#1884 Slowing kidney disease with weight loss: a randomised controlled feasibility study (SLOW-CKD Feasibility Study)
Authors: Conley Marguerite , Hepburn Kirsten , Mayr Hannah , Mudge David , Holland Justin , Tonges Tammy , Modderman Richard , Gerzina Sally , Johnson David W , Viecelli Andrea , Maclaughlin Helen 
Published: May 2024

Abstract

Background and Aims
Obesity is a modifiable risk factor for chronic kidney (CKD) and progression to kidney failure. Low energy diets (LEDs) (800 to 1000 kcal/day) are an established weight management strategy and have demonstrated the ability to facilitate 10 to 15 kg weight loss and induce diabetes remission. However, the use of LEDs in adults with CKD is limited and there have been no randomised controlled trials (RCT) exploring their use. Before initiating a definitive trial, there is first a need to assess feasibility and safety. The primary aim of this study was to test the feasibility, acceptability and safety of a low energy diet and weight management program in individuals with obesity and CKD.

Method
The SLOW-CKD Feasibility Study, a 6-month multi-centre RCT in kidney outpatient clinics in Brisbane Australia, targeted adults with stages 1-3 CKD and a body mass index (BMI) ≥ 30 kg m2 with proteinuria (urinary albumin to creatinine ratio &gt;3 mg/mmol). Participants wererandomised (1:1). The LED group followed a 3-month LED (800-1000 kcal/day) with meal replacements and low-calorie foods, with fortnightly dietitian support. Following this, participants entered a 3-month weight maintenance phase,emphasising healthy eating and commencing a physical activity program guided by an exercise physiologist. The usual care group was offered weight loss support through the kidney clinic, involving referral to a dietitian or weight loss program if agreeable. Primary outcomes included safety (study related serious adverse events [SAEs] and adverse events [aEs]) and feasibility (recruitment rate, retention rate, target weight loss). Secondary outcomes explored changes in anthropometry and clinical measures, patient-reported outcomes, and participant experiences through semi-structured interviews. Pre-defined safety and feasibility outcome criteria are presented in Table 1.

Results
Overall, 49 participants consented to participate (mean age 52.4 ± 3.8 years, 57% male). The incidence of SAEs was low and comparable between the two groups. There were two SAEs in the LED group (hypoglycaemia and acute kidney injury both requiring hospital admission) and one in the control (hypoglycaemia requiring hospital admission). The most common AE was hyperkalaemia with three episodes (&gt;6.0 mmol/L) in each group. Two of the three feasibility criteria were met deeming the intervention feasible—see Table 1. Mean weight loss for the initial 3-month study period was 10.6 kg ± 5.1 kg in the LED group and 0.7 kg ± 4.3 for the usual care group (p = &lt;0.00).

Conclusion
Our findings provide important preliminary evidence that LEDs are relatively safe, feasible, and demonstrate promising efficacy as a treatment option for obesity in adults with CKD. A definitive RCT exploring the use of LEDs to improve clinical outcomes and slow progression of CKD is warranted.