title: Metabolic Syndrome and Kidney Stone Disease: A Systematic Review of Literature.
abstract: BACKGROUND
  Worldwide obesity has more than doubled since 1980 with more than 600 million obese patients in 2014. Metabolic syndrome (MetS) is the co-occurrence of metabolic abnormalities, including centrally distributed obesity, hypertension, dyslipidemia, and hyperglycemia. With a concurrent rise in the incidence of kidney stone disease, we wanted to conduct a systematic review focused on the association of MetS to nephrolithiasis.
  
  
  METHODS
  A systematic review was performed according to the Cochrane and preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines on all English language articles for the following relevant keywords: association, metabolic syndrome, metabolic syndrome traits, syndrome X, nephrolithiasis, kidney stones, and renal calculi. Our inclusion criteria were studies comparing the prevalence of kidney stone disease in patients with and without MetS.
  
  
  RESULTS
  The initial literature search identified 355 potentially relevant studies. After screening, 22 full text articles were reviewed and 6 (219,255 patients) were included in the final review. All studies displayed increasing odds of nephrolithiasis with increasing number of MetS traits, where patients with three or more MetS traits tended to have a higher prevalence of nephrolithiasis. Studies also showed different significant components of MetS contributing to nephrolithiasis.
  
  
  CONCLUSIONS
  Our review shows a definite association of MetS with kidney stone disease. Although multifactorial in etiology, lifestyle and dietary factors seem to be increasingly important in prevention of stone disease.
authors.affiliation: 1 Department of Urology, University Hospital Southampton NHS Foundation Trust , Southampton, United Kingdom .
authors.forename: Yee
authors.initials: Y
authors.lastname: Wong
authors.affiliation: 2 Department of Chemical Pathology, University Hospital Southampton NHS Foundation Trust , Southampton, United Kingdom .
authors.forename: Paul
authors.initials: P
authors.lastname: Cook
authors.affiliation: 3 Public Health, Primary Care and Population Sciences (PCPS), University Hospital Southampton NHS Foundation Trust , Southampton, United Kingdom .
authors.forename: Paul
authors.initials: P
authors.lastname: Roderick
authors.affiliation: 1 Department of Urology, University Hospital Southampton NHS Foundation Trust , Southampton, United Kingdom .
authors.forename: Bhaskar K
authors.initials: BK
authors.lastname: Somani
mesh_terms: D006801:Humans; D007669:Kidney Calculi / Q000453:epidemiology*; D024821:Metabolic Syndrome / Q000453:epidemiology*; D016017:Odds Ratio; D015995:Prevalence; D012307:Risk Factors