Prevalence and Risk of Protein-Energy Wasting Assessed by Subjective Global Assessment in Older Adults With Advanced Chronic Kidney Disease: Results From the EQUAL Study

Abstract

Objectives: Prevalence and risk factors for protein-energy wasting (PEW) are poorly studied in the nondialysis, older population with advanced chronic kidney disease (CKD). Our aim was to evaluate the prevalence of PEW in advanced stage CKD patients aged greater than 65 years. Furthermore, we aimed to describe risk factors for PEW in the overall study population and among obese individuals.

Design: Prospective observational cohort study.

Methods: The EQUAL study, a European Quality Study on treatment in advanced chronic kidney disease, is a multicenter prospective observational cohort study in six European countries. We included patients aged ≥65 years with incident glomerular filtration rate <20mL/min/1.73m² not on dialysis attending nephrology care. PEW was assessed by 7-point Subjective Global Assessment (7-p SGA).

Results: In general, the study cohort (n = 1,334) was overweight (mean body mass index [BMI] 28.4 kg/m²). The majority of the patients had a normal nutritional status (SGA 6-7), 26% had moderate PEW (SGA 3-5), and less than 1% had severe PEW (SGA 1-2). Muscle wasting and loss of fat tissue were the most frequent alterations according to the SGA subscales, especially in those aged >80 years. The prevalence of PEW was higher among women, increased with age, and was higher in those with depression/dementia. PEW was the most common in those with underweight (BMI <22 kg/m²), 55% or normal weight (BMI 22-25 kg/m²), 40%. In obese individuals (BMI >30 kg/m²), 25% were diagnosed with protein wasting. Risk factors for SGA ≤5 in obese people were similar to those for the overall study population.

Conclusion: This European multicenter study shows that the prevalence of PEW is high in patients with advanced CKD aged >65 years. The risk of PEW increases substantially with age and is commonly characterized by muscle wasting. Our study suggests that focus on nutrition should start early in the follow-up of older adults with CKD.