Objectives To investigate the prevalence of co-morbidities, the use of antihypertensive drugs and the status of blood pressure control among hypertensive outpatients in China.

Methods A multi-centre cross-sectional study in hypertensive outpatients was carried out in 46 hospitals from 22 provinces from June to December 2009. Consecutive sampling method was adopted. Essential hypertensive patients with eligible inclusion criteria were included, with at least 100 patients in each hospital. The information of demography, physical examinations and biochemical analyses were collected. A total of 5206 hypertensive outpatients were included in current analysis ( 50% were men, mean age was 58.6 ± 10.5 years). Co-morbidities were defined according to the Guidelines on Hypertension Control in China (2010).

Results 1) The prevalence of co-morbidities among hypertensive outpatients: 42.6% of hypertensive outpatients had co-morbidities. Diabetes was the most common co-morbidity (23.4%), followed by coronary heart disease (19.1%, in which myocardial infarction was 4.2%), chronic cardiac failure (3.8%), and renal disease (2.0%). 2) The use of antihypertensive drugs: calcium channel blocker was most commonly used among the patients (57%), followed by angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blockers (ARB) (44.8%), β-blockers (28.3%), and diuretics (8.3%). Nearly half of the patients (49.1%) used two or more antihypertensive drugs. 3) The use of antihypertensive drugs among hypertensive outpatients with co-morbidity: calcium channel blocker was the most commonly used antihypertensive drug (56.8%), followed by ACEI or ARB (51.8%). The use of recommended treatment for patients with a particular co-morbidity was as follows: 51.3% of the patients with diabetes used ACEI or ARB, 66.5% of the patients with myocardial infarction used ACEI or ARB, and 53.4% used β-blockers. The use of ACEI or ARB was observed in 67.0% and 57.3% of the patients accompanying with heart failure and renal disease, respectively. 4) The control rate of hypertension: 46.3% of the hypertensive outpatients with concomitant diseases maintained their blood pressure under 140/90 mmHg. The goal of antihypertensive therapy (BP<130/80 mmHg) was achieved in 19.3%, 21.4% and 15.9% of the patients with coronary heart disease, renal disease, or diabetes, respectively.

Conclusions Co-morbidities are highly prevalent in hypertensive outpatients in China. Calcium channel blocker and ACEI /ARB are the most commonly used antihypertensive drugs. The control rates for patients with co-morbidities are rather low. There is a big room for the improvement of using recommended antihypertensive drugs and increasing the control rate in hypertensive outpatients with co-morbidities.