Chapter 07Connections

Sleep, cortisol and the hormone web

Sleep, melatonin, cortisol, insulin and the sex hormones pull on each other in both directions. To improve the whole web, start with sleep.

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Fig. 07 · Twelve connections Hover a hormone to trace it
Sleep Testosterone Insulin resistance Melatonin Cortisol dysregulation Mood · cognition Progesterone Estrogen 1 2 3 4 5 6 7 8 9 10 11 12 12
Both ways One way Affects mood Sleep's links
Optimal07 · Connections

A web, not a line

Sleep, melatonin, cortisol, insulin and the sex hormones pull on each other in both directions. Each numbered line is one connection.

Hover any hormone or number in the diagram to trace it.

Start with sleep

1Sleep ↔ Melatonin

Each supports the other. REM sleep declines with age from mid-life. Start here.

2Sleep ↔ Cortisol

Less sleep raises ACTH and cortisol, flattens the curve and removes the overnight low. A flat curve is itself a marker of insomnia.

4Sleep ↔ Insulin resistance

Less sleep lowers insulin sensitivity and raises diabetes risk. Insulin resistance delays sleep onset and increases snoring.

Melatonin and cortisol

3Melatonin ↔ Cortisol

High cortisol means low melatonin. A flat cortisol curve gives a flat melatonin curve.

Insulin resistance

5Insulin resistance ↔ Cortisol

More insulin raises ACTH and cortisol and disables the off switch. Cortisol impairs glucose uptake and β-cell insulin release.

6Insulin resistance → Testosterone

In women, it raises GnRH and LH and lowers SHBG: more free testosterone and acne (the PCOS pattern). In men, insulin resistance tends to lower testosterone instead.

7Insulin resistance → Estrogen

Visceral fat increases aromatase, which raises estrogen.

Cortisol and the sex hormones

8Testosterone ↔ Cortisol

Testosterone lowers cortisol. Chronically high cortisol lowers testosterone.

9Cortisol → Progesterone

Chronic stress and high cortisol can lower progesterone, mainly by disrupting ovulation, and with it allopregnanolone: anxiety, poorer sleep.

10Estrogen ↔ Cortisol

Estrogen raises cortisol and CRH and impairs the off switch.

What reaches mood

11Cortisol, sleep → Mood

Structural change in the hippocampus, prefrontal cortex and amygdala.

12Sex hormones → Mood

Testosterone, progesterone and estrogen all shape mood and cognition.

To improve the whole web, start with sleep

Sleep connects directly to melatonin, cortisol and insulin resistance, and through them to the rest of the web.

Hover any hormone to see everything it touches.