How Worsening Metabolic Syndrome—Including High Blood Sugar, Hypertension, and Obesity—Can Impact Cancer Risk

More than one in four adults in the United States has metabolic syndrome, a cluster of conditions, such as high blood sugar and hypertension, that occur at the same time.

Scientists have already revealed that metabolic syndrome raises the risk of stroke, diabetes, and cardiovascular disease. Now, a new study has found that metabolic syndrome can also elevate a person’s chances of developing cancer.

While some conditions associated with metabolic syndrome are already known risk factors for cancer—a study published in 2023, for example, estimated that obesity causes as many as 8% of cancers—the new research shows how individual conditions work together over time to elevate cancer risk, lead author Han-Ping Shi, MD, PhD, a gastroenterology, oncology, obesity, and nutrition specialist at the Capital Medical University in Beijing, told Health. 

The study’s results also highlight the importance of managing metabolic syndrome through various strategies, such as a healthy lifestyle and regular medical screenings, she said.

“Early intervention can potentially lower the risk of developing cancer,” Shi added.

How Metabolic Syndrome Influences Cancer Risk

The new study, published in the journal Cancer, included more than 44,000 adults with an average age of 49 who lived in Tangshan, a city southeast of Beijing.

The participants were cancer-free but had all five conditions included in metabolic syndrome (a person must have at least three to qualify for a diagnosis): High blood pressure, low levels of HDL or “good” cholesterol, elevated fat in the blood (triglycerides), high blood sugar, and a large waistline. 

After four years of monitoring the participants, researchers divided them into four groups based on the severity of their metabolic syndrome: low and stable (10.6%), moderately low (40.8%), moderately high (41.5%), or elevated and increasing (7.1%).

About nine years into the study, the team checked in to see which participants had been diagnosed with cancer. They found that people with metabolic syndrome were 30% more likely to develop cancer. The risk was higher for people with more severe conditions and even higher for those whose conditions worsened over time.

People who had worsening metabolic syndrome were twice as likely to develop breast cancer, more than three times as likely to develop endometrial cancer, 4.5 times more likely to develop kidney cancer, and about 1.6 times more likely to develop liver cancer compared to the low and stable group.

The researchers also tracked C-reactive protein, a marker of chronic inflammation. People with higher levels of C-reactive protein had an increased risk of developing breast, endometrial, colon, and liver cancer. People who had consistently high or unmanaged metabolic syndrome but not elevated C-reactive protein had an elevated chance of developing kidney cancer. 

“Chronic inflammation is caused by several lifestyle factors including stress, diet, activity level, and is well recognized as a risk factor for cancer development,” Tomi Akinyemiju, PhD, a cancer epidemiologist at the Duke School of Medicine who was not involved in the research, told Health.

Chronic inflammation causes tumorigenesis, a process that turns normal cells into tumor cells, Akinyemiju explained.

Hormonal imbalance and insulin resistance may also occur in people with metabolic syndrome, further fostering an environment conducive to cancer development and progression, Shi said.

One limitation of the study is that all participants lived in the same city in China, weakening the ability to apply the results outside of that setting. However, the results are consistent with prior studies conducted in Europe, Israel, Mexico, West Africa, and the U.S. 

Sonali Thosani, MD, an associate professor in the Department of Endocrine Neoplasia and Hormonal Disorders at the University of Texas MD Anderson Cancer Center in Houston, said the study should serve as a warning for U.S. residents.

“We should be very concerned,” Thosani told Health. “Higher rates of metabolic syndrome along with the average American diet, which is worse than the Chinese diet, will increase our risk of developing these cancers.”

Conditions Doctors ‘Know How to Fix’

Although researchers have focused much of their attention on studying the effects of obesity, Akinyemiju said it’s important to learn how conditions work together to influence disease risk.

“Meeting that threshold of having metabolic syndrome is way more harmful than having any individual condition,” she added.

The good news is that “it’s not clinically difficult to treat metabolic syndrome,” she said. “We know how to fix it.”

In general, maintaining a healthy body weight helps prevent disease. Still, you don’t have to be overweight to be diagnosed with metabolic syndrome.

“The more we can help people control diabetes, lipid levels, and blood pressure, the better,” Akinyemiju said. “These are conditions we know how to fix.”