Hypertriglyceridemia: Is it all genetic?
My last article talked about high triglycerides (TG) and how they may be a detriment to your health, specifically increasing your risk of heart disease. Again, remember that normal levels are <150mg/dl, borderline high 150-199mg/dl, high 200-499mg/dl, and very high >500mg/dl. Abnormal triglyceride levels can occur as either a primary (no other cause except perhaps unfortunate genes) or a secondary phenomenon. Treating the actual level is important, but often times it requires control of another medical condition contributing to the high triglyceride levels.
There are certain medical conditions that can contribute to high TG levels. Obesity contributes to high levels, and not surprisingly, eating a diet high in triglycerides contributes to obesity. Often other cholesterol abnormalities are present such as high LDL or low HDL levels. Losing weight can significantly improve all cholesterol levels. Diabetes is also another common contributor to high TG levels. Hypothyroidism or low thyroid levels can raise TG levels alone or in concert with LDL levels. Thyroid hormone supplements generally can correct these abnormalities. (see my May 2005 article on thyroid disease and cholesterol). Oral estrogen-progestin contraceptives also slightly raise your TG levels and the rise generally resolves once treatment is stopped. Lastly, certain medications such as tamoxifen for the treatment of breast cancer, certain beta blockers for the treatment of high blood pressure or heart disease, thiazide diuretics for the treatment of high blood pressure, and steroids may cause elevated TG levels. These effects are generally reversible.
If no other medical problem can be found that is causing high TG levels, then the condition is considered primary. Primary hypertriglyceridemia results from some abnormality in either the production or clearance of the carriers of triglycerides. These defects are genetic and several genes may be involved. Different severities of high TG levels and other cholesterol abnormalities are also seen depending on the genetic defect. Also, some of these genes can be easily passed on from generation to generation. If a parent is found to have one of the primary disorders of TG regulation, then their children should be screened as well.
Since high TGs are often induced or exacerbated by another medical condition, first line treatment involves controlling or correcting the underlying condition. This may involve diet and exercise for obesity, tight sugar control for diabetes, thyroid hormone for hypothyroidism, and avoidance of certain medications. As a side note, other risk factors for heart disease such as smoking and high blood pressure should be aggressively controlled as well. Lifestyle changes through diet and exercise alone can have a substantial effect on lowering TG levels, whether the problem is primary or secondary. For example, an obese person who loses 10-15lbs on a heart healthy diet coupled with aerobic exercise may reduce their levels by 33%. Unfortunately, if the levels don't fall low enough, then medication may be recommended. In my next article, I will review the indications for drug treatment for high TG levels and the various drugs available.