Beyond Renal Function: Malnutrition and Sarcopenia in ADPKD

Autosomal dominant polycystic kidney disease (ADPKD) is a multisystem disorder in which progressive renal, and frequently hepatic, enlargement drives a distinctive body-composition phenotype that is often poorly captured by conventional anthropometric measures. Converging evidence shows that a substantial proportion of adults develop protein-energy malnutrition and early sarcopenia, frequently overlooked due to elevated BMI, visceral adiposity and cyst-related abdominal mass. SGA, BIA and imaging-based studies identify intra-abdominal organomegaly as the dominant determinant of nutritional risk and a factor associated with accelerated eGFR decline, independent of baseline renal function, proteinuria and imaging class. Hallmark alterations, extracellular water expansion, reduced phase angle and loss of skeletal muscle mass, reflect a catabolic milieu driven by mass effect, metabolic dysregulation and glycolytic reprogramming of cyst-lining cells. These findings position malnutrition as an independent prognostic determinant in ADPKD and support the early incorporation of structured nutritional assessment and lean-mass-preserving strategies into routine care. Emerging dietary approaches show promise but remain investigational. Critical research gaps include the need for interventional trials and integrated longitudinal studies to define the therapeutic potential of nutritional optimization in modifying the trajectory of the disease.