title: Consumption of nitrate containing vegetables and the risk of chronic kidney disease: Tehran Lipid and Glucose Study.
abstract: BACKGROUND
  There is growing evidence regarding the potential properties of nitrate-rich foods in development of chronic diseases. In this study, we investigated the association of nitrate-containing vegetables (NCVs) and the risk of chronic kidney disease (CKD).
  
  
  METHODS
  We evaluated 1546 eligible adult participants of the Tehran Lipid and Glucose Study (TLGS), at baseline (2006-2008) and again after 3 years (2009-2011). Dietary intake was collected using the validated semi-quantitative food frequency questionnaire. Nitrate-containing vegetables and its categories including high-, medium-, and low-nitrate vegetables were defined. Estimated glomerular filtration rate (eGFR) and CKD were defined. Association between NCVs and CKD in the cross-sectional phase and the predictability of NCVs consumption in CKD occurrence were assessed using multivariable logistic regression models with adjustment for potential confounders.
  
  
  RESULTS
  Mean dietary intake of energy-adjusted NCVs was 298.0 ± 177.3 g/day. Highest compared to the lowest tertile of NCVs was accompanied with a significantly lower mean eGFR (76.6 vs. 83.3, mL/min/1.73 m(2), p < 0.001) and a higher prevalence of CKD (21.7 vs. 9.9%, p < 0.001). At baseline, higher intake of high-NCVs was associated with a 48% higher chance of having CKD (OR = 1.48, 95% CI = 1.05-2.13). After 3 years of follow-up, there was no significant association between consumption of total NCVs and its categories with the occurrence of CKD.
  
  
  CONCLUSIONS
  Considering the lack of association between high-NCVs intakes and the risk of CKD in prospective analysis, additional research is recommended to clarify possible effect of nitrate intakes from vegetables on kidney function.
authors.affiliation: a Nutrition and Endocrine Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran ;
authors.forename: Parvin
authors.initials: P
authors.lastname: Mirmiran
authors.affiliation: a Nutrition and Endocrine Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran ;
authors.forename: Zahra
authors.initials: Z
authors.lastname: Bahadoran
authors.affiliation: a Nutrition and Endocrine Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran ;
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Golzarand
authors.affiliation: a Nutrition and Endocrine Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran ;
authors.forename: Golaleh
authors.initials: G
authors.lastname: Asghari
authors.affiliation: b Endocrine Research Center, Research Institute for Endocrine Sciences , Shahid Beheshti University of Medical Sciences , Tehran , Iran.
authors.forename: Fereidoun
authors.initials: F
authors.lastname: Azizi
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004032:Diet; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007492:Iran / Q000453:epidemiology; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009566:Nitrates / Q000009:adverse effects / Q000032:analysis*; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology*; D012307:Risk Factors; D014675:Vegetables
chemical_list: D009566:Nitrates
keywords: Chronic kidney diseases; fruits and vegetables; nitrate