Many people are aware that cardiovascular disease (CVD), also sometimes called heart disease, is the leading cause of death among U.S. men and women. CVD does not choose its victims randomly; therefore risk factor identification is crucial to CVD prevention and treatment. A risk factor is either a behavior or a characteristic that is predictive of a higher risk for disease. There are many well-known major risk factors such as abnormal blood cholesterol level, hypertension (high blood pressure), tobacco use, prediabetes, family history, sedentary lifestyle, obesity and age. Contributing risk factors include elevated blood triglyceride level and chronic stress. Receiving regular medical exams is the most important way to identify and monitor these risk factors.
Risk Factor Clustering
You probably have heard about many of these CVD risk factors but what is much less commonly known is that certain risk factors often go hand in hand. This is known as ‘risk factor clustering’, which was first observed more than a quarter century ago. For Example:
How is Metabolic Syndrome Identified?
It is relatively easy for physicians to identify MetSyn. Let’s take a look at the cut points:
Can Anything Be Done to Prevent Metabolic Syndrome?
In 2004, my colleagues and I were among the first to report on the prevalence of metabolic syndrome in 7104 Cooper Clinic women; all of whom had a maximal treadmill stress test to determine their cardiorespiratory fitness level 3. The women were divided into five fitness groups (quintiles) based on their age and treadmill performance. We found a very strong trend for decreased prevalence of MetSyn across fitness quintiles. This is summarized below:
The following year, an important step in MetSyn research was taken while again using the Cooper Clinic data base. This time, Dr. Mike LaMonte and colleagues sought to determine if baseline cardiorespiratory fitness level could help predict the development of MetSyn in the future 4. Using 9007 men and 1491 women who did not have MetSyn at the time of their baseline exam, the researchers tracked the subjects for an average of approximately 6 years. Moderately and highly fit men and women were substantially less likely to develop MetSyn during the follow-up period when compared to low fit men and women. Thus, currently having a moderate or high level of cardiorespiratory fitness provides some protection against development of MetSyn in the future.
Can Having a Moderate to High Fitness Level Decrease my Risk of Death if I Have Metabolic Syndrome?
Around this same period of time, another important MetSyn paper was published from the Cooper Clinic database by Dr. Peter Katzmarzyk 5. He studied 15,466 men without MetSyn and 3757 men with MetSyn. Men in the lowest quintile of cardiorespiratory fitness were characterized as unfit, while men in the remaining four quintiles were characterized as fit. During many years of follow-up after their initial Cooper Clinic exam, a total of 480 men died. In the group without MetSyn at baseline as well as the in the group with MetSyn at baseline, fit men were substantially less likely to die during the follow-up when compared to unfit men.
These and other studies tell us many things. First, individuals with moderate to high levels of cardiorespiratory fitness are less likely to have MetSyn than low fit individuals. Second, having a moderate to high level of cardiorespiratory fitness today provides some protection against developing MetSyn in the future. Third, if you already have MetSyn, having a moderate to high level of cardiorespiratory fitness gives substantial protection against premature death. So once again this shows the tremendous impact fitness has on our health.
How Do I Achieve a Moderate Level of Cardiorespiratory Fitness?
A good way for most people to achieve a moderate level of cardiorespiratory fitness is to follow the latest federal guidelines for physical activity:
2 The Expert Panel. Executive Summary of the Third Report of the National Cholesterol Education Program (NCEP) Expert panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III). JAMA. 2001;285:2486-2497.
3 Farrell SW, Cheng YJ, Blair SN. Prevalence of the Metabolic Syndrome across Cardiorespiratory Fitness Levels in Women. 2004. Obesity Research. 2004;12:824-830.
4 LaMonte MJ, Barlow CE, Jurca R, Kampert JB, Church TS, Blair SN. Cardiorespir