Characteristics of hypertension in Chinese and their relevance for the choice of antihypertensive drugs

According to the 4th National Nutrition and Health Survey in 2002, the prevalence of hypertension in China was 18.8%. Despite that, the treatment rate among hypertensive patients was 82%, the control rate remained low in persons with hypertension (6%), because of the low awareness in general (30%) and the low control rate among treated hypertensive patients (25%). One of the major reasons for the increasing prevalence of hypertension is unbalance of dietary sodium and potassium intakes. In the International Study of Macro/Micro-nutrients and Blood Pressure (INTERMAP), Chinese, compared with American, British, and Japanese populations, had highest dietary sodium intakes and lowest potassium intakes, leading to a two to three times higher sodium/potassium ratio. High dietary sodium intakes may change the circadian rhythm of 24 h blood pressure, which is characterized by a higher night-time blood pressure. Indeed, the prevalence of isolated night-time hypertension, defined as a night-time blood pressure of at least 120 mmHg systolic or 70 mmHg diastolic and a daytime systolic/diastolic blood pressure less than 135/85 mmHg, was higher in Chinese than in Europeans. The complications of hypertension are also different across ethnicities, being mainly stroke instead of myocardial infarction in Chinese. Blood pressure lowering provides more protection against stroke than myocardial infarction, and calcium channel blockers provide more protection against stroke than other classes of antihypertensive drugs. Current Chinese hypertension guidelines recommend calcium channel blockers as the first of the five classes of antihypertensive drugs for stage 1 and low-risk hypertension.