Sleep quality is an important correlate of insulin resistance in postmenopausal women with and without metabolic syndrome (MetS), according to a recent study. Participants included 347 overweight/obese postmenopausal women without type 2 diabetes (age: 57.5 ± 6.5 years; body mass index [BMI]: 31.7 ± 3.7 kg/m²; 54% with MetS). Sleep quality was assessed with the 6-item Medical Outcomes Study Sleep Scale; values were categorized into quartiles. Insulin resistance was calculated from fasting glucose and insulin with the homeostasis model assessment of insulin resistance (HOMA2-IR) method. Researchers found:

• Women with the worst sleep quality had significantly higher HOMA2-IR values than women in all other quartiles, and women with MetS had significantly higher HOMA2-IR values than women without MetS, but the relationship between sleep quality and HOMA2-IR did not differ between those with or without MetS.
• Women with MetS in the worst quartile of sleep quality had higher HOMA2-IR values than all other women.
• Taking >30 minutes to fall asleep, frequent restless sleep, and frequent daytime drowsiness were each related to higher HOMA2-IR values.