Several biomarkers have been associated with predicting life expectancy in older adults, particularly those over 70. Here are some of the most significant ones:

1. Inflammatory markers:

   • C-reactive protein (CRP)

   • Interleukin-6 (IL-6)

2. Metabolic markers:

   • Glycated hemoglobin (HbA1c)

   • Fasting glucose levels

3. Cardiovascular markers:

   • N-terminal pro-brain natriuretic peptide (NT-proBNP)

   • Troponin T

4. Nutritional markers:

   • Serum albumin

   • Vitamin D levels

5. Hormonal markers:

   • Dehydroepiandrosterone sulfate (DHEA-S)

   • Insulin-like growth factor 1 (IGF-1)

6. Kidney function markers:

   • Estimated glomerular filtration rate (eGFR)

   • Cystatin C

7. Telomere length

8. DNA methylation patterns (epigenetic clock)

9. Grip strength (while not a blood biomarker, it's a strong predictor of mortality)

It's important to note that no single biomarker can accurately predict life expectancy on its own. A combination of these markers, along with other factors like lifestyle, genetics, and overall health status, provides a more comprehensive picture.

GPT4o answer:

Predicting life expectancy in people older than 70 can be complex due to the interplay of various health factors. However, several biomarkers are commonly studied and considered significant in this context:

1. Inflammatory Markers:

   • C-Reactive Protein (CRP): Elevated levels are associated with inflammation and have been linked to increased mortality risk.

   • Interleukin-6 (IL-6): High levels indicate systemic inflammation and are correlated with various age-related diseases and mortality.

2. Cardiovascular Markers:

   • N-terminal pro b-type Natriuretic Peptide (NT-proBNP): High levels are indicative of heart failure and cardiovascular stress, associated with a higher risk of mortality.

   • Troponin: Elevated levels suggest myocardial injury and are associated with an increased risk of cardiovascular events and death.

3. Metabolic Markers:

   • Hemoglobin A1c (HbA1c): Reflects average blood glucose levels over the past 2-3 months, with higher levels indicating poor glycemic control and increased mortality risk.

   • Cholesterol Levels: Both high and low levels of LDL cholesterol can be associated with increased mortality in the elderly.

4. Renal Function Markers:

   • Creatinine and Estimated Glomerular Filtration Rate (eGFR): Indicators of kidney function, with impaired function being a predictor of increased mortality.

   • Albuminuria: Presence of albumin in urine indicates kidney damage and is associated with higher mortality risk.

5. Nutritional Markers:

   • Albumin: Low serum albumin levels are indicative of poor nutritional status and are associated with increased mortality.

   • Vitamin D: Deficiency is linked to various adverse health outcomes and higher mortality.

6. Hematologic Markers:

   • White Blood Cell Count (WBC): Elevated counts can indicate infection or inflammation, associated with higher mortality.

   • Hemoglobin: Both low and very high levels can be linked to increased mortality risk.

7. Functional Markers:

   • Gait Speed: A simple measure of physical function, with slower gait speed being a strong predictor of mortality.

   • Grip Strength: Reduced grip strength is associated with higher mortality and poor health outcomes.

8. Other Biomarkers:

   • Telomere Length: Shorter telomeres are associated with cellular aging and increased mortality risk.

   • Fibrinogen: High levels indicate inflammation and are linked to cardiovascular events and mortality.

These biomarkers, individually or in combination, can help predict life expectancy and guide interventions to improve health outcomes in the elderly. Regular monitoring and comprehensive assessments are essential for accurate predictions and effective health management.