Low rate of resistant hypertension in Chinese patients with hypertension: an analysis of the HOT-CHINA study

OBJECTIVE The rate of resistant hypertension in China is unknown. This is an analysis of resistant hypertension based on Hypertension Optimal Treatment Study in China. METHODS The study was conducted in 148 cities in mainland China from April 2001 to February 2002, which included 54,590 hypertensive patients (≥18 years of age), and used a five-step treatment programme. Patients not achieving blood pressure (BP) target (<140/90 mmHg) within 2 weeks received preplanned additional drugs. Resistant hypertension was defined in the participants with uncontrolled hypertension after 2 weeks of treatment on Step 5. RESULTS The rate of resistant hypertension was 1.9%. Patients with resistant hypertension were characterized by following features: higher male percentage (65.6 vs. 60.2%); younger age (59.51±13.02 vs. 61.76±12.27 years); higher BMI (24.8±3.5 vs. 24.0±3.4 kg/m); longer disease course; higher fasting blood glucose (6.60±2.69 vs. 5.99±2.12 mmol/l); higher total cholesterol (5.67±1.63 vs. 5.32±1.24 mmol/l); higher triglycerides (2.15±1.32 vs. 1.96±1.09 mmol/l); and higher percentage of grade 3 hypertension (71.1 vs. 27.2%) (all P<0.001). Patients with resistant hypertension also had a higher rate of metabolic syndrome (45.9 vs. 35.4%), diabetes mellitus (25.5 vs. 14.7%) and history of myocardial infarction (4.7 vs. 3.3%) or stroke (17.0 vs. 11.6%) (P<0.001). Multivariate analyses revealed an association of resistant hypertension with younger age, higher BP, BMI, longer disease course, higher fasting blood glucose and total cholesterol (P<0.05). CONCLUSION Resistant hypertension in Chinese patients is associated with overweight/obesity, higher BP and metabolic syndrome. The rate of resistant hypertension in China, however, is much lower than previously reported. Another intriguing characteristic is the association of resistant hypertension with younger age.