title: Long-term effects of moderate protein diet on renal function and low-grade inflammation in older adults with type 2 diabetes and chronic kidney disease.
abstract: OBJECTIVE
  The aim of this study was to determine the long-term effects of a moderate protein diet (MPD) on renal function, low-grade inflammation, and oxidative stress in older adults with type 2 diabetes, which to date are unclear.
  
  
  METHODS
  Seventy-four older adults with type 2 diabetes and chronic kidney disease (stage G3b-G4) were enrolled in the study. During the 4-wk baseline period (T0), all patients were asked to follow a normal protein diet regimen, providing 1.1 g/kg daily. Successively, all patients were asked to follow an MPD, for 36 mo, providing 0.7 g/kg daily, for only 6 d/wk. Patients who refused to follow an MPD treatment were included in the control (NPD [normal protein diet] group). During the 36 mo of the study, creatinine clearance, blood urea nitrogen, proteinuria, blood pressure, glycated hemoglobin (Hb)A1c, fat-free mass, low-grade inflammation (interleukin-6 and C-reactive protein) were evaluated monthly and oxidative stress (urinary 8-epiprostaglandin [Epi-PG]F2α) was evaluated every 3 mo.
  
  
  RESULTS
  During T0, mean creatinine clearance, proteinuria, blood urea nitrogen, blood pressure, HbA1c, fat free mass, low-grade inflammation, and oxidative stress were similar in both groups. After 36 mo, a significant reduction in decline of renal function was observed in the MPD group but not in controls (2.4 ± 0.2 versus 5.7 ± 0.5 mL·min·y, respectively; P < 0.05 versus control). Similarly, a significant reduction in proteinuria, serum interleukin-6, serum C-reactive protein, and urinary 8-Epi-PGF2α excretion, was observed in the MPD group (P < 0.05 versus NPD).
  
  
  CONCLUSIONS
  In older adults with type 2 diabetes, long-term effects of an MPD regimen are associated with a significant decline of renal function, proteinuria, low-grade inflammation, and oxidative stress without a change in fat-free mass.
authors.affiliation: Department of Medical, Surgical, Neurologic, Metabolic and Geriatric Sciences, Second University of Naples, Naples, Italy. Electronic address: mauro.giordano@unina2.it.
authors.forename: Mauro
authors.initials: M
authors.lastname: Giordano
authors.affiliation: Department of Medical, Surgical, Neurologic, Metabolic and Geriatric Sciences, Second University of Naples, Naples, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Ciarambino
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, University of Catania, Catania, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Castellino
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, University of Catania, Catania, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cataliotti
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, University of Catania, Catania, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Malatino
authors.affiliation: Department of Translational Medical Sciences, University of Naples "Federico II", Naples, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Ferrara
authors.affiliation: Department of Medical, Surgical, Neurologic, Metabolic and Geriatric Sciences, Second University of Naples, Naples, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Politi
authors.affiliation: Department of Medical, Surgical, Neurologic, Metabolic and Geriatric Sciences, Second University of Naples, Naples, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Paolisso
mesh_terms: D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications; D003928:Diabetic Nephropathies / Q000097:blood / Q000209:etiology; D004032:Diet; D018753:Diet, Protein-Restricted; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000009:adverse effects; D015237:Dinoprost / Q000031:analogs & derivatives / Q000097:blood; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000209:etiology; D015850:Interleukin-6 / Q000097:blood; D007668:Kidney / Q000187:drug effects* / Q000503:physiopathology; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D010349:Patient Compliance; D011507:Proteinuria / Q000209:etiology; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000209:etiology; D013997:Time Factors
chemical_list: D004044:Dietary Proteins; D015850:Interleukin-6; C075750:8-epi-prostaglandin F2alpha; D002097:C-Reactive Protein; D015237:Dinoprost
keywords: Decline of renal function; Elderly; FFM; Low-grade inflammation; Moderate protein diet; Proteinuria; Type 2 diabetes; Urinary 8-Epi-PGF 2 alpha