Basics
To start with we need to understand the gas exchange system in the body. The illustration above shows the path of red blood cells and the oxygen transport cycle. Both oxygen and carbon dioxide are transported around the body in the blood: from the lungs to the organs and again to the lungs.
Hemoglobin
The carrier of oxygen is the hemoglobin molecule that is contained in the red blood cells and over time it becomes glycated (sugar becomes attached) It is the hemoglobin that is referred to when you have a blood test for HBa1C levels.
HbA1c is a measure of glycated (sugar-clogged) hemoglobin in your blood averaged over the last 3 months. This is used as it is theorised that new red blood cells are made to replace old 'worn out ones' after around three months. The body makes between 1 to 2 million new red blood cells every second!
Many of us are told by our doctor that our A1c is a "little high" but nothing to worry about. This is bad advice and can lead to blocked arteries down the road. New research shows that you should have only one goal when it comes to your HbA1c and this video explains it all. Know your A1c and know what your goal-A1c really should be. Your health depends on it.
JACC study:
Background
The metabolic injury caused by protein glycation, monitored as the level of glycated hemoglobin (HbA1c), is not represented in most risk scores (i.e., Systematic Coronary Risk Estimation or atherosclerotic cardiovascular disease risk scale).
Objectives
The purpose of this study was to assess the association between HbA1c and the extent of subclinical atherosclerosis (SA) and to better identify individuals at higher risk of extensive SA using HbA1c on top of key cardiovascular risk factors (CVRFs).
Methods
A cohort of 3,973 middle-aged individuals from the PESA (Progression of Early Subclinical Atherosclerosis) study, with no history of cardiovascular disease and with HbA1c in the non-diabetic range, were assessed for the presence and extent of SA by 2-dimensional vascular ultrasound and non-contrast cardiac computed tomography.
https://www.jacc.org/doi/full/10.1016/j.jacc.2021.03.335
HbA1c Profile in the Study Population and Association With Subclinical Atherosclerosis
(A) Distribution of HbA1c across the sample. The color code represents the selected HbA1c categories used in the study. (B) Presence of SA in each vascular territory stratified by HbA1c category. HbA1c = glycated hemoglobin; SA = subclinical atherosclerosis.
Other Research
Pre-diabetes damages: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5583955/