The age-related association between serum creatinine and cardiorespiratory morbidity and mortality and fractures among adults with cerebral palsy.

Purpose: Serum creatinine may be an objective biomarker of salient health issues in adults with cerebral palsy (CP). The objective was to assess the age-related association between serum creatinine with 3-year risk of cardiorespiratory morbidity/mortality and fracture among adults with CP.

Patients And Methods: This retrospective cohort study used medical records between Jan. 1, 2012 and Oct. 2, 2022 from adults ≥18 years old with CP. The association between baseline serum creatinine with the 3-year risk of all-cause mortality, respiratory/cardiovascular morbidity/mortality, and fracture was assessed by age and sex using logistic regression. The discriminative ability of serum creatinine alone and in conjunction with other variables was assessed.

Results: Over the 3-year follow-up, 8.3% of 1368 adults with CP had all-cause mortality, 25.6% had respiratory morbidity/mortality, 12.4% had cardiovascular morbidity/mortality, and 8.9% sustained a fracture. The association between serum creatinine with outcomes was dependent on age. For younger adults, lower creatinine had a higher odds ratio (OR) for all-cause mortality, respiratory morbidity/mortality, and fracture. For 51-60 year olds, higher creatinine had a higher OR for cardiovascular morbidity/mortality. Serum creatinine alone had modest prediction of outcomes, and generally improved prediction when added to models that included sex and co-occurring intellectual disabilities and epilepsy (c-statistic range, 0.54-0.84).

Conclusions: Lower serum creatinine may reflect frailty while higher levels may reflect kidney dysfunction, helping to explain the differential associations by age. Serum creatinine may be a useful biomarker as part of risk prediction models for these salient health issues for adults with CP.