, according to a study published in PLOS Genetics.
Prior studies have investigated height as a risk factor for chronic diseases, such as a higher risk for atrial fibrillation and a reduced risk of cardiovascular disease. It’s been consistently difficult, however, to eliminate the confounding influences of diet, socioeconomics, lifestyle behaviors, and other environmental factors that may interfere with a person’s reaching their expected height based on their genes.
This study, however, was able to better parse those differences by using Mendelian randomization within the comprehensive clinical and genetic dataset of a national health care system biobank. Mendelian randomization uses “genetic instruments for exposures of interest under the assumption that genotype is less susceptible to confounding than measured exposures,” the authors explained. The findings confirmed previously suspected associations between height and a range of cardiovascular and metabolic conditions as well as revealing new associations with several other conditions.
Prior associations confirmed, new associations uncovered
The results confirmed that being tall is linked to a higher risk of atrial fibrillation and varicose veins, and a lower risk of coronary heart disease, high blood pressure, and high cholesterol. The study also uncovered new associations between greater height and a higher risk of peripheral neuropathy, which is caused by damage to nerves on the extremities, as well as skin and bone infections, such as leg and foot ulcers.
The meta-analysis “identified five additional traits associated with genetically-predicted height,” wrote Sridharan Raghavan, MD, assistant professor of medicine at the University of Colorado Anschutz Medical Campus, and colleagues. “Two were genitourinary conditions – erectile dysfunction and urinary retention – that can be associated with neuropathy, and a third was a phecode for nonspecific skin disorders that may be related to skin infections – consistent with the race/ethnicity stratified results.”
Removing potential confounders
F. Perry Wilson, MD, associate professor of medicine at Yale University, New Haven, Conn., who was not involved in the study, said the findings were not particularly surprising overall, but it’s striking that the researchers had ”such a large cohort with such detailed electronic health records allowing for the comparison of genetic height with a variety of clinical outcomes.” He also noted the study’s strength in using Mendelian randomization so that the exposure is the predicted genetic height instead of a person’s measured height.
“This is key, since lots of things affect actual height – nutrition is an important one that could certainly be linked to disease as well,” Dr. Wilson said. ”By using genetic height, the authors remove these potential confounders. Since genetic height is “assigned” at birth (or conception), there is little opportunity for confounding. Of course, it is possible that some of the gene variants used to predict genetic height actually do something else, such as make you seek out less nutritious meals, but by and large this is how these types of studies need to be done.”