Lack of association between activity or fitness and loss of control of hypertension.

BACKGROUND

Many treated hypertensive patients have inadequate control of their blood pressure. Physical activity and cardiorespiratory fitness are important in the development and treatment of hypertension. Less is known about their relationships with hypertension control in the context of long-term management.

OBJECTIVES

To identify whether patients with lower levels of activity or fitness are at risk for loss of control of hypertension.

METHODS

Follow-up blood pressure measurements were recorded over the period of a year in a cohort of initially controlled hypertensive patients, under the care of 50 family physicians in a variety of practice settings. A questionnaire for a one-year recall of leisure time physical activity and the Step Test, an indirect measure of maximal oxygen consumption, were administered to the patients at the end of the period of blood pressure observations. The study group for the activity questionnaire consisted of 385 patients; 310 of whom undertook the fitness test. Sociodemographic, clinical and lifestyle factors were analyzed as potential confounders in the relationships of main interest in this study: between activity and fitness, respectively, with loss of control of hypertension.

RESULTS

Sixteen per cent of patients (95% CI 12, 20) had an increase of 20 mmHg systolic or 10 mmHg diastolic from baseline to the average of three follow-up blood pressures, and 14% (95% CI 11, 18) had blood pressures above the entry thresholds on at least two of three follow-up visits. No associations were found between loss of control of hypertension and physical activity or cardiorespiratory fitness.

CONCLUSIONS

Lower levels of physical activity and fitness are not associated with loss of hypertension control. The identification of patients at risk for loss of hypertension control, which could be useful in targeting selected groups for increased follow-up and in understanding the high prevalence of uncontrolled hypertension, requires further study.