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Family doctors have not paid much attention to levels of triglycerides - a common type of blood fats - in their younger patients. But now Israeli researchers who have followed up more than 13,000 male IDF soldiers in the professional army for over a decade have found that high triglycerides as early as one's 20s are an easily measured biomarker for heart disease in midlife.
The major study was done by Dr. Iris Shai and Dr. Assaf Rudich of Ben-Gurion University of the Negev in Beersheba; Dr. Amir Tirosh, a BGU graduate student and now a resident at Sheba Medical Center at Tel Hashomer; and researchers from the IDF Medical Corps. Since it was published on Sunday, in the prestigious journal Annals of Internal Medicine of the American College of Physicians, it has aroused a great deal of interest in Israel and around the world.
The article was accompanied in the journal by a special editorial by Dr. Michael Criqui of the University of California at San Diego. He praised the study for its very important impact on preserving health and identifying at an early stage those men at high risk of heart disease.
The team investigated risk factors for common diseases such as diabetes and heart disease by examining the health records of IDF soldiers in the professional army aged 26 to 45 who were apparently healthy.
The team looked at the level of triglycerides - one of the circulating blood's lipids - measured after 12 hours of fasting. In their follow-up of the men they found it was an important risk factor for heart disease.
The risk associated with higher triglycerides was independent of other known risk factors, including obesity, family history of heart disease and or LDL ("bad") cholesterol. In addition, when they combined two measurements of triglycerides taken five years apart, they were able to identify young men at increased risk for heart disease.
Men who had low triglycerides in the first measurement and a high level after five years were those who gained more weight, became less physically active and reported a decline in the habit of eating breakfast regularly. These men had a nearly seven-fold increased risk of developing heart disease compared to men with stable low triglycerides.
Conversely, men who had high triglycerides during the first measurement, but low level in the second were those who lost weight, increased physical activity and reported an increase in eating breakfast regularly. These men were about 50 percent less likely to develop heart disease compared to men with high triglycerides in both measurements.
The team found that triglycerides appeared to correspond to lifestyle factors, which are major determinants of the risk for heart disease but are very hard to assess and monitor in the clinic. With the growing problem of obesity in children and young adults, diseases of later decades of life tend to appear earlier, even in the forth and fifth decades. Yet, the risk factors for common diseases in young adults are largely unknown.
The results do not necessarily reflect a similar danger in women, Tirosh told The Jerusalem Post Monday.
"There are too few cases of heart disease in women of this age, so we can't say that the effect is the same," he said. "The first measurements were 10 years ago, when there were very few women in the permanent army. It would be speculative to say if it is same in women as in men, as there are hormonal influences."
The IDF is a good place to conduct the research since soldiers are a "captive audience" who can be tested years later at specific times.
Tirosh could not say when young people should first be tested for triglyceride levels, as this requires further research, including an interventional study that tries to bring down the levels and determines whether this is cost effective. But a family doctor who sends his healthy patients for blood tests is free to test triglycerides as well. It is also important to monitor levels to see if they rise or fall, he said.
The team is now concluding a study of soldiers with high triglycerides and type 2 diabetes and the interaction between them.