The panel / Screening and safety

Sleep screen

Sleep apnoea is the single most consequential thing this panel looks for that is not a blood test. It produces the same symptoms as low testosterone, it lowers testosterone independently of your weight, and it compounds the main risk of the treatment. Missing it is how a man ends up on therapy that makes him worse.

What it measures

A validated questionnaire that estimates your likelihood of obstructive sleep apnoea, covering snoring, witnessed pauses in breathing, daytime tiredness, blood pressure, body size, age, neck circumference and sex. It is a screen, not a diagnosis. A positive screen leads to a sleep study.

How the screen works

STOP-BANGRoughly 90 percent sensitivity for detecting apnoea

Its roleA screening step, with a sleep study to confirm

ConfirmationHome-based studies are now an option for most men

We use STOP-BANG rather than the Epworth Sleepiness Scale deliberately. The Epworth measures only how likely you are to doze off, and its sensitivity for apnoea is around 42 to 47 percent, which means it misses more than half. Plenty of men with significant apnoea do not feel especially sleepy.

Why it is on the panel

Because the relationship runs in both directions and the treatment interacts with it. Pooled data across 24 case-control studies found significantly lower testosterone in men with apnoea, driven by intermittent overnight oxygen dips, independent of age and weight. Going the other way, low testosterone promotes the central and airway fat that worsens apnoea. And testosterone therapy raises haematocrit, which untreated apnoea also raises, so the two stack.

How it is done

InstrumentSTOP-BANG questionnaire

SettingAt the first visit, with the history

If positiveReferral for a sleep study

Study typeHome-based or in-lab

CostIncluded in the first visit

Partner inputValuable, since witnessed pauses are often unknown to you

Interpretation

Reading the result

The score sorts men into risk bands rather than producing a yes or no.

Bands used in practice

Low scoreApnoea is unlikely, and the rest of the panel carries more weight.

Score of 3 or moreRaised risk. A sleep study is the next step.

High score with severe obesitySubstantial likelihood. In one severe obesity cohort, 62 percent had low testosterone.

Any score with witnessed apnoeaReferred regardless, because that observation carries real weight.

In that severe obesity cohort, an apnoea-hypopnoea index above 30 independently predicted lower testosterone after adjusting for BMI, diabetes and inflammation. The apnoea was doing work the weight alone did not explain.

What the screen does not tell you

6 things that move it

It is a probability estimate, not a diagnosis. Only a sleep study confirms.

Specificity is modest, around 32 to 34 percent, so a positive screen produces some false alarms.

Absence of daytime sleepiness does not exclude apnoea, which is exactly why the Epworth alone is inadequate.

Alcohol in the evening and sedatives worsen apnoea on the night they are taken.

Nasal congestion and sleeping position both affect severity night to night.

Routine screening of genuinely asymptomatic adults is not currently recommended, which is a different question from screening symptomatic men.

What happens next

A positive screen leads to a sleep study before, not after, any decision about testosterone therapy.

Confirmed apnoea is treated first, because treating it addresses the symptoms, the cardiovascular risk and the haematocrit at once.

Testosterone therapy is approached cautiously where apnoea is untreated, particularly at higher doses, because it can worsen sleep-disordered breathing.

Testosterone is rechecked after apnoea is treated, rather than assumed to be unchanged.

Straight answers

Partly, sometimes, and we would rather be straight about this than oversell it. Two meta-analyses found no significant testosterone change after CPAP. A 2026 longitudinal study did find a significant rise after three months, independently of weight change, particularly in severe apnoea. The fair reading is that CPAP is not a hypogonadism treatment, but it may help in severe cases, and it is worth doing on its own merits regardless.