Evidence check: SHBG in the context of Schlaf

SHBG (sex hormone-binding globulin) is a carrier protein for testosterone and estradiol. Its link to sleep is primarily discussed via insulin resistance and metabolic pathways: sleep deprivation or obstructive sleep apnea can reduce insulin sensitivity, which in turn suppresses hepatic SHBG production. Some cross-sectional studies report lower SHBG levels in individuals with sleep apnea or short sleep duration, while others find no significant association. The evidence is largely associative and not causal; randomized controlled trials are lacking. Moreover, SHBG is influenced by many factors (liver function, thyroid, diet, medications), so a single measurement without clinical context has limited value for assessing sleep quality. For MyBody-X, SHBG might be useful as part of a broader hormone panel, but not as a standalone sleep biomarker. The evidence base is mixed and does not support strong clinical recommendations.