Early Life Domains as Predictors of Obesity and Hypertension Comorbidity: Findings from the 1970 British Cohort Study (BCS70)

Background Obesity and hypertension are major public health problems and are associated with adverse health outcomes. To model realistic prevention scenarios and inform policy, it may be helpful to conceptualise early lifecourse domains of risk and incorporate such information when predicting comorbidity outcomes. We identify exposures across five pre-hypothesised childhood domains and explore them as predictors of obesity and hypertension comorbidity in adulthood. Methods The analytical sample included 7858 participants in the 1970 British Cohort Study. The outcome was obesity (BMI of ≥30) and hypertension (blood pressure>140/90mm Hg or self-reported doctor’s diagnosis) comorbidity at age 46. Early life domains included: ‘prenatal, antenatal, neonatal and birth’, ‘developmental attributes and behaviour’, ‘child education and academic ability’, ‘socioeconomic factors’ and ‘parental and family environment’. We conducted prediction analysis of the outcome in three stages:(1) stepwise backward elimination to select variables for inclusion for each domain (2) calculation of predicted risk scores of obesity-hypertension for each cohort member within each domain (3) multivariable logistic regression analysis including domain-specific risk scores, sex and ethnicity to assess how well the outcome could be predicted. We additionally included potential adult predictors of obesity-hypertension comorbidity as sensitivity analysis. Results Including all domain-specific risk scores in the same model, all five domains were significant predictors of obesity-hypertension comorbidity. The predictive power of the model, measured by the area under the curve (AUC), was 0.63 (95%CI 0.61-0.65). Including adult predictors increase the AUC to 0.68 (95%CI 0.66-0.70), and three early life domains - the parental and family environment domain (OR 1.11 95%CI 1.05-1.17) the socioeconomic factors domain (OR 1.09 95%CI 1.04-1.16), and the education and academic ability domain (OR 1.07 95%CI 1.02-1.13) remained predictors of obesity-hypertension comorbidity. Conclusions We found three robust domains for predicting obesity-hypertension comorbidity. Interventions that address these early life factors could reduce the burden of comorbidity.