Adverse waist-to-height ratio trajectories during childhood linked to early cardiometabolic risk

New research being presented at this year's European Congress on Obesity (ECO) in Malaga, Spain (11-14 May) reveals that adverse waist-to-height ratio trajectories (a marker for central obesity) during childhood may increase cardiometabolic and cardiovascular risk at 10 years old.

Notably, children with gradually increasing central obesity from birth were more likely to show early signs of metabolic and cardiovascular risk by age 10. This included elevated blood pressure and higher levels of biomarkers linked to systemic inflammation and metabolic dysfunction, such as triglycerides, insulin resistance (HOMA-IR), glycoprotein acetyls (GlycA), and high-sensitivity C-reactive protein (hs-CRP).

With rapidly rising rates of childhood obesity worldwide, it is important to understand how central obesity during childhood is already linked to early signs of metabolic deterioration, including elevated blood pressure and circulating biomarkers associated with future cardiometabolic disease."

Dr. David Horner, lead author from the University of Copenhagen, Denmark

Obesity in childhood and adolescence has been associated with cardiovascular, metabolic, neurological, musculoskeletal diseases and premature death in adulthood. Early detection of overweight and obesity in children is critical to enable interventions that may prevent long-term health consequences.

The build-up of belly fat deep within the abdomen is known to be a greater risk factor for cardiovascular and metabolic disease than body mass index (BMI) alone. Waist-to-height ratio (dividing waist circumference by height) is an indicator of central obesity and a key predictor of cardiometabolic health.

To explore how adverse waist-to-height ratio trajectories during childhood can help predict cardiometabolic and cardiovascular risk by age 10, researchers analysed data from 700 children enrolled in the Copenhagen Prospective Studies on Asthma in Childhood (COPSAC₂₀₁₀)-a longitudinal population-based mother-child cohort study.

The children were followed at 14 regular clinical visits from 1 week of life until the age of 10 years. Children's cardiometabolic risk was derived from composite scores (adjusted for age and sex) of HDL cholesterol (so-called "good cholesterol"), triglycerides (blood fats), glucose, blood pressure (height-adjusted), and HOMA-IR (insulin resistance).

The researchers identified three distinct waist-to-height ratio trajectories from 1 week to 10 years: a stable "reference group" comprising two-thirds of the children; a "rising then stabilising" group including roughly 1 in 6; and a "slow-rising" group also including roughly 1 in 6.

After adjusting for potential confounding factors, including sociodemographics, puberty status, and lifestyle factors such as physical activity, sleep, and diet, the researchers found that children in the "slow-rising" group had cardiometabolic risk scores 0.79 standard deviations higher, and cardiovascular disease risk scores 0.53 standard deviations higher, than those in the reference group. These shifts represents a significant shift away from the reference population risk level, indicating substantially worse cardiometabolic health by age 10.

This "slow-rising" group also had higher systolic blood pressure, alongside elevated levels of C-peptide (suggesting the body is producing excess insulin), HOMA-IR (a marker of insulin resistance associated with type 2 diabetes and other metabolic disorders), glycoprotein acetyls (GlycA) and high-sensitivity C-reactive protein (hs-CRP), both markers of chronic inflammation linked to cardiovascular disease.

In addition, these children had lower levels of HDL cholesterol (often referred to as "good" cholesterol), painting a broader picture of early warning signs for future heart and metabolic disease.

Compared to the reference group, the "rising then stabilising" group had significantly lower haemoglobin A1c (HbA1c) levels, indicating better blood sugar control, and slightly higher apolipoprotein B (ApoB) levels, an independent risk factor for cardiovascular disease.

When researchers took into account how much belly fat the children had at age 10, they found this explained most of the differences in health risk between the groups. As Dr Horner explains: "This means that the children's current level of abdominal fat--not just how their fat developed over time-was the strongest predictor of their heart and metabolic health. Once this factor was included in the analysis, the earlier pattern of gradual fat gain ("slow-rising" group) was no longer linked to higher risk on its own. This suggests that where a child ends up, how much belly fat they have at age 10, matters more than how they got there. In other words, it's the amount of central fat at that age, not necessarily the pattern of gain over time, that plays the biggest role in determining their present-day risk for heart and metabolic problems."

He adds: "Our findings highlight that an elevated waist-to-height ratio at age 10 is a key clinical indicator of cardiometabolic risk in children. This reinforces the importance of monitoring central obesity in routine care, not only tracking weight, but specifically measures of central obesity as part of standard assessments. As clinical focus shifts from weight alone to identifying children with early signs of metabolic risk, waist-to-height ratio offers a simple and effective tool for detecting central obesity with cardiometabolic relevance. Identifying children with elevated ratios can help clinicians target those at greater risk of metabolic dysfunction, supporting more personalised interventions and early prevention of long-term complications."

The authors note that this is an observational study, meaning it shows a strong association but does not conclusively prove that adverse central obesity patterns in childhood increase cardiometabolic risk by age 10. As part of this work, the team is currently analysing repeated blood samples using metabolomics to gain deeper insight into the biological mechanisms linking central obesity to cardiometabolic and cardiovascular disease risk.

As Dr Horner explains, "We plan to expand this analysis to include longitudinal metabolomic data throughout childhood and to hopefully validate findings in another independent mother-child cohort."