A new study out of Be’er Sheva University, Israel, has found that adolescent’s body mass index (BMI) can predict early occurrences of diabetes and heart disease in adulthood. The large cohort study which followed 37,000 teenagers for 17 years found that elevated BMI at adolescence and at adulthood are independently of each other associated with the risk of coronary heart disease.
The study, published in the New England Journal of Medicine, assessed the occurrence of both diseases in young adulthood, an age group that has been rarely studied, but has experienced an increase in the incidence of these diseases in recent decades.
The joint research team was lead by Dr. Amir Tirosh (Sheba Tel-Hashomer’s Talpiot program and Brigham and Women’s Hospital and Harvard Medical School’s) researchers Dr. Iris Shai and Dr. Assaf Rudich, from Ben-Gurion University of the Negev. With additional researchers from the Israeli Defense Forces (IDF) Medical Corps and Tel Hashomer Hospital, the team followed IDF career personnel beginning at age 17.
The IDF recorded BMI of personnel at baseline and again every few years. During a mean follow-up period of 17 years, the average BMI of the participants rose at a rate of 0.2-0.3 units per year, rising to an average weight gain of approximately 15 Kg. (~30 lbs) between ages 17 and 30. The researchers were able to control for multiple risk factors for both diseases, including age, fasting blood glucose, blood lipids, blood pressure, smoking, exercise habits and family history.
The researchers found that it was possible to predict the increased risk for developing both diabetes and coronary heart disease even if the BMI was within the normal range (<25). A BMI of 25 or more is considered overweight while 30 BMI or higher is considered obese.
According to the study, every rise in one unit of BMI was associated with ~10 percent increased risk for type 2 diabetes in early adulthood, and a 12 percent increase in the risk for heart disease. Remarkably, this elevated risk was significant at a BMI at age 17 of 23.4 or higher for diabetes and 20.9 or higher for heart disease. For diabetes, BMI at age 17 predicted the risk mainly since it associated with BMI later in life. However, for heart disease, both BMI at adolescence as well as BMI at adulthood independently of each other predicted the risk of the disease. During the 17 year study period, 1,173 new cases of diabetes and 327 new cases of heart disease were diagnosed.