---
license: mit
library_name: pyaging
tags:
- pyaging
- aging-clock
- biology
- dna-methylation
---

# systemsage

Composite Systems Age integrates the 11 mortality-associated physiological-system scores plus a DNAm chronological-age prediction through PCA and Cox elastic-net regression, then rescales the result to an age-like value.

| | |
|---|---|
| **Predicts** | multisystem biological age |
| **Species** | Homo sapiens |
| **Tissue** | whole blood |
| **Data type** | DNA methylation |
| **Model type** | PCA + elastic net regression |
| **Year** | 2025 |

## Use with pyaging

```python
import pyaging as pya

pya.pred.predict_age(adata, ["systemsage"])
```

Browse every clock in the [pyaging Clock Catalogue](https://pyaging.readthedocs.io).

## Citation

Sehgal, R., Markov, Y., Qin, C., et al. (2025). Systems Age: a single blood methylation test to quantify aging heterogeneity across 11 physiological systems. Nature Aging, 5, 1880–1896.

https://doi.org/10.1038/s43587-025-00958-3