Metabolic syndrome is preventable, even among obese patients
Is it possible to be fat and fit?
Yes -- but not forever, according to Prakash Deedwania, MD, of the University of California at San Francisco School of Medicine.
"Obesity is never healthy; it's just a question of time," Deedwania said. "You can be fat and fit, and you will probably be okay for a little while. But to remain fat and fit is difficult. Most obese people will convert to a metabolically unhealthy state."
Nearly 38% of U.S. adults are obese and another 33% are overweight. And about 35% of American adults -- including nearly 50% of those age 60 years or older -- are estimated to have metabolic syndrome.
"Metabolic syndrome is worse than obesity," said Carl Lavie, MD, of the John Ochsner Heart and Vascular Institute in New Orleans. "Although abdominal obesity is one of the components of metabolic syndrome, some people without abdominal obesity have metabolic syndrome and some obese people do not."
"Metabolic syndrome is associated with high cardiovascular risk and risk of increased mortality," Lavie continued. "More obese people have metabolic syndrome than non-obese people, but regardless of weight, higher physical activity and a diet lower in simple sweets and carbs may help prevent metabolic syndrome, as will having a higher level of fitness."
Though definitions vary slightly around the world, the American Heart Association classifies metabolic syndrome as a clustering of three or more of the following characteristics:
- Abdominal obesity (a waist circumference of greater than 40 inches in men, or greater than 35 inches in women)
- Serum triglycerides of 150 mg/dL or greater
- High-density lipoprotein (HDL) cholesterol of less than 40 mg/dL in men or less than 50 mg/dL in women
- Systolic blood pressure of 130 mm Hg or greater, or diastolic blood pressure of 85 mm Hg or greater
- Fasting glucose of 100 mg/dL or greater
"Metabolic syndrome is a conglomeration of risk factors," said Deedwania. "Individually, these factors are unhealthy, but when three or more of them come together, it gives you good information about potential problems ahead."
Obesity and Heart Health
Recent studies have examined the links between obesity, metabolic syndrome, and cardiovascular disease. Earlier this year, an analysis of 6,809 Multi-Ethnic Study of Atherosclerosis (MESA) participants suggested that metabolically healthy obesity may be transient. Followed for a median of 12.2 years, almost half of the people who had metabolically healthy obesity developed metabolic syndrome, which was associated with cardiovascular risks that progressively increased with time.
"Metabolically healthy obesity is not a stable condition and also not necessarily an indicator of low cardiovascular disease risk," said lead author Morgana Mongraw-Chaffin, PhD, of Wake Forest School of Medicine in Winston-Salem, NC. "Instead, metabolically healthy obesity appears to be a transient condition on the pathway between obesity and the development of cardiovascular events."
Last year, The Health Improvement Network (THIN) study, a prospective cohort study of people initially free of cardiovascular disease, also reported that seemingly healthy obesity isn't really healthy. "On a population-level, our data in 3.5 million individuals clearly show that healthy obesity is a temporary state with many people going on to develop vascular disease risk factors," said corresponding author G. Neil Thomas, PhD, of the University of Birmingham in the United Kingdom.
THIN showed that during an average follow-up of 5.4 years, obese individuals with no metabolic abnormalities had higher risks of coronary heart disease, cerebrovascular disease, and heart failure than normal-weight metabolically healthy people. There was a clear increased risk of vascular disease among people with healthy obesity, Thomas noted: "For instance, the risk for heart failure was almost double."
Although people with healthy obesity include younger active individuals, most people in this group are at an early stage of a trajectory toward developing vascular risk factors, Thomas added. And it's here where physicians may need to step in. "Failure to monitor the progress of disease and control the developing risk factors will lead to avoidable morbidity and mortality," he said.
Staving Off Metabolic Syndrome at the Clinical Level
While obesity in general is associated with metabolic syndrome, visceral adiposity poses a particular concern, explained Deedwania, who was one of the first physicians to define metabolic syndrome more than 30 years ago.
"Doctors need to look at the patient," Deedwania said. "Ask the patient to take off their shirt. Even a thin person can have visceral obesity; these people have very high risk of diabetes and subsequent cardiovascular disease."
"Then look at the patient's profile and habits, measure their blood pressure, calculate their BMI, take their waist circumference, and get a simple biochemical profile – a fasting lipid panel," he continued. "But some of that can come later. If you simply look at the patient and their habits and profile, that's a good start."
Metabolic syndrome is preventable, even among obese patients. This is one of the most important points physicians can convey, Deedwania said. "Metabolic syndrome is a lifestyle disease -- a disease of our dietary habits and our lack of exercise." While some patients are more prone to obesity and metabolic syndrome than others, genetics are a minor component, he noted. "Good lifestyle habits -- 30 to 35 minutes of brisk walking five times a week, or just losing 7% to 8% of body weight, can prevent metabolic syndrome from developing."
"Even people who have metabolic syndrome can alter their future risk of diabetes and cardiovascular disease by losing weight, eating a prudent diet low in saturated fat, doing physical activity, and eating low glycemic index foods," Deedwania said.
And underestimating the risks that seemingly healthy obese patients face may have dire consequences, Mongraw-Chaffin added.
"The very serious implications are that many of those with obesity may not be getting the resources and recommendations they need to avoid cardiovascular disease," she said. "It is a huge prevention opportunity that is being wasted, both for individuals with metabolically healthy obesity as well as for public health."
The physicians and researchers interviewed in this article declared no competing interests.
Source Reference: Aguilar M, et al "Prevalence of the metabolic syndrome in the United States, 2003-2012." JAMA 2015; 313(19):1973-1974
Journal of the American College of Cardiology
Source Reference: Mongraw-Chaffin M, et al "Metabolically healthy obesity, transition to metabolic syndrome, and cardiovascular risk" Journal of the American College of Cardiology 2018; 71(17):1857-1865
Journal of the American College of Cardiology
Source Reference: Caleyachetty R, et al "Metabolically healthy obese and incident cardiovascular disease events among 3.5 million men and women" Journal of the American College of Cardiology 2017; 70(12): 1429-1437
Read the original artlce on Medpage Today: Obesity, Metabolic Syndrome, and Cardiovascular Disease