Large ones are more at risk of thrombosis, small ones have a higher risk of a heart attack: A US research team has investigated the connections between body size and certain diseases. An overview.

People stretch towards the sky. They keep getting bigger and bigger. In 1896 German men were on average just over 1.67 meters tall, in 2017 almost 1.80 meters. And women, too, have now grown a full ten centimeters, averaging 1.66 meters in height. This size development can be seen almost worldwide. But the change is not only visible in the length of the trouser legs, but also in medicine. Because the body size of a person also has an impact on health, it increases the risk of certain diseases. A team of US scientists has now examined the connections. The results were recently published in the journal “PLOS Genetics”.

It is becoming increasingly clear that there is a connection between body size and certain diseases. A German study in 2019 showed that short people have an increased risk of type 2 diabetes, while a Swedish analysis in 2017 showed a higher risk of thrombosis for tall people. According to meta-analyses, they also develop cancer somewhat more frequently. However, it is unclear whether body size itself represents the actual risk or whether there are factors that affect it. A team led by physician Sridharan Raghavan from the University of Colorado has now investigated connections between various diseases and a person’s actual height and height predicted based on their genetics.

Data from more than 250,000 people

Using a database containing genetic and health information, the team analyzed information on more than 250,000 adults for more than 1,000 diseases and traits. The analysis confirms that tall people have 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 found new connections: according to this, tall people have an increased risk of peripheral neuropathy, which is caused by nerve damage in the extremities, and of skin and bone infections such as leg and foot ulcers. Overall, there is evidence that adult height can affect over a hundred clinical characteristics, Raghavan said in a statement. Among them are several diseases that are associated with lower life expectancy and poorer quality of life. However, further studies must confirm that height is a risk factor for several common diseases in adults.

For Norbert Stefan, Professor of Clinical-Experimental Diabetology at the University Hospital in Tübingen, the result comes as no surprise: It has been known for years that numerous genes determine how tall or short a person becomes. It is precisely these genes that are not only linked to body size, but also to other processes in the body and are therefore directly or indirectly associated with certain disease risks.

Don’t overrate genetics

“Nevertheless, genetics should not be overestimated,” emphasizes the doctor, socioeconomic factors could also play a role: According to studies, tall people often have a higher social status. This goes hand in hand with the fact that they are less affected by certain common diseases. Environmental factors would probably have an even greater impact, says Stefan, referring to China, where body size has been increasing for years: “One reason for this is that people there are consuming more and more milk and whey products that contain the IGF-1 and IGF-2 genes activate and that already in the womb.” These genes would drive body growth and—once activated—remain active throughout life. IGF-1 promotes cell growth, which explains the increased risk of certain types of cancer in tall people.

However, stronger IGF-1 activation also ensures that fats in the organs are burned better. Therefore, fatty liver is less common in tall people, says Stefan, referring to his own studies. At the same time, because they have greater leverage due to their longer limbs and thus burn more energy with every movement, their risk of type 2 diabetes and heart attacks is lower. However, long extremities also mean long leg veins – the blood has to be pumped a longer way to the heart, which increases the risk of thrombosis. Accordingly, tall people in particular should exercise regularly on long-haul flights or long car journeys, drink enough and wear support stockings on the plane.

In small people, on the other hand, the risk of type 2 diabetes and a heart attack is greater – regardless of their body fat mass: “If these people gain weight, their risk is significantly higher than in tall people who are getting fatter,” emphasizes the diabetologist: “The smaller, the more agile you should be.”

Body size is a very underestimated topic in everyday clinical practice that deserves more attention, says Stefan: “That’s why work like the current study is so important.” Although there are already some such publications, a medical conclusion is only rarely drawn from body size in practice: “But since people are getting bigger and bigger, that’s a problem, because these connections will continue to gain in importance.”