(RxWiki News) If you're trying to lose some weight but don't know where to start, focus on your belly. When too much fat builds up around the belly early in life, it could mean heart troubles down the road.
A new study found that the heart arteries of young adults who, year after year, gain more abdominal fat were more likely to be lined with high levels of calcium than the arteries of those who maintained a healthy weight.
Too much calcium in the arteries may be a warning sign of heart disease, these researchers wrote.
"Keep your weight in check."
Jared Reis, PhD, of the Division of Cardiovascular Sciences at the National Heart, Lung, and Blood Institute in Bethesda, Maryland, was lead author of this study on heart health in those who developed abdominal obesity, or belly fat, over a period of time.
Dr. Reis and his fellow researchers monitored 3,275 men and women who ranged from 18 to 30 years old when the study began in 1985. No study participants were obese at the start of this 25-year investigation.
All study participants' waist sizes and other health markers were measured at certain points throughout the investigation, specifically during years 2, 5, 7, 10, 15, 20 and 25. At years 15, 20 and 25 the build-up of calcium in the heart's arteries was also measured.
More than a quarter of study participants, or 902 people, developed coronary heart calcification — a calcium build-up in the heart's arteries that can cause major heart problems and possibly lead to a heart attack.
During the years of follow-up, 40.4 percent of the participants became obese. Meaning that their body mass index (BMI) — a calculation that considers height and weight together — was more than 30.
A BMI of up to 29.9 means a person is overweight; a person with a BMI of 30 or more is considered obese.
Also during the years of follow-up, 41 percent of the participants developed abdominal obesity. That meant the men’s waistlines grew to 40.2 inches or more and the women’s waistlines grew to 34.6 inches or more.
Among the study participants who had been obese for more than 20 years, 38.2 percent had coronary artery calcification.
Of those specifically with abdominal obesity for more than 20 years, 39.3 percent had arteries that were lined with calcium deposits.
By comparison, among study participants who never became obese, 24.9 percent had coronary artery calcification after 20 years. Among those who never developed abdominal obesity, 24.7 percent had too much calcium in the arteries of their hearts after 20 years.
The study’s overweight participants had become officially obese, on average, when they were roughly 35 years old. Those with abdominal obesity, on average, gained those dangerous levels of belly fat a few months before their 38th birthday.
The longer study participants were overweight in general and overweight around the waistline in particular, the more they had harmful calcium building up in their heart's arteries.
Those with long-term obesity also tended to have higher rates of diabetes and high blood pressure, among other diseases, and used more prescription medications to treat those disorders.
Sarah Samaan, MD, a cardiologist and physician partner at the Baylor Heart Hospital in Plano, Texas, told dailyRx that the study makes some practical suggestions for an American public that, overall, is gaining weight at increasingly earlier ages.
"Obesity is associated with many unhealthy lifestyle choices, including a diet anchored by fast food and processed food and a sedentary lifestyle," Dr. Samaan said. "It raises the risks for high cholesterol, high blood pressure and diabetes, which are major contributors to heart disease."
She added that coronary artery calcification can lead to build-up of harmful cholesterol that hardens and limits the amount of space left for blood to flow through the arteries: "Once the process has started, it can be difficult to reverse, and usually requires [drug] therapy to control. This, in turn, raises healthcare costs and exposes patients to potential drug side effects."
It is estimated that as much as 85 percent of heart disease is preventable, Dr. Samaan said.
The study's researchers also noted the importance of preventing obesity-related heart disease.
"Our findings suggest that preventing or at least delaying the onset of obesity in young adulthood may substantially reduce the risk of coronary [arteries with plaque build-up] and limit its progression later in life," the researchers wrote.
Their findings, the researchers added, are "...critical, given the obesity epidemic."
They continued, "With a doubling of obesity rates for adults and a tripling of rates for adolescents during the last three decades, younger individuals are experiencing a greater cumulative exposure to excess [weight] during their lifetime.
"These findings suggest that the longer duration of [abdominal obesity]...and an earlier age at onset will have important implications on the future burden of coronary [plaque] and potentially on the rates of clinical cardiovascular disease in the United States," they wrote.
Study participants were recruited from Birmingham, Alabama; Chicago, Illinois; Minneapolis, Minnesota; and Oakland, California. Of the study participants, 45.7 percent were black and the remainder were white. By gender, 50.6 percent were women and 49.4 percent were men.
This study was published July 16 in JAMA, the Journal of the American Medical Association.
The researchers did not report any investments or involvement that would influence study design and outcomes. Kaiser Research Foundation and the National Heart, Lung, and Blood Institute funded the study.