Association of Body Roundness Index with Cardiovascular Diseases in Middle-Aged and Older Chinese Adults with Cardiovascular-Kidney-Metabolic Syndrome Stage 0-3: Evidence from the CHARLS Study
Based on data from 7,566 middle-aged and older Chinese adults in the CHARLS study, this research demonstrates that a higher Body Roundness Index (BRI) is independently and linearly associated with an increased risk of incident cardiovascular disease in those with cardiovascular-kidney-metabolic syndrome stages 0–3, outperforming BMI and ABSI in predictive accuracy.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Heart disease and stroke remain the leading causes of death and disability across the globe, a burden that has grown steadily over the last few decades. In China, these conditions have become the primary cause of mortality, making the search for ways to predict and prevent them a critical public health priority. For many years, doctors have relied on body mass index, a simple calculation based on height and weight, to gauge a person's risk. However, this measure has a blind spot: it cannot tell the difference between muscle and fat, nor can it reveal where that fat is stored. Fat tucked deep inside the abdomen, surrounding vital organs, is far more dangerous to the heart than fat stored under the skin. To address this, researchers have developed a new tool called the Body Roundness Index. This measure uses a person's waist size and height to estimate how round their body is, offering a sharper picture of that dangerous abdominal fat.
A team of researchers from Zhengzhou, China, recently put this new tool to the test on a large group of middle-aged and older adults. They focused on a specific group of people who were at risk for heart problems but had not yet suffered a major event. These individuals fell into what medical experts call "Cardiovascular-Kidney-Metabolic Syndrome" stages zero through three. This framework groups together people who have risk factors like high blood pressure, diabetes, or kidney issues, or those who show early signs of organ damage, but who have not yet been diagnosed with heart disease. The researchers wanted to know if the Body Roundness Index could predict who among these people would develop heart disease or stroke in the future, and whether it was a better predictor than the traditional body mass index.
The study drew upon data from the China Health and Retirement Longitudinal Study, a massive national survey that tracks the health of older adults. The researchers selected 7,566 participants who were free of heart disease at the start of the study and who fit into the early stages of the risk syndrome. They measured the participants' height and waist circumference to calculate their Body Roundness Index and then followed them for up to nine years. During this time, they tracked who developed heart disease, who had a stroke, and who remained healthy. The team also looked at how common conditions like high blood pressure and high cholesterol might explain the link between body shape and heart trouble.
The results were clear and consistent. As the Body Roundness Index went up, the risk of developing heart disease or stroke also went up in a steady, linear fashion. For every single unit increase in this index, the risk of developing cardiovascular disease rose by 15.4 percent. The risk of stroke increased even more sharply, by 18.7 percent for each unit. When the researchers compared the people with the highest body roundness scores to those with the lowest, the difference was stark: those in the highest group faced significantly higher risks of heart attack and stroke than those in the lowest group. This pattern held true even after the researchers accounted for age, sex, lifestyle habits like smoking and drinking, and other health conditions.
The study also explored why a rounder body shape leads to higher risk. The analysis suggested that high blood pressure and abnormal levels of fats in the blood, known as dyslipidemia, act as middlemen in this process. About 11 percent of the increased risk associated with a higher Body Roundness Index was explained by these two factors. This means that carrying excess abdominal fat tends to raise blood pressure and disrupt cholesterol levels, which in turn damages the heart and blood vessels. While diabetes and metabolic syndrome were also considered, their role in explaining the risk was less clear once the other factors were taken into account.
Perhaps most importantly, the researchers found that the Body Roundness Index was a far better predictor of future heart trouble than the traditional body mass index. When they tested how well each measure could distinguish between those who would get sick and those who would not, the Body Roundness Index scored significantly higher. It outperformed both the standard body mass index and another shape-based measure called the A Body Shape Index. This suggests that for people in the early stages of heart-kidney-metabolic risk, simply measuring the waist and height provides a more accurate warning signal than weighing a person.
The strength of this link varied slightly depending on who was being measured. The association between body roundness and heart risk was stronger in men than in women, and it was also more pronounced in people living in cities and those with higher levels of education. This might reflect differences in how fat is distributed in men versus women, or how lifestyle factors in urban environments interact with body shape. The study also noted that the predictive power of the index seemed to grow as a person's overall health risk increased, becoming most useful for those in the later stages of the risk syndrome.
This research offers a practical path forward for doctors and public health officials. By using a simple measurement of waist size and height, they can identify individuals who are at high risk for heart disease long before a crisis occurs. This is particularly valuable for the millions of people who are currently in the early stages of metabolic and kidney issues but have not yet suffered a heart attack. The findings support the idea that looking at body shape, rather than just weight, provides a clearer window into the future health of the heart. While the study cannot prove that changing one's body shape will automatically lower risk, it strongly suggests that monitoring this specific measure could help catch dangerous trends early, allowing for timely interventions to protect the heart and kidneys.
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