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GOTHENBURG, Sweden — Childhood obesity is a growing public health concern for a laundry list of reasons, one being high blood pressure. New research shows that people who are obese during their childhood or teen years are more likely to suffer from high blood pressure starting at age 50.
A Swedish population-based study revealed that blood pressure among adult men increased in a linear association with higher childhood BMI (at 8 years-old) and greater BMI change during puberty (BMI at 20 years minus childhood BMI), independent of one another. Among women, blood pressure during middle age increased linearly in relation to greater pubertal BMI change only.
“Our results suggest that preventing overweight and obesity beginning in childhood matters when it comes to achieving a healthy blood pressure in later life,” says lead author Dr. Lina Lilja from the University of Gothenburg in a statement. “Children and teenagers living with overweight or obesity might benefit from targeted initiatives and lifestyle modifications to reduce the substantial disease burden associated with high blood pressure in later life from diseases such as heart attacks, strokes, and kidney damage.”
Hypertension is a public health challenge worldwide, affecting more than a billion adults. Currently, the World Health Organization estimates that 1.28 billion adults between 30 and 79 years-old are living with hypertension across the globe. High blood pressure is the leading cause of heart attacks, strokes, and chronic kidney disease while being one of the most preventable and treatable conditions out there. Some of the top risk factors are unhealthy diets, physical inactivity, and being overweight or obese.
To conduct this study, researchers analyzed data on 1,683 individuals (858 men and 825 women) born between 1948 and 1968 who were involved in two population-based cohorts. The BMI Epidemiology Study Gothenburg (BEST) cohort and the Swedish CardioPulmonary bioImage Study (SCAPIS) were used to investigate the association between BMI during development and systolic and diastolic blood pressure between the ages of 50 and 64.
The team measured the developmental BMI of participants from the BEST Gothenburg cohort utilizing school health care records for children ages seven and eight and records of military enrollment for young adults between 18 and 20. Until 2010, it was mandatory for young men to enroll in the military in Sweden. For middle-aged people, blood pressure information was taken from participants in the SCAPIS study who were not being medically treated for high blood pressure at the time of blood pressure measurement. The analyses were adjusted for birth year. Standard deviation was used to show what is within a normal range compared to the average.
Results showed that, for men, an increase of one BMI unit from the average BMI in childhood (BMI 15.6kg/m2) was linked with a 1.30 mmHg increase in systolic blood pressure (the top/first number) and a 0.75 mmHg increase in diastolic blood pressure (the bottom/second number). Additionally, a one BMI unit increase from the average pubertal BMI (equivalent to an average pubertal BMI change of 5.4kg/m2) in men was linked with a 1.03 mmHg increase in systolic blood pressure and a 0.53 mmHg increase in diastolic blood pressure in middle age, independent of each other.
In women, a one BMI unit increase in pubertal BMI was associated with a 0.96 mmHg increase in systolic blood pressure and a 0.77 mmHg increase in diastolic blood pressure in middle age, irrespective of childhood BMI. Interestingly, childhood BMI was not associated with changes in either systolic or diastolic blood pressure during midlife, regardless of pubertal BMI change.
“Although the differences in blood pressure are not very large, if blood pressure is slightly elevated over many years, it can damage blood vessels and lead to cardiovascular and kidney disease,” says co-author Dr. Jenny Kindblom from Sahlgrenska University Hospital in Sweden. “Our findings indicate that high blood pressure may originate in early life. Excessive fat mass induces chronic low grade inflammation and endothelial dysfunction [impaired functioning of the lining of the blood vessels] already in childhood. Higher amounts of visceral abdominal fat increases the risk of developing hypertension in adults. And we have previously shown that a large pubertal BMI change in men is associated with visceral obesity [fat around the internal organs] at a young adult age. So enlarged visceral fat mass might, in individuals with a high BMI increase during puberty, be a possible mechanism contributing to higher blood pressure.”
“This study is important given the rising tide of obesity among children and teens. It is vital that we turn the focus from high blood pressure in adults to include people in younger age groups,” Dr. Kindblom adds.
Given that these findings are observational, more studies are necessary to have a greater understanding of whether there are certain ages in childhood and/or adolescence when BMI is especially important as it relates to blood pressure in adulthood. The researchers also point out limitations such as that a causal relationship cannot be established between BMI and high blood pressure based on this study. Additionally, blood pressure was only measured at a single point in time, and other possible risk factors that could have affected the results couldn't be accounted for. Moreover, the results can't be generalized because most of the participants were White, so the results might not be as applicable to other ethnic groups.
The researchers are scheduled to present their findings at the European Congress on Obesity (ECO).
