Cardiometabolic Risk Trajectories in Young Adults Across 16 Middle East and North African Countries, 1990-2018: A Sex-Asymmetric Divergence

Background: The INTERHEART-Middle East study identified the Middle East and North Africa (MENA) region as having the youngest age at first acute myocardial infarction (AMI) globally, with a population-attributable risk of 97.5% across nine modifiable risk factors. The population-level trajectories of cardiometabolic risk factors that precede this premature MI signature in young MENA adults remain incompletely characterized. Methods: NCD Risk Factor Collaboration (NCD-RisC) modeled prevalence estimates were analyzed across 16 MENA countries (Bahrain, Egypt, Iran, Iraq, Jordan, Kuwait, Lebanon, Libya, Morocco, Oman, Qatar, Saudi Arabia, Syria, Tunisia, United Arab Emirates, Yemen) in adults aged 20-29 and 30-39 years, stratified by sex: obesity and diabetes prevalence through 2022, hypertension prevalence through 2019 (ages 30-39 only, by data availability), and non-HDL cholesterol through 2018. Five-year age bands were aggregated into 20-29 and 30-39 groups by equal-weighted mean (with UN World Population Prospects 2024 population-weighted aggregation tested as a sensitivity analysis). Each country x sex x age-band x risk-factor series was analyzed using (1) joinpoint regression for the average annual percent change (AAPC); (2) posterior probability of true 1990-to-endpoint change derived from published credible intervals; and (3) a mixed-effects model with a year x region (MENA vs. rest-of-world [ROW]) interaction and country-level random slopes. Sensitivity analyses excluded conflict-affected states and Iran. Results: MENA diverged significantly from ROW in 6 of 14 sex x age-band comparisons, with a sex-asymmetric direction. In men, MENA worsened faster than ROW: obesity, ages 20-29 (AAPC +3.49%/year; p=0.009); obesity, ages 30-39 (AAPC +2.65%/year; p=0.043); and diabetes, ages 30-39 (AAPC +1.90%/year; p=0.014). In women, MENA improved faster than ROW: hypertension, ages 30-39 (AAPC -0.58%/year; p=0.001); non-HDL cholesterol, ages 20-29 (p=0.017); and non-HDL cholesterol, ages 30-39 (p=0.017). Country-level posteriors confirmed near-universal regional patterns: 60 of 64 obesity cells showed a very probable increase since 1990, and 52 of 64 (81%) non-HDL cholesterol cells showed a probable or very probable decrease. Five of the six divergent findings survived correction for multiple testing. Conclusion: Cardiometabolic risk in young MENA adults is diverging from global patterns in a sex-asymmetric way: obesity and diabetes are accelerating in young men, while hypertension and lipid profiles are improving in young women. This pattern maps directly onto the young-male AMI signature reported by INTERHEART-Middle East and identifies obesity and diabetes in young men as the most urgent targets for regional primary prevention.