MMPI correlates of sleep and respiratory disturbance in obstructive sleep apnea

Study Objective-To evaluate associations between polysomnographic variables in obstructive sleep apnea (OSA) and a variety of psychological responses (including depressive symptoms) as assessed by the Minnesota Multiphasic Pe rsonality inventory (MMPI). Design-Cross-sectional. Setting-University slee p disorders center Patients-One-hundred seventy eight consecutive clinical OSA patients. Interventions-Not applicable. Measurements and Results-Patien ts completed the MPI prior to overnight diagnostic polysomnography. Fifty-e ight percent demonstrated at least one MMPI elevation (mean=1.8 elevations) , with Depression (D) elevated for 32%, Hypochondriasis (Hs) for 30%, and H ysteria (Hy) for 21%. Thirty-eight percent demonstrated two or more elevati ons, with several variations of Hs-D and Hs-D-Hy configurations evident. "C onversion V" profiles were fairly rare, and a large number of miscellaneous configurations occurred once. Significant correlations were detected betwe en several MMPI scale scores and total sleep time, the apnea-hypopnea index (AHI) during REM, and particularly arterial oxygen saturation, even when p artialling out variance related to body mass index (BMI). In contract, D sc ores were not correlated with any polysomnographic parameters. Based upon M MPI configuration, the sample was subdivided into the following seven profi le groups: Nonelevated (n=74); Single D (n=11); Single non-D (n=25); Combin ed D plus (a) HS or HY (n=7), (b) Hs and Hy (n=10), or (c) other (n=29); an d Multiple non-D (n=22). Multivariate analysis controlling for age and gend er indicated higher AHI in the Single non-D, Combined D plus other, and Mul tiple non-D groups, compared to the Single D group. Also, there was lower a verage oxygen saturation in the Multiple non-D group, compared to Single D, Single non-D, and Nonelevated groups. The Combined D plus HS and/or Hy gro ups did not differ from each other or from other groups, even when merged. The Multiple non-D findings were unattributable to any specific scale OF ov erall number of elevations. Conclusions-OSA patients who have core depressi ve symptoms (as measured by MMPI scale D) without significant psychological symptoms in other areas tend to have less severe OSA, whereas those with a diverse set of other psychological symptoms overshadowing depressive sympt oms (e.g., somatic focus, emotional reactivity, family/marital problems, co gnitive problems, etc.) tend to have greater AHI and lower oxygen saturatio n. although it seems probable that these MMPI differences primarily reflect OSA effects, prospective research is needed to confirm this hypothesis.