Hobbs shows risks and rewards of predictive health

Emory's Predictive Health Institute got a qualified endorsement from its keynoter, Dr. Helen Hobbs of UT Southwestern in Dallas (right).

The PHI wants to marry computing, genetics, and prevention, combining what we learn about your specific genetic make-up with more general knowledge into customized health plans.

Hobbs, who did her undergraduate work at Stanford (Go Cardinal) keynoted today's symposium at Emory because her studies on the causes of heart disease point the way toward the kinds of insights the PHI wants to come up with.

She warned, however, that disease as a whole is complex, that genetics are just one set of risk factors, and that, in general, healthy living is our best defense.

But her own work combining population studies, genetics, and the study of enzymes in the body remains a model for what Emory and Georgia Tech, its partner in the PHI, want to embrace, and her talk did not disappoint.

Hobbs described how a large group study helped her isolate specific genetic risk factors for heart trouble, even isolated a specific enzyme whose absence can mitigate the problem our livers have disposing of LDL cholesterol.

The enzyme, called PCSK9, "reduces the number of LDL receptors in the liver." She even found an individual without it who had very low cholesterol, excellent health, and thus no side effects from lacking it.

But finding a drug that will inhibit PCSK9 has proven difficult. She was left with the fact that LDL levels rise as we age, subject to differences in both diet and genes, and that heart disease follows when a threshold level is reached.

"If we're talking about prevention it's changing diet, keeping people thin, so we look like the Chinese and don't have these high levels of cholesterol as we age," she said.

Studies have shown heart disease to be rare in rural China due to diet and exercise. They have also shown how young Americans, in apparently good health, can have partial artery blockages from accumulated LDL cholesterol.

Already Americans are making changes, and using statins (like simvastatin and Lipitor) to reduce cholesterol, which is having an impact on heart disease rates.

But we may be starting too late. The diet risks begin in youth, the rising LDL levels begin in youth, so "starting statins earlier, at low doses" may be part of our future approach, she said.

"For this disease it's not that complicated," Hobbs concluded. Step away from the doughnut.

And if they do find a drug that acts against PCSK9 consider it, especially if your genetic make-up indicates you're at major risk.