Meta‐analysis of four studies [29, 47, 55, 59] reported significantly lower SHBG levels in women with PCOS and OSA, compared to those without OSA (SMD = −0.62, 95% CI = −0.82 to −0.42, I2 = 0%; p < 0.00001, 438 participants; Figure 4D). This evidence concerns the gene SHBG and obstructive sleep apnea syndrome.