[The impact of gender factor on the candidate gene study of essential hypertension].
OBJECTIVE
To study the impact of gender factor on the candidate gene study of essential hypertension (EH).


METHODS
The polymerase chain reaction (PCR) was performed to analyze the ACE gene I/D polymorphism of hypertensive patients (50 men and 50 women) and normal controls (50 men and 50 women). The investigation was further focused on possible influence of sex proportion on the conclusion of this kind of research.


RESULTS
The frequency of DD genotype in male hypertensive patients is significantly higher than that in male normal controls (chi(2) = 6.98, P = 0.004). The frequency of D allele in male EH group is significantly higher than that of male normal controls (chi(2) = 6.87, P = 0.009), while no significant difference was observed for II and ID genotype between male EH group and control group (P > 0.05). For female EH group and normal controls, there were no significant differences in frequency of genotype and allele (P > 0.05), the distribution ratio of DD genotype in male EH group is significantly different from that of female EH group (chi(2) = 4.06, P = 0.044). Furthermore, males with DD genotype in EH group had higher SBP and PP than that of males with II and ID genotype (P < 0.05). However, there was no significant difference in DBP in all three genotypes (P > 0.05). At the same time, there was no difference in SBP, DBP and PP (P > 0.05) between II and ID genotype in male EH group. In female hypertensive patients, there was no significant difference in SBP, DBP and PP between all three genotypes (P > 0.05).


CONCLUSIONS
The relationship between DD genotype in male and EH (especially SBP and PP) is closer than any other genotype-EH relationships in both male and female. The gender factor, as a probable confounding factor, can affect many candidate gene studies of essential hypertension including ACE gene I/D polymorphism, and thus biases the conclusion.
Liu
Jun
J
Cardio-Cerebrovascular Control and Research Center, Shandong Academy of Medical Sciences, Jinan 250062, China.
Lu
Fang-hong
FH
Wen
Pei-e
PE
Jin
Shi-kuan
SK
Wu
Fan
F
Zhao
Ying-xin
YX
Liu
Zhen-dong
ZD
Sun
Shang-wen
SW
D000368:Aged; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D006973:Hypertension / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D011110:Polymorphism, Genetic; D012737:Sex Factors
C488034:ACE protein, human; D007703:Peptidyl-Dipeptidase A