Burden of family history on cardiovascular risk factors and target organ injury in adolescents: the ExAMIN Youth SA study

The global rise in obesity and hypertension among youth adds to the burden of cardiovascular disease (CVD) in later life. Evidence on how family history (FH) of CVD influences cardiovascular risk factors and target organ injury (TOI) in youth remains limited. We examined the relationship of TOI markers with cardiovascular risk factors in adolescents stratified by the absence (no-FH)/presence of FH of CVD and lifestyle risk. We included 682 school-going adolescents (mean age: 11 years) from the follow-up phase of the Exercise, Arterial Modulation and Nutrition in Youth South Africa study. Data on self-reported FH of CVD and lifestyle risk, demographics, anthropometrics, blood pressure, physical activity, and urinary glucose were collected. Cardiovascular ultrasound was used to determine carotid intima-media thickness (cIMT), left ventricular mass index (LVMI), and relative wall thickness (RWT). Cardiovascular risk factors and TOI markers were similar between the two groups except for higher socioeconomic status (SES) in the FH group ( p < 0.001). Carotid-IMT independently associated with lower SES in the no-FH group while the odds for cIMT>75th percentile was associated with the White population group and lower SES in the FH group. In both groups, RWT inversely associated with age, and additionally with the Black population group in the FH group. LVMI associated positively (β = 0.46 vs. β = 0.25, both p < 0.02) and RWT inversely (β=–0.27 vs. β=–0.49, both p < 0.001) with BMI z-score in both the FH and no-FH groups. Higher BMI z-scores associated with a threefold increase in the odds of both LVH>50 g/m 2.16 and RWT < 0.32 cm/m 2 in both groups. In the no-FH group, elevated urinary glucose was associated with a fourfold increase in LVH and lower RWT. Age associated with higher odds of RWT < 0.32 cm/m 2 in the FH group. TOI in adolescents associated with a combination of social determinates, FH, and modifiable cardiometabolic risk factors. While FH identified a subgroup with greater overall risk burden, BMI z-score emerged as the strongest correlate of cardiac remodelling, independent of FH. These findings underscore the importance of early identification and prevention strategies targeting obesity and other modifiable risk factors across all adolescents. The study was retrospectively registered on ClinicalTrials.gov on 12 August 2019 (NCT04056377).