title: Reference values and factors associated with renal resistive index in a family-based population study.
abstract: Increased renal resistive index (RRI) has been recently associated with target organ damage and cardiovascular or renal outcomes in patients with hypertension and diabetes mellitus. However, reference values in the general population and information on familial aggregation are largely lacking. We determined the distribution of RRI, associated factors, and heritability in a population-based study. Families of European ancestry were randomly selected in 3 Swiss cities. Anthropometric parameters and cardiovascular risk factors were assessed. A renal Doppler ultrasound was performed, and RRI was measured in 3 segmental arteries of both kidneys. We used multilevel linear regression analysis to explore the factors associated with RRI, adjusting for center and family relationships. Sex-specific reference values for RRI were generated according to age. Heritability was estimated by variance components using the ASSOC program (SAGE software). Four hundred women (mean age±SD, 44.9±16.7 years) and 326 men (42.1±16.8 years) with normal renal ultrasound had mean RRI of 0.64±0.05 and 0.62±0.05, respectively (P<0.001). In multivariable analyses, RRI was positively associated with female sex, age, systolic blood pressure, and body mass index. We observed an inverse correlation with diastolic blood pressure and heart rate. Age had a nonlinear association with RRI. We found no independent association of RRI with diabetes mellitus, hypertension treatment, smoking, cholesterol levels, or estimated glomerular filtration rate. The adjusted heritability estimate was 42±8% (P<0.001). In a population-based sample with normal renal ultrasound, RRI normal values depend on sex, age, blood pressure, heart rate, and body mass index. The significant heritability of RRI suggests that genes influence this phenotype.
authors.affiliation: Division of Nephrology, University Hospital of Geneva, Rue Gabrielle-Perret-Gentil 4, 1211 Geneva, Switzerland. belen.ponte@hcuge.ch.
authors.forename: Belén
authors.initials: B
authors.lastname: Ponte
authors.forename: Menno
authors.initials: M
authors.lastname: Pruijm
authors.forename: Daniel
authors.initials: D
authors.lastname: Ackermann
authors.forename: Philippe
authors.initials: P
authors.lastname: Vuistiner
authors.forename: Ute
authors.initials: U
authors.lastname: Eisenberger
authors.forename: Idris
authors.initials: I
authors.lastname: Guessous
authors.forename: Valentin
authors.initials: V
authors.lastname: Rousson
authors.forename: Markus G
authors.initials: MG
authors.lastname: Mohaupt
authors.forename: Heba
authors.initials: H
authors.lastname: Alwan
authors.forename: Georg
authors.initials: G
authors.lastname: Ehret
authors.forename: Antoinette
authors.initials: A
authors.lastname: Pechere-Bertschi
authors.forename: Fred
authors.initials: F
authors.lastname: Paccaud
authors.forename: Jan A
authors.initials: JA
authors.lastname: Staessen
authors.forename: Bruno
authors.initials: B
authors.lastname: Vogt
authors.forename: Michel
authors.initials: M
authors.lastname: Burnier
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Martin
authors.forename: Murielle
authors.initials: M
authors.lastname: Bochud
mesh_terms: D000328:Adult; D000367:Age Factors; D001794:Blood Pressure / Q000235:genetics / Q000502:physiology*; D003430:Cross-Sectional Studies; D005190:Family; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D007668:Kidney / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000502:physiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012737:Sex Factors; D013557:Switzerland; D018616:Ultrasonography, Doppler, Duplex; D014655:Vascular Resistance / Q000235:genetics / Q000502:physiology*
keywords: reference values; ultrasonography