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Age-Related Changes in Proinsulin Processing in Normoglycemic Individuals.

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  • 1Institute of Endocrinology, Prague, Czech Republic, Faculty of Science, Charles University, Prague, Czech Republic.

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|December 20, 2023
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As people age, their bodies become less sensitive to insulin, but healthy older adults compensate by increasing insulin production. This leads to a decrease in proinsulin, indicating more efficient insulin processing in aging individuals.

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Area of Science:

  • Endocrinology
  • Gerontology
  • Metabolic Research

Background:

  • Understanding age-related changes in glucose homeostasis is crucial for identifying pathological shifts.
  • Limited research exists on insulin processing in healthy aging adults compared to diabetic populations.

Purpose of the Study:

  • To investigate changes in proinsulin secretion and processing during natural aging in individuals with normal glucose tolerance.
  • To analyze the relationship between aging, insulin sensitivity, and beta-cell function.

Main Methods:

  • Cross-sectional study of 761 healthy individuals (aged 18-90 years) with normal fasting glycemia.
  • Measurement of body composition, glucose, proinsulin, insulin, C-peptide, and calculation of HOMA indices (HOMA F, HOMA R).
  • Statistical analysis using ANOVA to assess the effects of sex and age.

Main Results:

  • Glycemia, insulin, C-peptide, and insulin resistance (HOMA R) increased with age up to 75 years.
  • Proinsulin levels and proinsulin-to-insulin/C-peptide ratios decreased with age up to 75 years.
  • Aging in normoglycemic individuals involves decreased insulin sensitivity compensated by enhanced insulin production.

Conclusions:

  • The aging process in healthy individuals is characterized by reduced insulin sensitivity, effectively managed by increased insulin production.
  • A decrease in circulating proinsulin with age suggests more efficient processing into mature insulin by healthy beta cells.