Impaired kidney function raises risk of heart problems in the elderly

A study published next week in the open access journal PLoS Medicine suggests that elderly people with damaged kidneys are at greater risk of cardiovascular disease, such as heart failure and stroke, and other causes of mortality.

The findings indicate that greater efforts should be made to encourage elderly people who have impaired kidney function alongside other risk factors—such as high blood cholesterol and high blood pressure, which are often a result of smoking and diet—to make lifestyle changes to avoid developing cardiovascular problems.

Most countries face increasing rates of cardiovascular disease and it is the single leading cause of death in the United States and many European countries. It has already been established that young and middle-aged people with a reduced estimated glomerular filtration rate (eGFR)—the measurement of the movement of waste and excess fluid through the kidneys—are more likely to develop cardiovascular disease than those with healthy kidneys. To establish how at risk elderly people with impaired kidney function were, Ian Ford of the University of Glasgow and colleagues analysed existing data from a three year clinical trial conducted among men and women aged between 70 and 82 in Scotland, Ireland and the Netherlands.

The trial—known as the Prospective Study of Pravastatin in the Elderly at Risk, or PROSPER trial—had been designed to test the effect of the statin pravastatin on the development of cardiovascular disease. Dividing the trial participants into four groups based on their eGFR at the start of the study, Ian Ford and colleagues established that the patients with a low eGFR—those with the most impaired kidney function—were twice as likely to die from any cause as those with healthier kidneys. They also established that the patients with the most damaged kidneys were three times more likely to have non-fatal heart failure or disease and were more likely to die as a result of heart disease or failure.

The data also showed that treatment with the drug pravastatin reduced the number of fatal and non-fatal heart problems more effectively amongst the group of patients with the most damaged kidneys—although the researchers warn that this finding is statistically borderline and say the most that can be concluded is that there is no reason to exclude elderly people with damaged kidneys from treatment with statins, the drugs that reduce blood cholesterol levels in those at risk of cardiovascular disease.