title: Procalcitonin and the inflammatory response to salt in essential hypertension: a randomized cross-over clinical trial.
abstract: OBJECTIVE
  Inflammation is considered as a major effector of arterial damage brought about by salt excess in animal models. In a randomized, single masked, cross-over study in 32 uncomplicated essential hypertensive patients, we assessed the effect of a short-term low-salt diet on biomarkers of innate immunity [procalcitonin (PCT), interleukin-6, C-reactive protein, and tumor necrosis factor-α (TNF-α)], adiponectin (ADPN, an anti-inflammatory cytokine), and leptin.
  
  
  METHODS
  Patients were randomized to either a 10-20 mmol sodium diet and sodium tablets (180 mEq/day) to achieve a 200 mmol intake per day or the same diet and identical placebo tablets, each for 2 weeks. At the end of each of these periods, all patients underwent a 24-h urine collection, a fasting blood sampling, and a 24 h ambulatory blood pressure monitoring.
  
  
  RESULTS
  In parallel with expected increase in plasma renin activity and aldosterone (P<0.001), both PCT (+33%) and TNF-α (9%) rose at low salt intake (P≤0.007) while ADPN underwent an opposite change (- 17%, P<0.001). In a linear regression analysis for repeated measurements, PCT was significantly and inversely related to urinary salt (weighted r=-0.27, P=0.03). Changes in inflammation biomarkers did not differ in salt-sensitive (n=7) and salt-resistant (n=25) patients.
  
  
  CONCLUSIONS
  In essential hypertensive patients, a very low salt diet generates a pro-inflammatory phenotype characterized by an increase in PCT and TNF-α and an opposite effect on an anti-inflammatory cytokine like ADPN.
authors.affiliation: CNR-IBIM Clinical Epidemiology and Pathophysiology of Renal Diseases and Hypertension, Dialysis and Transplantation Unit of Reggio Calabria, Reggio Calabria, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Mallamaci
authors.forename: Daniela
authors.initials: D
authors.lastname: Leonardis
authors.forename: Patrizia
authors.initials: P
authors.lastname: Pizzini
authors.forename: Sebastiano
authors.initials: S
authors.lastname: Cutrupi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Tripepi
authors.forename: Carmine
authors.initials: C
authors.lastname: Zoccali
mesh_terms: D000450:Aldosterone / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D018592:Cross-Over Studies; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D007249:Inflammation / Q000139:chemically induced*; D010919:Placebos; D011498:Protein Precursors / Q000097:blood*; D012083:Renin / Q000097:blood; D016037:Single-Blind Method; D017673:Sodium Chloride, Dietary / Q000009:adverse effects*
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D010919:Placebos; D011498:Protein Precursors; D017673:Sodium Chloride, Dietary; D000450:Aldosterone; D002116:Calcitonin; D012083:Renin; D015740:Calcitonin Gene-Related Peptide