High BMI Can Result in Cardiovascular Disease in Young Populations

Younger patients with a high body mass index may be at risk of hypertension and hypertrophy.

Overweight and obesity is generally thought to cause cardiovascular problems in mid-to-late life. Despite more children and adolescents developing obesity, there have been few studies examining the effect of high body mass index (BMI) among this population.

Higher BMI was found to cause poor cardiovascular health in younger populations, according to a study presented at the European Society of Human Genetics conference.

In the study, the authors gathered data from the Avon Longitudinal Study of Parents and Children (ALSPAC) to determine how BMI may affect cardiovascular health among young patients.

“ALSPAC is a world-leading birth cohort study, started in the early 1990s with the inclusion of more than 14,000 pregnant mothers and their partners and children, and provides an excellent opportunity to study environmental and genetic contributions to a person's health and development. It was therefore ideal for this purpose,” said researcher Kaitlin Wade, PhD.

The authors hypothesized that high BMI would result in earlier occurring cardiovascular risks. Since observational studies are unable to determine correlation and causation, the investigators used genetics data from the database to detect a link between high BMI and heart disease.

The authors discovered a link between high BMI and hypertension and high left ventricular mass index (LVMI) among patients aged 17 to 21, according to the study. A common marker for heart disease is the thickening of the left ventricle (hypertrophy), which makes the heart work harder to pump blood.

However, a higher BMI was not observed to effect heart rate among younger patients. This finding contradicts previous studies that found a link between BMI and heart rate. The authors report that the contradiction was likely due to other involved factors.

“Our results showed that the causal impact of higher BMI on cardiac output was solely driven by the volume of blood pumped by the left ventricle (stroke volume),” Dr Wade said. “This, at least in part, can explain the causal effect of higher BMI on cardiac hypertrophy and higher blood pressure that we observed in all our analyses.”

These findings confirm the benefit of efforts used to combat obesity in younger populations to prevent the onset of cardiovascular changes, according to the study. By increasing physical activity, young patients may prevent cardiovascular disease and lower BMI.

"It is the first time that the nature of this relationship has been shown in group of young adults where it has been possible to draw improved conclusions about its causation," Dr Wade said.

The authors are now working to discover the relationship between high BMI and disease mechanisms, including the chemical processes involved with the gut microbiome.

"Whilst randomised [sic] controlled trials are important for disentangling cause and effect in disease, they are expensive, time-consuming and labour [sic]-intensive. Modern genomics allows us to detect causality more quickly and cheaply, and the availability of large quantities of genetic data means that we can overcome the limitations of observational epidemiological studies,” Dr Wade concluded. “We believe that there are clear messages for cardiovascular health in our findings and we hope that they may lead to increased efforts to tackle obesity from early life.”