SNPwatch: Common Genetic Variations May Keep Blood Pressure Down

SNPwatch gives you the latest news about research linking various traits and conditions to individual genetic variations. These studies are exciting because they offer a glimpse into how genetics may affect our bodies and health; but in most cases, more work is needed before this research can provide information of value to individuals. For that reason it is important to remember that like all information we provide, the studies we describe in SNPwatch are for research and educational purposes only. SNPwatch is not intended to be a substitute for professional medical advice; you should always seek the advice of your physician or other appropriate healthcare professional with any questions you may have regarding diagnosis, cure, treatment or prevention of any disease or other medical condition.

The ease with which you can measure your blood pressure using one of those cuff machines at the pharmacy belies just how important this number is to your health.   Chronically high blood pressure, which affects about one in three adults in the United States, increases the risk for stroke, heart attack, heart and kidney failure and aneurysms.

Studies have so far failed to find common genetic variations associated with blood pressure, although there is strong evidence that genetic factors do play a part.   Now, new research published online Sunday in Nature Genetics has identified two variants that not only help explain differences in blood pressure, but could also point the way to new therapeutics.

In a study of 14,473 people, Christopher Newton-Cheh and colleagues identified three genetic variations associated with increased blood levels of two different “natriuretic peptides” — blood pressure-lowering hormones released by heart cells.

Further investigation of these three variations in an additional 29,717 people revealed that two of them are also associated with small reductions in blood pressure — 0.9-1.5 mm Hg for systolic (the top number in a blood pressure reading) and 0.3-0.8 mm Hg for diastolic blood pressure (the bottom number).   The variations were also linked to 10-15% decreased odds of having high blood pressure or being prescribed blood pressure-lowering medication.

(23andMe customers can use the table at the end of this post to check their data at these SNPs.)

While the reductions in blood pressure associated with these variations may seem small (a normal blood pressure reading is something like 120 mm Hg/80 mm Hg), the authors note that even a 1 mm Hg reduction in systolic blood pressure has been associated with an 8% lower risk of death from stroke or heart attack.   They speculate that lifelong lowered blood pressure, as might be expected in someone carrying these genetic variations, could magnify this effect.

According the authors, there is already active research aimed at finding drugs that activate natriuretic peptides.

“Our finding that genetic variation … associated with natriuretic peptide concentrations was also associated with blood pressure and hypertension suggests that these agents might prove useful for the treatment of hypertension,” the authors write, although they do add that more studies will be necessary to fully explore the role of the genetic variants in blood pressure regulation and cardiovascular physiology.

These results are currently applicable only to people with European ancestry.

SNP Less Common Version Increased Natriuretic Peptide Levels Decreased Systolic B.P. Decreased Diastolic B.P. Odds of Hypertension (1 or 2 copies) Notes
rs17376328 A Yes Yes Yes 0.85 Proxy for SNP described in paper, rs5068
rs198358 C Yes Yes Yes 0.90
rs632793 G Yes No No N/A 23andMe does not currently provide data for this SNP