Cardiovascular disease (CVD) is a leading cause of death worldwide, with risk factors such as obesity and being overweight significantly increasing the likelihood of developing this condition.

However, there is a notion of being ‘healthy obese’ which suggests that individuals who are obese but do not exhibit other risk factors such as high blood pressure or high cholesterol levels may be at a lower risk of developing cardiovascular disease. This article explores the hidden risk of cardiovascular disease in individuals who are considered ‘healthy obese’.

Defining Healthy Obesity

The concept of ‘healthy obesity’ refers to individuals who are obese based on their body mass index (BMI), but do not display metabolic abnormalities such as insulin resistance, high blood pressure, or dyslipidemia.

These individuals may have normal glucose levels, normal blood lipid profiles, and blood pressure within the healthy range. However, recent research suggests that even in the absence of these traditional risk factors, ‘healthy obese’ individuals may still be at an elevated risk of cardiovascular disease.

Hidden Risks of ‘Healthy Obesity’

While it is true that ‘healthy obese’ individuals may not exhibit traditional risk factors for cardiovascular disease, studies have shown that they are still susceptible to developing CVD.

Research has found that even in the absence of metabolic abnormalities, excess adiposity associated with obesity can lead to chronic inflammation and oxidative stress, which are significant contributors to the development of cardiovascular disease.

Inflammatory Markers in ‘Healthy Obesity’

Adipose tissue, particularly visceral fat, is not metabolically inert. It releases various adipokines and cytokines, including C-reactive protein (CRP) and interleukin-6 (IL-6), which are markers of chronic inflammation.

‘Healthy obese’ individuals may have normal levels of these markers, but recent studies have found that they still have a higher overall burden of inflammatory markers compared to individuals with a normal weight. These elevated levels of inflammation increase the risk of atherosclerosis and subsequent cardiovascular events.

Endothelial Dysfunction and Vascular Health

Endothelial dysfunction, which refers to impaired function of the endothelium, the inner lining of blood vessels, is an early marker of atherosclerosis and a predictor of cardiovascular disease.

Studies have shown that ‘healthy obese’ individuals have reduced endothelial function compared to individuals with a normal weight. This dysfunction is attributed to factors such as increased oxidative stress, reduced nitric oxide bioavailability, and increased inflammation, all of which can contribute to the development of CVD.

Insulin Resistance and Metabolic Flexibility

Insulin resistance, a hallmark of metabolic syndrome and type 2 diabetes, is often associated with obesity.

While ‘healthy obese’ individuals may have normal glucose levels and insulin sensitivity, they still exhibit impaired metabolic flexibility, which refers to the ability to switch between different fuel sources (glucose and fatty acids) efficiently. This impaired flexibility can lead to abnormal lipid metabolism, accumulation of lipids in non-adipose tissues such as the liver and skeletal muscles, and ultimately contribute to the development of cardiovascular disease.

Impact of Weight Cycling on Cardiovascular Health

Weight cycling, also known as yo-yo dieting, is common among obese individuals attempting to lose weight. However, frequent episodes of weight loss followed by weight regain can have a detrimental impact on cardiovascular health.

Studies have shown that ‘healthy obese’ individuals who have a history of weight cycling may have an increased risk of developing cardiovascular disease compared to individuals with a stable weight. This suggests that the fluctuations in weight and adiposity associated with weight cycling can have long-term adverse effects on cardiovascular health.

Long-term Outlook for ‘Healthy Obese’ Individuals

While ‘healthy obese’ individuals may have a lower risk of developing cardiovascular disease compared to their metabolically abnormal counterparts, the long-term outlook for their cardiovascular health is not entirely reassuring.

Research has shown that as ‘healthy obese’ individuals age, their risk of developing metabolic abnormalities and subsequent cardiovascular disease increases. In fact, some studies have found that the risk of cardiovascular events in ‘healthy obese’ individuals is similar to or even higher than that in metabolically abnormal obese individuals.

This underscores the importance of adopting a comprehensive approach to cardiovascular risk assessment and management in individuals across all weight categories.

Conclusion

The notion of ‘healthy obesity’ is increasingly being challenged by emerging evidence suggesting that even in the absence of metabolic abnormalities, individuals who are obese are still at an elevated risk of developing cardiovascular disease. Chronic inflammation, endothelial dysfunction, impaired metabolic flexibility, and the impact of weight cycling are all factors that contribute to this hidden risk.

Acknowledging the potential risks associated with ‘healthy obesity’ is crucial in optimizing cardiovascular risk assessment, prevention, and management strategies. A holistic approach, encompassing lifestyle modifications, regular cardiovascular screenings, and individualized intervention plans, can help reduce the burden of cardiovascular disease in both metabolically normal and abnormal obese individuals.