The previous edition of the guideline was in 2008. The recent revision looks at metabolic risk in the light of the latest research on blood pressure and blood fats.
The emphasis is on measures to identify and decrease the risk of developing type 2 diabetes and atherosclerotic cardiovascular disease (ASCVD) rather than on defining metabolic syndrome.
ACSVD is a type of heart or artery disease that develops as a result of atherosclerosis, a condition in which fatty deposits build up inside artery walls and cause them to narrow and impede blood flow. This process can lead to stroke and heart attack.
While the focus is on people aged between 40 and 75 years, the guide also applies to older and younger adults.
A recent paper in the Journal of Clinical Endocrinology & Metabolism details the new document.
The recommendations urge doctors to make regular checks of peoples’ blood pressure, waist size, blood sugar, blood fats, and high density lipoprotein (HDL) cholesterol, which people sometimes call good cholesterol.
They urge doctors to measure waist size as a routine part of clinical exams. People should receive blood pressure checks at least every year, but more frequently if blood pressure is high.
The checks are in addition to the usual ones doctors use for assessing heart disease risk, such as smoking, family history, and low density lipoprotein (LDL) cholesterol, or bad cholesterol.
Metabolic risk factors
The measurements assess five metabolic risk factors that can raise a person’s risk of type 2 diabetes and ASCVD.
Waist size is a measure of abdominal fat, a high amount of which can indicate metabolic risk. Similarly, having low levels of HDL cholesterol, elevated blood sugar, and high levels of triglycerides (blood fats) are also potential indicators of metabolic risk.
“Doctors haven’t been doing enough to measure waist circumference,” says Dr. James L. Rosenzweig of the Hebrew Rehabilitation Hospital in Boston, MA, “but it’s essential to identifying patients at metabolic risk earlier and preventing more cases of heart disease and diabetes.”
Dr. Rosenzweig is chair of the panel that developed and wrote the guidelines.
People who have three or more of the five risk factors are at metabolic risk and therefore have a higher chance of developing type 2 diabetes and ASCVD.
The guideline suggests that doctors screen those with one or two risk factors every 3 years and those with three or more on a more frequent basis.
While the revised document discusses new medical options, it emphasizes that doctors should give priority to changing lifestyle and behavior.
Lifestyle and behavior changes
The guideline gives some specific recommendations on lifestyle and behavior changes.
For example, individuals at metabolic risk who have excess weight – according to body mass index (BMI), waist size, or both – should aim to lose 5% or more of their body weight during their first year of adopting a healthful lifestyle.
Another recommendation is that when treating people with prediabetes, doctors should prescribe lifestyle changes to reduce blood sugar before resorting to drug prescription.
Individuals at metabolic risk should also undergo “global assessment of 10-year risk for either coronary heart disease or atherosclerotic cardiovascular disease” to guide decisions on appropriate medical and drug treatments.
“Global risk assessment includes the use of one of the established cardiovascular risk equations,” note the authors.
The purpose of a global risk assessment of a disease is to guide efforts to prevent it by assessing its major risk factors. The risk factor measurements go into an equation that calculates the risk of experiencing a major disease event in a certain period.
For example, a 10-year global risk assessment for coronary heart disease uses equations that bring together risk factors, such as cholesterol levels and blood pressure, to calculate the percentage risk of experiencing a significant health event in the next 10 years.
A 10% global 10-year risk of coronary heart disease, for instance, means that there is a 1 in 10 chance of having a heart attack or dying in the next 10 years.
Future directions and genetic risk
The guideline document also has a section on knowledge gaps that warrant further research.
One such gap concerns the “identification and analysis of genetic markers for metabolic risk” and how they relate to ASCVD and type 2 diabetes.
In an extensive discussion about this topic, the authors conclude that while genetic markers appear able to predict ASCVD and type 2 diabetes, the risk prediction equations have not yet incorporated them.
They also point out that by changing their lifestyle to a more healthful one, a person can reduce the risk of ASCVD and type 2 diabetes “at any level of genetic risk and may have slightly greater benefits for individuals at higher genetic risk.”
Currently, however, there is no data to back up the hypothesis that when people know their genetic risk, they are likely to change behavior and adopt more healthful lifestyles, add the authors.
“We emphasize the importance of lifestyle, dietary, and behavioral changes as the first line treatment. However, treatment with medication is appropriate if goals are not met with lifestyle changes alone.”
Dr. James L. Rosenzweig