Cardiovascular-Kidney-Metabolic Syndrome and Life Expectancy in U.S. Adults

Cardiovascular-kidney-metabolic (CKM) syndrome has gained global attention for the clustering of conditions that markedly increase mortality risk. Prior studies have described the relative mortality risk of CKM stages, yet the impact on life expectancy remains underexplored.

This study aimed to quantify the association between CKM syndrome and life expectancy in U.S. adults and to assess variations by sex and race/ethnicity.

A total of 20,764 participants aged ≥30 years with confirmed CKM syndrome were included from the National Health and Nutrition Examination Survey 1999 to 2018. CKM stages 0 to 4 were defined per standardized questionnaires, physical examinations, and laboratory tests. Life expectancy was estimated using life table methods.

Over a median 9.33-year follow-up, 3,956 deaths occurred. The estimated 40-year life expectancy declined with advancing CKM stages: 41.82 (95% CI: 41.51-42.13) years at stage 0, 42.03 (41.72-42.34) at stage 1, 40.57 (40.28-40.86) at stage 2, and 35.01 (34.78-35.24) at stage 3/4. At age 40, men with CKM stage 0 had 5.80-year (95% CI: 5.74-5.86) life expectancy advantage over those with stage 3/4; the difference in women was 7.39 years (7.31-7.48). CKM stage 2 (adjusted HR: 4.00; 95% CI: 1.40-11.47) and stage 3/4 (11.03; 3.67-33.16) were significantly associated with increased cardiovascular mortality. Mexican Americans exhibited the greatest reduction in 40-year life expectancy (12.72 years) compared to White (6.55 years) and Black (5.93 years) participants.

Advanced CKM syndrome (stage 3/4) confers marked life expectancy reductions, particularly among Mexican Americans, underscoring the urgent need for early detection and targeted interventions.