ACE inhibitors, such as quinapril (Accupril) and enalapril (Vasotec), are medications prescribed to treat high blood pressure and manage congestive heart failure (CHF). Studies have also shown that ACE inhibitors prevent some of the decline in physical function common in CHF patients. However, decline in physical strength and functioning is also associated with the aging process, even in people without CHF. Now, a study published in a recent issue of The Lancet suggests that ACE inhibitors may also prevent decline in physical function among women without CHF who are taking the drugs solely to treat high blood pressure.

About the study

Researchers at Wake Forest University and colleagues analyzed data from the Women's Health and Aging Study (WHAS)—a study of the cause and course of disability among moderately and severely disabled elderly women in Baltimore, Maryland. The WHAS study followed 1002 disabled women aged 65 and older from November 1992 to February 1995. Disability in this study was age-related, meaning that the women could no longer perform certain activities of daily living or self-care. Women who lived in nursing homes or were too cognitively impaired to answer interview questions were excluded from the WHAS study.

At the start of the WHAS study and every 6 months for the next 3 years, the women were examined by a nurse and answered questions about their medical status, use of medications, and physical activity. The examination included measurement of muscle strength at the knee and walking speed on a 4-meter course. Medical information that was self-reported by the women was corroborated by their physicians and medical records.

For this recent analysis of the effect of ACE inhibitors on physical functioning, researchers analyzed data on 641 of the women in the WHAS study who did not have CHF when the study began. The researchers compared the decline of knee strength and walking speed among women who took ACE inhibitors regularly, those who took them intermittently, those who took other blood pressure-lowering medications, and those who took no blood pressure medication.

The findings

Over the 3 years of the study, women who had ever taken ACE inhibitors during the study period experienced a smaller decline in knee muscle strength and walking speed compared with women who did not take ACE inhibitors. Of particular interest, the average decline in walking speed among women taking ACE inhibitors was 8 to 10 times lower than among the other groups.

The researchers also examined how higher and lower doses of ACE inhibitors affected physical function. Among continual users of ACE inhibitors, the average decline in knee strength in the low-dose group was 1.2 kg, but the high-dose group experienced a 1.1 kg average increase in strength. Similarly, average walking speed decreased by 4.9 cm per second in the low-dose group, but increased by 6.0 cm per second in the high-dose group.

In calculating all statistics, the researchers accounted for the effects of other factors that affect physical function, such as age, body mass index, diabetes, heart disease, and stroke.

There are limitations to this study, however. All of the participants were older women with high blood pressure, so it's not clear how these results may apply to older men and people without high blood pressure. In addition, the women in this study were frail and disabled to some degree before the study began, so it's also unclear how ACE inhibitors may affect older people who have not yet lost any physical function. Finally, because so few participants took hormone replacement therapy (HRT), the researchers were not able to assess what role, if any, HRT may have played in the changes in physical function.

How does this affect you?

Should older women start taking ACE inhibitors solely to maintain their physical strength and functioning? No. These findings suggest that older women who take ACE inhibitors for high blood pressure may receive an added benefit of better physical function. If these findings are confirmed in future studies, ACE inhibitors may become a preferred blood pressure-lowering medication for older people due to this additional benefit.

But if you really want to maintain your physical strength and endurance as you age, your best bet is regular exercise and a healthful diet. Studies have shown that people who use their muscles during regular exercise gain and maintain strength better than people who do not exercise—no matter what age. And a healthful diet can help provide your muscles and bones the nutrients they need to stay strong. Regular exercise and a healthful diet can also help prevent many diseases and conditions, such as heart disease, stroke, diabetes, and osteoporosis, that can lead to frailty and disability.