The prevalence and risk factors associated with hypertension subtypes among ethnic Dai adults in rural China

Objective Hypertension is an important risk factor for cardiovascular disease. The purpose of this survey was to determine the prevalence of hypertension subtypes and the risk factors associated with hypertension subtypes among ethnic Dai adults in rural China. Methods A population-based survey was carried out with 2150 rural inhabitants aged 50 years or older. The definition of hypertension was a systolic blood pressure (SBP) ≥140 mmHg and/or a diastolic blood pressure (DBP) ≥90 mmHg, or a current treatment plan with an antihypertensive medication. Hypertension included the following subtypes: systolic–diastolic hypertension (SDH), isolated systolic hypertension (ISH) and isolated diastolic hypertension (IDH). All participants were interviewed, had physical examinations performed, and had blood pressure measurements taken. Multivariate logistic regression analysis was applied to analyse the risk factors for hypertension. Results The prevalence of HBP was 43.2% (95% CI: 41.1-45.3). The subtype-specific prevalence of hypertension was 16.5% (95% CI: 14.9-18.0) for SDH, 24.2% (95% CI: 22.4-26.0) for ISH and 2.5% (95% CI: 1.9-3.2) for IDH. Among hypertensive participants, 37.9% were SDH, 56.8% were ISH and 5.8% were IDH. Older age is a risk factor for HBP and ISH. Obesity, smoking, drinking and history of hypertension are risk factors for HBP, SDH, ISH and IDH (OR>1). Of the hypertensive participants, the awareness of hypertension in our study was 25.0% for HBP, 34.7% for SDH, 20.0% for ISH and 9.3% for IDH. The rates of treatment and control were 23.8% and 6.9% for HBP, 26.8% and 7.9% for SDH, 23.1% and 6.3% for ISH and 11.1% and 5.6% for IDH, respectively. Conclusions Among Dai people in rural China, the prevalence of hypertension is high, and the awareness, treatment and control of hypertension is low. ISH is the most frequent kind of high blood pressure in rural elderly people. With the ageing population in China, ISH remains an important public health problem and a challenging issue for practising physicians in rural China. Public health strategies should regularly provide more information about hypertension to both the local physicians and the general population. To reduce cardiovascular events, a combination of drugs and lifestyle changes are strongly recommended.