Autonomic neuropathy increases the risk of obstructive sleep apnea in obese diabetics.

BACKGROUND

Nonobese diabetics with diabetic autonomic neuropathy (DAN) show an elevated prevalence of obstructive sleep apnea-hypopnea (OSAH).

OBJECTIVE

It was the aim of this study to assess if the presence of DAN could further increase the risk of developing OSAH in obese diabetics.

METHODS

Eighteen obese diabetic patients, 8 with DAN [age 57 +/- 5 years, body mass index (BMI) 35 +/- 4] and 10 without DAN (age 56 +/- 8 years, BMI 37 +/- 5), were recruited. Ten age-matched obese subjects were studied as controls (age 53 +/- 12 years, BMI 34 +/- 3). All subjects underwent a cardiorespiratory sleep study in the in-hospital sleep laboratory to obtain the apnea-hypopnea index (AHI) and oxygen desaturation indices.

RESULTS

Diabetics with DAN (Ob-DAN+) had a higher AHI than diabetics without DAN (Ob-DAN-) and controls, amounting to 39.5 +/- 13 versus 15.8 +/- 12 (p < 0.01) and 19.3 +/- 21 (p < 0.05), respectively. A moderate-to-severe OSAH (AHI > or = 15) occurred in all Ob-DAN+ and only in 4 Ob-DAN- and 4 control patients. Moreover, the indices reflecting the impairment of oxygen saturation (SaO(2)) during sleep such as the mean lowest SaO(2) and sleep time with a SaO(2) <90% were more severely affected in Ob-DAN+ patients compared with the other groups and were associated with longer obstructive respiratory events.

CONCLUSIONS

Apneas-hypopneas are more frequent and last longer in Ob-DAN+ than in other obese subjects, with or without diabetes.