Objective: Despite evidence
of a relationship between obstructive sleep apnea (OSA), metabolic
dysregulation and diabetes mellitus (DM), it is uncertain whether OSA treatment
can improve metabolic parameters. We sought to determine effects of long-term
continuous positive airway pressure (CPAP) treatment on glycemic control and DM
risk in patients with cardiovascular disease (CVD) and OSA. <strong>Research
Design and Methods: </strong>Blood, medical history, and personal data were
collected in a <strong>substudy of 888 participants in the </strong>Sleep Apnea
Cardiovascular Endpoints (SAVE) trial in which patients with OSA and stable CVD
were r<strong>andomized</strong> to receive CPAP plus Usual Care, or Usual Care alone.
Serum glucose and glycated hemoglobin A<sub>1c</sub> (HbA<sub>1c</sub>) were measured
at baseline, and six months, two- and four years, and incident diabetes diagnoses recorded. Results:
Median follow-up was 4.3 years. In those with pre-existing DM (n=274), there
was no significant difference between CPAP and Usual Care groups in serum
glucose, HbA<sub>1c</sub> or anti-diabetic medications during
follow-up. There were also no significant between-group differences in participants
with pre-diabetes (n=452), nor in new diagnoses of DM. Interaction testing suggested
that women with diabetes did poorly in the Usual Care group while their counterparts
on CPAP therapy remained stable. <strong>Conclusions</strong><b>:</b> Among patients with established CVD
and OSA, we found no evidence that CPAP therapy over several years affected glycemic
control in those with diabetes or pre-diabetes, or DM risk over standard of
care treatment. The potential differential effect according
to sex deserves further investigation.
CPAP treatment, glycemia and diabetes risk in obstructive sleep apnea and comorbid cardiovascular disease
