title: Association between serum immunoglobulin G4 concentration and cardiac function among elderly cardiology inpatients.
abstract: OBJECTIVE
  To study whether there is an association between serum immunoglobulin G4 (IgG4) concentration and cardiac function among cardiology inpatients.
  
  
  METHODS
  This retrospective study included 91 patients who had sinus rhythm. Of 91 patients, 70 patients (77%) were aged ≥ 60 years (elderly group) and the remaining 21 patients (23%) were aged <60 years (younger group).
  
  
  RESULTS
  Serum IgG4 concentrations were found to be negatively correlated with brain natriuretic peptide (BNP) and with E/e', an indicator for cardiac diastolic function in the elderly group, but not in the younger group. In contrast, IgG4 was significantly correlated with neither left ventricular mass nor ejection fraction in either group. Multivariate regression analysis showed that, in the elderly group, the association between IgG4 and E/e', and that between IgG4 and BNP, were independent of age, sex, systolic blood pressure and renal function; log-transformed IgG4 showed a negative association with log-transformed E/e' and log-transformed BNP, with a standardized correlation coefficient of -0.26 (95% confidence interval -0.49 to -0.03, P = 0.030 and -0.22 (95% confidence interval -0.44 to -0.11, P = 0.043), respectively.
  
  
  CONCLUSIONS
  Serum IgG4 concentration might be associated with cardiac diastolic function among elderly cardiology inpatients.
authors.affiliation: Department of Cardiology, Osaka Medical College, Osaka, Japan.
authors.forename: Kazushi
authors.initials: K
authors.lastname: Sakane
authors.forename: Kensaku
authors.initials: K
authors.lastname: Shibata
authors.forename: Shu-ichi
authors.initials: S
authors.lastname: Fujita
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Shimamoto
authors.forename: Takahide
authors.initials: T
authors.lastname: Ito
authors.forename: Shun
authors.initials: S
authors.lastname: Kizawa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Morita
authors.forename: Koichi
authors.initials: K
authors.lastname: Sohmiya
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hoshiga
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Ishizaka
mesh_terms: D000367:Age Factors; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D002318:Cardiovascular Diseases / Q000097:blood* / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006760:Hospitalization; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology; D020097:Natriuretic Peptide, Brain / Q000097:blood; D012189:Retrospective Studies; D013318:Stroke Volume / Q000502:physiology; D014463:Ultrasonography
chemical_list: D007074:Immunoglobulin G; D020097:Natriuretic Peptide, Brain
keywords: cardiac function; diastolic function; heart failure; hypertrophy