How Fatigue and Insulin Resistance Are Linked

Metabolic-Health@outlook.com
16 hours ago
2 min read

Are you feeling tired all of the time?

In very simple and quick terms, insulin resistance affects your energy Metabolism. Insulin resistance means the body’s cells don’t respond effectively to insulin, especially muscle, fat, and liver cells. Insulin resistance is a topic I have studied for over 20 years. Insulin resistance prevents glucose enter cells, leading to less cellular energy (ATP) and increased fatigue, even if blood sugar is high. Try to think of it like having fuel (glucose) but the engine (your cells) can’t use it well.

In addition to this above, insulin resistance is associated with low-grade, chronic inflammation. Such pro-inflammatory cytokines (e.g., TNF-α, IL-6) affect the central nervous system, leading to mental fatigue, reduced motivation and poor concentration.

Insulin resistance can also cause type 2 diabetes, a condition that is known to affect sleep. It is well known that people with poor glucose control have poor sleep quality, restless legs or nocturia and even, potentially, obstructive sleep apnoea. An area I covered as part of my PhD. Indeed, waking in the night to need the toilet can be an easy sign of insulin resistance.

But back to sleep and general tiredness. Insulin resistance is linked to impaired mitochondrial function. This means cells have reduced capacity to generate ATP, directly contributing to muscle weakness and physical fatigue. Lastly, insulin resistance often causes unstable glucose levels, with post-meal highs (hyperglycaemia) and reactive dips (hypoglycaemia-like symptoms. These fluctuations can result in energy crashes and brain fog.

Studies show that patients with pre-diabetes or Type 2 diabetes report higher levels of fatigue than healthy controls.

Insulin resistance has been associated with fatigue even in non-diabetic individuals, especially those with: