A Gene for Metabolic Syndrome?

It turns out that there may be a gene for metabolic syndrome, which would appear to argue that there is such a thing as metabolic syndrome.

I have previously described the running battle now going on between heart specialists and diabetes specialists over the issue of whether metabolic syndrome really exists - with the cardiologists saying "yes" and the diabetologists saying "no" - and have suggested that this dust-up is primarily a turf battle between specialties.

Metabolic syndrome is related to insulin resistance, and is diagnosed (if one is inclined to diagnose it) if any three of the following are present:

• Elevated waist circumference: 40 inches or more for men; 35 inches or more for women
• Elevated triglycerides: 150 mg/dL or higher
• Reduced HDL (“good”) cholesterol: less than 40 mg/dL in men; less than 50 mg/dL in women
• Elevated blood pressure: 130/85 mm Hg or higher
• Elevated fasting glucose: 100 mg/dL or higher

Whether or not you agree that metabolic syndrome is a distinct clinical entity (rather than a collection of risk factors), people who have it are at a greatly increased risk of significant cardiovascular disease.

Last week, researchers from the Washington University School of Medicine in St. Louis reported that they have discovered that a particular gene - the CD36 gene - seems to control an individual's propensity to develop metabolic syndrome. They found five variants in the CD36 gene that make metabolic syndrome more likely, and one variant that seems to protect against metabolic syndrome. This new finding would appear to be a serious blow against the metabolic syndrome nihilists.

While the various medical specialists duke it out (a process that, turf battles being very serious business, may take longer than Jarndyce vs. Jarndyce), anyone with a family history of type 2 diabetes or of metabolic syndrome ought to do everything they can to maintain a healthy weight, and get plenty of exercise. You can read more about metabolic syndrome here.

_{Love-Gregory L, Sherva R, Sun L, et al. Variants in the CD36 gene associate with the metabolic syndrome and high-density lipoprotein cholesterol. Hum Mol Genet 2008; 17: 1695-1704.}