Pre-Existing Diabetes, CVD Increase Risk of Worsening Intermittent Hypoxemia

Tuomas Karhu

In order to determine sleep apnea (SA) related comorbidities, a recent study investigated the relationship between pre-existing hypertension, diabetes, or cardiovascular disease (CVD) and the severity of intermittent hypoxemia (IH) based on oxygen desaturation index (ODI) and novel desaturation parameters.

As a result, investigators, led by Tuomas Karhu, Department of Applied Physics, University of Eastern Finland, found IH to be more severe in patients with pre-existing CVD at baseline and both pre-existing diabetes and CVD has associations with expedited worsening of IH.

Methods

The team used data from the Sleep Heart Health Study (SHHS), a multi-center community-based cohort study of patients enrolled between 1995 - 2006 in the United States.

The design of the SHHS was to determine association between sleep-disordered breathing and related health consequences, including CVDs.

Both baseline and follow-up data was available on polysomnography (PSG), to determine from the apnea–hypopnea index (AHI), for 2,647 participants. Following exclusion for incomplete background information (n = 112), a total of 2535 participants were included in the analysis.

The study defined CVD as myocardial infarction, heart failure, coronary angioplasty, coronary artery bypass graft, and stroke, which were determined based on medical history interview. In addition, hypertension was defined as systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mm Hg, or hypertension medication was used. Diabetes was determined through patient-report or usage or insulin.

Investigators noted all patients underwent 2 polysomnographic recordings at 5.2 years apart.

Further, covariate adjusted linear regression analysis investigated the difference in severity of intermittent hypoxemia at baseline between each comorbid group and participants free from all comorbidities (n = 1264).

Results

Of the total patient population included in the study, 1164 patients had hypertension, 170 patients had diabetes, and 265 patients had CVD at baseline.

Data show diabetes-presence or CVD-presence groups were generally older, with a higher BMI and NC-H (P <.05), in comparison to the corresponding absence groups and no-comorbidity group.

Further, the team noted that the oxygen desaturation index (ODI), desaturation severity, and desaturation duration were significantly higher at the baseline in all presence groups compared to the no-comorbidities group.

After linear regression analysis, investigators found a higher ODI (β = 1.77; 95% CI, 0.41 – 3.13, P = .011), desaturation severity (β = 0.07, 95% CI, 0.00 – 0.14, P = .048), and desaturation duration (β = 1.50, 95% CI, 0.31 – 2.69, P = .013) in patients with preexisting CVD at baseline.

In addition, investigators observed an increase in ODI (β = 3.59, 95% CI, 1.78 – 5.39], P < .001), desaturation severity (β = 0.08, 95% CI, 0.02 – 0.14, P = .015), and desaturation duration (β = 2.60; 95% CI: 1.22 – 3.98, P < .001) in patients with diabetes during follow-up.

Finally, the data show an increase in ODI (β = 2.73, 95% CI, 1.15 – 4.32, P = 0.001) and desaturation duration (β = 1.85, 95% CI: 0.62 – 3.08, P = .003) in patients with CVD.

Conclusion

Investigators concluded that due to IH being an essential consequence of sleep apnea, patients would benefit from screening and follow-up monitoring.

“The detection of SA would enable preventative actions for its further worsening, such as lifestyle counseling or initiation of treatment,” investigators wrote. “These actions could mitigate the development of future SA-related comorbidities and adverse health consequences.”

The study, “Diabetes and cardiovascular diseases are associated with the worsening of intermittent hypoxaemia,” was published in Journal of Sleep Research.