It is holiday season and no single figure dominates this time of year like Santa Claus. The figure of Santa Claus is likely based on a combination of ancient legends including St Nicholas (a Greek saint known for his gift giving), Father Christmas (England) and Sinterklaas (a Dutch legend). The name “Santa Claus” was first used in the US press in 1773. The caricature of Santa Claus as a jolly, rotund, white bearded, red suit wearing elf was first defined by Thomas Nast (a famous political cartoonist who lived in Morristown New Jersey) in an illustration for Harper’s Weekly in 1863. How rotund is Santa? According to NORAD (the North American Aerospace Defense Command), who tracks Santa’s course across the world on Christmas Eve, Santa is 5 feet 7 inches tall and weighs about 260 pounds. This would put Santa’s Body Mass Index (BMI) at 40.72 kg/m2 which places him squarely in the obese category. How does Santa’s obesity, his round belly and visceral fat affect his risk for heart disease? Should we be worried about Santa?
It is estimated that 42% of the adults in the United States are obese. Being overweight (BMI 25-29 kg/m2) or obese (BMI >30 kg/m2) increases the risk for cardiovascular disease and cardiovascular death. The BMI was invented in the 1830’s by a Belgian astronomer who was trying to categorize different types of people. The mathematical formula for BMI relies on only two variables, height and weight. Since its inception, the BMI (and similar calculations) have been used by insurance companies to calculate the risk of dying. Since 1972, the BMI has been used to define obesity, even though it is not a perfect measure. Amongst its flaws, it cannot distinguish between fat and muscle. Consider a 6-foot 9-inch 250-pound man. His BMI is 26.8 kg/m2 putting him in the overweight category. However, if this man is a muscular perennial NBA All Star, then no one would consider him overweight. His higher BMI is due to muscle, not fat. Another flaw is that the BMI cannot distinguish between subcutaneous fat (fat deposited under the skin; think “pinch an inch” or those love handles that have popped up over the years) and visceral fat. Visceral fat is fat deposited in and around the organs in the abdomen and chest. Visceral fat poses many more health risks than subcutaneous fat. Visceral fat interferes with blood sugar regulation and lipid storage, leading to diabetes, elevated triglycerides, high blood pressure and subsequent heart disease. Waist circumference may be a better measure of visceral fat than BMI. Obesity is defined by a waist circumference >40 inches in men and > 35 inches in women. An elevated waist circumference is associated with heart artery disease and increased risk for cardiac death. Body fat percentage is an even better indicator of obesity than body weight or BMI. Body fat percentage greater than 30% in men and 35% in women is considered obese (the acceptable range is 20-29%).
The heart is considered a visceral organ and thus prone to fat accumulation. Normally fat is present in two areas in the heart. Epicardial fat is present between the heart muscle and the pericardium (the sac that encompasses the heart). Epicardial fat provides a layer of fat on the heart muscle and around the heart arteries. It has beneficial effects both anatomically and functionally. It acts as a buffer and provides mechanical protection for the heart arteries. Epicardial fat also secretes a variety of active substances and since it is in close proximity to the heart arteries these substances help in the regulation of the internal environment of the arteries. These fat depots also store fatty acids and act as an energy supplier for the heart. During times of high demand, the fatty acids are released into the heart muscle. Unfortunately, excess epicardial fat increases inflammation which in turn promotes and worsens blockage in the heart arteries and increases the risk for atrial fibrillation. Pericardial fat is the second type of fat seen in the heart and is located between the two layers of the pericardium (the pericardium surrounds the heart and the visceral layer is adjacent to the heart muscle while the parietal pericardium faces outside the heart). Like epicardial fat, pericardial fat provides mechanical protection for the heart and helps keep the heart contracting smoothly and friction free (you could say the heart is a well-greased machine!). Also, like epicardial fat, an excess of pericardial fat is detrimental. Excess pericardial fat is associated with congestive heart failure. Both types of fat can be detected and quantified by cardiac CT or MRI scan. CT scan for coronary calcium also provides the opportunity to look for excess epicardial and/or pericardial fat.
After Santa has given out all of his gifts on Christmas Eve (and eaten a billion cookies in the process), how should we treat Santa’s obesity and visceral fat? Obesity management involves 5 interventions: behavioral changes, nutrition, physical activity, medications and surgery. Lifestyle modifications can produce 5% to 10% weight loss. Newer medications have been quite effective in reducing weight. Semaglutide (Ozempic) can reduce weight by 10-15% while tirzepatide (Mounjaro) can result in 15-20% weight loss. On average, surgical procedures reduce weight by 20-30%, but even greater reductions can occur. Do these weight loss strategies reduce cardiac outcomes and cardiac fat? Surgery reduces the risk for dying from any cause by 37%, heart failure by 54% and heart attack by 37%. Semaglutide has recently been shown to improve cardiac outcomes by 20%, especially in the those with established cardiac disease or diabetes. Lastly weight loss by lifestyle modification or surgery reduces epicardial fat thickness by 9% to 32%.
So, this year instead of leaving Santa milk and cookies on Christmas Eve, perhaps a plate of vegetables and a prescription for Ozempic would be better for his health.
