Sex-specific socioeconomic inequalities in trajectories of anthropometry, blood pressure and blood-based biomarkers from birth to 18 years: a prospective cohort study

Background Evidence on when socioeconomic inequalities in conventional cardiometabolic risk factors emerge and how these change over time is sparse but important in identifying pathways leading to socioeconomic inequalities in cardiovascular disease (CVD). We examine socioeconomic inequalities in trajectories of cardiometabolic risk factors across childhood and adolescence. Methods Data were from offspring of the Avon Longitudinal Study of Parents and Children (ALSPAC), born in 1991/1992. Socioeconomic position (SEP) was measured using maternal education from questionnaires administered to mothers at 32-weeks’ gestation. Cardiometabolic risk factors were measured from birth/mid-childhood to age 18 years (y) and included fat and lean mass (9y–18y), systolic and diastolic blood pressure (SBP, DBP), pulse rate and glucose (7y-18y), high-density lipoprotein cholesterol (HDL-c), non-HDL-c and triglycerides (birth-18y). We examined the sex-specific associations between SEP and trajectories of risk factors using linear spline multilevel models. Results Among 6,517-8,952 participants with 11,948-42,607 repeated measures, socioeconomic inequalities in fat mass were evident at age 9y and persisted throughout adolescence, with graded associations across levels of SEP among females only. By 18y, fat mass was 12.32% (95% Confidence Interval (CI):6.96,17.68) lower among females and 7.94% (95% CI:1.91,13.97) lower among males with the highest SEP compared to the lowest. Socioeconomic inequalities in SBP and DBP trajectories were evident at 7y, narrowed in early adolescence and re-emerged between ages 16y-18y, particularly among females. Socioeconomic inequalities in lipid trajectories emerged, among females only, between birth and 9y in non-HDL-c, 7y and 18y in HDL-c and 9y and 18y in triglycerides while inequalities in glucose emerged among males only between ages 15y-18y. Conclusion Prevention targeting the early life course may be beneficial for reducing socioeconomic inequalities in CVD especially among females who have greater socioeconomic inequalities in cardiometabolic risk factors than males at the end of adolescence. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The UK Medical Research Council and Wellcome (grant ref: 217065/Z/19/Z) and the University of Bristol provide core support for ALSPAC. A comprehensive list of grants funding is available on the ALSPAC website (). KON is supported by a Health Research Board (HRB) of Ireland Investigator Led Award (ILP-PHR-2022-008). This funding source had no role in the design and conduct of this study. This publication is the work of the authors and KON will serve as guarantor for the contents of this paper. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Ethical approval for the study was obtained from ALSPAC Ethics and Law Committee and the Local Research Ethics Committees. Informed consent for the use of data collected via questionnaires and clinics was obtained from participants following the recommendations of the ALSPAC Ethics and Law Committee at the time. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes While the ALSPAC data used in these analyses are de-identified, there are legal restrictions on sharing these data imposed by the custodians of the data, The University of Bristol. Further information can be found here: [http://www.bristol.ac.uk/media-library/sites/alspac/documents/researchers/data-access/ALSPAC\_Access\_Policy.pdf][1]. All data enquiries can be sent to: ALSPAC-exec{at}bristol.ac.uk; Tel: +44 (0)117 331 0167. [http://www.bristol.ac.uk/media-library/sites/alspac/documents/researchers/data-access/ALSPAC\_Access\_Policy.pdf][1] [1]: http://www.bristol.ac.uk/media-library/sites/alspac/documents/researchers/data-access/ALSPAC_Access_Policy.pdf