title: Association of dietary protein and dairy intakes and change in renal function: results from the population-based longitudinal Doetinchem cohort study.
abstract: Evidence has suggested that protein from dairy may be less detrimental to renal health than protein from nondairy products. However, to our knowledge, no previous studies have used cystatin C-based measures of the estimated glomerular filtration rate (eGFR).
  
  
  
  We investigated the associations of sources of protein and dairy with the change in the eGFR in persons with a normal or mildly decreased eGFR.
  
  
  
  We included 3798 participants, aged 26-65 y, from the Doetinchem Cohort study who were examined ≥3 times 5 y apart. Intakes of protein and dairy and subtypes of protein and dairy were assessed at each round. With the use of the Chronic Kidney Disease Epidemiology Collaboration equation, the eGFR was estimated from cystatin C with all available samples per participant examined in one assay run. Generalized estimating equation models, which were adjusted for lifestyle, biological, and other dietary factors (monounsaturated fat, polyunsaturated fat, phosphorus, magnesium, calcium, and vitamin D) were performed.
  
  
  
  The mean baseline eGFR in the total cohort and in subjects with a mildly decreased eGFR (≥1 eGFR of 60-90 mL · min-1· 1.73 m-2during follow-up; n = 1326) was 108.6 and 95.2 mL · min-1· 1.73 m-2, and the mean annual decline in both groups was 1.01 and 1.34 mL · min-1· 1.73 m-2, respectively. Intakes of total, vegetable, animal, and nondairy protein, dairy protein, cheese, total dairy, high-fat dairy, and fermented dairy were not associated with eGFR changes. In individuals with a mildly decreased eGFR, higher consumption of milk, milk products, and low-fat dairy was associated with less annual decline in the eGFR (P-trend = 0.003). These associations were partially explained by dietary components of dairy (monounsaturated fat, polyunsaturated fat, phosphorus, magnesium, calcium, and vitamin D; P-trend < 0.04).
  
  
  
  Higher low-fat dairy consumption, but not sources of protein, is associated with less annual decline in the eGFR, particularly in individuals with a mildly decreased eGFR. These associations are partly attributable to other major components of dairy. Confirmation of these results will improve our ability to understand the role of dairy consumption in the prevention of renal dysfunction.
authors.affiliation: Center for Nutrition, Prevention and Health Services, National Institute of Public Health and the Environment, Bilthoven, Netherlands; gerrie-cor.herber@rivm.nl.|Department of Internal Medicine and Cardiovascular Research Institute, Maastricht University Medical Center, Maastricht, Netherlands.
authors.forename: Gerrie-Cor M
authors.initials: GM
authors.lastname: Herber-Gast
authors.affiliation: Center for Nutrition, Prevention and Health Services, National Institute of Public Health and the Environment, Bilthoven, Netherlands.
authors.forename: Sander
authors.initials: S
authors.lastname: Biesbroek
authors.affiliation: Center for Nutrition, Prevention and Health Services, National Institute of Public Health and the Environment, Bilthoven, Netherlands.|Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, Netherlands; and.
authors.forename: Wm Monique
authors.initials: WM
authors.lastname: Verschuren
authors.affiliation: Department of Internal Medicine and Cardiovascular Research Institute, Maastricht University Medical Center, Maastricht, Netherlands.
authors.forename: Coen DA
authors.initials: CD
authors.lastname: Stehouwer
authors.affiliation: Department of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
authors.forename: Ron T
authors.initials: RT
authors.lastname: Gansevoort
authors.affiliation: Department of Nephrology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
authors.forename: Stephan Jl
authors.initials: SJ
authors.lastname: Bakker
authors.affiliation: Center for Nutrition, Prevention and Health Services, National Institute of Public Health and the Environment, Bilthoven, Netherlands.
authors.forename: Annemieke Mw
authors.initials: AM
authors.lastname: Spijkerman
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D002136:Calcium, Dietary / Q000008:administration & dosage; D015331:Cohort Studies; D055316:Cystatin C / Q000652:urine; D003611:Dairy Products / Q000032:analysis*; D018752:Diet, Fat-Restricted; D004041:Dietary Fats / Q000008:administration & dosage; D004044:Dietary Proteins / Q000008:administration & dosage*; D002149:Energy Intake; D015444:Exercise; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000502:physiology*; D008137:Longitudinal Studies; D008274:Magnesium / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D015596:Nutrition Assessment; D010758:Phosphorus / Q000008:administration & dosage; D012307:Risk Factors; D014807:Vitamin D / Q000008:administration & dosage
chemical_list: D002136:Calcium, Dietary; D055316:Cystatin C; D004041:Dietary Fats; D004044:Dietary Proteins; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D014807:Vitamin D; D010758:Phosphorus; D008274:Magnesium
keywords: dairy; dietary proteins; general population; longitudinal study; renal function