New research found that asking seniors how much they weighed in their 20s and 40s accurately predicted heart failure risk.
Ideally, doctors treating older people would have ready access to accurate weight histories from lifelong medical records.
In reality, however, medical records tend not to accompany people as they change their primary care doctors.
After studying more than 6,000 older adults, researchers from the Johns Hopkins School of Medicine in Baltimore, MD, concluded that just asking older individuals how much they weighed when they were 20 and 40 years old could help predict their risk of heart failure.
"Self-reported lifetime weight," they write in a report of the study that features in the Journal of the American Heart Association, "is a low-tech tool easily utilized in any clinical encounter."
Obesity and heart failure
Previous studies have shown that the more years that individuals spend with obesity, the more likely they are to have a higher risk of heart failure.
"That is why," explains senior study author Dr. Erin D. Michos, who is an associate professor of medicine, "measuring a person's weight at older ages may not tell the whole story about their risk."
There is mounting evidence that individuals who have only recently developed obesity are overall in less danger compared with counterparts who have a history of obesity, she adds.
Heart failure, also known as congestive heart failure, is a severe condition. It develops when heart muscle gradually weakens and stiffens until it cannot pump enough oxygen- and nutrient-rich blood to the body's organs and tissues.
The Centers for Disease Control and Prevention (CDC) estimate that around 5.7 million people have heart failure in the United States, where the condition contributed to 1 in 9 deaths in 2009.
Around half of those diagnosed with heart failure do not live more than 5 years following diagnosis.
A practical way to obtain weight history
Dr. Michos notes that while it is useful to have the current BMI measure when making such an assessment in older adults, having a weight history would be even more helpful.
So, she and her team set out to investigate if there might a practical way of obtaining a weight history that is good enough to inform routine clinical assessment.
They used data from the Multi-Ethnic Study of Atherosclerosis (MESA) on 6,437 people living in six different states in the U.S. The individuals, of which 53 percent were female, had joined the study during 2000-2002 when their average age was 62 years.
Regarding ethnic composition, the cohort was around 39 percent white, more than 26 percent African-American, 22 percent Hispanic, and just over 12 percent Chinese-American.
At the start of the study, the participants had filled in questionnaires that asked them about their weight when they were 20 and 40 years old.
During an average follow-up of 13 years, there was a total of five in-person visits that included weight measurement.
The investigators converted the weight measurements into BMI by dividing the weight in kilograms by the square of the height in meters. They classed BMIs under 25 as normal, between 25 and under 30 as overweight, and 30 and above as being in the obesity range.
Weight history tied to heart failure risk
During the follow-up, 290 individuals had developed heart failure. Another 828 had experienced heart attacks, strokes, or other conditions due to arterial plaque buildup, or had died because of one of these conditions.
Dr. Michos says that, as they expected, there was a link between the weight measures that came from the follow-up visits and the risk of developing heart failure.
For every 5 kilograms per square meter of extra BMI, the risk of developing heart failure went up by 34 percent. This was after accounting for other possible risk factors, such as smoking, age, exercise, diabetes, and blood pressure.
However, further analysis also revealed that reporting having had obesity at age 20 was linked to an above threefold risk of heart failure. Reporting having had obesity at age 40 was tied to a twofold risk.
These risks were in comparison to those who reported having BMIs in the normal range at those two ages.
Doctors should ask about weight history
The team notes that self-reporting can be subject to bias from imperfect memory, but they suggest that most older adults have a reasonable ability to recall how much they weighed when they were younger.
They propose that just asking about weight history can be a help. And yet, while it is an easy thing to incorporate into routine clinical assessments, most doctors don't ask the question.
Dr. Michos calls for further research on how best to include self-reported weight history in clinical practice and electronic health records.
"Our findings emphasize the importance of lifelong maintenance of a healthy weight, as greater cumulative weight from young adulthood is more risky to heart health."
Dr. Erin D. Michos