muU/mL) at both periods. The 3 to 12 months percent change in calculated creatinine clearance (3-12 months DeltaCrCL) was calculated. RESULTS: Patients with persistent hyperinsulinemia showed a higher increase in 3 to 12 months DeltaCrCL compared with those with persistent normoinsulinemia (12% [-20/40] vs. -0.03% [-12/18], P=0.035). We performed a multivariate linear regression analysis with the 3 to 12 months DeltaCrCL as the dependent variable and different factors that may induce hyperfiltration, including persistent hyperinsulinemia, as covariates. Persistent hyperinsulinemia was a risk factor for increased CrCL (beta 0.09, 95% CI 0.07/0.12, P=0.035). CONCLUSION: In nondiabetic recipients during the first posttransplant year, hyperinsulinemia induced increments in CrCL. As this may herald future renal dysfunction, hyperinsulinemia should not be ignored as a potential target in this population.

Prediabetes in patients receiving tacrolimus in the first year after kidney transplantation: a prospective and multicenter study.

BACKGROUND: Tacrolimus-based immunosuppression, the most widely used regimen in kidney transplantation, increases the risk of new onset diabetes after transplantation (NODAT). However, the prevalence, evolution and risk factors of different prediabetic alterations: impaired fasting glucose, impaired glucose tolerance, and provisional diabetes, have not been established. METHODS: In this multicenter and prospective study we evaluated 154 nondiabetic kidney transplant recipients receiving tacrolimus, mycophenolate mofetil and low dose steroids. An oral glucose tolerance test was performed 3 and 12 months after transplantation and prediabetes was defined by American Diabetes Association criteria. RESULTS: Prediabetes was highly prevalent and showed little variation between 3 and 12 months (36% and 33%, respectively). Impaired glucose tolerance was the most frequent abnormality observed (23% and 25%, respectively) observed. In addition, 20% of recipients showed NODAT by 1 year. Multivariate analysis showed that age (odds ratio [OR]: 1.07, 95% confidence interval [CI]: 1.004-1.14), pretransplant body mass index (OR: 1.3, CI: 1.09-1.6) and triglyceride/high density lipoprotein-cholesterol ratio, a marker of insulin resistance, (OR: 1.4, CI: 1.05-1.9) were independent risk factors for prediabetes. CONCLUSION: One in two recipients with tacrolimus-based immunosuppresion showed prediabetes or NODAT by 1 year posttransplantation when properly investigated. Older age and high pretransplant body mass index and triglyceride/high density lipoprotein-cholesterol ratio were risk factors for prediabetes. These findings may help applying early interventions to prevent the disorder.

Unmasking glucose metabolism alterations in stable renal transplant recipients: a multicenter study.

BACKGROUND AND OBJECTIVES: Emerging information indicates that glucose metabolism alterations are common after renal transplantation and are associated with carotid atheromatosis. The aims of this study were to investigate the prevalence of different glucose metabolism alterations in stable recipients as well as the factors related to the condition. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A multicenter, cross-sectional study was conducted of 374 renal transplant recipients without pre- or posttransplantation diabetes. A standard 75-g oral glucose tolerance test was performed. RESULTS: Glucose metabolism alterations were present in 119 (31.8%) recipients: 92 (24.6%) with an abnormal oral glucose tolerance test and 27 (7.2%) with isolated impaired fasting glucose. The most common disorder was impaired glucose tolerance (17.9%), and an abnormal oral glucose tolerance test was observed for 21.5% of recipients with a normal fasting glucose. By multivariate analysis, age, prednisone dosage, triglyceride/high-density lipoprotein cholesterol ratio, and beta blocker use were shown to be factors related to glucose metabolism alterations. Remarkably, triglyceride levels, triglyceride/high-density lipoprotein cholesterol ratio, and the proportion of recipients with impaired fasting glucose were already higher throughout the first posttransplantation year in recipients with a current glucose metabolism alteration as compared with those without the condition. CONCLUSIONS: Glucose metabolism alterations are common in stable renal transplant recipients, and an oral glucose tolerance test is required for its detection. They are associated with a worse metabolic profile, which is already present during the first posttransplantation year. These findings may help planning strategies for early detection and intervention.