Objectives Resistant hypertension (RH) is a common clinical problem, but the exact prevalence of RH is unknown. Recently, data from the National Health and Nutrition Examination Survey indicated that the prevalence of RH was 12.8% in the USA. It is noticeable that the prevalence of RH in China has not been reported. The aims of the study were to investigate the prevalence of RH in an urban community and the outpatient departments of cardiology of a tertiary hospital in Chengdu, which is located in West China.
Methods From 2011 to 2012, 2740 adults with hypertension from the outpatient departments of cardiology of a tertiary hospital were sequentially evaluated and 583 adults with hypertension from an urban community were recruited by random sampling method. Definition of RH was established by JNC7, described as failure to achieve goal BP (<140/90 mmHg in the general hypertensive population and <130/80 mmHg in patients with diabetes or chronic kidney disease) when patients adhere to full doses of an appropriate regimen of 3 antihypertensive drugs, including a diuretic.
Results In 2740 patients from the outpatient departments, 2257 (82.4%) were taking medications for hypertension. In 583 patients from community, 331 (56.8%) were taking anti-hypertension medications. The prevalence of RH in the antihypertensive drug–treated patients was 1.8% in the community (2.0% for men, 1.7% for women, respectively) and 7.0% in the outpatient departments (7.2% for men, 6.7% for women, respectively) (P < 0.001, between the community and the outpatient departments). To compare with figures in the USA, we redone statistics on the basis of RH definition they adopted (if blood pressure was ≥ 140/90 mmHg and using antihypertensive medications from 3 different drug classes or using drugs from ≥ 4 antihypertensive drug classes regardless of blood pressure). The prevalence of RH was then rised to 4.2% in the community (5.3% for men, 3.9% for women, respectively) and 13.5% in the outpatient departments (13.4% for men, 13.5% for women, respectively) (P < 0.001, between the community and the outpatient departments). Comparing the types of antihypertensive medications used by patients with RH, use of diuretics in our clinic is significantly lower than in the USA (51% vs 85.6%, P < 0.001).
Conclusions The prevalence of RH in the general population was evidently lower in West China than in the USA. As a key drug for treating RH, the use of diuretics was lower in West China than in the USA, while, the prevalence of RH was evidently lower in West China than in the USA, which might be explained by ethnic difference.