Combined AGT M235T-ACE I/D genotype and risk of essential hypertension in Vietnamese adults: a hospital-based case-control study.

BACKGROUND

Essential hypertension is influenced by conventional risk factors and genetic susceptibility. We tested the prespecified hypothesis that the combined AGT M235T-ACE I/D TT/DD genotype is associated with essential hypertension in Vietnamese adults.

METHODS

We conducted a hospital-based case-control study among 471 Vietnamese Kinh adults at the University Medical Center, Ho Chi Minh City, Vietnam, including 238 cardiology-clinic participants with essential hypertension and 233 health-screening participants without hypertension. Hypertension was defined according to Vietnamese guideline thresholds as office systolic blood pressure  ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg, or current antihypertensive treatment; controls had no history of hypertension, were not receiving antihypertensive medication, and had office blood pressure < 140/90 mmHg. The primary exposure was TT/DD versus non-TT/DD. Multivariable logistic regression adjusted for age, sex, overweight or obesity, diabetes mellitus, salt-rich diet, smoking, alcohol misuse, physical inactivity, and family history of hypertension.

RESULTS

TT/DD was observed in 37 of 238 cases (15.55%) and 15 of 233 controls (6.44%). TT/DD was associated with hypertension in crude analysis (OR 2.67, 95% CI 1.38-5.40; p = 0.002) and remained associated after adjustment (adjusted OR 3.26, 95% CI 1.53-6.92; p = 0.002). In an exploratory six-category model using (MM + MT)/II as the reference, TT/DD was the only genotype category significantly associated with hypertension, although the estimate was imprecise (adjusted OR 3.46, 95% CI 1.24-9.70; p = 0.018).

CONCLUSIONS

The combined AGT M235T-ACE I/D TT/DD genotype was associated with essential hypertension in this hospital-based Vietnamese sample. Because of the case-control design, hospital-based recruitment, covariate imbalance, and absence of external replication, the finding should be interpreted as associative and hypothesis-generating.