Adults with autism are up to four times more likely than others to have chronic physical health conditions, new research suggests, and lifestyle factors don’t appear to be the reason why.

On average, adults on the spectrum have low blood pressure, arrhythmias, asthma, prediabetes and other conditions at rates that are 1.5 to 4.3 times higher. The increased occurrence does not appear to be tied to typical risk factors like smoking, alcohol use or a person’s body mass index, according to findings published recently in the journal Autism.

The study looked at 1,156 adults with autism and 1,212 without the developmental disorder who took part in an anonymous, online survey.

“This is a first step in better understanding why autistic individuals are so much more likely to have chronic physical health problems,” said Elizabeth Weir, a graduate student at the University of Cambridge who led the study.

Weir noted that other biological, environmental, lifestyle or health care factors could be behind the increased risk seen in those with autism.

Even within the population of people with autism, researchers noted that experiences varied. Women with autism, for example were four times more likely to have prediabetes compared to females who are not on the spectrum. But men with and without autism were equally likely to have the condition.

Accordingly, the researchers said that it’s likely unreasonable to apply a one-size-fits-all approach to health care for those with autism.

“This new study highlights the physical health risks to autistic individuals, and has important implications for their health care,” said Simon Baron-Cohen, director of the Autism Research Centre at the University of Cambridge and one of the researchers who worked on the study. “Understanding the reasons why these disparities exist will allow us to better support autistic individuals and improve the quality and length of their lives.”