The overall rate of 31.4% recorded for controlled SBP and DBP in this study, though marginally better than 25.4% obtained in a teaching hospital in the same region, was comparable to the rates obtained in other studies. This, however, is a far cry from the rates of control of 46% found by Hussain et al. in Sudan and 50.3% found by Cuspidi et al. in Italy. This study found that the control of clinic DBP was better than SBP in both men and women on antihy pertensive therapy, though the difference in men is only marginal. Our finding is similar to many other studies, which recorded lower rates of control of SBP than DBP. Researchers from the Framingham Heart Study found SBP values below 140 mmHg in 49% and diastolic BP less than 90 mmHg in 89.7% of all treated hypertensives.
Reasons have been advanced to explain this differential control of SBP and DBP. First, currently available antihypertensive drugs lower DBP more than SBP. This is because the increase in arterial stiffness, which underlies SBP elevation, is less easily reversible, compared to the increase in arteriolar resistance to blood flow that characterizes DBP elevation. Secondly, physicians may adopt a less-aggressive therapeutic attitude when DBP values are lower than 90 mmHg, even when SBP values are still higher than 140 mmHg. This may be due to the historical preoccupation that elevated DBP conferred a greater risk for cardiovascular events than SBP, which was thought to be part of the normal aging process.
Blood pressure control was better in men compared to women in this study. The reason for this is not immediately obvious but may be due to better income earning by men which makes it possible for men to better afford their drugs. The overall female-to-male ratio of clinic attendance during the study period was about 2:1, and this may partly explain the female preponderance.
With, aging the percentage of treated hypertensives with controlled SBP was progressively decreased, while the control of DBP progressively improved. This may be partly due to the tendency for SBP to rise with age in many populations, while DBP starts to decline after the age of 55 to 60 years. Additionally, there is a tendency for the mean DBP to fall below or close to control level with increasing age even among untreated hypertensives, a pattern that is independent of physicians, practices. canadian pharmacy generic viagra
The overall poor degree of blood pressure control and the poor control of systolic blood pressure relative to diastolic blood pressure found in this study, coupled with the rising life expectancy of Nigerians, may put the population at a high risk for cardiovascular complications. Attempts should, therefore, be made to improve blood pressure control and to develop drugs that will equally or better reduce systolic blood pressure, compared to diastolic blood pressure. More importantly, SBP is now being seen as the primary outcome parameter for the diagnosis and treatment of hypertension and is a major indicator for the development of cardiovascular disease. Therefore, greater emphasis should be placed on achieving goal SBP levels in all patients with hypertension, especially those who are older.