From a recent study published in the JAMA Network Open, a new definition of metabolic health based on the risk of cardiovascular disease is identified by the researchers. But what actually is Metabolically Healthy Obesity(MHO)? And how is it affecting chronic disease?
Can Obese People With Healthy Metabolisms Avoid Chronic Illnesses?
Metabolically Healthy Obesity(MHO) is an idea that is obtained from clinical surveillance in which a group of people doesn’t show any irregularities in cardiovascular metabolism. But according to the perspective of the present global society, all obese people are unhealthy.
To bring a change in this thought, many studies have been conducted to uncover that some obese people are metabolically healthy and led to an argument that size doesn’t matter in being healthy.
In Metabolically Healthy Obese people, there is less chance of getting affected by obesity-related diseases just like metabolically healthy normal-weight people, and on the other hand, Metabolically Unhealthy Obese(MUHO) people have higher chances of getting affected by both obesity-related diseases and also cardiovascular diseases.
MHO people will have healthy blood pressure, normal blood sugar levels, normal blood lipid levels(cholesterol and triglycerides). An increased level in any of these values will result in a high risk of developing cardiovascular disease.
Even still nowadays debates are going on this physical composition that lacks the unified definition of metabolic health identification. Theoretically, the chances of cardiovascular disease and the risk of death in people with MHO are similar to that in people who are of normal weight.
However, from many other large group studies, it is identified that in people with MHO there is a rise in the death rate due to cardiovascular disease and many other issues even though they don’t have any metabolic syndrome.
This study included mortality data of 386,420 individuals from various anthropometric and metabolic factors provided a clear definition of whether the obese participants are metabolically healthy or unhealthy.
By this definition, more than 40% of obese individuals with obesity are classified as MHO and 20% of individuals had no rise in the risk of cardiovascular disease and mortality while compared with Metabolically Healthy and Normal Weight(MHNW) individuals.
On the other hand, people who are classified as Metabolically Unhealthy were at higher risk when compared with Metabolically Healthy and Normal Weight(MHNW) people regardless of BMI category in both groups. The results were strong after recording the typical sources of bias for the link between obesity and mortality.
Forthcoming studies on cardiovascular diseases and mortality risks on MHO have yielded inconsistent results. The use of different definitions of Metabolically Healthy(MH) may be responsible for the observed heterogeneity. Often, a lack of metabolic syndrome or insulin resistance has been used to identify MHO, but with different criteria and within limits.
When the results of separate studies based on different definitions of metabolic syndrome or HOMA-IR based on overall mortality risk for cardiovascular disease were summarized in meta-analyses, individuals with MHO were still at higher risk than those with MHNW, especially long-term.
In this study, the MHO defined by either of these two definitions showed inconsistent results between the two groups, and the associations were not independent of the new definition. However, the definition was related to the risk of death, regardless of other definitions. This finding suggests that the definition makes a better distinction between risky and non-risky individuals.
However, the results suggest that the definition may only be able to detect the low-risk MHO phenotype in people with a BMI below 40. Higher mortality was observed in obese people (BMI ≥40), regardless of MH.
According to another study published in The Journal of Clinical Investigation, the risk of cardiovascular disease is higher in Metabolically Healthy Obese(MHO) people when compared with Metabolically Healthy and Lean (MHL) people, but is lower when compared with Metabolically Unhealthy Obese(MUO) people.
Also, the risk of advancing cardiovascular diseases is directly related to the increase in early metabolic abnormalities regardless of the MHO phenotype remaining stable or converting to MUO.