Variation at the beta-1 adrenoceptor gene locus affects left ventricular mass in renal failure.
OBJECTIVE
To examine the relationship between this variation in the beta1AR gene and the effect on LV mass.


BACKGROUND
Left ventricular (LV) mass is an important cardiovascular risk factor. Beta-1 adrenoceptors (betaAR) are predominately located in the heart and their variation may, therefore, affect LV mass. A known polymorphism of the betaAR changes the amino acid at position 389 from glycine to arginine within an area critical for G-protein coupling and so cell signalling. The arginine-form of the receptor has been demonstrated to have increased GTP binding.


METHODS
We studied 249 patients attending a renal clinic, 37% of whom were on renal replacement therapy (RRT). Raw LV mass was calculated by echocardiography. LV mass index (LVMI) and LV mass indexed to height2.7 were derived thereafter. Individuals were genotyped for the beta1AR variation and categorised CC if both alleles encoded for arginine at position 389, GG if both alleles encoded for glycine and CG if heterozygous.


RESULTS
There was a highly significant difference in raw LV mass, LV mass index and LV mass indexed to height2.7 between the GG group when compared to both the CC and CG genotypes groups (p<0.05). The strength of the relationship was maintained when patients on RRT or taking beta-blockers were excluded (p<0.05).


CONCLUSIONS
These data suggest that genetic variation at this locus is of importance in defining left ventricular mass.
Stanton
Tony
T
Division of Cardiovascular and Medical Sciences, University of Glasgow, Gardiner Institute, Western Infirmary, Scotland, UK. ts39u@clinmed.gla.ac.uk
Inglis
Gordon C
GC
Padmanabhan
Sandosh
S
Dominiczak
Anna F
AF
Jardine
Alan G
AG
Connell
John M C
JM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001483:Base Sequence; D015331:Cohort Studies; D004452:Echocardiography; D005260:Female; D014644:Genetic Variation; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000150:complications / Q000000981:diagnostic imaging / Q000235:genetics*; D007676:Kidney Failure, Chronic / Q000150:complications / Q000175:diagnosis* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D011943:Receptors, Adrenergic, beta / Q000235:genetics*; D012016:Reference Values; D006435:Renal Dialysis; D018570:Risk Assessment; D012720:Severity of Illness Index; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology
D011943:Receptors, Adrenergic, beta