Cu to Zn ratio, physical function, disability, and mortality risk in older elderly (ilSIRENTE study)

Area of Science:

• Gerontology
• Biomarkers
• Nutritional Science

Background:

• The copper to zinc ratio (CZr) is implicated in aging and mortality.
• Limited data exist on CZr's association with physical and functional status in the very old.

Purpose of the Study:

• To examine the relationship between serum CZr and physical performance, muscle strength, functional status, and survival in individuals aged 80+.
• To determine if CZr is an independent predictor of these outcomes or if its associations are influenced by other factors.

Main Methods:

• Longitudinal study (ilSIRENTE) of 346 individuals aged 80 years or older.
• Adjusted linear regression models assessed associations between baseline CZr and physical/functional measures.
• Consideration of hematological and inflammatory biomarkers (albumin, cholesterol, urea, IL-6, CRP).

Main Results:

• CZr showed stronger associations with physical and functional measures than copper or zinc alone, prior to adjustment for inflammatory parameters.
• Higher CZr tertiles were associated with greater physical decline over 2 years.
• Elevated CZr predicted increased mortality risk at 4 years (adjusted hazard ratio 1.92).

Conclusions:

• Serum CZr is confirmed as a predictor of mortality in the very old.
• The association of CZr with physical/functional performance appears to be mediated by inflammatory markers.
• Further research is needed to elucidate the precise role of CZr in aging and functional decline.