High-Normal Protein Intake Is Not Associated With Faster Renal Function Deterioration in Patients With Type 2 Diabetes: A Prospective Analysis in the DIALECT Cohort

Abstract

OBJECTIVE To study the prospective association between dietary protein intake and renal function deterioration in patients with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS Prospective analyses were performed in data of 382 patients of the Diabetes and Lifestyle Cohort Twente (DIALECT) study. Dietary protein intake was determined by the Maroni equation from 24-h urinary urea excretion. Renal function deterioration was defined as need for renal replacement therapy or a persistent increase of ≥50% in serum creatinine. Cox proportional hazards models were used to calculate hazard ratios (HRs) for the association between dietary protein intake and renal function deterioration. Threshold levels represent the dietary protein intake at which there was a significantly increased and reduced hazard of renal function deterioration. RESULTS Renal function deterioration occurred in 53 patients (14%), with a median follow-up duration of 6 (interquartile range 5–9) years. Mean dietary protein intake was 91 ± 27 g/day (1.22 ± 0.33 g/kg ideal body weight/day). Dietary protein intake was inversely associated with renal function deterioration (HR 0.62 [95% CI 0.44–0.90]). Patients with an intake <92 g/day had an increased hazard for renal function deterioration (HR 1.44 [95% CI 1.00–2.06]), while patients with an intake >163 g/day had a decreased hazard for renal function deterioration (HR 0.42 [95% CI 0.18–1.00]). Regarding dietary protein intake per kilogram body weight, patients with an intake <1.08 g/kg/day had an increased hazard for renal function deterioration (HR 1.63 [95% CI 1.00–2.65]). CONCLUSIONS In patients with T2D, unrestricted dietary protein intake was not associated with an increased hazard of renal function deterioration. Therefore, substituting carbohydrates with dietary protein is not contraindicated as a part of T2D management, although it may have a positive effect on body weight while minimizing loss of muscle mass.

Response to Comment on Oosterwijk et al. High-Normal Protein Intake Is Not Associated With Faster Renal Function Deterioration in Patients With Type 2 Diabetes: A Prospective Analysis in the DIALECT Cohort. Diabetes Care 2022;45:35–41

“…In agreement with expectations expressed in the comment letter by Heyman et al (1), most of the patients (72%) included in the Diabetes and Lifestyle Cohort Twente used agents that exert renin angiotensin aldosterone system (RAAS) blockade (2). None of the included patients used an inhibitor of sodium-glucose cotransporter 2 (SGLT2).…”

Comment on Oosterwijk et al. High-Normal Protein Intake Is Not Associated With Faster Renal Function Deterioration in Patients With Type 2 Diabetes: A Prospective Analysis in the DIALECT Cohort. Diabetes Care 2022;45:35–41

“…In their outstanding report, Oosterwijk et al ( 1 ) show that renal outcome is superior in patients with diabetes fed on a high-protein diet compared with that of patients subjected to normal or low-protein diet. These unforeseen and surprising findings contradict our common practice, as for decades, low-protein diet has been recommended especially for patients with chronic kidney disease (CKD), a strategy aimed at slowing its progression.…”

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

“…In clinical practice, to reach such a rather specific target for protein intake, it is strongly recommended to refer these patients with advanced CKD for counselling by a dietician, especially to prevent malnutrition. It is important to mention that recent findings from the observational DIALECT cohort demonstrated that a higher dietary protein intake, with an average of 1.22 ± 0.33 g/kg/day in persons with T2D, was not associated with faster renal function deterioration [10], and these results apply to the full range of kidney function. It appears, therefore, that when counselling these patients, it is more important to avoid protein intake from being too low, rather than too high, and that it is rather safe for long-term kidney function to accept higher protein intake.…”

“…It has very recently been found in T2D that higher dietary protein intake is not associated with faster renal function deterioration, which applies to the full range of kidney function [10]. A beneficial association between dietary protein intake and development of CKD has also been previously found in the Ongoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) [11].…”