Monitoring metabolic health in the adolescent population of Rarotonga: a multi-year cross-sectional study from 2016 to 2023

The Cook Islands, a small Pacific nation, carries a high burden of obesity (75%) and non-communicable disease (NCD) among adults. Primary prevention before adulthood, including school-based strategies, is a priority. Local evidence is crucial but challenging in resource-limited, low-population settings. This study presents data on the prevalence of risk factors associated with metabolic syndrome (MetS) among adolescents in Rarotonga, the main island of the Cook Islands. A multi-year cross-sectional survey of NCD risk factors in Year 9 students (median age: 13.8 years) between 2016–2019 and 2022–2023 ( n = 783) represented 65% of the cohort ( n = 1214). Data analysis used descriptive statistics with 5% significance testing. The prevalence of risk factors include: 22.1% overweight, 37.6% obese; 39.1% Waist-to-Height ratio (WtHR) > 0.5 (study years: χ 2 p < 0.001); 9.4% high Blood Pressure (BP) (gender: χ 2 p < 0.001, study years: χ 2 p = 0.005); 8.1% elevated Total blood Cholesterol (TC) (study years: χ 2 p = 0.003); 37.1% elevated fasting Blood Sugar Levels (fBSL) (study years: χ 2 p = 0.007). Where all measures were available ( n = 261), 27.6% of participants were living with obesity and ≥ 2 risk factors. Body-Mass-Index-for-Age (BMI-for-age) percentile and WtHR risk category proportions were positively correlated (χ 2 p < 0.001) with 78.9% of those with obesity falling into the increased risk WtHR category. Significant associations (all p < 0.001) were identified between elevated BP and BMI-for-age categories, WtHR, and TC levels. The multi-year cross-sectional approach enabled valid data within a low-resource setting that confirmed extremely high levels of overweight and obesity in the Year 9 student population. We argue that including waist circumference measures alongside BMI-for-age was a first step to enabling greater depth of understanding of the risk levels in this population. Some risk factors associated with MetS have been assessed, but investment in improving glucose and lipid monitoring is strongly recommended. This study highlights the importance of monitoring paediatric MetS in the Cook Islands. It suggests that it should be used longitudinally to inform the impact of interventions from early life through to adolescence.