Diet composition among renal transplant recipients : Focusing on prevention of cardiovascular disease

Abstract

Background: Cardiovascular disease (CVD) is one of the major causes of death among renal transplant recipients (RTRs). Prevalence of both hypertension, glucoseintoleranse, dyslipidemia, and overweight are shown to be high. These are risk factors that may be influenced by diet. Renal failure is still present after transplantation. According to National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NFK KDOQI) children with CKD stage 2 to 5 after transplantation require dietary management in the same way as children with similar GFRs before transplantation.

Objectives: The aim of this master thesis was to evaluate the need for dietary treatment among Norwegian paediatric RTRs. Dietary composition was evaluated in relation to prevention of CVD. The diet in RTRs was compared to the diet in healthy children and adolescents to evaluate the influence of prior CKD on the current diet. The study also aimed to estimate the prevalence of different stages of CKD, and to evaluate whether the recorded diet was in accordance to NKF KDOQI guidelines regarding restrictions in intake of protein and phosphorous.

Methods: This was a prospective cross-sectional study in 16 9-15 year-old RTRs. Dietary data was collected using pre-coded food diaries for four days. A short questionnaire was used to collect data regarding dietetic counselling. Data from the UNGKOST2000 survey were used as control data. Data collected in the HENT-study at Rikshospitalet were used when evaluating the prevalence of the different stages of CKD.

Results: Diet composition among the paediatric RTRs was not optimal for prevention of CVD; percentage of energy from saturated fat was high, percentage of energy from added sugar was higher than recommended, intake of iron was low among the girls, and intake of dietary fibre, and fruits and vegetables was low. The RTRs had a higher percentage of energy from protein and fat, and a lower percentage form carbohydrates compared to the healthy control subjects. Sixty-two percent of the participants in the HENT-study had a GFR corresponding to CKD stage 3-4. Intake of protein and phosphorous were higher than recommended in the NKF KDOQI guidelines. Eighty percent of the RTRs participating in the study would like to have dietetic counselling after the transplantation.

Conclusion: The RTRs do not necessarily have a dietary composition very different from the population in general. Still, some improvement in diet can be done in relation to prevention of CVD. Dietary management among RTRs in the same way as children with similar GFRs before transplantation may be beneficial. Considering their elevated risk of CVD, a healthy lifestyle should be strongly emphasised for these patients. By including dietetic counselling as part of the transplantation program, every patient would be provided dietary guidance, and an important signal would be sent to the patients that diet and an overall healthy lifestyle is an important part of the treatment and management after a renal transplantation.