Impact of age, sex and frailty on the heart: HF risk & interventions

Heart failure is a serious disease that happens when the heart cannot pump blood very well. It occurs most often in older men and women. But how many years someone has lived is not the whole story. People age at different rates. Those who are aging quickly are said to be frail. Frailty is important because, compared to fit people, frail people are much more likely to develop heart failure regardless of their age. They also develop a type of heart failure in which the heart has trouble relaxing. This is especially true in frail older women. Even though heart failure is most likely to happen in frail older men and women, most research uses young animals, mostly males. We can do better. Our research group has discovered how to measure frailty in aging mice, using methods developed in people. We measured many different health problems in individual mice and used this information to estimate a frailty score. We found that even though the heart becomes very large in frail male animals, the ability of the heart to contract weakens. We even saw these changes not just in whole hearts but in individual heart cells. We also discovered that the effects of age on the heart are quite different between the sexes. The goal of this research project is to find out how age and frailty affect the heart and whether this differs between the sexes. We will see if these changes make hearts more susceptible to diseases like heart failure. We also will treat mice with a drug that lowers frailty in both sexes and see if this prevents adverse effects of age and frailty on the heart. This research project is important because it will help us understand the links between age, sex, frailty and heart failure and will help us understand if treatment of frailty can improve heart function in older people.