title: Complement C3 Is the Strongest Predictor of Whole-Body Insulin Sensitivity in Psoriatic Arthritis.
abstract: OBJECTIVE
  To evaluate the correlation between inflammatory measures and whole-body insulin sensitivity in psoriatic arthritis (PsA) patients.
  
  
  METHODS
  For the present study, 40 nondiabetic PsA patients were recruited. A standard oral glucose tolerance test (OGTT) was performed. The insulin sensitivity index (ISI), insulinogenic index (IGI) and oral disposition index (ODI) were calculated from dynamic values of glucose and insulin obtained during OGTT.
  
  
  RESULTS
  In our study population, mean ISI was 3.5 ± 2.5, median IGI was 1.2 (0.7-1.8), mean ODI 4.5 ± 4.5. In univariate correlation analysis, ISI correlated inversely with systolic blood pressure (sBP) (R = -0.52, p = 0.001), diastolic blood pressure (dBP) (R = -0.45, p = 0.004) and complement C3 (R = -0.43, p = 0.006) and ODI correlated inversely with sBP (R = -0.38, p = 0.02), dBP (R = -0.35, p = 0.03) and complement C3 (R = -0.37, p = 0.02). No significant correlations were found between analyzed variables and IGI. In a stepwise multiple regression, only complement C3 entered in the regression equation and accounted for approximately 50% of the variance of ISI. Using a receiver operating characteristic (ROC) curve we identified the best cut-off for complement C3 of 1.32 g/L that yielded a sensitivity of 56% and a specificity of 96% for classification of insulin resistant patients.
  
  
  CONCLUSIONS
  In conclusion, our data suggest that serum complement C3 could represent a useful marker of whole-body insulin sensitivity in PsA patients.
authors.affiliation: Department of Health Sciences, University of Catanzaro "Magna Graecia", Catanzaro, Italy.|Rheumatology Department of Lucania, San Carlo Hospital of Potenza and Madonna delle Grazie Hospital of Matera, Potenza, Italy.
authors.forename: Francesco
authors.identifier: http://orcid.org/0000-0001-8194-8642
authors.initials: F
authors.lastname: Ursini
authors.affiliation: Rheumatology Department of Lucania, San Carlo Hospital of Potenza and Madonna delle Grazie Hospital of Matera, Potenza, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: D'Angelo
authors.affiliation: Department of Health Sciences, University of Catanzaro "Magna Graecia", Catanzaro, Italy.
authors.forename: Emilio
authors.initials: E
authors.lastname: Russo
authors.affiliation: Department of Health Sciences, University of Catanzaro "Magna Graecia", Catanzaro, Italy.
authors.forename: Kassandra
authors.initials: K
authors.lastname: Nicolosi
authors.affiliation: Pugliese-Ciaccio Hospital, Catanzaro, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gallucci
authors.affiliation: Department of Biomedicine and Prevention, University Tor Vergata, Rome, Italy.
authors.forename: Agostino
authors.initials: A
authors.lastname: Chiaravalloti
authors.affiliation: Department of Health Sciences, University of Catanzaro "Magna Graecia", Catanzaro, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Bruno
authors.affiliation: Department of Health Sciences, University of Catanzaro "Magna Graecia", Catanzaro, Italy.
authors.forename: Saverio
authors.initials: S
authors.lastname: Naty
authors.affiliation: Department of Health Sciences, University of Catanzaro "Magna Graecia", Catanzaro, Italy.
authors.forename: Giovambattista
authors.initials: G
authors.lastname: De Sarro
authors.affiliation: Rheumatology Department of Lucania, San Carlo Hospital of Potenza and Madonna delle Grazie Hospital of Matera, Potenza, Italy.
authors.forename: Ignazio
authors.initials: I
authors.lastname: Olivieri
authors.affiliation: Department of Health Sciences, University of Catanzaro "Magna Graecia", Catanzaro, Italy.
authors.forename: Rosa Daniela
authors.initials: RD
authors.lastname: Grembiale