Abstract
Lifestyle medicine is the application of exercise, nutrition, and other lifestyle habits to maintain and improve human health. It is becoming clear that the typical elements of pharmacologic medicine apply to lifestyle medicine. These include the following principles: dosing is important; not every agent works identically in all individuals; variations in response are partly related to genetic factors. An equally important concept is apparent: the interaction between pharmacologic therapy and lifestyle approaches is just now becoming important in the application of the principles of personalized lifestyle medicine in clinical practice. Also, the principles of personalized or precision medicine apply to lifestyle medicine—the goal is the right therapy, for the right person, for the right condition, at the right time. Predicting who will respond in what manner to what lifestyle intervention in the presence or absence of pharmacologic therapy will enable precision lifestyle medicine in the future.
Keywords
Exercise, genetics, genomics, precision medicine, pharmacogenetics, adverse responders, exceptional responders
Introduction
Lifestyle medicine is the medical discipline concerned with the application of exercise, nutrition, and other lifestyle habits to maintain and improve human health. Other habitual behaviors impact health—these include smoking; maintaining psychological health and reducing psychological stress; maintaining energy balance, good sleep habits; and regular life patterns. They all are part of a comprehensive lifestyle medicine program ( Fig. 2.1 ). As more resources begin to be devoted to the promises of preventive medicine in attempts to impact human health and healthcare costs on a wide scale, so has the interest in the promises of lifestyle medicine to contribute to this effort.
As lifestyle medicine gains traction and more knowledge is gained, it is becoming clear that the typical elements of pharmacologic medicine apply to lifestyle medicine. These include the following principles: dosing is important; not every agent works identically in all individuals; variations in response are partly related to genetic factors. Also, the interaction between pharmacologic therapy and lifestyle approaches is just now becoming important in the application of the principles of personalized lifestyle medicine in clinical populations. Perhaps, a more important concept is becoming apparent: the principles of personalized medicine apply to lifestyle medicine—the goal is the right therapy, for the right person, for the right condition, at the right time. To accomplish the goals of personalized lifestyle medicine, we will have to develop predictors of individual response to the interaction between pharmacologic therapy and lifestyle behaviors. One hope is that genetic profiling at the individual level will not only predict the onset of disease, but also the manner in which pharmacologic therapy and lifestyle interact to effect disease progression and treatment.
To illustrate the principles of personalized lifestyle medicine and how they have been built on a growing body of knowledge, our examples will focus on exercise medicine—an element of lifestyle medicine—to illustrate the essential elements of a personalized lifestyle medicine program.
Elements of a Lifestyle Medical Program
Dose Effects
As the medical community learns more about lifestyle approaches to human health, one realizes that the principles of pharmacology apply to lifestyle medicine: there are dose effects that must be considered in prescribing lifestyle for prevention and treatment.
Over the last decade or so, investigators have attempted to understand the effects of different exercise amounts, intensities, and modes on risk factors for cardiometabolic disease: the studies of a targeted risk reduction intervention through defined exercise (STRRIDE) studies offer an example of a series directed directly at this issue . Among other important observations, STRRIDE has challenged the common wisdom that more is exercise is always better—that more vigorous intensity exercise is superior to less intense exercise . These principles are illustrated in Fig. 2.2 .
Clearly, for favorable changes in HDL-cholesterol ( Fig. 2.2A ) and reduction in waist circumference ( Fig. 2.2B ) more exercise of any intensity is superior to less exercise . In contrast, more favorable changes in serum triglycerides ( Fig. 2.2C ) and insulin sensitivity ( Fig. 2.2D ) occur with a moderate intensity exercise than with an exercise program of the same total energy expenditure, but of a more vigorous intensity. The same response is observed for improvement of metabolic syndrome score in this population . The logical conclusion from these studies is self-evident: the intensity of exercise that should be prescribed for an individuals should be personalized—individualized—to the particular clinical problem that is of the greatest importance for that individual’s health. For improvements in HDL-cholesterol or fat mass, the more exercise the better; however, for insulin sensitivity, plasma triglycerides, and diabetes risk, when the exercise is of the same total amount (distance), brisk waking is preferable to jogging exercise.
Lifestyle Pharmacology
As important as are lifestyle behaviors for human health, in the current era, lifestyle behaviors cannot be consider in isolation—both lifestyle factors and modern pharmacology must work together in the same medical environment; how lifestyle and pharmacology work together, or even interfere, must be considered. Although the interaction between physical exercise and pharmacotherapy is a young area of investigation, there already have been some surprising observations. Mikus et al. observed a significant interaction between statin therapy and exercise on insulin action: concomitant treatment with statin therapy eliminates the improvement in insulin sensitivity observed in individuals exercising in the absence of statin therapy . Interestingly, pharmacologic effects can interact with exercise in an intensity-specific fashion: women on estrogen therapy improve insulin sensitivity as do men of the same age; however, although women not on estrogen respond to moderate intensity exercise as men, women not on estrogen therapy do not improve insulin sensitivity ( Fig. 2.3 ) .
