Treatment of sleep-disordered breathing with positional therapy: long-term results.

PURPOSE: The aim of the present study was to assess the efficacy of a sleep position trainer (SPT) in patients with an established diagnosis of positional obstructive sleep apnea and to evaluate the adherence after 1-year follow-up. METHODS: Polysomnography (PSG) was performed at baseline and after 1 year of SPT use. Patients received questionnaires to assess treatment satisfaction and subjective adherence. Data on objective adherence and number of vibrations initiated by the SPT were collected from the SPT device. RESULTS: Nine out of 58 patients stopped using the SPT during the first year of treatment (16%). Thirty-four middle-aged and overweight patients underwent a PSG after 1 year of SPT use (male/female ratio, 28/6; overall apnea/hypopnea index (AHI), 16/h). A significant reduction in overall AHI to 6/h was observed using treatment (p < 0.001). The median percentage of supine sleep decreased significantly to 1% with SPT (p < 0.001). The mean objective SPT use in 28 patients was 7.3 ± 0.9 h/night and 69 ± 26% of the nights. Furthermore, 75% of the patients reported a better sleep quality since the start of SPT treatment. CONCLUSIONS: Long-term treatment with the SPT was found to be effective in reducing overall AHI. Time spent sleeping in supine position was reduced to almost zero in the continuing users. Patient satisfaction was high when using the SPT.

Following trends in steam sterilizer performance by quantitative monitoring of non-condensable gases.

Standards require a daily steam penetration test before starting production with a steam sterilizer. In many cases the results of steam penetration tests are not used for improvements or optimization of processes. This study aimed to detect whether trend analysis with an objective and quantifying steam penetration test has added value for the end-user. The databases of an objective quantifying steam penetration test, from the hospital and the manufacturer, are coupled and analysed. In this study, the databases included five steam sterilizers and approximately a four-year period. Based on the analysis, the process of the sterilizers was optimized. The results of the steam penetration tests became more stable over longer periods. This may result in lengthened periods between maintenance and validation. The analysis demonstrates that an objective, quantifying steam penetration test delivers more insights and knowledge of the functioning of the steam sterilization process. This knowledge may be used to optimize the process and reduce costs for the end-user.

Sleep misperception, EEG characteristics and autonomic nervous system activity in primary insomnia: a retrospective study on polysomnographic data.

Misperception of Sleep Onset Latency, often found in Primary Insomnia, has been cited to be influenced by hyperarousal, reflected in EEG- and ECG-related indices. The aim of this retrospective study was to examine the association between Central Nervous System (i.e. EEG) and Autonomic Nervous System activity in the Sleep Onset Period and the first NREM sleep cycle in Primary Insomnia (n=17) and healthy controls (n=11). Furthermore, the study examined the influence of elevated EEG and Autonomic Nervous System activity on Stage2 sleep-protective mechanisms (K-complexes and sleep spindles). Confirming previous findings, the Primary Insomnia-group overestimated Sleep Onset Latency and this overestimation was correlated with elevated EEG activity. A higher amount of beta EEG activity during the Sleep Onset Period was correlated with the appearance of K-complexes immediately followed by a sleep spindle in the Primary Insomnia-group. This can be interpreted as an extra attempt to protect sleep continuity or as a failure of the sleep-protective role of the K-complex by fast EEG frequencies following within one second. The strong association found between K-alpha (K-complex within one second followed by 8-12 Hz EEG activity) in Stage2 sleep and a lower parasympathetic Autonomic Nervous System dominance (less high frequency HR) in Slow-wave sleep, further assumes a state of hyperarousal continuing through sleep in Primary Insomnia.

Platelet alpha2-adrenoceptor density in humans: relationships to stress-induced anxiety, psychasthenic constitution, gender and stress-induced changes in the inflammatory response system.

BACKGROUND: This study examined the effects of psychological stress on platelet alpha2-adrenergic receptor (alpha2-AR) binding sites in relation to stress-induced anxiety and changes in the inflammatory response system (IRS). METHODS: The maximum number of binding sites (Bmax) and their affinity (Kd) for [3H]rauwolscine, a selective alpha2-AR antagonist, and the stimulated production of tumor necrosis factor-alpha (TNFalpha), the Th1-like cytokine, interferon-gamma (IFNgamma), and the Th2-like cytokines, interleukin-10 (IL-10) and IL-5, were measured in 35 university students a few weeks before (baseline) as well as on the day before a difficult, oral examination (stress condition). The State-Trait-Anxiety Inventory (STAI) was recorded during both conditions. The Minnesota Multiphase Personality Inventory (MMPI-2) was used to assess psychasthenia (Scale 7). RESULTS: Academic examination stress induced a significant increase in alpha2-AR density in students whose STAI scores increased in the stress period, in female students and in students who scored higher on psychasthenia. There were significant and positive correlations between stress-induced anxiety and changes in alpha2-AR density. Stress-induced anxiety was accompanied by a pro-inflammatory and Th1-like response, i.e. increased IFNgamma and TNFalpha production. The stress-induced changes in platelet alpha2-AR density were significantly and positively related to the production of TNFalpha, IL-10 and IL-5 and negatively to that of IFNgamma. CONCLUSIONS: Subchronic psychological stress in humans induces increased alpha2-AR density, which is related to stress-induced anxiety, an anxiety-prone constitution and female sex. Increased alpha2-AR density is accompanied by a Th2-like response and increased TNFalpha production. The results suggest that: (i) alpha2-AR density is sensitive to graded differences in stress-induced anxiety; and (ii) psychological stress is accompanied by intertwined responses in the catecholaminergic system, such as alpha2-ARs, and the IRS, such as Th1/Th2-like functions and the production of TNFalpha.

Serotonergic markers and lowered plasma branched-chain-amino acid concentrations in fibromyalgia.

The aims of the present study were to examine serotonergic markers, i.e. [3H]paroxetine binding characteristics and the availability of plasma tryptophan, the precursor of serotonin (5-HT), and the plasma concentrations of the branched chain amino acids (BCAAs), valine, leucine and isoleucine, in fibromyalgia. The [3H]paroxetine binding characteristics, B(max) and K(d) values, and tryptophan and the competing amino acids (CAA), known to compete for the same cerebral uptake mechanism (i.e. valine, leucine, isoleucine, phenylalanine and tyrosine), were determined in fibromyalgia patients and normal controls. There were no significant differences in the [3H]paroxetine binding characteristics (B(max) and K(d)) between fibromyalgia and control subjects. There were no significant differences in plasma tryptophan or the tryptophan/CAA ratio between fibromyalgia patients and normal controls. In the fibromyalgia patients, there were no significant correlations between [3H]paroxetine binding characteristics or the availability of tryptophan and myalgic or depressive symptoms. Patients with fibromyalgia had significantly lower plasma concentrations of the three BCAAs (valine, leucine and isoleucine) and phenylalanine than normal controls. It is hypothesized that the relative deficiency in the BCAAs may play a role in the pathophysiology of fibromyalgia, since the BCAAs supply energy to the muscle and regulate protein synthesis in the muscles. A supplemental trial with BCAAs in fibromyalgia appears to be justified.

Higher serum prolyl endopeptidase activity in patients with post-traumatic stress disorder.

BACKGROUND: It is reported that psychiatric disorders, such as depression and schizophrenia, are associated with changes in serum activity of prolyl endopeptidase (EC 3.4.21.26), a cytosolic endopeptidase, which cleaves peptide bonds on the carboxylside of proline in proteins of relatively small molecular mass. AIMS AND METHODS: The aims of the present study were to examine serum PEP activity in patients with post-traumatic stress disorder (PTSD) versus healthy volunteers. PEP activity has been determined by a fluorimetric assay. RESULTS: Serum PEP activity was significantly higher in patients with PTSD than in normal volunteers. Serum PEP activity was significantly higher in patients with PTSD and concurrent major depression than in patients with PTSD without major depression. In PTSD patients, there were no significant correlations between serum PEP activity and severity of PTSD symptoms. CONCLUSIONS: The results show that PTSD and, in particular, PTSD with concurrent major depression is associated with increased activity of PEP. RELEVANCE: these results may be of importance for the (i) neuroendocrine pathophysiology of PTSD since PEP degrades neuropeptides, such as arginine vasopressin (AVP) and thyrotropin releasing hormone (TRH); and (ii) etiology of PTSD, since PEP degrades behaviorally active neuropeptides, such as AVP, TRH, oxytocin, neurotensin and substance P, which play a key role in positive reinforcement, social interactions, emotions and stress responsivity.

Influence of psychological stress on immune-inflammatory variables in normal humans. Part II. Altered serum concentrations of natural anti-inflammatory agents and soluble membrane antigens of monocytes and T lymphocytes.

The effects of academic examination stress on serum concentrations of interleukin (IL)-1 receptor (R) antagonist (A), soluble(s) IL-2R, sIL-6R, soluble glycoprotein 130 (sgp130), Clara cell protein (CC16), sCD8 and sCD14 were evaluated in 38 university students. The relationships among changes in the above immune-inflammatory variables, levels of serum cortisol, and scores on the Perceived Stress Scale (PSS) or the State-Trait Anxiety Inventory (STAI) were examined. Academic examination stress was associated with significant increases in PSS and STAI scores, and in serum sgp130 and sCD8 values. Academic examination stress was associated with significantly decreased serum sCD14 concentrations in students with high, but not low, stress perception. There were stress-induced differences in serum IL-1RA, sIL-6R and CC16 concentrations between students with high vs. low stress-induced anxiety. The stress-induced increase in serum sCD8 was significantly more pronounced in male students, whereas the increase in serum sgp130 was more pronounced in female students taking contraceptive drugs. These results suggest that: (1) psychological stress induces immune-inflammatory changes pointing toward complex regulatory responses in IL-6 signalling, a decreased anti-inflammatory capacity of the serum, and interactions with T cell and monocytic activation; and that (2) sex hormones may modify stress-induced immune-inflammatory responses.

Elevated serum interleukin-6 (IL-6) and IL-6 receptor concentrations in posttraumatic stress disorder following accidental man-made traumatic events.

BACKGROUND: Recently, it has been reported that serum interleukin-1 beta (IL-1 beta), but not soluble IL-2 receptor (sIL-2R), concentrations were significantly higher in patients with posttraumatic stress disorder (PTSD) than in normal volunteers, and that psychological stress in humans is associated with increased secretion of proinflammatory cytokines, such as IL-6. METHODS: The aim of the present study was to examine the inflammatory response system in patients with PTSD through measurements of serum IL-6, sIL-6R, sgp130 (the IL-6 signal transducing protein), sIL-1R antagonist (sIL-1RA; an endogenous IL-1 receptor antagonist), CC16 (an endogenous anticytokine), and sCD8 (the T suppressor-cytotoxic antigen). RESULTS: Serum IL-6 and sIL-6R, but not sgp130, sIL-RA, CC16, or sCD8, concentrations were significantly higher in PTSD patients than in normal volunteers. Serum sIL-6R concentrations were significantly higher in PTSD patients with concurrent major depression than in PTSD patients without major depression and normal volunteers. There were no significant relationships between serum IL-6 or sIL-6R and severity measures of PTSD. CONCLUSIONS: The results suggest that PTSD is associated with increased IL-6 signaling. It is hypothesized that stress-induced secretion of proinflammatory cytokines is involved in the catecholaminergic modulation of anxiety reactions.

Decreased platelet alpha-2 adrenoceptor density in major depression: effects of tricyclic antidepressants and fluoxetine.

BACKGROUND: It has been suggested that major depression is accompanied by a subsensitivity of central alpha 2-adrenoceptors (alpha 2-ARs) and, consequently, by an impaired negative feedback on the presynaptic catecholaminergic neuron, which, in turn, may induce a disinhibition of noradrenergic output and norepinephrine release in response to any activation. METHODS: The maximum number of platelet binding sites (Bmax) and their affinity for [3H]-rauwolscine, a selective alpha 2-AR antagonist, were measured in unmedicated and medicated major depressed patients and in normal volunteers. Specific binding was defined as that inhibited by idazoxan, another alpha 2-AR antagonist. RESULTS: Unmedicated major depressed patients had significantly decreased platelet [3H]-rauwolscine binding Bmax values compared to normal volunteers. [3H]-rauwolscine binding Kd values did not differ significantly between unmedicated major depressed patients and normal controls. [3H]-rauwolscine binding Kd values were significantly higher in depressed patients treated with tricyclic antidepressants than in unmedicated patients. Subchronic treatment with fluoxetine did not significantly alter either [3H]-rauwolscine binding Bmax or Kd values. [3H]-rauwolscine binding Bmax values were significantly greater in men than in women. CONCLUSIONS: The results suggest that i) major depression is accompanied by decreased platelet alpha 2-AR density; and that ii) subchronic treatment with tricyclic antidepressants, but not fluoxetine, results in a decreased affinity of rauwolscine for platelet alpha 2-ARs.

Serotonergic and noradrenergic markers of post-traumatic stress disorder with and without major depression.

Some studies have suggested that disorders in the peripheral and central metabolism of serotonin (5-HT) and noradrenaline (NE) may play roles in the pathophysiology of post-traumatic stress disorder (PTSD). This study examines (1) the availability of plasma total tryptophan, the precursor of 5-HT, and tyrosine, the precursor of NE; and (2) the platelet 5-HT transporter and alpha 2-adrenoceptor (alpha 2-AR) binding sites in patients with PTSD and healthy volunteers. High-performance liquid chromatography (HPLC) was employed to measure plasma tryptophan and tyrosine as well as amino acids known to compete with the same cerebral transport system; that is, valine, leucine, phenylalanine, and isoleucine. The maximum number of binding sites (Bmax) and their affinity (Kd) for binding to [3H]-paroxetine and [3H]-rauwolscine, a selective alpha 2-AR antagonist, were determined. [3H]-paroxetine and [3H]-rauwolscine binding Kd values were significantly higher in patients with PTSD than in healthy volunteers. [3H]-rauwolscine binding Kd values were significantly higher in patients with PTSD and concurrent major depression (MD) than in PTSD patients without MD and healthy volunteers. Plasma tyrosine concentrations and the ratio of tyrosine/valine + leucine + isoleucine + phenylalanine + tryptophan were significantly higher in PTSD patients with MD than in those without MD and healthy volunteers. The results show that PTSD is accompanied by lower affinity of paroxetine binding sites and that PTSD with concurrent MD is accompanied by lower affinity of alpha 2-ARs and increased plasma tyrosine availability to the brain. The results suggest that (1) serotonergic mechanisms, such as defects in the 5-HT transporter system, may play a role in the pathophysiology of PTSD; and (2) that catecholaminergic mechanisms, such as increased precursor availability and lowered affinity of alpha 2-ARs, may play a role in the pathophysiology of PTSD with concurrent MD.

Increased 24-hour urinary cortisol excretion in patients with post-traumatic stress disorder and patients with major depression, but not in patients with fibromyalgia.

There is now firm evidence that major depression is accompanied by increased baseline activity of the hypothalamic-pituitary-adrenal (HPA) axis, as assessed by means of 24-h urinary cortisol (UC) excretion. Recently, there were some reports that fibromyalgia and post-traumatic stress disorder (PTSD), two disorders which show a significant amplitude of depressive symptoms, are associated with changes in the baseline activity of the HPA axis, such as low 24-h UC excretion. The aim of the present study was to examine 24-h UC excretion in fibromyalgia and PTSD patients compared to normal controls and patients with major depression. In the three patient groups, severity of depressive symptoms was measured by means of the Hamilton Depression Rating Scale (HDRS) score. Severity of fibromyalgia was measured using a dolorimetrically obtained myalgic score, and severity of PTSD was assessed by means of factor analytical scores computed on the items of the Composite International Diagnostic Interview (CIDI), PTSD Module. Patients with PTSD and major depression had significantly higher 24-h UC excretion than normal controls and fibromyalgia patients. At a threshold value of > or = 240 micrograms/24 h, 80% of PTSD patients and 80% of depressed patients had increased 24 h UC excretion with a specificity of 100%. There were no significant differences in 24-h UC excretion either between fibromyalgia patients and normal controls, or between patients with major depression and PTSD patients. In the three patient groups, no significant correlations were found between 24-h UC excretion and the HDRS score. In fibromyalgia, no significant correlations were found between 24-h UC excretion and the myalgic score. In PTSD, no significant correlations were found between 24-h UC excretion and severity of either depression-avoidance or anxiety-arousal symptoms. In conclusion, this study found increased 24-h UC excretion in patients with PTSD comparable to that in patients with major depression, whereas in fibromyalgia no significant changes in 24-h UC were found.

Effects of psychological stress on serum prolyl endopeptidase and dipeptidyl peptidase IV activity in humans: higher serum prolyl endopeptidase activity is related to stress-induced anxiety.

There is now some evidence that psychiatric disorders, such as major depression, schizophrenia and post-traumatic stress disorder are associated with significant alterations in the serum activity of peptidases, such as prolyl endopeptidase (PEP) and dipeptidyl peptidase IV (DPP IV). The aims of the present study were to examine the effects of psychological stress on serum PEP and DPP IV activity in humans. Thirty-eight university students had repeated measurements of serum PEP and DPP IV activity a few weeks before and after (baseline conditions) as well as the day before a difficult academic examination (stress condition). Subjects were divided into anxiety responders and nonresponders to stress according to their stress-induced increase in the Spielberger State Anxiety Inventory. Serum PEP activity was somewhat lowered by stress in female, but not male, students. Serum PEP activity was significantly higher in the two baseline conditions and during the stress condition in anxiety responders than in anxiety nonresponders. There were no significant effects of stress on serum DPP IV activity and no significant differences between anxiety responders and nonresponders. Serum PEP and DPP IV activity were significantly higher in men than in women. The results suggest that increased baseline serum PEP activity is related to stress-induced anxiety.

Influence of academic examination stress on hematological measurements in subjectively healthy volunteers.

Some recent reports showed that a brief exposure to a mental stressor during 3-20 min may induce hematological changes in humans. The aim of the present study was to examine the effects of academic examination stress on erythron variables, such as the number of red blood cells (RBC), hemoglobin (Hb), hematocrit (Ht), mean corpuscular volume (MCV), mean cell Hb (MCH), mean cell Hb concentration (MCHC), RBC distribution width (RDW), and serum iron and transferrin (Tf). The above variables were determined in 41 students in three conditions, i.e. the stress condition (the day before a difficult oral exam) and two baseline conditions, i.e. a few weeks earlier and later. At the same occasions, subjects completed the Perceived Stress Scale (PSS), the state version of the State-Trait Anxiety Inventory (STAI) and the Profile of Mood States (POMS). Academic examination stress significantly increased Ht, Hb, MCV, MCH and MCHC and significantly decreased RDW. There were significant relationships between the stress-induced changes in the PSS, STAI and POMS scores and those in Ht, Hb, MCV and MCH (allpositive) and RDW (negative). It is concluded that academic examination stress induces significant hematological changes indicative of an increased number of large RBC and increased hemoglobinisation, which cannot be explained by shifts of fluid out of the intravascular space, concentrating non-diffusible blood constituents.

The effects of psychological stress on humans: increased production of pro-inflammatory cytokines and a Th1-like response in stress-induced anxiety.

There is some evidence that, in humans and experimental animals, psychological stress may suppress or enhance immune functions, depending on the nature of the stressor and the immune variables under consideration. The possibility that psychological stress may affect the production of pro-inflammatory and immunoregulatory cytokines was investigated in 38 medical students, who had blood samplings a few weeks before and after as well as one day before an academic examination. Psychological stress significantly increased the stimulated production of tumour necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), IL-1 receptor antagonist (IL-1Ra), interferon gamma (IFN-gamma) and IL-10. Students with high stress perception during the stressful condition had a significantly higher production of TNF-alpha, IL-6, IL-1Ra and IFN-gamma than students with a low-stress perception. Students with a high anxiety response had a significantly higher production of IFN-gamma and a lower production of the negative immunoregulatory cytokines, IL-10 and IL-4, than students without anxiety. These findings suggest that, in humans, changes in the production of the pro-inflammatory cytokines, TNF-alpha, IL-6 and IFN-gamma, and negative immunoregulatory cytokines, IL-10 and IL-4, take part in the homeostatic responses to psychological stress and that stress-induced anxiety is related to a T-helper-1-like response.

The influence of psychological stress on total serum protein and patterns obtained in serum protein electrophoresis.

BACKGROUND: Significant alterations in total serum protein (TSP) patterns obtained in serum protein electrophoresis and serum proteins have been reported in patients with major depression and in subjects submitted to a combination of psychological and physical stress. The aim of the present study was to examine the effects of academic examination stress, on TSP and patterns obtained in serum protein electrophoresis. METHODS: TSP and the concentrations and percentages of the major electrophoretically separated serum proteins were measured in 41 healthy biomedical students the day before a difficult academic examination (i.e. the stressful condition), as well as a few weeks before and after the stressful condition (i.e. two baseline conditions). RESULTS: Academic examination stress increased TSP and the alpha 1, alpha 2, beta and gamma concentrations in stress-reactors, but not in stress non-reactors (as defined by changes in the Perceived Stress Scale). Academic examination stress reduced the percentage of albumin in the stress-reactors, but not in stress non-reactors. There were significant positive relationships between the stress-induced changes in TSP and serum alpha 2, beta and gamma concentrations and the stress-induced changes in the Perceived Stress Scale. CONCLUSIONS: The results show that even mild psychological stress of short duration can lead to measurable changes in TSP and in patterns obtained in serum protein electrophoresis.

The prediction of suicidal intent in depressed patients.

The aim of the present study was to examine the relationships between suicidal ideation or suicidal attempts and severity of depression, presence of personality disorders, and sociodemographic factors in a population of depressed in-patients. A total of 338 adult depressed psychiatric in-patients were examined and classified according to DSM-III criteria as having major depression with or without melancholic or psychotic features, adjustment disorder with depressed mood or dysthymic disorder. Scores on the Hamilton Depression Rating Scale (HDRS), Beck Depression Inventory (BDI) and Zung Self-Rating Depression and Anxiety Scales (SDS and SAS) were measured. We found that suicidal ideation was significantly related to severity of depression (according to the HDRS and all self-rating scales), a lower global assessment of functioning the year before hospitalization, and previous psychiatric hospitalizations. The items with the strongest predictive value for suicidal ideation were hopelessness, depressed mood, feelings of guilt, loss of interest and low self-esteem. These symptoms predicted 43% of the variance in suicidal ideation. None of the above predictors of suicidal ideation was related to suicidal attempts. Depressed patients with a personality disorder attempted significantly more suicidal attempts and showed more suicidal ideation than depressed patients without personality disorder. No significant correlations were found between suicidal ideation or suicide attempts and gender, marital status, employment status or psychosocial stressors during the previous 6 months.

Effects of psychological stress on serum immunoglobulin, complement and acute phase protein concentrations in normal volunteers.

The aim of this study was to examine the effects of academic examination stress on serum immunoglobulins (Igs), i.e. IgA, IgG, IgM, complement factors, i.e. C3c and C4, and acute phase proteins, i.e. alpha 1-acid glycoprotein (alpha 1-S), haptoglobin (Hp) and alpha 2-macroglobulin (alpha 2-M). Thirty-seven university students participated in this study. Serum was sampled a few weeks before and after as well as one day before a difficult academic examination. On the same occasions, students completed the Perceived Stress Scale (PSS). Students were divided into two groups, i.e. those with high- and low-stress perception as defined by changes in the PSS score. Academic examination stress induced significant increases in serum IgA, IgG, IgM, and alpha 2-M in students with high-stress perception, but not in these with low-stress perception. The stress-induced changes in serum IgA, C3c, and alpha 1-S concentrations were significantly higher in students with high-stress perception than in those with a low-stress perception. The stress-induced changes in serum IgA, IgM, C3c, C4, alpha 1-S, Hp and alpha 2-M were normalized a few weeks after the stress condition, whereas IgG showed a trend toward normalization. There were significant positive relationships between the stress-induced changes in the PSS and serum IgA, IgG, IgM and alpha 2-M. These findings suggest that psychological stress is accompanied by an altered secretion of serum Igs, complement factors and some acute phase proteins.

Lower serum high-density lipoprotein cholesterol (HDL-C) in major depression and in depressed men with serious suicidal attempts: relationship with immune-inflammatory markers.

Recently, there have been some reports that changes in serum lipid composition may be related to suicide, major depression and immune-inflammatory responses. Findings from our laboratory suggest that major depression is accompanied by reduced formation of cholesteryl esters and perhaps by impairment of reverse cholesterol transport. The latter is reportedly accompanied by lower serum high-density lipoprotein cholesterol (HDL-C). The aim of this study was to examine whether (i) major depression is accompanied by lower serum HDL-C or by abnormal levels of serum total cholesterol, triglycerides, low-density lipoprotein-C (LDL-C) or vitamin E, (ii) suicidal attempts are related to lower serum HDL-C and (iii) there are significant associations between serum HDL-C and immune/inflammatory markers. A total of 36 subjects with major depression, of whom 28 patients showed treatment resistance, as well as 28 normal control subjects, had blood sampled for the assay of the above lipids, serum zinc (Zn), albumin (Alb) and flow cytometric determination of the T-helper/T-suppressor (CD4+/CD8+) T-cell ratio. In total, 28 depressed subjects had repeated measures of these variables both before and after treatment with antidepressants. Serum HDL-C and total cholesterol, as well as the HDL-C/cholesterol ratio, were significantly lower in subjects with major depression than in normal controls. Serum HDL-C levels were significantly lower in depressed men who had at some time made serious suicidal attempts than in those without such suicidal behaviour. Treatment with antidepressants for 5 weeks did not significantly alter either serum HDL-C or other lipid variables. Serum HDL-C levels were significantly and negatively correlated with the (CD4+/CD8+) T-cell ratio, and positively correlated with serum Alb and Zn. These results suggest that (i) lower serum HDL-C levels are a marker for major depression and suicidal behaviour in depressed men, (ii) lower serum HDL-C levels are probably induced by the immune/inflammatory response in depression and (iii) there is impairment of reverse cholesterol transport from the body tissues to the liver.

Increased serum soluble CD8 or suppressor/cytotoxic antigen concentrations in depression: suppressive effects of glucocorticoids.

There is now some evidence that depression and, in particular, major depression, is accompanied by signs of an immune response, and that there are reciprocal relationships between immune function and increased hypothalamic-pituitary-adrenal (HPA) axis activity in depression. To further examine the above phenomena, this study has assayed serum soluble CD8 (sCD8) concentrations in 22 normal controls, 27 minor depressed, 37 major depressed, and 26 melancholic depressed patients. Serum sCD8 was significantly higher in depressed patients versus normal controls. Thirty-five percent of the depressed subjects had increased sCD8 serum levels (i.e., > 560 U/mL) with a specificity of 95.4%. Dexamethasone administration (1 mg PO) had a significant suppressive effect on serum sCD8. In depressed subjects, there were significant and negative relationships between serum sCD8 and postdexamethasone cortisol values. The results suggest the presence of an ongoing lymphocyte activation in depression, which may be down-regulated by increased HPA axis activity in that illness.