Differential control of systolic and diastolic blood pressure in blacks with essential hypertension.

OBJECTIVE

The risk of cardiovascular and renal diseases has been shown to be higher for systolic blood pressure than diastolic blood pressure. The aim of this study was to assess the differential control of systolic and diastolic blood pressure in Nigerians with primary hypertension.

DESIGN AND SETTING

This was a prospective observational study carried out at the Medical Outpatient Department of the State Hospital, Abeokuta, Nigeria. Ethical approval for the study was obtained from the ethical committee of the hospital.

METHODOLOGY

The study population consisted of 185 consecutive patients (65 males, 120 females), aged 35-85 years with primary hypertension who had been on drugs one- to 25 years prior to the onset of the study. Clinic blood pressure control was assessed during a year period. Six consecutive clinic blood pressure readings were recorded for each patient and the average calculated (systolic blood pressure and diastolic blood pressure separately). Patients were classified into subgroups based on the pattern of blood pressure control.

RESULTS

Clinic systolic blood pressure and diastolic blood pressure was controlled in 58 patients (31.4%). Systolic blood pressure control was less frequent than diastolic blood pressure control (35.7% versus 51.4%, p<0.05). Patients with uncontrolled systolic blood pressure were significantly older than patients with only uncontrolled diastolic blood pressure (66.7+/-7.4 versus 52.9+/-8.7 years, p<0.001).

CONCLUSION

Systolic blood pressure is less frequently controlled than diastolic blood pressure in Nigerians treated for primary hypertension. This may increase the patient's risk of developing stroke, and cardiovascular and renal complications.