Height may impact over 100 clinical traits
The study relied on data from the U.S. Veteran Affairs Million Veteran Program with 222,300 non-Hispanic White and 58,151 non-Hispanic Black participants. The researchers first estimated the likelihood of participants’ genetic height based on 3,290 genetic variants determined to affect genetic height in a recent European-ancestry genome-wide meta-analysis. Then they compared these estimates with participants’ actual height in the VA medical record, adjusting for age, sex, and other genetic characteristics.
In doing so, the researchers found 345 clinical traits that were associated with the actual measured height in White participants plus another 17 clinical trials linked to actual measured height in Black participants. An overall 127 of these clinical traits were significantly associated with White participants’ genetically predicted height, and two of them were significantly associated with Black participants’ genetically predicted height.
In analyzing all these data together, the researchers were largely able to separate out those associations between genetically predicted height and certain health conditions from those associations between health conditions and a person’s actual measured height. They also determined that including body mass index as a covariate had little impact on the results. The researchers conducted the appropriate statistical correction to ensure the use of so many variables did not result in spurious statistical significance in some associations.
“Using genetic methods applied to the VA Million Veteran Program, we found evidence that adult height may impact over 100 clinical traits, including several conditions associated with poor outcomes and quality of life – peripheral neuropathy, lower extremity ulcers, and chronic venous insufficiency. We conclude that height may be an unrecognized nonmodifiable risk factor for several common conditions in adults.”
Height linked with health conditions
Genetically predicted height predicted a reduced risk of hyperlipidemia and hypertension independent of coronary heart disease, the analysis revealed. Genetically predicted height was also linked to an approximately 51% increased risk of atrial fibrillation in participants without coronary heart disease but, paradoxically, only a 39% increased risk in those with coronary heart disease, despite coronary heart disease being a risk factor for atrial fibrillation. Genetically predicted height was also associated with a greater risk of varicose veins in the legs and deep vein thrombosis.
Another novel association uncovered by the analysis was between women’s genetically predicted height and both asthma and nonspecific peripheral nerve disorders. “Whether these associations reflect differences by sex in disease pathophysiology related to height may warrant exploration in a sample with better balance between men and women,” the authors wrote. “In sum, our results suggest that an individual’s height may warrant consideration as a nonmodifiable predictor for several common conditions, particularly those affecting peripheral/distal extremities that are most physically impacted by tall stature.”
A substantial limitation of the study was its homogeneity of participants, who were 92% male with an average height of 176 cm and an average BMI of 30.1. The Black participants tended to be younger, with an average age of 58 compared with 64 years in the White participants, but the groups were otherwise similar in height and weight.* The database included data from Hispanic participants, but the researchers excluded these data because of the small sample size.
The smaller dataset for Black participants was a limitation as well as the fact that the genome-wide association study the researchers relied on came from a European population, which may not be as accurate in people with other ancestry, Dr. Wilson said. The bigger limitation, however, is what the findings’ clinical relevance is.