Ultra-Processed Food Consumption, Poorer Nutritional Quality, and Lower Muscle Mass in Immediate and Late Postkidney Transplant Periods.

OBJECTIVE: To assess the consumption of ultra-processed foods (UPFs) in the immediate (2 months after transplantation) and late post-transplant (14 months after transplantation) periods among kidney transplant patients and to examine its correlation with nutritional quality and body composition. DESIGN AND METHODS: A cross-sectional analysis of 96 kidney transplant recipients divided into 2 groups: immediate post-transplant (n = 71) and late post-transplant (n = 25). Sociodemographic, anthropometric, and laboratory data were collected and grouped in a database. Food intake was evaluated by a validated food frequency questionnaire and foods were divided according to the NOVA classification system. The consumption of UPFs was calculated and statistical analyses were performed to evaluate its correlation with nutritional components and body composition. RESULTS: The consumption of UPFs was 649.4 [420.0-1061.72] kcal/day, accounting for 33.3 ± 11.9% of the total daily energy intake. The immediate post-transplant group showed higher total daily energy and UPFs intake compared to the late post-transplant group (P = .002 and P = .046, respectively), although the energy contribution of UPFs was similar between both groups. UPFs intake was positively correlated with higher percentages of total fat, trans fat, saturated, monounsaturated fat, polyunsaturated fat, starch, and sodium (P < .05 for all analyses). An inverse correlation was observed between UPFs consumption and the percentage of protein and carbohydrates in the food intake (P = .025 and P = .008, respectively). In the immediate post-transplant group, a higher intake of UPFs was correlated with lower muscle mass (r = -0.250, P = .037). CONCLUSIONS: The findings of this study reveal a pattern of increased consumption of UPFs among kidney transplant patients in comparison to the national average. This higher intake of UPFs was correlated with lower nutritional quality during both periods. Moreover, a significant correlation was observed between UPFs consumption and adverse body composition parameters, specifically in the immediate post-transplant period.

What is Known About Dietary Interventions and Body Weight Management After Kidney Transplantation? A Scoping Review.

OBJECTIVE: Several studies report weight gain after kidney transplantation, which is commonly related to poor outcomes. However, recommendations for dietary interventions aiming to manage these patients' weight are still scarce in the literature. Thus, this review seeks to describe the state of literature on the effect of dietary interventions on weight after kidney transplantation. DESIGN: Scoping review. METHODS: This review was designed according to the recommendations for scoping reviews elaborated by the Joanna Briggs Institute. Studies assessing the effect of dietary interventions on body weight after kidney transplantations were searched in MEDLINE, EMBASE, and Clinicaltrials.gov databases up to June 28, 2021. Two independent reviewers summarized the data collected. RESULTS: Thirteen (503 patients) of the 4.983 articles identified in the searched databases were included in our study. Most studies were published before 2010 and presented incomplete methodology descriptions. Nutritional counseling and dietary prescriptions according to the Step 1 diet of the American Heart Association (AHA) were the most common interventions. Only 2 studies evaluated changes in body weight as primary outcome. Three studies were randomized clinical trials (RCT), and none of these found the adopted interventions to demonstrate benefits. CONCLUSION: Our scoping review evinced a scarcity of data available in the literature addressing this topic. Most studies were not controlled and presented poor methodological quality. Moreover, these studies included small sample sizes, so that the assessment of dietary interventions in these patients still lacks power for definitive conclusions. Prospective RCT should be conducted to define effective in preventing weight gain or weight loss after kidney transplant.

Risk factors associated with weight gain after kidney transplantation: A cohort study.

BACKGROUND: Renal transplantation is the best modality of renal replacement therapy for patients with end-stage renal disease. However, it is associated with weight gain and metabolic abnormalities, which adversely impact transplant outcomes. OBJECTIVE: The objective of this study was to identify the risk factors of one-year weight gain after renal transplantation. METHODS: A retrospective cohort study was conducted with 374 patients that underwent kidney transplantation between January 2006 and July 2013. Clinical and laboratory variables were collected from electronic records, and the outcome of interest was weight gain during the first year after renal transplantation. The data were reported as mean ± standard deviation, median (interquartile range) or number of subjects (%). The association between variables were assessed via chi-square test and ANOVA. For analysis of risk factors related to the outcomes of interest, multivariable logistic regression models were used. RESULTS: There were 181 (48.4%) female patients, 334 (89.3%) with white ethnicity and the mean age was 44.4 ± 12.8 years. The mean BMI pre-transplant was 24.7 ± 4.1 kg/m2, and 35 (9.9%) patients were classified as obese; 119 (33.6%) as overweight; 187 (52.8%) as normal weight; and 13 (3.7%) as malnourished. After one year of follow-up, the mean BMI was 26.2 ± 5.0 kg/m2, and 61 (17.3%) patients were classified as obese; 133 (37.8%) as overweight; 148 (42.0%) as normal weight; and 10 (2.8%) as malnourished. Weight gain was observed in 72.7% patients, and the average increase was 7.12 ± 5.9 kg. The female gender, lower pre-transplant body weight, lower number of hospitalizations, and a kidney received from a living donor were associated with weight gain by more than 5% in the first year post-transplant. CONCLUSION: Female gender and lower pre-transplant body weight were independently associated with weight gain by more than 5% in the first year after kidney transplantation; lower rates of hospitalization and donation from living donors were also risk factors for this outcome.

Body Fat Estimation in Kidney Transplant Recipients: Skinfolds Thickness Compared With Dual-Energy X-Ray Absorptiometry.

OBJECTIVE(S): The aim of the study was to compare the method of estimating the body fat percentage (BF%) by skinfold thickness to dual-energy X-ray absorptiometry (DEXA) in kidney transplant recipients. DESIGN AND METHODS: This is a longitudinal study that evaluated patients at 3 (n = 46) and 12 months (n = 37) after kidney transplantation at Hospital de Clínicas in Porto Alegre, Brazil. The Durnin and Womersley equation was used to estimate the body density, and the Siri equation was used to estimate BF%, using measurements of 4 skinfolds: biceps, triceps, subscapular, and suprailiac. DEXA was used as a reference. Paired t-test, Pearson correlation coefficient, Bland and Altman plots, and receiver operating characteristic curves adjusted by gender were used for statistical assessment. RESULTS: There was a positive correlation between the methods at 3 (r = 0.783; P < .001) and at 12 months (r = 0.824; P < .001) after transplantation. The BF% values were underestimated by skinfolds when compared with DEXA at 3 (29.43 ± 9.64% vs. 33.16 ± 8.74%; P < .001) and 12 months (29.84 ± 8.40% vs. 33.93 ± 9.13%; P < .001). According to the Bland and Altman analyses, the mean difference between both methods was 3.72 ± 6.11% (95% confidence interval: -15.7 to 8.3%) at 3 months and 4.09 ± 5.24% (95% confidence interval: -14.4 to 6.2%) at 12 months. The skinfold equation was a good predictor of high fat percentage when compared with DEXA at 3 (area under the curve and 95% confidence interval = 0.873 [0.766-0.980]; P = .004) and 12 months after kidney transplantation (area under the curve and 95% confidence interval = 0.857 [0.731-0.983]; P = .004). CONCLUSION(S): The skinfold thickness underestimated the BF% when compared with DEXA, but the 2 methods presented a modest correlation and agreement at 3 and 12 months after kidney transplantation. The skinfold thickness also presented a modest performance to detect patients with increased BF% at both times.

Association between progranulin serum levels and dietary intake.

INTRODUCTION: Progranulin (PGRN) is secreted by adipose tissue and has been linked to obesity, insulin resistance and type 2 diabetes mellitus. There is evidence that a high fat diet increases PGRN expression in rodent adipose tissue. In humans, the relationship between diet composition and concentration of PGRN is still unknown. OBJECTIVE: To investigate the association between dietary intake and serum PGRN levels. METHODS: This is an exploratory cross-sectional study including 85 subjects. Demographic, clinical, laboratory and anthropometric data were collected. Serum PGRN was determined by enzyme-linked immunosorbent assay after overnight fasting. Dietary intake was assessed by food frequency questionnaire validated for Brazilian southern population. Focused principal component analyses (FPCA) was used to verify the association of dietary components and food groups with PGRN levels. Sensitivity analyses were performed including only subjects with reporting according to the Goldberg and Black cut-offs of energy intake-energy expenditure ratio between 0.76 and 1.24. RESULTS: The median PGRN was 51.96 (42.18 to 68.30) ng/mL. Analyzing all sample, the FPCA showed no association of serum PGRN with total energy, protein, carbohydrate, fat and its types, fiber intake and dietary glycemic index; but a significant and positive association between solid fats and PGRN levels (p<0.05). Including only subjects with reporting according cut-off of energy intake-energy expenditure ratio between 0.76 and 1.24, FCPA showed significant and positive association of serum PGRN with saturated fatty acids and solid fats intake (p<0.05). In this subgroup, PGRN correlated with saturated fatty acids (r = 0.341; p = 0.031). Solid fats intake was independently associated to serum PGRN (beta = 0.294; p = 0.004) in multivariate model. CONCLUSION: The dietary intake of solid fats, mainly represented by saturated fatty acids, is associated to serum PGRN concentration in human subjects.

Progranulin serum levels in human kidney transplant recipients: A longitudinal study.

BACKGROUND: The adipokine progranulin has metabolic proprieties, playing a role in obesity and insulin resistance. Its levels seems to be dependent of renal function, since higher progranulin concentration is observed in patients with end-stage kidney disease. However, the effect of kidney transplantation on progranulin remains unknown. OBJECTIVE: To assess the serum progranulin levels in kidney transplant recipients before and after kidney transplantation. METHODS: Forty-six prospective kidney transplant recipients were included in this longitudinal study. They were evaluated before transplantation and at three and twelve months after transplantation. Clinical, anthropometric and laboratorial measurements were assessed. Progranulin was determined with enzyme-linked immunosorbent assays. RESULTS: Serum progranulin significantly decreased in the early period after transplantation (from 72.78 ± 2.86 ng/mL before transplantation to 40.65 ± 1.49 ng/mL at three months; p<0.01) and increased at one year (53.15 ± 2.55 ng/mL; p<0.01 vs. three months), remaining significantly lower than before transplantation (p<0.01) (pover time<0.01). At one year after transplantation, there was a significant increase in body mass index, trunk fat and waist circumference compared to immediate period after transplantation. Progranulin was associated with waist circumference and fasting plasma glucose after adjusted for age, gender, study period, glomerular filtration rate, interleukin-6, high sensitivity C reactive protein and adiponectin. CONCLUSION: Progranulin serum levels are increased before transplantation and a reduction is observed in the early period after transplantation, possibly attributed to an improvement in renal function. At one year after transplantation, an increment in progranulin is observed, seems to be independent of glomerular filtration, and remained significantly lower than before transplantation.

Intestinal microbiota changes after solid organ transplantation: a systematic review

Introduction: The intestinal microbiota may undergo changes after solid organ transplantation. The purpose of this systematic review was to characterize the intestinal microbiota of patients undergoing solid organ transplantation. Methods: MEDLINE, EMBASE and Cochrane Library databases were searched from inception to July 21, 2017. Studies of patients undergoing solid organ transplantation that evaluated changes in intestinal microbiota composition and one of the following outcomes were included: post-transplant weight, new-onset diabetes after transplantation, delayed graft function, acute rejection, graft and patient survival, and post-transplant infections. Results: Out of 765 studies found in this search, two studies (86 patients) fulfilled inclusion criteria. Both studies assessed kidney transplantation recipients, and a reduction in bacterial species diversity after transplantation was observed. Changes in intestinal microbiota were associated with acute rejection in both studies. One study reported diarrhea and urinary infections, while the other one reported urinary and respiratory infections. None of them reported other outcomes of interest. Conclusion: Changes in intestinal microbiota were observed after kidney transplantation, and they were associated with higher incidence of acute rejection and infections in transplant recipients. However, data are still scarce and more studies are needed to evaluate if microbiota changes have an impact on post-transplant outcomes. (AU)

Effect of an intensive nutrition intervention of a high protein and low glycemic-index diet on weight of kidney transplant recipients: study protocol for a randomized clinical trial.

BACKGROUND: Excessive weight gain is commonly observed within the first year after kidney transplantation and is associated with negative outcomes, such as graft loss and cardiovascular events. The purpose of this study is to evaluate the effect of a high protein and low glycemic-index diet on preventing weight gain after kidney transplantation. METHODS: We designed a prospective, single-center, open-label, randomized controlled study to compare the efficacy of a high protein (1.3-1.4 g/kg/day) and low-glycemic index diet versus a conventional diet (0.8-1.0 g/kg/day of protein) on preventing weight gain after kidney transplantation. A total of 120 eligible patients 2 months after transplantation will be recruited. Patients with an estimated glomerular filtration rate through the modification of diet of renal disease (MDRD) formula < 30 mL/min/1.73 m2 or urinary albumin excretion > 300 mg/24 h will be excluded. Patients' diets will be allocated through simple sequential randomization. Patients will be followed-up for 12 months with nine clinic appointments with a dietitian and the evaluations will include nutritional assessment (anthropometrics, body composition, and resting metabolic rate) and laboratory tests. The primary outcome is weight maintenance or body weight gain under 5% after 12 months. Secondary outcomes include body composition, resting metabolic rate, satiety sensation, kidney function, and other metabolic parameters. DISCUSSION: Diets with higher protein content and lower glycemic index may lead to weight loss because of higher satiety sensation. However, there is a concern about the association of high protein intake and kidney damage. Nevertheless, there is little evidence on the impact of high protein intake on long-term kidney function outcome. Therefore, we designed a study to test if a high protein diet with low-glycemic index will be an effective and safe nutritional intervention to prevent weight gain in kidney transplant patients. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02883777 . Registered on 3 August 2016.