Lifestyle interventions and hypertension

Roughly 40% of cases of hypertension are attributable to genetic factors and perhaps 40% to lifestyle factors, particularly diet, salt intake, weight, and exercise. Previous short-term studies have shown that, without question, interventions addressing these factors lower blood pressure. The issue, however, is whether lifestyle and blood pressure improvements are sustained over the long term and are therefore cost-effective.

In the real world, in clinical practice, it is the uncommon patient who adheres to dietary changes and keeps weight off. Therefore, are intensive efforts such as those used in this study warranted or cost-effective? Some say yes. Others consider such efforts lost time in the effort to normalize blood pressure. These views weigh on health care policy in terms of funding and reimbursement for nonpharmacologic measures.

The Prospective Registry Evaluating Myocardial Infarction: Events and Recovery (PREMIER) results support the value of nonpharmacologic measures. Weight loss and the reduced likelihood of developing hypertension were still evident after 18 months. Although the average response was modest, 25% of subjects maintained the target weight loss of 6.8 kg for 18 months. The study also demonstrated the effectiveness of group process, which is more cost-effective than intensive individual attention and can be more conveniently located, for example, at work sites.

These results essentially replicate those of the Diet, Exercise, and Weight-Loss Intervention Trial (DEW-IT), in which subjects lost 4.9 kg and daytime blood pressure fell 12/7 mm Hg.¹ On the other hand, results of studies such as the second phase of the Trial of Hypertension Prevention (TOHP) study are more sobering.² At the 36-month follow-up, subjects had regained nearly all of the 4.4 kg they had lost in the first 6 months.

Two limitations of the current study further mitigate the positive findings. First, the subjects were self-selected, highly motivated individuals, who are the most likely to adhere to lifestyle changes. They were not representative of the average patient. Second, the improved habits were fading somewhat by the end of the 18 months, at which time subjects had regained some of the lost weight and were less stringent in avoiding sodium.

Are costly lifestyle interventions worthwhile? I believe the answer is a qualified yes. On one hand, an intensive population-wide intervention would probably not be cost-effective, as most patients fail to sustain lifestyle changes. On the other hand, the PREMIER study demonstrates that interventions directed at motivated individuals can be successful and probably cost-effective.

One final thought. Because in our era, regrettably, it is money that seems to motivate people, one has to wonder whether a monetary incentive, such as a reduced health premium cost, would improve motivation to maintain healthy lifestyle changes. Crude as it sounds, an intervention trial that incorporates tangible monetary gain as an incentive might prove interesting!