The accelerating crisis of metabolic multimorbidity in young U.S. adults: a 26-year analysis of national trends, disparities, and projections to 2031.

BACKGROUND AND AIMS: The U.S. faces a silent cardiometabolic crisis as metabolic multimorbidity increasingly affects younger populations. Although individual conditions are well described, national trends in metabolic multimorbidity among young adults remain poorly defined. We examined 26-year national trends (1999-2024) and projected patterns through 2031 among decedents aged 25-44 to inform urgent public health action.

METHODS AND

RESULTS

We analyzed national Multiple Cause of Death microdata for 3,600,474 young adult decedents (1999-2024). Metabolic conditions (obesity, hypertension, type 2 diabetes, chronic kidney disease, dyslipidemia) were identified using ICD-10 codes. Multimorbidity was defined as ≥2 conditions and severe multimorbidity as ≥3. Metabolic multimorbidity increased nearly fourfold from 0.38% (1999) to 1.43% (2024). It rose from 1.36% (2021) to 1.43% (2024) despite declining overall mortality, signaling growing disease concentration. Forecasts project further increases to 1.65-1.73% by 2031. Severe multimorbidity surged 24-fold (0.003% to 0.072%), while ≥1 metabolic condition nearly doubled (5.14% to 10.08%). Hypertension prevalence doubled (2.59% to 5.36%), obesity nearly tripled (1.28% to 3.52%), diabetes increased >4-fold (0.15% to 0.69%), CKD rose modestly (1.37% to 1.58%), and dyslipidemia tripled (0.13% to 0.43%). Obesity-hypertension was the most frequent combination (41.02%). Prevalence was higher in females than males (1.00% vs. 0.87%, p < 0.001) and highest among Black (1.47%) and Other race (1.14%) versus White decedents (0.74%) (p < 0.001).

CONCLUSION

Metabolic multimorbidity among young U.S. adults has risen dramatically, with severe disease accelerating fastest, and marked racial and sex disparities. Immediate prevention, integrated care, and structural policy reform are essential to prevent escalating cardiovascular and disability burdens.