Cosegregation of albuminuria and blood pressure: the Insulin Resistance Atherosclerosis (IRAS) family study.
BACKGROUND
Albuminuria was shown to be heritable and to share common genetic determinants with blood pressure (BP) in individuals of white ethnicity. Our aim in this study was to examine the familial aggregation of albuminuria and its phenotypic, genetic, and environmental correlations with BP in nondiabetic individuals of Hispanic (HA) and African American (AA) ethnicity.


METHODS
The study included 129 large HA and AA families, providing 1405 nondiabetic individuals; those on antihypertensive medications were excluded. The albumin/creatinine ratio (ACR) in a random urine sample was used as a measure of albuminuria. A variance component approach was used in the analysis.


RESULTS
After adjusting for age, sex, and body mass index (BMI), the heritabilities of ACR, systolic BP (SBP) and diastolic BP (DBP) were 11%, 26%, and 28%. The phenotypic correlations between ACR and each of SBP and DBP in HA (r = 0.17 and r = 0.16 respectively) and AA (r = 0.26 and r = 0.16) were significant. When partitioned into genetic and environmental factors, the genetic correlations between ACR and each of SBP and DBP were significant in HA (r(g) = 0.49 for each), whereas the environmental correlations were not. Conversely, the genetic correlations between ACR and SBP/DBP were not significant in AA (although with DBP it was not significantly different from that of HA), whereas a significant environmental correlation was observed between ACR and SBP (r(e) = 0.28, P < .001).


CONCLUSIONS
Both albuminuria and BP exhibit familial aggregation in nondiabetic HA and AA. In HA, but not in AA, ACR and especially SBP share common genetic determinants. The mechanism of this ethnic heterogeneity is unclear but merits further investigation.
Guo
Xiuqing
X
Cedars-Sinai Medical Center, Los Angeles, California 90048, USA. Xiuqing.Guo@cshs.org
Cui
Jinrui
J
Wagenknecht
Lynne E
LE
Norris
Jill M
JM
Haffner
Steven M
SM
Darwin
Christine
C
Jinagouda
Sujata
S
Rotter
Jerome I
JI
Saad
Mohammed F
MF
D000328:Adult; D001741:Black or African American / Q000235:genetics; D000418:Albumins / Q000378:metabolism; D000419:Albuminuria / Q000208:ethnology / Q000235:genetics / Q000503:physiopathology*; D001161:Arteriosclerosis / Q000208:ethnology / Q000209:etiology* / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology*; D003404:Creatinine / Q000097:blood / Q000652:urine; D005190:Family / Q000208:ethnology; D005260:Female; D020022:Genetic Predisposition to Disease; D006630:Hispanic or Latino / Q000235:genetics; D006801:Humans; D006973:Hypertension / Q000208:ethnology / Q000209:etiology / Q000503:physiopathology; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D010641:Phenotype; D014481:United States / Q000208:ethnology
D000418:Albumins; D003404:Creatinine