Obesity Paradox in Contemporary Cardiology Practice

Obesity is considered a risk factor for cardiovascular diseases (CVD). There is evidence that the entire spectrum of CVD is increased in obesity, including coronary heart disease, stroke, hypertension, heart failure, peripheral vascular disease, arrhythmias, and atrial fibrillation. Interestingly, it's also known that obese patients with established CVD do better than their leaner counterparts for subsequent events and when they undergo invasive procedures.

"The so-called obesity paradox has been reported in patients undergoing coronary revascularisation procedures (coronary artery bypass grafting and percutaneous coronary intervention [PCI]) and in those with chronic heart failure and in several other cardiac disease states," notes an editorial article in JACC: Cardiovascular Interventions.

In particular, a new study by Holroyd et al. reports that an independent association of elevated body mass index (BMI) to reduced mortality after PCI still exists in contemporary UK practice. BMI is the most commonly used metric to delineate obesity and is a strong predictor of CVD outcomes. However, the editorial seeks to highlight the fact that cardiorespiratory fitness may be an important mediator of outcomes.

"Cardiorespiratory or physical fitness appears to have significant prognostic implications among the obese and overweight individuals. In fact, there is evidence that cardiorespiratory fitness modulates and modifies the relationship between obesity and CVD outcomes," write Debabrata Mukherjee, MD, and Chandra Ojha, MD, both from the Department of Internal Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, in the editorial. They cited several studies showing the benefits of cardiorespiratory fitness to patients with obesity. For example, the population-based Rotterdam Study examined the association between overweight and obesity and CVD risk as a function of physical activity levels and reported that the beneficial impact of physical activity on CVD might outweigh the negative impact of BMI among middle-aged and elderly people.   

According to Drs. Mukherjee and Ojha, it's important for practicing clinicians to stress and promote cardiorespiratory fitness among overweight and obese patients. "We should emphasise the importance of physical activity for everyone across all BMI levels, with 30 to 60 minutes of moderate intensity aerobic activity, such as brisk walking, at least 5 days and preferably 7 days per week," they write. "Consistent with national guidelines, we also recommend that patients with established CVD undergo risk assessment with a physical activity history or an exercise test before starting an exercise programme."

Source: JACC: Cardiovascular Interventions
Image Credit: Pixabay