Impact of individualised dietary counselling on nutritional status and quality of life after kidney transplantation: a longitudinal study

Abstract

Kidney transplant recipients (KTRs) are at risk of malnutrition and obesity, which may impact their quality of life (QoL). Individual dietary counselling (IDC) can benefit KTRs’ nutritional status. This study aims to investigate the impact of IDC on nutritional status and QoL among KTRs. This study comprised three phases, which was conducted from March 2021 to August 2023. Participants aged 18 to 65 years were recruited from 108 Military Central Hospital in Hanoi, Vietnam. In Phase I, a longitudinal study was conducted to determine changes in nutritional status and QoL of 86 KTRs over a year. Before transplantation (T0), 46.6% of KTRs were malnourished (Nutrition Risk Index < 100). The number decreased to 20.9% one year after transplantation (T12) (p<0.05). Propotion of obesity (body mass index, BMI >25 kg/m2) remained (at 9.3%) from T0 to T12, but the change in BMI within each KTR was statistically significant (p<0.05). Incidence of metabolic syndrome among KTRs increased from 40.7% at T0 to 46.5% at T12. Malnutrition and obesity were identified as primary contributors to impaired kidney function, and these factors were linked to variations in QoL among KTRs even after accounting for sex, age, and other biochemical markers. Findings from Phase I served as a basic to develop a nutrition handbook for KTRs in Phase II. The handbook provided guidance on dietary intake to support KTRs. Content validation was involved by experts (n=6) and target audience (n=38). Phase II results showed that the handbook was concise and easy to understand. In Phase III, a 6-month randomised control trial involving 97 participants. Participants were randomly assigned to individualised dietary counselling (IDC, n=50) or control (CG, n=47) groups to assess the impact of IDC on nutritional status with the handbook as an intervention material. In IDC group, mean change in body weight between baseline and end-line measurements was -0.3kg. Energy intake (mean ± standard deviation: 30.6±10.4kcal/kg) and protein intake (1.3±0.4g/kg) remained consistent after intervention. Compared to CG group, dietary intake was moderately affected by the intervention in KTRs (eta-square, η2 >0.06, p<0.05). The six months of intervention has a small effect on clinical biomarkers such as blood pressure, fasting glucose and total cholesterol, and low-density lipoprotein cholesterol (η2 < 0.06, p<0.05). In conclusion, the nutritional status of KTRs improved significantly within one-year post-kidney transplantation. IDC had a moderate impact on maintaining dietary intake, and a small effect on biochemical markers improvements over six months. When resources permit, a nutrition management program with IDC should be provided to all KTRs to help improve QoL and overall health