It's clear that weight loss and exercise can help reduce blood pressure, but do they produce enough of a change to reverse physical changes to the cardiovascular system that increase disease risk? They may. A study published in the Archives of Internal Medicine shows that moderate changes to eating and exercise habits produce measurable improvements in left ventricle parameters in hypertensive individuals.

Lifestyle interventions

Researchers from the University of North Carolina recruited 82 overweight, but otherwise healthy, adults with an average blood pressure of 140/93. Each was randomly assigned to one of three groups. The exercise group performed an aerobic activity (walking, jogging, biking) for 35 minutes, 3 or 4 times per week. The weight control group attended weekly behavior modification classes designed to teach lasting weight management strategies. The control group was wait-listed for treatment. Electrocardiograms performed at baseline and at the end of the study measured left ventricular mass, relative wall thickness, end diastolic dimension, posterior wall thickness, and septal thickness.

Effect of weight loss and exercise

At the end of the 6-month intervention, those in the weight control group lost an average of 7.4 kg (16 lbs), while those in the exercise group lost an average of 2.3 kg (5 pounds). Both intervention groups showed significant improvements in peak oxygen consumption. Participation in both the intervention groups produced marked improvements in diastolic pressure (p<0.001) and marginal improvements in systolic pressure (p<0.09).

Post-study electrocardiograms showed that those in both intervention groups had significant reductions in posterior wall thickness, septal thickness, and relative wall thickness (all p<0.05). Reductions in left ventricular mass index in the intervention groups showed a trend toward significance (p<0.08). (The authors say that the reduced effect of this last reading may be in part due to the increase in chamber size associated with increased exercise.) The most obvious improvements were seen in those who lost weight and exercised regularly, but even without weight loss, regular aerobic exercise was associated with decreased posterior wall and septal thickness, and marginal decreases in relative wall thickness.

Clinical implications

Other studies have shown that medication-induced reductions in blood pressure result in improvements in left ventricular hypertrophy. These results, however, show that similar results can be achieved with weight loss and increased physical activity --- the type of lifestyle changes that physicians are likely to recommend to their mildly hypertensive patients as a reasonable first line of treatment.