1103 Understanding the Role of Sleep as a Risk Factor for Suicidal Ideation in Active Duty Service Members

Introduction

Suicide is an important public health concern with many factors contributing to increased risk. Sleep is one such factor that may elevate risk, yet this association is not well understood. By identifying the strongest sleep-related predictors of suicidal ideation (SI), providers may be able to better intervene and reduce risk of suicide.

Methods

Data were obtained from the clinical database at the National Intrepid Center of Excellence (NICoE). Patients were active duty service members, predominantly male, and with a mean age of 38. As part of standard care, patients receive a polysomnography sleep study and complete a battery of intake measures offering a comprehensive view of sleep. Individual symptoms were analyzed in an effort to understand the role of each sleep symptom within the context of the many other factors that may contribute to SI in service members.

Results

Of the many data points collected during polysomnography, only rapid eye movement (REM) sleep latency and minimum sleeping heart rate were related to SI. REM latency was associated with increased odds of SI, while minimum sleeping heart rate was related to decreased odds. Subjective reports of bad dreams, trauma-specific bad dreams, sleepiness, and sleep quality were related to increased odds of SI. Notably, subjective reports of sleep were associated with greater odds than objective measures. Traumatic nightmares had the greatest odds, with these patients being much more likely to have SI.

Conclusion

These results support the importance of considering sleep factors when evaluating SI in service members. Subjective sleep reports, specifically, appear to be particularly important, as they were associated with increased odds of SI. These findings focus on the role of individual sleep factors in increasing the odds of SI and suggest it is important to evaluate sleep in combination with comorbid conditions when conducting risk assessments.

Support

N/A

Profile of endothelial and leukocyte activation in Fabry patients

Fabry disease is an X-linked recessive disorder resulting in the deposition of globotriaosylceramide in numerous cell types including vascular endothelial cells. Because this disease is associated with vascular injury and a high recurrence rate of thrombotic events, measurements of factors regulating endothelium and leukocyte interaction may provide insight into the mechanisms leading to a prothrombotic state. Twenty-five patients with Fabry disease and 25 control subjects participated in the study. Plasma from all 25 Fabry patients and 15 of the 25 controls were studied for multiple endothelial factors. Leukocyte integrins were measured by flow cytometry in 21 Fabry patients and 10 controls. The concentrations of soluble intercellular adhesion molecule-1, vascular cell adhesion molecule-1, P-selectin, and plasminogen activator inhibitor were significantly higher and thrombomodulin was significantly lower in Fabry patients. Expression of the integrin CD11b on monocytes was also significantly higher in the Fabry patients. This study reveals measurable evidence for endothelium and leukocyte activation that is consistent with a prothrombotic state in Fabry patients compared with controls. Further investigations of these findings may help to understand the mechanism of stroke in Fabry disease and provide indicators (or markers) of efficacy of future therapeutic intervention.

Prospective study of neurological responses to treatment with macrophage-targeted glucocerebrosidase in patients with type 3 Gaucher's disease

We prospectively evaluated the clinical and biochemical responses to enzyme-replacement therapy (ERT) with macrophage-targeted glucocerebrosidase (Ceredase) infusions in 5 patients (age, 3.5-8.5 years) with type 3 Gaucher's disease. The patients were followed for up to 5 years. Enzyme dosage ranged from 120 to 480 U/kg of body weight/month. Systemic manifestations of the disease regressed in all patients. Neurological deficits remained stable in 3 patients and slightly improved in 1. One patient developed myoclonic encephalopathy. Cognitive deterioration occurred in 1 patient and electroencephalographic deterioration in 2. Sequential cerebrospinal fluid (CSF) samples were obtained during the first 3 years of treatment in 3 patients and were analyzed for biochemical markers of disease burden. Glucocerebroside and psychosine levels were not elevated in these specimens, whereas chitotriosidase and quinolinic acid were elevated in 2 patients. Progressive decrease in the CSF levels of these latter macrophage markers during 3 years of treatment implies a decreased number of Gaucher cells in the cerebral perivascular space. Similar changes were not observed in the patient who had a poor neurological outcome. In conclusion, ERT reverses systemic manifestations of type 3 Gaucher's disease and appears to reduce the burden of Gaucher cells in the brain-CSF compartment in some patients.

Molecular biology of atherothrombotic brain infarction

Because reduced high density lipoproteins may contribute to atherothrombotic brain infarction, we performed molecular biologic and metabolic studies to characterize high density lipoprotein metabolism with respect to its role in reverse cholesterol transport, to clone the high density lipoprotein receptor, and to determine gene polymorphism for apolipoprotein A-I, the major protein of high density lipoprotein, because altered structure may impair reverse cholesterol transport. For high density lipoprotein metabolism measurements, high density lipoprotein 3 was isolated, purified, and labeled with iodine-125. The radiolabeled high density lipoprotein 3 was reinjected, and daily blood samples were taken for 10 days. Synthesis rates and fractional catabolic rates were determined from the specific activities and daily decrements. Preliminary data indicate that stroke-prone individuals' fractional catabolic rates for high density lipoprotein 3 are twice those of normal individuals. Also, the conversion of high density lipoprotein 3 to high density lipoprotein 2 is reduced in these individuals, suggesting that high density lipoprotein may be abnormally processed in individuals prone to atherothrombic brain infarctions. We surveyed more than 100 patients with carotid stenosis using a 2.2-kb probe for the apolipoprotein A-I gene. A subset of these patients displays polymorphism with restriction enzymes SacI or PstI. These preliminary findings suggest that gene polymorphism for apolipoprotein A-I may provide a molecular clue of atherothrombic brain infarction.