An abstract presented at CHEST 2021 showed that women who entered pregnancy with sleep-disordered breathing were associated with higher levels of insulin resistance and potential risk of gestational diabetes.
Typically thought to occur late in pregnancy, the relationship between SDB and abnormal glucose metabolism has been indicated to increase potential risk of gestational diabetes. However, researchers note that it remains unclear whether this relationship starts in early pregnancy or develops following exposure to SDB in pregnancy.
“This is significant because relationships between early pregnancy SDB and insulin resistance are largely unstudied,” the study authors said.
Seeking to assess the association between SDB and its severity with glucose metabolism in early pregnancy, they examined women with singleton pregnancies who had risk factors for obstructive sleep apnea (OSA), a form of SDB that has been linked with high blood pressure, cardiovascular disease, and Alzheimer disease.
Including pregnant women with OSA risk factors, such as body mass index (BMI) greater than or equal to 27 kg/m2 and habitual snoring, participants underwent in-home level III sleep apnea testing (HSAT) and homeostatic model assessment (HOMA) based on fasting glucose and C-peptide levels in early pregnancy (N = 192).
Use of chronic steroid therapy, history of pregestational diabetes, and use of continuous positive airway pressure were noted as exclusion criteria for the study.
“We derived measures of SDB (respiratory-event index [REI] and oxygen saturation index [ODI]) and glucose metabolism parameters (insulin resistance [HOMA-IR] and ꞵ-cell function [HOMA-%B]),” they added. “HSAT and HOMA were performed at a median gestational age (interquartile range) of 11 (3) and 15 (4) weeks, respectively.”
Of the study cohort, 61 participants (32%) were diagnosed with OSA, as measured by REI values greater than or equal to 5 events per hour. After adjusting for gestational age at testing, maternal age, BMI, ethnicity, and race, findings showed that women diagnosed with OSA had higher levels of insulin resistance than those not diagnosed.
In performing linear regression analysis and analysis of variance to examine the association between measures of SDB and glucose metabolism parameters, REI, as a continuous value, was significantly associated with HOMA-IR (B = 0.18; P = .041).
Conversely, OSA diagnosis (REI ≥ 5 events/hour) was not associated with HOMA-IR after adjusting for BMI (P > .05), with ODI significantly associated with HOMA-IR prior to adjusting for covariates (B = 0.22; P = .002), but not after adjustment (P = .24). No significant associations were observed between REI or ODI and HOMA-%B (P > .34).
“Our data suggest that women with SDB may enter pregnancy at a higher risk for gestational diabetes, instead of developing that risk over the course of pregnancy,” concluded the researchers. “This could imply SDB screening and treatment should occur earlier in pregnancy.”
They added that further investigation is warranted to investigate if treatment for SDB in early pregnancy could improve glucose metabolism.