title: Heritability, determinants and reference values of renal length: a family-based population study.
abstract: OBJECTIVE
  In this population-based study, reference values were generated for renal length, and the heritability and factors associated with kidney length were assessed.
  
  
  METHODS
  Anthropometric parameters and renal ultrasound measurements were assessed in randomly selected nuclear families of European ancestry (Switzerland). The adjusted narrow sense heritability of kidney size parameters was estimated by maximum likelihood assuming multivariate normality after power transformation. Gender-specific reference centiles were generated for renal length according to body height in the subset of non-diabetic non-obese participants with normal renal function.
  
  
  RESULTS
  We included 374 men and 419 women (mean ± SD, age 47 ± 18 and 48 ± 17 years, BMI 26.2 ± 4 and 24.5 ± 5 kg/m(2), respectively) from 205 families. Renal length was 11.4 ± 0.8 cm in men and 10.7 ± 0.8 cm in women; there was no difference between right and left renal length. Body height, weight and estimated glomerular filtration rate (eGFR) were positively associated with renal length, kidney function negatively, age quadratically, whereas gender and hypertension were not. The adjusted heritability estimates of renal length and volume were 47.3 ± 8.5 % and 45.5 ± 8.8 %, respectively (P < 0.001).
  
  
  CONCLUSIONS
  The significant heritability of renal length and volume highlights the familial aggregation of this trait, independently of age and body size. Population-based references for renal length provide a useful guide for clinicians.
  
  
  CONCLUSIONS
  • Renal length and volume are heritable traits, independent of age and size. • Based on a European population, gender-specific reference values/percentiles are provided for renal length. • Renal length correlates positively with body length and weight. • There was no difference between right and left renal lengths in this study. • This negates general teaching that the left kidney is larger and longer.
authors.affiliation: Department of Nephrology, Lausanne University Hospital (CHUV), Lausanne, Switzerland.
authors.forename: Menno
authors.initials: M
authors.lastname: Pruijm
authors.forename: Belen
authors.initials: B
authors.lastname: Ponte
authors.forename: Daniel
authors.initials: D
authors.lastname: Ackermann
authors.forename: Philippe
authors.initials: P
authors.lastname: Vuistiner
authors.forename: Fred
authors.initials: F
authors.lastname: Paccaud
authors.forename: Idris
authors.initials: I
authors.lastname: Guessous
authors.forename: Georg
authors.initials: G
authors.lastname: Ehret
authors.forename: Ute
authors.initials: U
authors.lastname: Eisenberger
authors.forename: Markus
authors.initials: M
authors.lastname: Mohaupt
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: D049628:Body Size / Q000235:genetics*; D005260:Female; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging* / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009929:Organ Size / Q000235:genetics*; D019655:Quantitative Trait, Heritable; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013557:Switzerland / Q000453:epidemiology; D014463:Ultrasonography / Q000379:methods* / Q000706:statistics & numerical data*