Personalized Nutrition in Patients with Type 2 Diabetes and Chronic Kidney Disease: The Two-Edged Sword of Dietary Protein Intake

In type 2 diabetes (T2D), there is a general and strong focus on carbohydrate restriction. However, this may have unwarranted consequences for those with concomitant chronic kidney disease (CKD) since decreasing intake of carbohydrates implies a higher proportion of dietary protein, which is of critical debate in patients with CKD due to its ambiguous implications in maintaining either kidney function or nutritional status. We evaluated adherence to the protein recommendations, taking into account the nutritional status of patients with T2D with or without CKD. Patients were divided in three groups according to their estimated Glomerular Filtration Rate (eGFR): mild to no CKD (eGFR > 60 mL/min/1.73 m(2)), moderate CKD (eGFR 30–60 mL/min/1.73 m(2)), or advanced CKD (eGFR < 30 mL/min/1.73 m(2)). Regarding adherence to the protein recommendations, 17% of the patients without advanced CKD consumed < 0.8 g/kg/day, 29% of the patients with moderate CKD consumed > 1.3 g/kg/day, and 60% of the patients with advanced CKD consumed > 1.0 g/kg/day. In addition, patients with moderate- or advanced CKD tend to have a lower muscle mass, normalized by height, compared to patients with mild to no CKD (p < 0.001), while body mass index was not significantly different between patients with or without CKD (p = 0.44). We found that although dietary protein restriction has not been indicated in either of the CKD stages, approximately 10% had a dietary protein intake < 0.8 g/kg/day, with accompanying risks of malnourishment and sarcopenia. Our main advice is to maintain a dietary protein intake of at least 0.8 g/kg/day in order to prevent patients from becoming malnourished and sarcopenic.