Blood cell parameters do not change during physiological human ageing

Area of Science:

• Gerontology
• Hematology
• Biostatistics

Background:

• Hematological values in the elderly lack standardized 'normal' ranges, leading to clinical challenges.
• Discrepancies in reported normal values for aged populations may stem from differing subject selection criteria.
• Defining 'healthy' in older adults is crucial for accurate physiological assessments.

Purpose of the Study:

• To investigate the impact of stringent versus conventional selection criteria on hematological parameters in healthy elderly individuals.
• To establish reliable reference ranges for blood cell counts in a rigorously defined healthy aged population.
• To determine if significant hematological alterations are inherent to aging or a result of less strict health criteria.

Main Methods:

• Comparison of blood cell parameters between two groups of elderly subjects (>75 years) selected by different criteria (Senieur protocol vs. conventional).
• Inclusion of sex-matched young adult controls (20-29 years) for parallel testing.
• Analysis of standard blood cell counts (e.g., red blood cells, white blood cells, platelets).

Main Results:

• Elderly subjects selected using stringent criteria (Senieur protocol) showed no clinically significant hematological alterations compared to young controls.
• Elderly subjects recruited with conventional criteria exhibited more pronounced differences in blood cell parameters.
• Blood cell parameters in Group A (stringent criteria) were consistent with those of young controls, indicating aging itself does not necessitate altered hematology.

Conclusions:

• Stringent selection criteria are essential for accurate biological investigations in gerontology.
• Hematological parameters in the elderly remain stable and unaltered when subjects are truly healthy.
• The study underscores the importance of robust participant screening to avoid misinterpreting physiological norms in aging research.