Sleep disturbances and their relationship to glucose tolerance in pregnancy

OBJECTIVE

To explore relationships among sleep disturbances, glucose tolerance, and pregnancy outcomes.

RESEARCH DESIGN AND METHODS

Four validated sleep questionnaires were administered to 169 pregnant women at the time of 50-g oral glucose tolerance testing (OGTT) during the second trimester. Pregnancy outcomes were analyzed in 108 women with normal glucose tolerance (NGT).

RESULTS

Of the participants, 41% had excessive daytime sleepiness (Epworth Sleepiness Scale [ESS] >8); 64% had poor sleep quality; 25% snored frequently; 29% had increased risk of sleep-disordered breathing (SDB); 52% experienced short sleep (SS); 19% had both increased SDB risk and SS (SDB/SS); and 14% had daytime dysfunction. Reported sleep duration inversely correlated with glucose values from 50-g OGTT (r = −0.21, P < 0.01). Each hour of reduced sleep time was associated with a 4% increase in glucose levels. Increased likelihood of gestational diabetes mellitus (GDM) was found in subjects with increased SDB risk (odds ratio 3.0 [95% CI 1.2–7.4]), SS (2.4 [1.0–5.9]), SDB/SS (3.4 [1.3–8.7]), and frequent snoring (3.4 [1.3–8.8], after adjustment for BMI). Among NGT subjects, preterm delivery was more frequent in those with increased ESS (P = 0.02), poor sleep quality (P = 0.02), and SS (P = 0.03). Neonatal intensive care unit admissions were associated with increased ESS (P = 0.03), SDB/SS (P = 0.03), and daytime dysfunction (P < 0.01) in mothers.

CONCLUSIONS

Pregnant women experience significant sleep disturbances that are associated with increased risk of GDM and unfavorable pregnancy outcomes. Pregnant women with increased SDB risk, frequent snoring, and sleep duration of <7 h/night have increased risk of developing GDM.Sleep-disordered breathing (SDB) is present in 24% of men and 9% of women in the U.S. population (1) and has been linked to insulin resistance and type 2 diabetes (2–5). Recent studies reveal that SDB is present in up to 86% of patients with type 2 diabetes (6,7). SDB severity has been associated with poorer glucose control (6).Decreases in both duration and quality of sleep are common in pregnant women as a result of hormonal and physical factors (8,9). Collectively, these disorders have been termed pregnancy-associated sleep disorders by the International Classification of Sleep Disorders (10).Prospective studies show that SDB symptoms increase during pregnancy (11). SDB in pregnancy has been associated with preeclampsia, intrauterine growth retardation, and preterm delivery (12,13). A few recent studies using questionnaires that variably assess snoring, SDB symptoms, and/or sleep duration report an association between short sleep (SS) and/or frequent snoring and glucose intolerance and gestational diabetes mellitus (GDM) (14–16).We used four validated sleep questionnaires to obtain a comprehensive evaluation of sleep duration and quality and assess associations with glucose tolerance and pregnancy outcomes.