Effect of Intensive Dietetic Care on Weight Gain and Metabolic Risk after Renal Transplant

Abstract

Kidney transplant is the preferred treatment for ESRD, however renal transplant recipients are at risk of gaining weight post transplant. This weight gain is often associated with the addition of cardiovascular risk factors and deleterious metabolic changes leading to long term complications. Implementing lifestyle interventions including frequent individualised dietary and physical activity advice may minimise post transplant weight gain and therefore lessen the risk of associated metabolic long term complications. The aim of this pilot trial was to investigate whether implementation of an intensive nutrition intervention, including physical activity advice, following kidney transplantation is effective in reducing weight gain in the first 6 months post-transplant. This pilot study was undertaken at Auckland City Hospital with renal transplant recipients who reside within the Auckland region. Participants met the following inclusion criteria: aged >18 years, stable graft function as determined by the investigator or the patients treating physician, willing and able to participate in all trial procedures for the 12 month trial duration and the ability to provide written consent. All participants were randomised to receive either intensive nutrition intervention or standard care. The participants in the standard care (STD) group received dietitian advice at 1, 3 and 12 months post transplant, the current standard of care for post transplant patients at Auckland City Hospital. Those allocated to the intensive nutrition intervention (INT) group received standard care with 8 additional dietitian appointments and individualised physical activity advice at 2, 3 and 6 months post transplant. Weight, anthropometry, dual energy x-ray absorptiometry for fat mass and fat-free mass (FFM) , neutron activation analysis for total body protein (TBP), resting energy expenditure (REE), total body potassium (TBK), total body water, biochemistry, physical activity (PA) level and quality of life (SF-36) measurements were taken at the baseline (1 month), 3 and 6 month assessments. Twenty-eight renal transplant recipients met the criteria for this trial, 27 of these completed the baseline assessment. One participant declined participation prior to the first baseline assessment and 5 withdrew from the trial during the 6 month follow-up period. There were no significant differences in baseline characteristics between the groups. At 6 months follow up intensive dietetic care did not result in any significant changes in weight between the STD and INT group (p=0.771). Over the 6-month period the changes in anthropometry and measures of body composition did not differ significantly between the groups. For the groups combined, TBP increased significantly over this period (p=0.024). REE did not change significantly between the groups over time, even after indexing against FFM or TBK. No statistical difference was seen for total physical activity minutes assessed by the PA questionnaire or grip strength and gait speed. Sit-to-stand time tended to show a greater improvement over time in the INT group (p=0.053). Both PA and gait speed increased significantly over the 6 months in the combined groups. Incidence of MS and NODAT at 6 months did not differ between the groups, with only one participant developing NODAT during the trial (in the STD group). However, more participants in the STD group were overweight, obese and centrally obese at the 6 month follow up, though this difference was not significant. No differences were seen for lipid profiles between the groups. However, both the STD and INT group had elevated LDL and total cholesterol at 6 months follow up. HbA1c and blood glucose were not significantly different between the groups but a time effect was seen with increases over the first 3 months followed by a reduction in glucose but not HBA1c. During the 6 month follow up, quality of life (QOL) showed General Health was the only domain with a significant time x group interaction (p=0.025), with no significant change in the INT group while in the STD group the score increased from baseline to 3 months and then decreased. QOL in all participants showed a significant improvement over time in all domains except Mental Health. Comparison with NZ norms showed no significant differences. Reported total energy, protein, fat and saturated fat intake did not change significantly over the 6 months in the intensive group. There was a decreasing trend observed in total energy intake from baseline, though this change was not significant. At 6 months follow up the intensive group did not meet the dietary recommendations provided by the dietitian, indicating poor dietary adherence. This research failed to show any benefits of intensive dietetic care on weight, anthropometric measures, body composition and metabolic risk following a renal transplant. Although the results do not show any advantage with more frequent dietetic input, there were several limitations to this study and a short follow up duration. Despite this, ongoing research with this group is encouraged to provide further insight into the effects of 12 months of dietetic input and to direct future research.