Prevalence and associated risk factors of resistant hypertension among Chinese hypertensive patients in primary care setting

Hypertension (HT) is a major public health problem globally, and it is the commonest chronic disease with a prevalence of 27% among people aged 15 years or above in Hong Kong. There is emerging literature confirmed that patients with resistant hypertension (RHT) give its increased risk for adverse clinical outcomes and higher rate of documented target organ damage. This study aims to identify the prevalence of RHT among Chinese hypertensive patients managed in public primary care setting of Hong Kong and exploring its associated risk factors. This is a cross-sectional descriptive study. Chinese hypertensive patients aged 30 or above with regular follow-up between 1st July 2019 and 30th June 2020 in 10 public primary care clinics under the Hospital Authority of Hong Kong were included. Demographic data, clinical parameters and drug profile of patients were retrieved from its computerized record system. The prevalence of RHT was identified and the associated risk factors of RHT were explored by multivariate logistic regression analysis. Among the 538 sampled Chinese hypertensive patients, the mean age was 67.4 ± 11.5 years old, and 51.9% were female. The mean duration of hypertension was 10.1 ± 6.4 years, with a mean systolic and diastolic blood pressure of 128.8 ± 12.3 and 72.9 ± 10.8 mmHg respectively. 40 out of 538 patients were found to have RHT, giving an overall prevalence of 7.43%. Four factors were found to be associated with increased risk of RHT, in ascending order of odds ratio: duration of hypertension (OR 1.08), male gender (OR 2.72), comorbid with type 2 diabetes mellitus (T2DM, OR 2.99), and congestive heart failure (CHF, OR 5.39). The prevalence of RHT among Chinese hypertensive patients in primary care setting of Hong Kong is 7.43%. RHT is more common in male patients, patients with longer duration of hypertension, concomitant T2DM and CHF. Clinicians should be vigilant when managing these groups of patients and provide aggressive treatment and close monitoring.