title: Sibling risk of hospitalization for heart failure - A nationwide study.
abstract: BACKGROUND
  The familial risks of heart failure (HF) remain largely undetermined. This nationwide follow-up study aimed at determining risk of hospitalization for HF conferred by affected siblings.
  
  
  RESULTS
  Swedish Multi-generation Register data, with records of at least one full sibling available at start of follow-up, were linked to the Hospital Discharge Register data for 1987-2010. The oldest participants were aged 78years in 2010. Relative risks, standardized incidence ratios (SIRs), of HF hospitalization were calculated for individuals with siblings hospitalized with HF compared with those whose siblings were not. Adjustments were made for common HF comorbidities, age, time period, socioeconomic status and region. During the 24year follow-up (1987-2010) 23,212 individuals (7155 females), were hospitalized because of HF. From this total, 1121 had at least one full sibling hospitalized for HF. Sibling risks were generally similar for males and females. The SIR of HF hospitalization was 1.62 (95% confidence interval 1.54-1.70) for individuals with one affected sibling and 15.46 (12.82-18.50) for individuals with two affected siblings. The SIR conferred by one or more affected siblings was 2.67 (2.24-3.16) below the age of 50years, 1.92 (1.75-2.10) between 50 and 59years of age, 1.63 (1.52-1.76) between 60 and 69years of age, and 1.54 (1.38-1.71) between 70 and 78years of age. Spouses had low familial risks: SIR=1.04 (1.03-1.06).
  
  
  CONCLUSIONS
  Familial factors are important risk factors in HF, with particularly high risks among individuals with two or more affected siblings and in early onset of HF.
authors.affiliation: Center for Primary Health Care Research, Lund University and Region Skåne, Malmö, Sweden. Electronic address: magnus.lindgren@med.lu.se.
authors.forename: Magnus P
authors.initials: MP
authors.lastname: Lindgren
authors.affiliation: Molecular Epidemiology and Cardiology, Department of Clinical Sciences, Lund University and Skåne University Hospital, Lund, Sweden; Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, USA.
authors.forename: J Gustav
authors.initials: JG
authors.lastname: Smith
authors.affiliation: Center for Primary Health Care Research, Lund University and Region Skåne, Malmö, Sweden.
authors.forename: Xinjun
authors.initials: X
authors.lastname: Li
authors.affiliation: Center for Primary Health Care Research, Lund University and Region Skåne, Malmö, Sweden.
authors.forename: Jan
authors.initials: J
authors.lastname: Sundquist
authors.affiliation: Center for Primary Health Care Research, Lund University and Region Skåne, Malmö, Sweden.
authors.forename: Kristina
authors.initials: K
authors.lastname: Sundquist
authors.affiliation: Center for Primary Health Care Research, Lund University and Region Skåne, Malmö, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Zöller
mesh_terms: D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D020022:Genetic Predisposition to Disease; D006333:Heart Failure / Q000453:epidemiology* / Q000235:genetics / Q000628:therapy; D006760:Hospitalization / Q000639:trends*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D035781:Siblings; D013548:Sweden / Q000453:epidemiology
keywords: Epidemiology; Genetics; Heart failure; Risk factors