Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Insulin: Dosing Regimen and Adverse Effects

Insulin: Dosing Regimen and Adverse Effects

Insulin-replacement therapy usually includes both long-acting insulin (basal) and short-acting insulin (to cater to postprandial needs). In a diverse group of type 1 diabetes patients, the average daily insulin dose is typically 0.5-0.7 units/kg body weight. However, obese patients and pubertal adolescents may need more due to insulin resistance.
The basal dose constitutes about 40%-50% of the total daily dose, with the rest as premeal insulin. The mealtime insulin dose should mirror...

Insulin: Biosynthesis, Chemistry, and Preparation

Insulin: Biosynthesis, Chemistry, and Preparation

The endoplasmic reticulum (ER) of pancreatic β-cells synthesizes preproinsulin, which consists of a signal peptide, A and B chains, and a C-peptide. Preproinsulin is then cleaved and folded into proinsulin, which translocates to the Golgi apparatus for sorting and packaging into secretory granules. In these granules, enzymatic clipping generates insulin and C-peptide.
Damage or functional impairment of β-cells inhibits insulin production, leading to diabetes. Diabetes treatment...

Glucose Homeostasis: Pancreatic Islets and Insulin Secretion

Glucose Homeostasis: Pancreatic Islets and Insulin Secretion

The pancreatic islets comprising only 1%-2% of the volume are highly vascularized and innervated mini-organs. They contain five endocrine cell types, including β cells that secrete insulin, which is synthesized as a single polypeptide chain, preproinsulin, processed to proinsulin, and finally to insulin and C-peptide. This process is complex and regulated, involving the Golgi complex, the endoplasmic reticulum, and the secretory granules of the β cell.
Insulin and C-peptide are...

Production of Pharmaceuticals

Production of Pharmaceuticals

Industrial insulin production uses genetically engineered E. coli expressing a proinsulin gene controlled by a tryptophan promoter and containing a methionine linker for later cleavage. The cells also carry ampicillin resistance for selective growth. Seed cultures are stored at −80 °C and production begins by thawing a small amount to inoculate starter cultures, which are progressively scaled to a 50,000-L bioreactor. In the bioreactor, E. coli grow in nutrient-rich media under...

Diabetes Mellitus: Type 2 and Gestational

Diabetes Mellitus: Type 2 and Gestational

Type 2 diabetes, characterized by insulin resistance, arises when the insulin receptors on cells lose responsiveness to insulin, diminishing the cell's capacity to take up glucose, resulting in elevated blood glucose levels. To receive a diagnosis of Type 2 diabetes, a series of blood glucose tests are necessary to assess whether the blood glucose falls within normal parameters. If the result is out of the normal range, a patient may be diagnosed as prediabetic or diabetic, depending on the...

Diabetes Mellitus: Overview and Type I Subtype

Diabetes Mellitus: Overview and Type I Subtype

Diabetes mellitus is a chronic metabolic disorder characterized by high blood glucose levels due to inadequate insulin production, insulin resistance, or both. The condition affects millions worldwide and can significantly impact their health and quality of life.
Type 1 diabetes is an autoimmune disease in which the immune system mistakenly attacks and destroys the insulin-producing beta cells in the pancreas. As a result, the body is unable to produce sufficient insulin, and individuals with...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Retraction Notice to: Stem cell and colorectal carcinogenesis.

Journal of medicine and life·2023

Same author

Demographic and Clinical Characteristics of the Full 2015-2018 Cohort of Romanian Fabry Disease Patients.

Current health sciences journal·2020

Same author

DIETARY PATTERNS AND THEIR ASSOCIATION WITH OBESITY: A CROSS-SECTIONAL STUDY.

Acta endocrinologica (Bucharest, Romania : 2005)·2019

Same author

PREVALENCE OF OVERWEIGHT AND OBESITY IN A ROMA POPULATION FROM SOUTHERN ROMANIA - CALARASI COUNTY.

Acta endocrinologica (Bucharest, Romania : 2005)·2019

Same author

Colorectal Chemoprevention.

Revista medico-chirurgicala a Societatii de Medici si Naturalisti din Iasi·2018

Same author

Stem cells and colorectal carcinogenesis.

Journal of medicine and life·2016

Search research articles

Related Experiment Video

Updated: Apr 29, 2026

Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay

Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay

Published on: July 15, 2025

Proinsulin and age in general population.

S Ateia¹, E Rusu², V Cristescu³

¹"Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania ; Medas Clinic, Bucharest, Romania.

Journal of Medicine and Life

|May 29, 2014

Summary

Fasting proinsulin levels increase with age in the general population, peaking in middle age. Obesity is strongly linked to higher proinsulin, independent of age.

Keywords:

C-peptide aging insulin resistance obesity proinsulin

More Related Videos

Assessing Insulin Clearance in Mice via In Situ Liver Perfusion

Assessing Insulin Clearance in Mice via In Situ Liver Perfusion

Published on: December 13, 2024

Homogeneous Time-resolved Förster Resonance Energy Transfer-based Assay for Detection of Insulin Secretion

Homogeneous Time-resolved Förster Resonance Energy Transfer-based Assay for Detection of Insulin Secretion

Published on: May 10, 2018

Related Experiment Videos

Last Updated: Apr 29, 2026

Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay

Precise Visualization of Insulin Receptors A and B in Murine Brain with an RNA In Situ Hybridization Assay

Published on: July 15, 2025

Assessing Insulin Clearance in Mice via In Situ Liver Perfusion

Assessing Insulin Clearance in Mice via In Situ Liver Perfusion

Published on: December 13, 2024

Homogeneous Time-resolved Förster Resonance Energy Transfer-based Assay for Detection of Insulin Secretion

Homogeneous Time-resolved Förster Resonance Energy Transfer-based Assay for Detection of Insulin Secretion

Published on: May 10, 2018

Area of Science:

Endocrinology
Metabolic Health
Population Health

Background:

Proinsulin (PI) is a precursor to insulin, and elevated levels can indicate pancreatic beta-cell dysfunction.
Understanding the relationship between proinsulin, age, and obesity is crucial for metabolic health assessment.

Purpose of the Study:

To investigate the association between fasting proinsulin levels and age in a general Romanian population.
To determine if obesity influences the relationship between proinsulin and age.

Main Methods:

A population-based sample of 656 Romanians aged 26-80 years was analyzed.
Fasting plasma proinsulin, glucose, insulin, C-peptide, and HbA1c were measured.
Homeostasis model assessment of insulin resistance (HOMA-IR) and other indices were calculated.

Main Results:

Proinsulin levels showed a non-linear association with age, peaking in the 59-67 year age group.
Fasting proinsulin levels significantly increased with higher Body Mass Index (BMI) categories (lean, overweight, obese).
Obesity prevalence did not correlate with age in this cohort.

Conclusions:

A significant association exists between advancing age and elevated fasting proinsulin levels in the general population.
Obesity is a key factor associated with increased proinsulin, irrespective of age.