Howard Hodis

Eat less fat. Exercise. Watch your cholesterol levels, your blood pressure, too.

These are the kind of deceptively simple public health messages that Howard N. Hodis, associate professor of medicine and preventive medicine, is bent on culling from his studies of the body’s blood vessels.

As director of the Atherosclerosis Research Unit (ARU), Hodis leads USC’s extensive research efforts into the dynamics of atherosclerosis – the clogging of the arteries that can lead to heart attack and stroke.

For Hodis, the word energetic seems an understatement. Besides continually writing grant proposals and renewals – he has “six in the hopper” right now – Hodis juggles his own clinical research projects, which are among the two dozen studies he oversees at ARU, and manages the unit’s 30 or so staff members.

Although he’s interested in a wide variety of things that influence atherosclerosis – antioxidants, post-menopausal women’s use of estrogen replacement therapy, diabetes and genetics – and his colleagues’ focus remains on finding out how people can prevent or better treat disease.

“With funding from the National Institutes of Health, the whole goal is to get a simple message out to people about what can help them cut their risk of heart attack and stroke,” Hodis said.

An estimated 2.2 million Americans have artery disease, which first appears as early as the teen years. Atherosclerosis leads to some 550,000 deaths from heart attack each year and is also a major cause of stroke, heart failure and angina or chest pain. So far, the ARU’s broad approach – developed by Hodis and core researchers Wendy Mack, associate professor of preventive medicine, Stan Azen, professor of preventive medicine, Alex Sevanian, professor of molecular pharmacology and toxicology in the School of Pharmacy, and Robert Selzer, senior scientist at Caltech/JPL – has paid off.

In a preliminary study of vitamin E, the team found that the antioxidant can slow the progression of vascular disease in men with atherosclerosis. That success secured funding to take the question to a more artery disease, and presumably heart disease, in people at low-to-average risk.

With colleagues in the deparments of obstetrics and gynecology, pathology and radiology, Mack and Hodis have also been active in women’s heart health research. Right now, they’re leading two studies on the heart-related benefits of estrogen replacement therapy in post-menopausal women. One study is looking at women with existing heart disease. The other is trying to answer the broader questions of heart health, such as whether healthy women benefit from estrogen, how much and from which components of the hormone.

Another focus of ARU research has emerged from a collaboration with diabetes researcher Thomas Buchanan, associate professor of medicine and obstetrics and gynecology. Diabetes and heart disease often coincide, with diabetics dying of cardiovascular-related diseases in 65 percent of cases. In two studies, Hodis and his colleagues hope to elucidate just how insulin intake affects arterial disease.

At the heart of Hodis’ work is an imaging tool called IMT that USC scientists developed with researchers from Caltech/Jet Propulsion Laboratory. IMT measurements allow researchers to non-invasively track the progression of athersclerosis and arterial disease directly in the carotid artery, the main neck artery. The technique uses ultrasound to directly visualize the lining of the blood vessels and any narrowing that disease may have caused.

In a study published in the Feb. 15 Annals of Internal Medicine, Hodis and his colleagues suggested that IMT itself could play an important clinical role in predicting people’s risk of heart attack and coronary death.

In the study of 146 men, the degree of atherosclerosis and the rate at which the arteries thickened during an average of nine years of follow-up were both predictors of a coronary event or death.

Men with the highest IMT levels were seven times more likely to suffer from a coronary event.

But whether the thickening happened quickly or slowly was even more predictive, Hodis said, independent of both absolute levels and other risk factors.

Men whose IMT levels increased the fastest were two to three times as likely to suffer from a coronary event during the follow-up.