Reciprocal interactions of obstructive sleep apnea and hypertension associated with ACE I/D polymorphism in males.
BACKGROUND
The angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism gene contributes to the genesis of hypertension (HTN) and may help explain the relationship between obstructive sleep apnea (OSA) and HTN. However, ACE is a pleiotropic gene that has several influences, including skeletal muscle and control of ventilation. We therefore tested the hypothesis that ACE polymorphism influences OSA severity.


METHODS
Male OSA patients (apnea-hypopnea index [AHI]>5 events/h) from 2 university sleep centers were evaluated by polysomnography and ACE I/D polymorphism genotyping.


RESULTS
We studied 266 males with OSA (age=48+/-13 y, body mass index=29+/-5 kg/m(2), AHI=34+/-25 events/h). HTN was present in 114 patients (43%) who were older (p<0.01), heavier (p<0.05) and had more severe OSA (p<0.01). The I allele was associated with HTN in patients with mild to moderate OSA (p<0.01), but not in those with severe OSA. ACE I/D polymorphism was not associated with apnea severity among normotensive patients. In contrast, the only variables independently associated with OSA severity among patients with hypertension in multivariate analysis were BMI (OR=1.12) and II genotype (OR=0.27).


CONCLUSIONS
Our results indicate reciprocal interactions between OSA and HTN with ACE I/D polymorphism, suggesting that among hypertensive OSA males, the homozygous ACE I allele protects from severe OSA.
Koyama
Renata G
RG
Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil.
Drager
Luciano F
LF
Lorenzi-Filho
Geraldo
G
Cintra
Fátima D
FD
Pereira
Alexandre C
AC
Poyares
Dalva
D
Krieger
José Eduardo
JE
Castro
Rosa M R P S
RM
Tufik
Sérgio
S
de Mello
Marco Túlio
MT
Pedrazzoli
Mario
M
D000328:Adult; D000368:Aged; D000483:Alleles; D015992:Body Mass Index; D005787:Gene Frequency / Q000235:genetics; D005838:Genotype; D006720:Homozygote; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000235:genetics*; D054643:INDEL Mutation; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000235:genetics*; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000235:genetics*
D007703:Peptidyl-Dipeptidase A