MedicalResearch.com Interview with:
Bengt Zöller, MD, PhD
Associate professor in Internal Medicine
Specialist Physician in Clinical Chemistry
Specialist Physician in Family Medicine
Lund University/ Region Skåne
Center for Primary Health Care Research
University Hospital, Malmö, Sweden
MedicalResearch.com: What is the background for this study?
Response: Previous studies have suggested an association between height and venous thromboembolism but association might be confounded. We therefore permed a Nationwide study including a cohort of siblings -a co sibling analysis to adjust for familial confounders (genetic and shared familial environmental factors).
MedicalResearch.com Interview with:
Prof. Majid Ezzati
Prof. Majid Ezzati, PhD
Faculty of Medicine, School of Public Health
Chair in Global Environmental Health
Imperial College, London
Adjunct Professor of Global Health and
Department of Global Health and Population
Harvard T.H. Chan
School of Public Health
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Human height is strongly influenced by the environment that we grow up in, from pregnancy through to late adolescence. If we have good nutrition, few illnesses and good healthcare, we are more likely to grow taller. In turn, height has a strong effect on our health in adulthood. Taller people on average live longer, have lower risk of heart disease (although they do have slightly elevated risks of some cancers).
We have collated the largest-ever database of height. We analysed 1472 studies with measured height on 18.6 million individuals. We made estimates of height for 18-year-old men and women from 1914 and 2014. Height has increased in every country in the world, but this has been very uneven. The tallest men in the world are now the Dutch, and the tallest women are the Latvians. The countries that have seen the most growth are South Korea for women and Iran for men. We have seen large increases in height in East Asia, and stagnation in much of the West over the last few decades. In parts of Africa height has actually decreased by 5-10 cm over this period.
Prof. Norbert Stefan
Prof. Norbert Stefan, MD
Department of Molecular Epidemiology
German Institute of Human Nutrition
MedicalResearch: What is the background for this study?
Prof. Stefan: Cardiovascular disease, type 2 diabetes, and cancer are among the most important causes of morbidity and mortality worldwide. Although the body mass index and waist circumference are established variables that help to predict the risk of these disease, adult height also predicts mortality independently of adiposity measures. However, compared to these risk factors, it has been somewhat neglected in clinical practice. Based on the finding that in recent decades the height of children and adults has steadily increased throughout the world, the question arises whether this secular trend in height might be a marker of a yet not well understood mechanism that affects not only stature, but also the development of cardiometabolic disease and cancer.
MedicalResearch: What are the main findings?
Prof. Stefan: We summarized and interpreted data from different areas of research and also could provide some novel data to better understand the causes of the worldwide increase in height and its relationships with cardiometabolic disease and incidence of cancer. There is strong epidemiological evidence that tall people, in comparison to short people, have a lower risk of cardiovascular disease and type 2 diabetes but have a higher cancer risk. Per 6.5 cm in height the risk of cardiovascular mortality decreases by six percent, but cancer mortality, by contrast, increases by four percent. We suspect that the increase in body height is a marker of overnutrition of high-calorie food rich in animal protein during different stages of growth. Thus, already in utero, lifelong programming might take place that until now has mainly been established for the insulin-like growth factor 1 and 2 and the IGF-1/2 system. Among other consequences, activation of this system causes the body to become more sensitive to insulin action, thus positively influencing the lipid metabolism. Accordingly, our new data show that tall people are more sensitive to insulin and have lower fat content in the liver, which may explain their lower risk for cardiovascular disease and type 2 diabetes. However, this activation of the IGF-1/2 system and other signaling pathways may be related to an increased risk of certain cancers, especially breast cancer, colon cancer, and melanoma because cell growth is permanently activated.
MedicalResearch.com: Interview with:
Dr. Aaron P. Thrift PhD
Public Health Sciences Division
Fred Hutchinson Cancer Research Center
Medical Research: What are the main findings of the study?
Dr. Thrift: We conclude that height is inversely associated with risk of esophageal adenocarcinoma, both in men and women. The association is not due to confounding from known risk factors or bias.