Differential control of systolic and diastolic blood pressure: Factors associated with lack of blood pressure control in rural community of Liaoning province, China

Abstract

The purpose of the study was to determine whether poor hypertension control is due to lack of systolic blood pressure control, diastolic blood pressure control or both. We analyzed data from 10854 Chinese patients (age ≥ 35 years old) with hypertension from 60 villages of Fuxin County between 2004 and 2005 in Liaoning province of China. We screened for hypertension with a systolic blood pressure of ≥ 140 mmHg or a diastolic blood pressure of ≥ 90 mmHg, or those who were taking antihypertensive therapy at the time of the examination. Blood pressure control was defined as systolic goal (systolic < 140 mmHg), diastolic goal (diastolic < 90 mmHg), or both (systolic < 140 mmHg and diastolic < 90 mmHg). Statistical analysis was performed using the software of Statistical Program for Social Sciences (SPSS) version 11.5, and a value of P < 0.05 was considered to indicate statistical significance. Of 10854 hypertensive patients (mean age 56.2 years, 50.2% women), 14.7% were controlled to systolic goal, 33.9% were controlled to diastolic goal, and 1.0%were controlled to both. Among 2450 subjects who were undergoing antihypertensive therapy (22.6% of all hypertensive patients), 6.5% were controlled to systolic goal, 22.1% were controlled to diastolic goal, and 4.3% were controlled to both. Thus, poor systolic blood pressure control was overwhelmingly responsible for poor rates of overall control to goal. Covariates associated with lack of systolic control in treated patients included older age (compared with patients aged 35 to 44 years, Odds Ratio (OR) for age 55 to 64 years, 1.814, 95% CI 1.087-3.028; OR for age ≥ 65 years, 2.753, 95% CI 1.558-4.863) and prevalent CVD (cardiovascular disease) (OR 0.666, 95% CI 0.464-0.956). The same covariates were associated with the lack of both control(systolic < 140 mmHg and diastolic < 90 mmHg). In this rural community-based sample of middle-aged and older subjects, overall rates of antihypertensive therapy and hypertension control were lower than those in the National Health and Nutrition Examination Survey conducted in 2002. Poor blood pressure control was overwhelmingly due to lack of systolic control, even among the treated subjects. Therefore, greater emphasis should be placed by clinicians and policymakers on the achievement of systolic goal levels in all hypertensive patients, especially in the elderly.