Sleep and lipids in posttraumatic stress disorder

Background : Sleep disturbances are among the most common symptoms of posttraumatic stress disorder (PTSD). There is growing evidence that sleep fragmentation and short sleep duration are risk factors for hyperlipidemia, diabetes, obesity, and other risk factors for vascular disease. No work has examined the association of sleep with lipid metabolism in PTSD. Methods : A cross-sectional 2×2 design (PTSD/control × male/female) included medication-free, nonobese, medically healthy subjects. The sample was comprised of 42 individuals with current chronic PTSD (52% female; M age = 30.81, SD = 6.55) and 45 age-and gender-matched controls without PTSD (51% female; M age = 30.04, SD = 8.07), ranging in age from 20 to 50 years. Sleep was monitored by diary for 1 week, and ambulatory polysomnography was performed over three nights on a research inpatient unit. Morning fasting lipids and adiponectin were measured after the second night of sleep. Results : PTSD subjects had significantly elevated total cholesterol, very-low-density lipoprotein (VLDL) cholesterol, and triglycerides relative to controls (all p's<.05) controlling for body fat percentage as measured by dual-energy X-ray absorptiometry scan. Lower total sleep time was significantly associated with higher total cholesterol, VLDL cholesterol, and triglycerides in the total sample (and these relationships were strongest in the PTSD group). Total sleep time from sleep diary was directly correlated with total adiponectin (r=.26, p=.04) and high-molecular-weight adiponectin (r=.27, p=.01) in the full sample, and this relationship was strongest in the control group. Discussion : The results suggest an association of sleep to cardiovascular risk factors in PTSD. Further research is needed to assess whether effective treatment of sleep in PTSD will favorably affect lipid metabolism.