The control of hypertension is one of the measures used most widely to evaluate the effectiveness of interventions aimed at this risk factor. In studies published in Spain, adequate control of blood pressure, with values below 140/90 mmHg, has been achieved in a low percentage of cases, e.g., 16.3% in a study based on a population of patients diagnosed as having hypertension and treated with drugs1, and 15.5% in a study of a population of patients aged 35-65 years2.
The repercussions of these elevated blood pressure values on health in the population is beyond question; however, it is also true that the consequences of poor control of hypertension vary enormously depending on the patient's cardiovascular risk. Treatment with antihypertensive drugs provides the greatest absolute benefits in patients with the greatest degrees of cardiovascular risk, who are most likely to benefit more from this intervention and from appropriate control of their hypertension. In view of this situation, the benefits would be different depending on whether the control of hypertension were inadequate only in patients at higher cardiovascular risk or whether patients at low risk were also included.
Patients with diabetes are a group at high cardiovascular risk for whom special care must be taken in controlling blood pressure. The association of hypertension with diabetes leads to a higher degree of risk, which can nonetheless be reverted with antihypertensive treatment, as studies have shown3. In addition, control measures should be stricter in these patients (target values < 130/85 mmHg) than in those without diabetes4.
Studies available to date on the control of hypertension do not report the cardiovascular risk or characteristics of the patients in whom the control of hypertension was optimum or deficient. The article published by Benítez et al. in this issue of Atención Primaria analyzes a very important group within the population with hypertension: patients who also have diabetes. Their data show that patients with diabetes who were followed at health care centers in the region of Catalonia do not represent a priority group for intervention aimed at controlling hypertension. (Although their study was limited to Catalonia, the same situation probably exists in the rest of Spain.) The authors found that the proportion of patients with diabetes in whom hypertension was well controlled (24.7%) was similar to that in the population without diabetes (25.7%), and that among the former, blood pressure was below the currently recommended criterion (< 130/85 mmHg) in only 6.7%. This finding illustrates, once again, the gap between expert recommendations and clinical practice. Despite the evidence, the criteria for appropriate control of risk factors continue to become stricter and more demanding.
Moreover, as the number of cardiovascular risk factors increases, so does the tendency for blood pressure to rise, in patients with and without diabetes. (The difference between these groups in the increase in blood pressure is statistically significant.) From the findings reported by Benítez et al., it can be concluded that primary care resources devoted to controlling hypertension are not being directed toward groups of patients who, because of their high cardiovascular risk, are considered top priorityi.e., patients with diabetes or other risk factors. This is suggested by the fact that blood pressure values in the latter were similar to, or even worse than, those in the entire sample of patients.
Further in-depth studies are needed to investigate the degree of control of risk factorsspecifically hypertensionwith particular attention to two groups of patients: those with diabetes and those at high cardiovascular risk, defined as a likelihood of having coronary disease of 20% or higher, as calculated from current risk tables. These patients, together with those who have clinically manifest cardiovascular disease, constitute the priority groups for intervention aimed at preventing cardiovascular disease.
One further notable feature of the study by Benítez et al. is that blood pressure was more poorly controlled in teaching centers. This conclusion was also reported in an evaluation of the Programa de Actividades Preventivas y de Promoción de Salud (Preventive Activities and Health Promotion Program)5. Such results should lead us to reflect carefully in order to determine the causes of these results and analyze the presence of confounding factors that lead to the poor control of hypertension.
