Nearly half of Hispanic adults with high cholesterol are unaware they have the condition, and only a third of them get treatment, a U.S. study finds.

Researchers reviewed data on more than 16,000 Hispanic adults aged 18 to 74 and found that younger people and individuals born in the U.S. were less likely to know if their cholesterol levels were elevated, and that men were less likely than women to get needed treatment.

“Hispanics have a high prevalence of high cholesterol due probably to a mix of genes and diet,” lead study author Dr. Carlos Rodriguez of Wake Forest School of Medicine in Winston-Salem, North Carolina said by email. “What is more surprising is the lack of awareness, treatment and control that needs to change.”

Cholesterol is a waxy, fat-like substance that can build up on artery walls, blocking blood flow and increasing the risk for heart disease and stroke.

Eating a healthy diet, exercising and avoiding tobacco and alcohol can curb the risk of developing high cholesterol, according to the U.S. Centers for Disease Control and Prevention.

Rodriguez and colleagues reviewed data on Hispanic patients screened at clinics in San Diego, Chicago, New York and Miami from 2008 to 2011, they report in the Journal of the American Heart Association.

Participants were classified as having high cholesterol if they were taking medications for the condition; if lab tests found elevated levels of low-density lipoprotein (LDL), the bad kind of cholesterol that builds up in blood vessels and can lead to blood clots and heart attacks; or if screening detected high levels of total cholesterol.

To measure awareness of the condition, researchers asked patients if a doctor or other clinician had ever told them they had high cholesterol. To assess treatment, they asked people with the condition if they were taking prescribed medication.

Despite a higher prevalence of high cholesterol among men, awareness of the condition was higher among women, a difference that was most pronounced among older participants.

People were more likely to be aware of the condition if they had other medical problems including high blood pressure, diabetes or excess weight. Participants with diabetes and high blood pressure, however, were also more likely to get treatment.

Although the likelihood of being treated for high cholesterol increased with age, only 32 percent and 54 percent of middle-aged and older Hispanics, respectively, actually got treatment.

Immigrants were less likely to get treatment than people born in the U.S., the study found.

It’s not surprising that younger adults and more recent immigrants are less likely to receive treatment, said Eileen Crimmins, a gerontology researcher at the University of Southern California in Los Angeles.

Older people are more likely to go to the doctor, increasing the odds that they might be screened for high cholesterol, noted Crimmins, who wasn’t involved in the study.

“Once you get into the medical system you are more likely to be diagnosed for something like high cholesterol,” she said in an email. “I do not think this is a problem unique to Hispanics, but for recent immigrants the lack of medical insurance might be higher than for others.”

The study findings might overestimate or underestimate awareness or treatment for high cholesterol, because researchers relied on patients' memory rather than a review of medical records, but the results ring true, said Dr. Robert Kauffman, a director of reproductive medicine and infertility at Texas Tech University Health Sciences Center School of Medicine in Amarillo.

At best, half of his Hispanic patients are still taking their high cholesterol medication a year after starting on it – “and I believe I have a good doctor-patient relationship with most of them,” Kauffman, who wasn’t involved in the study, said by email.

Lack of insurance or inability to afford medication may motivate some people, but it’s not the only factor, he said.

“Many men and women – despite good patient education efforts – simply elect not to take medication, fail to change habits like being sedentary with no exercise program, refuse to change dietary and caloric intake, etc.,” Kauffman said. “Some of this is disease denial. If they feel healthy, they rationalize taking medication is not needed.“