This large genetic study has been performed by the U.S. Department of Veteran Affairs’ Million Veteran Program (MVP) and the results were published in the latest issue of the journal
Lead scientist Dr. Sridharan Raghavan from the VA Eastern Colorado Health Care System described the results as “a significant contribution to understanding how height is related to clinical conditions from an epidemiologic perspective.” He also said that more research is needed before the results might lead to changes in clinical care, especially for non-cardiovascular conditions. However, the results highlight the association between height and clinical conditions that impact the lives of Veterans, he explains. “The broad scope of our study yielded a catalog of clinical conditions associated with genetically predicted height. In other words, these are conditions for which height might be a risk factor, or protective factor, irrespective of other environmental conditions that also could impact height and health.”
Height is generally not considered a risk factor for any disease. But past research has shown a link between how tall a person is and the likelihood of experiencing multiple health conditions. The question of whether this relationship has a biological basis or is caused by other factors still remains unanswered.
How tall a person grows as an adult is partly due to genes inherited from their parents. But environmental factors such as nutrition, socioeconomic status and demographics (e.g., age or gender) also play a role in determining eventual height. That is why it can be difficult to find a link between height and disease risk, especially for non-cardiovascular conditions.
To explore this link, VA researchers looked at genetic and clinical data from more than 280,000 Veterans enrolled in the MVP. They compared this data with a list of 3,290 genetic variants related to height from a recent genome analysis.
They found that the risk levels of 127 different clinical conditions may be linked to the genetically predicted height of white patients. Fewer data are available on this population because Black patients are under-represented in genetic studies. But in this analysis, the clinical characteristics associated with height are generally consistent throughout Black and white patients. About 21% of Veterans in the MVP study are Black. A minimum of 48 links identified in white patients also applies to Black patients. The researchers report that all the most important findings related to low risk of coronary heart disease and high risk of atrial fibrillation, peripheral neuropathy and circulatory disorders are found in Black and white participants.
Overall, genetically predicted height is associated with lower and higher disease risk, depending on the condition. Being tall will protect people from heart problems. The study concludes that being tall reduces the risk of cardiovascular conditions like high blood pressure, high cholesterol and coronary heart disease. But the risk of atrial fibrillation was higher in taller participants. These links have been shown in previous research.
Conversely, being tall may increase the risk of most heart conditions considered in this study. This is especially true for peripheral neuropathy and circulatory disorders involving the nerves.
Peripheral neuropathy is an infection of the nerves outside the brain and spinal cord, especially in the limbs. Prior studies have linked height with slow nerve conduction and nerve problems. The MVP study confirms this link using genetic tools, which suggest a higher risk for neurological problems in taller individuals.
The researchers linked genetically predicted height to conditions such as erectile dysfunction and urinary retention, both of which are associated with neuropathy.
Raghavan called the findings on peripheral neuropathy “particularly interesting” and he discussed this finding with medical colleagues who frequently visit patients with peripheral neuropathy. They confirmed that taller people often show worse neuropathy, but were unaware of other studies describing this link.
Conditions such as cellulitis, skin lesions, chronic foot ulcers and osteomyelitis are associated with height. Being tall seems to increase the risk of conditions such as varicose veins and thrombosisblood clots in the veins.
The taller you are, the greater the risk of cancers especially for skin and thyroid cancers to some extent but it depends on other factors too. It is evident that a taller person has more cells; more cells mean more the possibility to get cancer. “Tall individuals are at increased risk for almost all cancers,” Leonard Nunney, PhD at the University of California, Riverside, told in a press release. “Skin cancers, such as melanoma, showed an unexpectedly strong relationship to height, which may be due to the higher levels of the hormone IGF-1 in taller adults.”
Height may also increase the risk of neuropathy or other conditions unrelated to circulation. Toe and foot deformities, conditions that can be caused by weight gain in taller individuals, are more common in people who are genetically predicted to be taller. Studies show that height increases the risk of asthma and certain neurological disorders in women but not in men.
Taken together, the results suggest that height may be an unidentified but biologically important and irreversible risk factor for many common conditions, particularly affecting the limbs. They say that it can be helpful to consider a person’s height when assessing risk and disease monitoring.
More research is needed before this can be translated into clinical care, says Raghavan. “I think our findings are a first step toward disease risk assessment in that we identify conditions for which height might truly be a risk factor,” he explains. “Future work will have to evaluate whether incorporating height into disease risk assessments can inform strategies to modify other risk factors for specific conditions.”
He also mentioned, “While the majority of participants are white, there are large numbers of Black and Hispanic participants, who have been underrepresented in genetic studies in the past.” Future research will also focus on the potential mechanisms that tie height to these health conditions.