Age-associated changes in oxidative stress and NAD+ metabolism in human tissue

Massudi H, Grant R, Braidy N, Guest J, Farnsworth B, Guillemin GJ · PLoS One

Tissue NAD+ fell strongly with age in both sexes (r=-0.71 in males, p=0.001; r=-0.54 in females, p=0.01). PARP activity rose with age in males (r=0.77) and SIRT1 activity fell (r=-0.61, p=0.007); the female associations were weaker.

Population

Human pelvic skin samples from donors aged newborn to 77 years

Intervention

None — tissue NAD+, PARP activity, SIRT1 activity and DNA damage measured against age

Comparator

Age as a continuous variable

Limitations

Cross-sectional and correlational — cannot establish that falling NAD+ causes anything. One tissue (skin), one cohort, and most associations held only in males.