Correlation between serum lipid, lipoprotein concentrations and anxious state, depressive state or major depressive disorder

Examining the cross-sectional relationship of platelet/high-density lipoprotein cholesterol ratio with depressive symptoms in adults in the United States

AIMS

Herein, we examined the correlation between platelet/high-density lipoprotein cholesterol ratio (PHR) and symptoms of depression among United States adults.

METHODS

Data acquired from the 2007-2018 National Health and Nutrition Examination Survey, involving individuals ≥ 20 years of age, with available PHR and depression diagnosis information. We employed weighted uni- and multivariable logistic regression analyses to assess the distinct correlation between PHR and depressive symptoms. Additionally, we conducted subgroup, interaction, and restricted cubic spline analyses.

RESULTS

In all, 28,098 subjects were recruited for analysis, with 8.04% depression status and 19.31 ± 0.11 mean PHR value. Depressive symptoms increased with higher quartiles of PHR. Following fully confounder adjustments in model 2, participants with the largest PHR quartiles exhibited a 53% (OR: 1.53, 95%CI: 1.00-2.33, P = 0.05) raised depressive symptoms, relative to participants with least PHR quartiles. Based on the two-piece-wise regression, the breakpoint was PHR = 23.76, and a positive association was more evident when PHR < 23.76 (OR = 1.06, 95%CI: 1.02-1.10, P = 0.01). When PHR ≥ 23.76, the correlation disappeared (P = 0.85). Using subgroup and interaction analyses, we revealed a positive relationship between PHR and depressive symptoms almost consistent among various population settings.

CONCLUSIONS

A convenient biomarker, the PHR was independently associated with an increased risk of depressive symptoms and may be a promising new bioindicator for the prediction of depression diagnosis.

Lipids in Psychiatric Disorders: Functional and Potential Diagnostic Role as Blood Biomarkers

Lipids are a crucial component of the human brain, serving important structural and functional roles. They are involved in cell function, myelination of neuronal projections, neurotransmission, neural plasticity, energy metabolism, and neuroinflammation. Despite their significance, the role of lipids in the development of mental disorders has not been well understood. This review focused on the potential use of lipids as blood biomarkers for common mental illnesses, such as major depressive disorder, anxiety disorders, bipolar disorder, and schizophrenia. This review also discussed the impact of commonly used psychiatric medications, such as neuroleptics and antidepressants, on lipid metabolism. The obtained data suggested that lipid biomarkers could be useful for diagnosing psychiatric diseases, but further research is needed to better understand the associations between blood lipids and mental disorders and to identify specific biomarker combinations for each disease.

The association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) and risk of depression among US adults: A cross-sectional NHANES study

BACKGROUND

NHHR (non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio) is a new lipid parameter used to assess the risk of cardiovascular disease. However, the association between NHHR and the risk of depression has not been studied before.

METHODS

We conducted a cross-sectional study using datasets from the National Health and Nutrition Examination Survey (NHANES) 2005-2016. The PHQ-9 questionnaire was used to evaluate depression. A weighted multivariable logistic regression model and a restricted cubic spline (RCS) model were applied to investigate the association between NHHR and depression risk. Additionally, subgroup and sensitivity analyses were conducted to test the robustness of the results.

RESULTS

In the total population, compared with the lowest reference group of NHHR, participants in the fourth quartile had a significantly increased risk of depression after full adjustments (OR: 1.61, 95%CI: 1.05-2.49). A linear dose-response relationship existed between NHHR and depression risk (P non-linearity = 0.264). The association remained significant in several subgroup analyses.

LIMITATIONS

The cross-sectional design and use of self-reported scales.

CONCLUSION

NHHR was significantly associated with a higher risk of depression in U.S. adults. Additional research on NHHR would help in depression prevention and treatment.

Apolipoprotein D as a Potential Biomarker in Neuropsychiatric Disorders

Neuropsychiatric disorders (NDs) are a diverse group of pathologies, including schizophrenia or bipolar disorders, that directly affect the mental and physical health of those who suffer from them, with an incidence that is increasing worldwide. Most NDs result from a complex interaction of multiple genes and environmental factors such as stress or traumatic events, including the recent Coronavirus Disease (COVID-19) pandemic. In addition to diverse clinical presentations, these diseases are heterogeneous in their pathogenesis, brain regions affected, and clinical symptoms, making diagnosis difficult. Therefore, finding new biomarkers is essential for the detection, prognosis, response prediction, and development of new treatments for NDs. Among the most promising candidates is the apolipoprotein D (Apo D), a component of lipoproteins implicated in lipid metabolism. Evidence suggests an increase in Apo D expression in association with aging and in the presence of neuropathological processes. As a part of the cellular neuroprotective defense machinery against oxidative stress and inflammation, changes in Apo D levels have been demonstrated in neuropsychiatric conditions like schizophrenia (SZ) or bipolar disorders (BPD), not only in some brain areas but in corporal fluids, i.e., blood or serum of patients. What is not clear is whether variation in Apo D quantity could be used as an indicator to detect NDs and their progression. This review aims to provide an updated view of the clinical potential of Apo D as a possible biomarker for NDs.

A combination of ketogenic diet and voluntary exercise ameliorates anxiety and depression-like behaviors in Balb/c mice

The positive effects of both ketogenic diet (KD) and regular voluntary exercise on anxiety and depression behavior have been recently reported in rodent animals, but the effects of pairing a KD with exercise on depression and anxiety are unknown. In this study, we aimed to investigate the effects of combination of KD and regular voluntary exercise on anxiety and depression-like behavior in Balb/c mice. We've demostrated that anxiety and depression levels decreased in KD-exercised (KD-Ex) mice. β-hydroxybutyrate (BHB) levels increased while glucose, insulin levels and LDL/HDL ratio decreased in KD-Ex mice. There was a negative correlation between BHB and the time spent in the closed arms of elevated plus maze (EPM) or the time spent in periphery walls of open field test (OFT) and the immobility time in forced swim test (FST) which all of them are indicators of low depression and anxiety levels. There was a positive correlation between LDL/HDL ratio and the time spent in the closed arms of EPM or the immobility time in FST. The immobility time in FST was positively correlated with insulin while the mobility time in FST was negatively correlated with glucose. In conclusion, these results suggest that decline in anxiety and depression-like behaviors resulted from KD with regular voluntary exercise may be associated with increased BHB levels and decreased LDL/HDL ratio and insulin or glucose levels. Further research is necessary for our understanding of the mechanisms by which pairing a KD with voluntary exercise influences brain and behavior.

The Effects of Statins on Neurotransmission and Their Neuroprotective Role in Neurological and Psychiatric Disorders

Statins are among the most widely used drug classes in the world. Apart from their basic mechanism of action, which is lowering cholesterol levels, many pleiotropic effects have been described so far, such as anti-inflammatory and antiatherosclerotic effects. A growing number of scientific reports have proven that these drugs have a beneficial effect on the functioning of the nervous system. The first reports proving that lipid-lowering therapy can influence the development of neurological and psychiatric diseases appeared in the 1990s. Despite numerous studies about the mechanisms by which statins may affect the functioning of the central nervous system (CNS), there are still no clear data explaining this effect. Most studies have focused on the metabolic effects of this group of drugs, however authors have also described the pleiotropic effects of statins, pointing to their probable impact on the neurotransmitter system and neuroprotective effects. The aim of this paper was to review the literature describing the impacts of statins on dopamine, serotonin, acetylcholine, and glutamate neurotransmission, as well as their neuroprotective role. This paper focuses on the mechanisms by which statins affect neurotransmission, as well as on their impacts on neurological and psychiatric diseases such as Parkinson's disease (PD), Alzheimer's disease (AD), vascular dementia (VD), stroke, and depression. The pleiotropic effects of statin usage could potentially open floodgates for research in these treatment domains, catching the attention of researchers and clinicians across the globe.

Gut microbiota-derived vitamins - underrated powers of a multipotent ally in psychiatric health and disease

Despite the well-established roles of B-vitamins and their deficiencies in health and disease, there is growing evidence indicating a key role of those nutrients in functions of the central nervous system and in psychopathology. Clinical data indicate the substantial role of B-vitamins in various psychiatric disorders, including major depression, bipolar disorder, schizophrenia, autism, and dementia, including Alzheimer's and Parkinson's diseases. As enzymatic cofactors, B-vitamins are involved in many physiological processes such as the metabolism of glucose, fatty acids and amino acids, metabolism of tryptophan in the kynurenine pathway, homocysteine metabolism, synthesis and metabolism of various neurotransmitters and neurohormones including serotonin, dopamine, adrenaline, acetylcholine, GABA, glutamate, D-serine, glycine, histamine and melatonin. Those vitamins are highly involved in brain energetic metabolism and respiration at the cellular level. They have a broad range of anti-inflammatory, immunomodulatory, antioxidant and neuroprotective properties. Furthermore, some of those vitamins are involved in the regulation of permeability of the intestinal and blood-brain barriers. Despite the fact that a substantial amount of the above vitamins is acquired from various dietary sources, deficiencies are not uncommon, and it is estimated that micronutrient deficiencies affect about two billion people worldwide. The majority of gut-resident microbes and the broad range of bacteria available in fermented food, express genetic machinery enabling the synthesis and metabolism of B-vitamins and, consequently, intestinal microbiota and fermented food rich in probiotic bacteria are essential sources of B-vitamins for humans. All in all, there is growing evidence that intestinal bacteria-derived vitamins play a significant role in physiology and that dysregulation of the "microbiota-vitamins frontier" is related to various disorders. In this review, we will discuss the role of vitamins in mental health and explore the perspectives and potential of how gut microbiota-derived vitamins could contribute to mental health and psychiatric treatment.

Alterations in acylcarnitines, amines, and lipids inform about the mechanism of action of citalopram/escitalopram in major depression

Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for major depressive disorder (MDD), yet their mechanisms of action are not fully understood and their therapeutic benefit varies among individuals. We used a targeted metabolomics approach utilizing a panel of 180 metabolites to gain insights into mechanisms of action and response to citalopram/escitalopram. Plasma samples from 136 participants with MDD enrolled into the Mayo Pharmacogenomics Research Network Antidepressant Medication Pharmacogenomic Study (PGRN-AMPS) were profiled at baseline and after 8 weeks of treatment. After treatment, we saw increased levels of short-chain acylcarnitines and decreased levels of medium-chain and long-chain acylcarnitines, suggesting an SSRI effect on β-oxidation and mitochondrial function. Amines-including arginine, proline, and methionine sulfoxide-were upregulated while serotonin and sarcosine were downregulated, suggesting an SSRI effect on urea cycle, one-carbon metabolism, and serotonin uptake. Eighteen lipids within the phosphatidylcholine (PC aa and ae) classes were upregulated. Changes in several lipid and amine levels correlated with changes in 17-item Hamilton Rating Scale for Depression scores (HRSD₁₇). Differences in metabolic profiles at baseline and post-treatment were noted between participants who remitted (HRSD₁₇≤ 7) and those who gained no meaningful benefits (<30% reduction in HRSD₁₇). Remitters exhibited (a) higher baseline levels of C3, C5, alpha-aminoadipic acid, sarcosine, and serotonin; and (b) higher week-8 levels of PC aa C34:1, PC aa C34:2, PC aa C36:2, and PC aa C36:4. These findings suggest that mitochondrial energetics-including acylcarnitine metabolism, transport, and its link to β-oxidation-and lipid membrane remodeling may play roles in SSRI treatment response.

From "Leaky Gut" to Impaired Glia-Neuron Communication in Depression

In the last three decades, the robust scientific data emerged, demonstrating that the immune-inflammatory response is a fundamental component of the pathophysiology of major depressive disorder (MDD). Psychological stress and various inflammatory comorbidities contribute to such immune activation. Still, this is not uncommon that patients with depression do not have defined inflammatory comorbidities, and alternative mechanisms of immune activation need to take place. The gastrointestinal (GI) tract, along with gut-associated lymphoid tissue (GALT), constitutes the largest lymphatic organ in the human body and forms the biggest surface of contact with the external environment. It is also the most significant source of bacterial and food-derived antigenic material. There is a broad range of reciprocal interactions between the GI tract, intestinal microbiota, increased intestinal permeability, activation of immune-inflammatory response, and the CNS that has crucial implications in brain function and mental health. This intercommunication takes place within the microbiota-gut-immune-glia (MGIG) axis, and glial cells are the main orchestrator of this communication. A broad range of factors, including psychological stress, inflammation, dysbiosis, may compromise the permeability of this barrier. This leads to excessive bacterial translocation and the excessive influx of food-derived antigenic material that contributes to activation of the immune-inflammatory response and depressive psychopathology. This chapter summarizes the role of increased intestinal permeability in MDD and mechanisms of how the "leaky gut" may contribute to immune-inflammatory response in this disorder.

Hypothesized behavioral host manipulation by SARS-CoV2/COVID-19 infection

Although not widely studied, behavioral host manipulation by various pathogens has been documented. Host manipulation is the process by which a pathogen evolves adaptations to manipulate the behavior of the host to maximize reproduction (Ro) of the pathogen. The most notable example is rabies. When a host is infected with the rabies virus it gets into the host's central nervous system and triggers hyper aggression. The virus is also present in the rabid animal's saliva so being bitten transmits the infection to a new host and the old host is left to eventually die if untreated. Toxoplasmosis is another example. When mice are infected they demonstrate a fearlessness toward cats, thus increasing their chances of being eaten. Toxoplasmosis needs the digestive tract of the feline to survive. Recent studies have shown that exposure to toxoplasmosis in humans (e.g., through cat feces) has also been associated with behavioral changes that are predicted to enhance the spread of the pathogen. Even the common influenza virus has been shown to selectively increase in-person sociality during the 48-hour incubation period, thus producing an obvious vector for transmission. Here we hypothesize that the novel coronavirus, SARS-CoV2, which produces the COVID-19 disease may produce similar host manipulations that maximize its transmission between humans.

Metabolomic Biomarkers in Anxiety Disorders

Anxiety disorders range among the most prevalent psychiatric disorders and belong to the leading disorders in the study of the total global burden of disease. Anxiety disorders are complex conditions, with not fully understood etiological mechanisms. Numerous factors, including psychological, genetic, biological, and chemical factors, are thought to be involved in their etiology. Although the diagnosis of anxiety disorders is constantly evolving, diagnostic manuals rely on symptom lists, not on objective biomarkers and treatment effects are small to moderate. The underlying biological factors that drive anxiety disorders may be better suited to serve as biomarkers for guiding personalized medicine, as they are objective and can be measured externally. Therefore, the incorporation of novel biomarkers into current clinical methods might help to generate a classification system for anxiety disorders that can be linked to the underlying dysfunctional pathways. The study of metabolites (metabolomics) in a large-scale manner shows potential for disease diagnosis, for stratification of patients in a heterogeneous patient population, for monitoring therapeutic efficacy and disease progression, and for defining therapeutic targets. All of these are important properties for anxiety disorders, which is a multifactorial condition not involving a single-gene mutation. This review summarizes recent investigations on metabolomics studies in anxiety disorders.

Examining the Influence of Early Life Stress on Serum Lipid Profiles and Cognitive Functioning in Depressed Patients

Background

Early childhood adversity is a strong predictor of the development of major depressive disorder (MDD), but not all depressed patients experience early life stress (ELS). Cardio-metabolic diseases and cognitive deficits often coincide in MDD and worsen its course and outcome. Adverse childhood experiences have been associated with elevated risk for cardiovascular disease (CVD), but little is known on the impact of ELS on cardiovascular risk factors in MDD. Here, we examined MDD patients with and without ELS to explore the effects of ELS on serum lipid and lipoprotein levels and on cognitive performances of the patients.

Methods

Participants with a mean age of 35 years (18–55 years) were recruited from the university mental health clinic and general community. Three groups, matched in age, gender and lifestyle were examined: MDD patients with ELS (n = 21), MDD patients without ELS (n = 21), and healthy controls (n = 20). The following CVD risk factors were assessed: serum lipids (total cholesterol, triglycerides, high- and low-density lipoproteins), body mass index and exercise in a typical week. MDD severity was measured by the Beck Depression Inventory. Childhood Trauma Questionnaire was used to assess early life adversities. Executive functions and attentional processes were assessed by the Wisconsin Card Sorting and Conners’ Continuous Performance tests.

Results

Major depressive disorder patients with ELS had higher serum triglyceride and lower HDL-cholesterol concentrations compared to MDD patients without ELS. Linear regression analysis revealed that the severity of ELS had a significant negative association with HDL-cholesterol levels and significant positive associations with the serum levels of TG and TC/HDL-cholesterol index. We also found significant associations between some specific trauma types and lipid profiles. Finally, we could detect significant associations between depression severity and specific domains of the cognitive tests as well as between lipid profiles and certain domains of the Wisconsin Card Sorting Test. However, we could not detect any association between the severity of ELS and cognitive performance.

Conclusion

After controlling for depressive symptom severity and lifestyle variables, ELS was found to be a strong predictor of serum lipid alterations. Several, inter-correlated pathways may mediate the undesirable effects of ELS on the course and outcome of MDD.

Serum lipids and brain-derived neurotrophic factor in a cross-section of male students with symptoms of depression at a university in Iran: an observational study

Background

Depression is a neuroprogressive disorder that is characterized by neurotransmitter derangement and decreased neurogenesis and neurotrophic factors including brain-derived neurotrophic factor (BDNF).

Objectives

To determine the lipid profiles and BDNF levels in university students at an institution in Iran and association of these factors with Beck Depression Inventory (BDI) scores.

Methods

We conducted an observational study of a cross-section of male students at the Ahvaz Jundishapur University of Medical Sciences in Iran. For each of the 100 participants, a BDI score was obtained and serum levels of BDNF were measured by enzyme-linked immunosorbent assay. Levels of serum lipids, including cholesterol, triglycerides, low-density lipoprotein (LDL), and high-density lipoprotein (HDL), were measured using a biochemical analyzer. Castelli’s risk index type I (CRI-I), Castelli’s risk index type II (CRI-II), CRI-I = TG/HDL-C and CRI-II = LDL-cholesterol/ HDL-cholesterol, and atherogenic index of plasma (AIP), AIP = log (triglycerides/HDL-cholesterol), were calculated.

Results

Based on BDI scores, lower levels of BDNF, triglycerides, cholesterol, and HDL, but higher levels of LDL were found in participants with higher BDI scores. CRI-I was also increased in participants with depression.

Conclusion

The levels of BDNF and lipid factors are associated with the severity of depression in Iranian male university students. Deranged levels of BDNF and lipids may predispose depressed students to cardiovascular diseases.

Serum lipidomic analysis for the discovery of biomarkers for major depressive disorder in drug-free patients

Lipidomic analysis can be used to efficiently identify hundreds of lipid molecular species in biological materials and has been recently established as an important tool for biomarker discovery in various neuropsychiatric disorders including major depressive disorder (MDD). In this study, quantitative targeted serum lipidomic profiling was performed on female subjects using liquid chromatography-mass spectrometry. Global lipid profiling of pooled serum samples from 10 patients currently with MDD (cMDD), 10 patients with remitted MDD (rMDD), and 10 healthy controls revealed 37 differentially regulated lipids (DRLs). DRLs were further verified using multiple-reaction monitoring (MRM) in each of the 25 samples from the three groups of independent cohorts. Using multivariate analysis and MRM data we identified serum biomarker panels of discriminatory lipids that differentiated between pairs of groups: lysophosphatidic acid (LPA)(16:1), triglycerides (TG)(44:0), and TG(54:8) distinguished cMDD from controls with 76% accuracy; lysophosphatidylcholines(16:1), TG(44:0), TG(46:0), and TG(50:1) distinguished between cMDD and rMDD at 65% accuracy; and LPA(16:1), TG(52:6), TG(54:8), and TG(58:10) distinguished between rMDD and controls with 60% accuracy. Our lipidomic analysis identified peripheral lipid signatures of MDD, which thereby provides providing important biomarker candidates for MDD.

Cardiovascular risk profile in burn survivors

OBJECTIVE

Burn patients have prolonged derangements in metabolic, endocrine, cardiac and psychosocial systems, potentially impacting on their cardiovascular health. There are no studies on the risk of cardiovascular disease (CVD) after-burn. The aim of our study was to record lipid values and evaluate CVD risk in adult burn survivors.

METHODS

In a cross-sectional study patients ≥18 years with burn injury between 18-80% total burn surface area (TBSA) from 1998 to 2012 had total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides measured via finger prick. Means were compared to optimal ranges. Multivariate regression models were performed to assess the association of lipids with age, years after-burn and total body surface area % (TBSA). A p value <0.05 was considered significant. The Framingham General Cardiovascular Risk Score (FGCRS) was calculated.

RESULTS

Fifty patients were included in the study. Compared to optimal values, patients had low HDL and high triglycerides. Greater %TBSA was associated with statistically significant elevation of triglycerides (p=0.007) and total cholesterol/HDL ratio (p=0.027). The median FGCRS was 3.9% (low) 10-year risk of CVD with 82% of patients in the low-risk category. Patients involved in medium/high level of physical activity had optimal values of HDL, TC/HDL and triglycerides despite the magnitude of TBSA%.

CONCLUSION

Adult burn survivors had alterations in lipid profile proportional to TBSA, which could be modified by exercise, and no increase in overall formally predicted CVD risk in this cross sectional study.

Blocking of carnitine palmitoyl transferase 1 potently reduces stress-induced depression in rat highlighting a pivotal role of lipid metabolism

Major depressive disorder is a complex and common mental disease, for which the pathology has not been elucidated. The purpose of this study is to provide knowledge about the importance of mitochondrial dysfunction, dysregulated lipid metabolism and inflammation. Mitochondrial carnitine palmitoyl transferase 1a (CPT1a) is a key molecule involved in lipid metabolism and mutations in CPT1a causing reduced function is hypothesized to have a protective role in the development of depression. Moreover, CPT1a is found to be upregulated in suicide patients with history of depression. Therefore, we hypothesized that inhibition of CPT1a activity can be developed as an innovative treatment strategy for depression. Stress exposure combined with different pharmacological treatment regimens; Etomoxir, CPT1 blocker, and Escitalopram, a favoured antidepressant drug, was applied in state-of-the-art chronic mild stress model. Etomoxir treatment induced statistical significant reduction of anhedonic behavior compared to vehicle treatment (p < 0.0001) and reversed depression-like phenotype in 90% of the rats (p = 0.0007), whereas Escitalopram only proved 57% efficacy. Moreover, Etomoxir revealed downregulation of interferon-γ, interleukin-17α and tumor necrosis factor-α. This indicate that alteration in metabolism is pivotal in the pathogenesis of depression, since CPT1 blockage is highly efficient in treating anhedonia and inflammation, thereby opening up for a novel class of antidepressant medication.

Is There a Link Between Cholesterol Level and the Risk of Developing Depression?

Depressive disorders and hypercholesterolemia are serious and common global problems. Many researchers have attempted to demonstrate association between concentration of the lipid fractions, depression as well as the rate of suicide, but the results are inconclusive. To overcome this lack of knowledge, we have summarized the studies concerning this relationship and published in recent years. All of articles included were published in peer reviewed journals and were identified through systematic query of PubMed with follow-up manual searches.

Concentrations of total cholesterol – TC, cholesterol – LDL-C, cholesterol - HDL-C other triglycerides and others atherogenic index and comorbidity with depressive disorders have been considered. While both positive and negative association between lipid fractions and depression have been shown in many studies, some data revealed no relationships between the two factors. In addition, we have also summarized the usage of statins and the occurrence of depressive disorders, and the results remain inconclusive.

In conclusion, our review did not reveal a clear relationship between lipid fractions and depression. Additional studies are needed as increased incidence of comorbidity between mood disorders and lipid disorders have been observed.

Depression and serum low-density lipoprotein: A systematic review and meta-analysis

BACKGROUND

A cross-sectional association between depression and serum low-density lipoprotein (LDL) has been noted in the literature. This study aims to employ meta-analytic techniques to clarify the relationship between depression and serum LDL.

METHODS

Published articles through April 2015 were identified through systematic query of PubMed with follow-up manual searches. Data from 36 studies reporting mean difference and 7 studies reporting odds ratios were analyzed separately.

RESULTS

Meta-analysis of studies modeling serum LDL as a continuous measure demonstrates overall significantly lower serum LDL in depression (Mean difference=-4.29, 95% CI=-8.19, -0.40, p=0.03). Meta-analysis of studies modeling serum LDL as a categorical measure demonstrates a marginally significant lower odds of depression in the presence of low serum LDL relative to high serum LDL (OR=0.90, 95% CI=0.80, 1.01, p=0.08).

LIMITATIONS

High heterogeneity was noted across sampled studies, which may be a function of variations in study design, participants sampled, or other factors. The potential for publication bias was also assessed.

CONCLUSIONS

This meta-analysis demonstrates a cross-sectional link between depression and low serum LDL.

A Retrospective Evaluation of the Inflammatory Marker C-Reactive Protein (CRP), Cholesterol and High-Density Lipoproteins in Patients with Major Depression: Preliminary Findings

The aim of this study was to retrospectively evaluate the role of C-reactive protein, total cholesterol and high-density lipoprotein cholesterol in patients suffering from Major Depression (MD). Data of C-reactive protein, total cholesterol (TC) and high-density lipoprotein cholesterol of 37 adult outpatients (17 men, 20 women) with a DSM-IV diagnosis of MD were analyzed. Depression was measured with the 17-item Hamilton Depression Rating Scale (HAM-D) and with the Beck Depression Inventory (BDI). Suicide risk was evaluated with the Scale of Suicide Ideation (SSI). Patients with a lifetime history of attempted suicide were categorized as having higher suicide risk. Higher suicide risk patients showed higher C-reactive protein levels and lower high-density lipoprotein cholesterol levels than lower suicide risk patients whereas total cholesterol levels were not statistically different. C-reactive protein positively correlated with BDI, HAM-D, SSI scores and with number of previous depressive episodes. High-density lipoprotein cholesterol correlated inversely with BDI, HAM-D and SSI scores, whereas, no significant correlations were found between Total Cholesterol and other variables including C-reactive protein. In linear regression models, C-reactive protein was predictor of more severe depression and increased suicide risk. Lower high-density lipoprotein cholesterol levels were significantly predictive of increased suicide risk.

A Meta-Analysis of Oxidative Stress Markers in Depression

OBJECT

Studies have suggested that depression was accompanied by oxidative stress dysregulation, including abnormal total antioxidant capacity (TAC), antioxidants, free radicals, oxidative damage and autoimmune response products. This meta-analysis aims to analyse the clinical data quantitatively by comparing the oxidative stress markers between depressed patients and healthy controls.

METHODS

A search was conducted to collect the studies that measured the oxidative stress markers in depressed patients. Studies were searched in Embase, Medline, PsychINFO, Science direct, CBMDisc, CNKI and VIP from 1990 to May 2015. Data were subjected to meta-analysis by using a random effects model for examining the effect sizes of the results. Bias assessments, heterogeneity assessments and sensitivity analyses were also conducted.

RESULTS

115 articles met the inclusion criteria. Lower TAC was noted in acute episodes (AEs) of depressed patients (p<0.05). Antioxidants, including serum paraoxonase, uric acid, albumin, high-density lipoprotein cholesterol and zinc levels were lower than controls (p<0.05); the serum uric acid, albumin and vitamin C levels were increased after antidepressant therapy (p<0.05). Oxidative damage products, including red blood cell (RBC) malondialdehyde (MDA), serum MDA and 8-F2-isoprostanes levels were higher than controls (p<0.05). After antidepressant medication, RBC and serum MDA levels were decreased (p<0.05). Moreover, serum peroxide in free radicals levels were higher than controls (p<0.05). There were no differences between the depressed patients and controls for other oxidative stress markers.

CONCLUSION

This meta-analysis supports the facts that the serum TAC, paraoxonase and antioxidant levels are lower, and the serum free radical and oxidative damage product levels are higher than controls in depressed patients. Meanwhile, the antioxidant levels are increased and the oxidative damage product levels are decreased after antidepressant medication. The pathophysiological relationships between oxidative stress and depression, and the potential benefits of antioxidant supplementation deserve further research.

Total serum cholesterol, atherogenic indices and their longitudinal association with depressive symptoms among US adults

Serum cholesterol, both total and lipoprotein fractions, has been associated with mid- and late-life depression. Using longitudinal data on a large and ethnically diverse sample of urban adults, the associations of serum lipid profile measured by high or low total cholesterol (TC; >200 mg dl(-1); <160 mg dl(-1)) and by atherogenic indices, namely high total cholesterol and low-density lipoprotein cholesterol relative to high-density lipoprotein cholesterol, with change in total and domain-specific depressive symptoms over time were examined. Findings were compared by sex. (Hypothesis 1) In addition, baseline depressive symptoms as predictors for longitudinal change in lipid profile trajectory were tested. (Hypothesis 2) Mixed-effects regression analyses stratified by sex was used. Sample sizes of participants (n) and repeated observations (n') were: Hypothesis 1 (Men: n=826 ; n'=1319; Women: n=1099 ; n'=1817); Hypothesis 2 (Men: n=738; n'=1230; Women: n=964; n'=1678). As hypothesized, a higher level of atherogenic indices was linked to faster increase in depressive symptom scores, particularly depressed affect and interpersonal problems, though this relationship was found only among women. Among men a U-shaped relationship between baseline TC and longitudinal increase in somatic complaints and a direct link between low TC and longitudinal putative improvement in positive affect was found. On excluding statin users among women, low TC was associated with slower increase in depressed affect over time, whereas high TC was associated with faster increase in interpersonal problems. In summary, atherogenic indices were directly linked to faster increase in depressive symptoms among women only. More studies are needed to explain these sex-specific associations.

Female attempted suicide patients with low HDL levels are at higher risk of suicide re-attempt within the subsequent year: a clinical cohort study

Our aims were, to clarify the blood lipid differences [Total serum cholesterol (TC), High-density lipoprotein (HDL), Low density lipoprotein (LDL), Triglyceride (TG)] between female patients who had attempted suicide and controls and to determine whether we could use the patients׳ initial lipid profiles to predict suicide re-attempt within the subsequent year. A total of 284 participants (110 cases and 174 controls) were recruited, with no differences in body mass index, age, blood sampling time and gender. Blood samples were collected from all participants for serum lipid profiles and assayed in an auto-analyzer. We divided the suicide re-attempter group into suicide attempters in the subsequent year (SSY) and suicide attempters after the subsequent year (SASY). The TC, LDL, and TG levels were significantly lower in the suicidal group than in the control group. HDL was significantly higher in the suicidal group than in the control group. Low TG (<70mg/dL) (OR (odds ratio)=12.8; 95% CI (confidence interval)=5.4-30.5; p<0.0001)and low LDL/HDL (<1.8) (OR=4.1; 95% CI=1.8-9.3; p=0.001) were significantly associated with a current suicide attempt. HDL levels in the SSY (41.5±4.5mg/dL) were lower than in the non-suicide attempters group (NSA) (50.9±10.3mg/dL) and SASY (58.7±12.8mg/dL)(d.f.=2, F=5.2, p=0.007). Serum HDL level may be a potential candidate predictor for the future risk of suicidality.

Advances in biomarkers of major depressive disorder

Major depressive disorder (MDD) is characterized by mood, vegetative, cognitive, and even psychotic symptoms and signs that can cause substantial impairments in quality of life and functioning. Biomarkers are measurable indicators that could help diagnosing MDD or predicting treatment response. In this chapter, lipid profiles, immune/inflammation, and neurotrophic factor pathways that have long been implicated in the pathogenesis of MDD are discussed. Then, pharmacogenetics and epigenetics of serotonin transport and its metabolism pathway, brain-derived neurotrophic factor, and abnormality of hypothalamo-pituitary-adrenocortical axis also revealed new biomarkers. Lastly, new techniques, such as proteomics and metabolomics, which allow researchers to approach the studying of MDD with new directions and make new discoveries are addressed. In the future, more data are needed regarding pathophysiology of MDD, including protein levels, single nucleotide polymorphism, epigenetic regulation, and clinical data in order to better identify reliable and consistent biomarkers for diagnosis, treatment choice, and outcome prediction.

HDL-cholesterol concentrations are inversely associated with Edinburgh Postnatal Depression Scale scores during pregnancy: results from a Brazilian cohort study

Serum lipids have been associated with depression in the adult population; however, this association during pregnancy remains unclear. The aim of this study was to evaluate the association between serum lipids and depressive symptom scores during pregnancy. A prospective cohort of 238 pregnant women was followed at the 5th-13th, 20th-26th and 30th-36th weeks of gestation. Depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale (EPDS). Serum concentrations (mg/dL) of triglycerides, total cholesterol, and low- and high-density lipoproteins (LDL-c; HDL-c) were the main exposures. Marital status (married/single), physical activity (active or very active/low or very low active), unplanned pregnancy (no/yes), pre-pregnancy BMI (<25/≥ 25 kg/m(2)), generalized anxiety disorder (no/yes) and current suicidal ideation (no/yes) were considered as potential confounders. Analyses were performed using linear mixed-effects models. The results showed that the EPDS mean score (95%CI) decreased with time during pregnancy trimesters [1st: 8.89 (95%CI = 8.28-9.51), 2nd: 7.32 (95%CI = 6.67-7.97) and 3rd: 7.08 (95%CI = 6.41-7.74)]. Suicidal ideation frequency at baseline was 18%. HDL-c concentrations were inversely associated with changes in EPDS score (β = -0.080, 95%CI = -0.157 to -0.002), while low or very low active women (β = 1.288, 95%CI = 0.630-1.946), with single marital status (β = 1.348, 95%CI = 0.163-2.534), unplanned pregnancy (β = 1.922, 95%CI = 0.714-3.131), generalized anxiety disorder (β = 2.139, 95%CI = 0.410-3.868) and current suicidal ideation (β = 1.927, 95%CI = 0.596-3.258) tended to have higher EPDS scores. No relationship was observed between other lipids and EPDS scores. HDL-c concentration was inversely associated with changes in depressive symptom scores during pregnancy after adjusting for socio-economic, demographic, behavioral, nutritional, biochemical and mental health disorders.

Plasma-based proteomics reveals lipid metabolic and immunoregulatory dysregulation in post-stroke depression

BACKGROUND

Post-stroke depression (PSD) is the most common psychiatric complication facing stroke survivors and has been associated with increased distress, physical disability, poor rehabilitation, and suicidal ideation. However, the pathophysiological mechanisms underlying PSD remain unknown, and no objective laboratory-based test is available to aid PSD diagnosis or monitor progression.

METHODS

Here, an isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic approach was performed to identify differentially expressed proteins in plasma samples obtained from PSD, stroke, and healthy control subjects.

RESULTS

The significantly differentiated proteins were primarily involved in lipid metabolism and immunoregulation. Six proteins associated with these processes--apolipoprotein A-IV (ApoA-IV), apolipoprotein C-II (ApoC-II), C-reactive protein (CRP), gelsolin, haptoglobin, and leucine-rich alpha-2-glycoprotein (LRG)--were selected for Western blotting validation. ApoA-IV expression was significantly upregulated in PSD as compared to stroke subjects. ApoC-II, LRG, and CRP expression were significantly downregulated in both PSD and HC subjects relative to stroke subjects. Gelsolin and haptoglobin expression were significantly dysregulated across all three groups with the following expression profiles: gelsolin, healthy control>PSD>stroke subjects; haptoglobin, stroke>PSD>healthy control.

CONCLUSIONS

Early perturbation of lipid metabolism and immunoregulation may be involved in the pathophysiology of PSD. The combination of increased gelsolin levels accompanied by decreased haptoglobin levels shows promise as a plasma-based diagnostic biomarker panel for detecting increased PSD risk in post-stroke patients.

Sex Differences in Associations of Depressive Symptoms with Cardiovascular Risk Factors and Metabolic Syndrome among African Americans

Young to middle-aged women usually have notably lower rates of cardiovascular disease (CVD) than their male counterparts, but African American women lack this advantage. Their elevated CVD may be influenced by sex differences in associations between depressed mood and CVD risk factors. This cross-sectional study examined whether relations between scores on the Center for Epidemiologic Studies-Depression (CES-D) scale and a spectrum of CVD risk factors varied by sex among African Americans (n = 1076; ages 30-64) from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. Sex-stratified multiple regressions and logistic regressions were conducted. Among women, CES-D scores correlated positively with systolic blood pressure and waist-to-hip ratio (P's < .05), but inversely with high-density lipoprotein cholesterol (HDL-C) (P < .01). Women had twice the odds for metabolic syndrome if CES-D scores ≥16 and had a ≥14% increase in odds of hypertension, abdominal obesity, and low HDL-C with each 5-unit increase in CES-D scores. Among men, CES-D scores correlated positively with high-sensitivity C-reactive protein (P < .05), and odds of hypertension increased by 21% with each 5-unit increase in CES-D scores. Depressive symptoms may promote premature CVD risk in African Americans, at least in part, via CVD risk factors and prevalent metabolic syndrome, particularly in African American women.

Principle component analysis combined with matrix-assisted laser desorption ionization mass spectrometry for rapid diagnosing the sera of patients with major depression

BACKGROUND

Previously, we demonstrated that 6M HCl hydrolysis followed by matrix-assisted laser desorption/ionization (MALDI-TOF) mass spectrometry is a useful technique to detect potential protein biomarkers in the sera collected from major depression (MD) patients and from healthy controls.

METHODS

In this study, the effects of various organic acids in hydrolyzing proteins in serum were first examined. The organic matrixes commonly used in MALDI analysis were also examined for characterizing the hydrolyzed peptides. Finally, principle component analysis (PCA) was used to analyze the MALDI mass spectra of acid-hydrolyzed serum samples.

RESULTS

It was found that 20% TFA and sinapinic acid were the optimal reagents for hydrolysis and MALDI matrix. Samples collected from MD patients and healthy controls were readily classified through PCA analysis. A receiver operating characteristic (ROC) curve based on the ratio of the intensities of the two fragment ions (m/z 8606 and 9287) indicated by PCA plot was also constructed. The area under the curve was 0.845; the sensitivity and specificity were both 80%.

CONCLUSIONS

An analytical platform employing trifluoroacetic acid to hydrolyze serum proteins followed by MALDI-TOF/MS and PCA analysis was developed to rapidly differentiate the sera between MD patients and healthy controls.

Comparative proteomic analysis of plasma from major depressive patients: identification of proteins associated with lipid metabolism and immunoregulation

Major depressive disorder is a common neuropsychiatric disorder contributing to several socio-economic burdens including disability and suicide. As the underlying pathophysiology of major depressive disorder remains unclear, no objective test is yet available for aiding diagnosis or monitoring disease progression. To contribute to a better understanding of its pathogenesis, a comparative proteomic study was performed to identify proteins differentially expressed in plasma samples obtained from first-onset, treatment-naive depressed patients as compared to healthy controls. Samples from the two groups were immunodepleted of seven high-abundance proteins, labelled with isobaric tags for relative and absolute quantitation and then analysed by multi-dimensional liquid chromatography-tandem mass spectrometry. The proteomic results were further validated by immunoblotting or enzyme-linked immunoadsorbent assays and analysed with the MetaCore database. The results demonstrate that the functions of the altered proteins are primarily involved in lipid metabolism and immunoregulation. These findings suggest that early perturbation of lipid metabolism and immunoregulation may be involved in the pathophysiology of major depressive disorder.

Alterations in lipid profile of autistic boys: a case control study

We hypothesize that autism is associated with alterations in the plasma lipid profile and that some lipid fractions in autistic boys may be significantly different than those of healthy boys. A matched case control study was conducted with 29 autistic boys (mean age, 10.1 +/- 1.3 years) recruited from a school for disabled children and 29 comparable healthy boys from a neighboring elementary school in South Korea. Fasting plasma total cholesterol (T-Chol), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), the LDL/HDL ratio, and 1-day food intakes were measured. Multiple regression analyses were performed to assess the association between autism and various lipid fractions. The mean TG level (102.4 +/- 52.4 vs 70.6 +/- 36.3; P = .01) was significantly higher, whereas the mean HDL-C level (48.8 +/- 11.9 vs 60.5 +/- 10.9 mg/dL; P = .003) was significantly lower in cases as compared to controls. There was no significant difference in T-Chol and LDL-C levels between cases and controls. The LDL/HDL ratio was significantly higher in cases as compared to controls. Multiple regression analyses indicated that autism was significantly associated with plasma TG (beta = 31.7 +/- 11.9; P = .01), HDL (beta = -11.6 +/- 2.1; P = .0003), and the LDL/HDL ratio (beta = 0.40 +/- 0.18; P = .04). There was a significant interaction between autism and TG level in relation to plasma HDL level (P = .02). Fifty-three percent of variation in the plasma HDL was explained by autism, plasma TG, LDL/HDL ratio, and the interaction between autism and plasma TG level. These results indicate the presence of dyslipidemia in boys with autism and suggest a possibility that dyslipidemia might be a marker of association between lipid metabolism and autism.

Association between depression and intima-media thickness of carotid bulb in asymptomatic young adults

OBJECTIVE

Although there is growing evidence that symptoms of depression influence the development of coronary artery disease, information on the underlying subclinical atherosclerotic process is scant in young adults. The study examined the association between symptoms of depression and subclinical atherosclerosis, determined by carotid intima-media thickness in asymptomatic young individuals.

METHODS

A cross-sectional study was performed in Bogalusa, Louisiana, a semi-rural biracial (black-white) community. A sample of 996 individuals aged 24 to 44 years (71% were white and 43% were male) enrolled in the Bogalusa Heart Study. The variables included symptoms of depression measured by the Center for Epidemiological Studies-Depression Scale; intima-media thickness of different segments of carotid artery by B-mode ultrasonography; measures of adiposity and glucose homeostasis, lipoproteins, and blood pressure; and cigarette smoking status.

RESULTS

Both the adjusted and the unadjusted associations between depression score and carotid bulb intima-media thickness were significant, whereas similar associations with internal carotid and common carotid thickness were nonsignificant. In the multivariable regression model, after adjusting for all covariates, a positive effect of depression scores (Center for Epidemiological Studies-Depression score) and a negative effect of interaction between depression score ratio of total cholesterol (TC)/high-density lipoprotein (HDL) were significant. In a subgroup analysis (among individuals with a ratio of TC/HDL < or = 5) a positive effect of depression on carotid bulb intima-media thickness was significant, whereas the interaction between depression and ratio of TC/HDL was nonsignificant. In subsequent analysis, if individuals with a higher ratio of TC/HDL were included, both depression and negative interaction term were significant.

CONCLUSION

The observations show the detrimental effect of depression on subclinical vascular changes in asymptomatic young individuals. The findings underscore the need for considering depression in risk factor profiling. Further study is recommended to investigate the basis of a lower carotid bulb intima-media thickness among subjects with a high depression score and a high ratio of TC/HDL.

Lipid levels in female patients with affective disorders

The role of serum lipids [total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG)] in the pathophysiology of mood disorders is not clear. The aim of this study was to determine lipid profiles in patients with affective disorders. The study included medication-free female subjects (41 patients with bipolar disorder, 22 in a manic and 19 in a depressive phase), 34 patients with major depression, and 50 healthy controls. Serum lipid levels were determined using standard laboratory tests. All patients had significantly lower HDL-C values than control subjects. Increased TG levels were found in patients with bipolar disorder compared with healthy subjects. The changes in lipid profiles persisted when data were adjusted for age, smoking and menopausal status. The results revealed no differences in cholesterol and LDL-C levels and body mass index, but significant differences in the ratios of cholesterol/HDL-C and LDL-C/HDL-C (atherogenic index) among groups. Our results suggest that low HDL-C levels and a high atherogenic index might be a hallmark of affective disorders. Since low HDL-C levels could be a risk factor for the development of coronary heart disease, further investigation of lipid metabolism in affective disorders is warranted.

Serum lipid concentrations in dogs with tail chasing

OBJECTIVE

To characterise lipid profile in dogs with tail chasing.

METHODS

Fifteen dogs with tail chasing were included in this study. A behavioural diagnosis was made for each dog on the basis of the dog's behavioural history, clinical signs and results of other medical assessments. None of the dogs had concurrent medical disease that would account for compulsive tail chasing. Blood samples were taken from each dog after a fasting period of 12 to 16 hours to measure total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and very low-density lipoprotein cholesterol levels. Fifteen control dogs were also enrolled on the basis of normal physical examination results, complete blood count and serum biochemistry profiles.

RESULTS

Dogs with tail chasing had significantly higher total cholesterol (P<0.01), high-density lipoprotein cholesterol (P<0.05) and low-density lipoprotein cholesterol (P<0.001) compared with control dogs. Very low-density lipoprotein cholesterol and triglyceride levels did not differ significantly between the groups.

CLINICAL SIGNIFICANCE

Tail chasing may be associated with serum cholesterol elevations in dogs. High serum cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol levels may be used as biochemical parameters of compulsive tail chasing in clinical settings.

Acid hydrolysis followed by matrix-assisted laser desorption/ionization mass spectrometry for the rapid diagnosis of serum protein biomarkers in patients with major depression

We have developed a technique combining acid hydrolysis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for the rapid study of the changes in the levels of positive and negative acute phase protein biomarkers in the sera of patients suffering from major depression. The serum proteins were first precipitated using an organic solvent; after separation, they were subjected to hydrochloric acid hydrolysis (6 M HCl) for 10 min. The resulting peptides were characterized using MALDI-TOF MS. Short-term treatment of the serum proteins with HCl efficiently removed interference from the abundant protein - albumin - and produced abundant peptide ion signals in the range of m/z 4000-10 000. This approach allowed us to rapidly detect the peptide ions originating from transferrin (a common negative acute phase protein) and fibrinogen (a common positive acute phase protein). The average ratios and (standard deviations) of the ion signals derived from transferrin/fibrinogen were 3.58 (+/-1.93) for the healthy control subjects and 1.02 (+/-0.52) for the patients suffering from major depression. The differences in transferrin/fibrinogen ratios between healthy controls and patients suggest that major depression will induce internal inflammation and cause either an increase in the level of fibrinogen or a decrease in the level of transferrin.

Homocysteine and serum lipids concentration in male war veterans with posttraumatic stress disorder

The evidence of increased cardiovascular disease (CVD) risk in posttraumatic stress disorder (PTSD) is accumulating. The present study aimed to determine whether chronic, combat-related PTSD is associated with serum lipid and homocysteine concentrations that could indicate higher CVD risk. The authors tested 66 war veterans with PTSD, 33 war veterans without PTSD, and 42 healthy volunteers for serum concentrations of homocysteine, total cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and triglycerides. All the subjects were men and the analyses were adjusted for age, body mass index and smoking. Potential influences of depression, anxiety, and psychotic symptoms on the outcome measures were checked by introducing the scores from the Hamilton Depression Rating Scale (HAM-D-17), the Hamilton Anxiety Scale (HAMA), and the Positive and Negative Syndrome Scale (PANSS) into the overall statistical model. No differences in total cholesterol, LDL-C, HDL-C and triglycerides were found between the groups. Non-smoking PTSD war veterans had higher homocysteine concentrations (mean=10.4 micromol/L, SD=1.7) when compared to non-smoking war veterans without PTSD (mean=8.2 micromol/L, SD=4.0, P=0.014) and both smoking (mean=8.7 micromol/L, SD=2.3, P=0.008) and non-smoking healthy volunteers (mean=8.8 micromol/L, SD=2.2, P=0.021). The results of our cross-sectional study are possibly confounded by many factors, especially behavioral and life-style related which are difficult to control comprehensively and might have influenced serum lipids and homocysteine concentration in a complex manner. An increase in the homocysteine concentration observed in the non-smoking PTSD patients needs further investigation with a carefully designed prospective study to confirm associated, possibly enhanced CVD risk.

Depressive symptoms and serum lipid fractions in middle-aged men: physiologic and health behavior links

OBJECTIVE

To investigate alternative hypothetical models that could clarify the relationship between depressive symptoms and serum cholesterol fractions, i.e., high-density lipoprotein (HDL) and low-density lipoprotein (LDL). It was hypothesized that the impact of the depressive symptoms on cholesterol fractions is mediated through health behavior and body mass index, and at the same time there would be a direct link from depression to cholesterol.

METHODS

The study sample consisted of 893 middle-age men who participated in a trial aimed at preventing the metabolic syndrome, Type 2 diabetes and cardiovascular diseases. Serum cholesterol was measured by the enzymatic method. Participants completed self-report questionnaires assessing health behavior and depressive symptoms.

RESULTS

Depressive symptoms consistently correlated statistically significantly with adverse lifestyle factors and, as hypothesized, positively with HDL. Path analyses supported the parallel existence of two main pathways: from depression through adverse health behavior to unfavorable cholesterol fraction balance, and a direct physiological link indicative of beneficial effect of depression on cholesterol levels.

CONCLUSIONS

It is concluded that, among a sample of men, depressive symptoms are linked to cholesterol fractions through two different pathways. An adverse relationship of depression with serum lipids HDL-LDL balance is partly mediated through harmful health behaviors. At the same time, the results indicate a direct, physiological link between depressive symptoms and cholesterol that has a beneficial influence on the HDL-LDL balance.

Low HDL cholesterol associates with major depression in a sample with a 7-year history of depressive symptoms

Long-term depression may increase the risk for adverse coronary events. Low levels of high-density lipoprotein cholesterol (HDL-C) have in particular been suggested to underlie this connection. A total of 124 participants with a recorded seven-year history of depressive symptoms (depressed, n=63) or euthymic state (controls, n=61) underwent a Structured Clinical Interview for DSM-IV to confirm their psychiatric diagnosis. Total cholesterol (TC), HDL-C and low-density lipoprotein cholesterol (LDL-C) levels, triglycerides, non-HDL-C and atherogenic indices (LDL-C/HDL-C and TC/HDL-C) were assessed. The HDL-C levels were lower and atherogenic indices higher in the depressed group compared with the controls. Furthermore, those with HDL-C level below the gender-adjusted median (<1.54 mmol/l in women, <1.16 mmol/l in men) were 2.4-fold more likely to be depressed in a model adjusting for age and non-HDL-C (p=0.019). After further adjustment for educational level, marital status, alcohol use, daily smoking and overweight this association remained significant (p=0.049). These findings suggest that compared with the healthy controls, those with long-term depression may have lower HDL-C values and higher atherogenic indices.

Serum lipid levels in seasonal affective disorder

Previous research has assessed the relationship between blood lipid levels and depression with contradictory results. Several studies have linked low cholesterol levels with impulsive, aggressive and suicidal behaviours. The aim of this pilot study was to examine serum lipids in a sample of patients suffering from seasonal affective disorder (SAD). We conducted a retrospective analysis of data on total serum cholesterol and serum triglycerides in 39 SAD patients and 40 non-seasonally depressed or schizophrenic control subjects. Study subjects had to be free of psychotropic drugs for at least 2 weeks. Analysis of covariance (ANCOVA) was performed to assess group differences. After adjustment for significant covariates SAD patients had significantly lower total cholesterol levels (5.21 +/- 1.14 mmol/l) than control subjects (5.94 +/- 1.11 mmol/l; p = 0.013). Moreover, hypercholesterolemia (total cholesterol > 5.20 mmol/l) was significantly less frequent in the SAD group (46.2%) than in the control group (75.0%; p = 0.012). Total serum triglycerides did not differ significantly between SAD patients (1.54 +/- 1.07 mmol/l) and controls (1.56 +/- 0.96 mmol/l; p = 0.126). The results of this study support the idea that low cholesterol levels may be of pathogenetic importance in SAD. Further study in larger clinical samples is warranted to clarify our findings.

Serum cholesterol concentration and distress in the initial days after childbirth

The link between mood disorders and cholesterol is characterized by some contradictory data. In particular, it is not clear whether health factors are responsible for lowered cholesterol levels and mood swings. The present study tests the association between serum cholesterol level and psychological distress in women in two different post-delivery hospital settings: rooming-in (RI) and no rooming-in (no-RI). On day 3 after childbirth, 147 RI and 209 no-RI women completed the Kellner Symptom Questionnaire (SQ), which evaluates anxiety, depression, somatic symptoms and hostility. Plasma cholesterol concentration was measured on the same day. There was a significant negative correlation between cholesterol and depressive symptoms in no-RI women, but not in the RI group. However, this correlation is characterized by an extremely small effect size (-0.15). The findings of this study cast further doubt on the hypothesis of a possible association between cholesterol and depression in the general population and in mothers who have just given birth.

Hypercholesterolemia in Asperger syndrome: independence from lifestyle, obsessive-compulsive behavior, and social anxiety

We report on elevated total cholesterol and low-density lipoprotein (LDL) levels in 22 individuals with Asperger syndrome compared with well-matched controls, after accounting for lifestyle variables and clinical symptomatology that could affect them. A potential role for dyslipidemia in the pathogenesis of some forms of autism is discussed.

Serum lipid profiles in major depression with clinical subtypes, suicide attempts and episodes

BACKGROUND

We tried to report the data between serum lipid profiles and major depression with different clinical subtypes, with or without suicide attempts, and with single episode or recurrent episodes.

METHOD

During a 2-year period, a total of 168 participants (109 patients with major depression and 59 subjects in a healthy control group) were recruited in this study. Blood samples for serum lipid profiles in all participants were collected. Data analysis was performed by using an analysis of covariance (ANCOVA) with body mass index (BMI) adjustment.

RESULTS

The data showed that there were no significant differences of any kind in serum lipid profiles between depressive patients with melancholic feature or atypical feature, with or without suicide attempts nor between depressive patients with single episode or recurrent episodes.

CONCLUSION

The results suggested there were no serum lipid profiles used as biological markers to distinguish the clinical subtypes, suicide attempts and episodes in patients with major depression.

Cholesterol-lowering therapy evokes time-limited changes in serotonergic transmission

A number of studies have reported an increased risk for violent deaths and depression in subjects with reduced serum cholesterol concentrations. Links with hypothesized impairment of serotonin neurotransmission have not been satisfactorily tested. In this investigation, the serum and membrane cholesterol, microviscosity of erythrocyte membranes, platelet serotonin uptake, and clinical parameters were determined during pharmacotherapy of 17 hypercholesterolemic patients. A significant decrease in serum cholesterol and a nonsignificant decrease in membrane cholesterol concentration were found after 2 months of simvastatin therapy. Serotonin transporter (SERT) activity was significantly increased following 1 month of simvastatin; the tendency to decrease the initial increase in SERT activity was evident following 2 months of therapy. Both membrane cholesterol and SERT activity returned to pre-treatment levels after more than 1 year of therapy. Microviscosity of plasma membranes, impulsivity, empathy, adventure, sensation seeking, and depressed mood were not markedly changed. These data indicate that long-term therapy has different effects on serotonin transmission from short-term (1- to 2-month) therapy. A significant increase in SERT activity was detected only during the first month of simvastatin therapy. This finding suggests that within this period some patients could be vulnerable to depression, violence, or suicide.

Mood Scores in Relation to Hormone Replacement Therapies during Menopause: A Prospective Randomized Trial

There is lack of studies in literature about the long-term effects of hormone replacement therapies and cholesterol levels on mood scores in menopause. In the present study we have investigated whether serum lipid levels affect mood scores in menopause and evaluated the long-term effects of the combined hormone replacement regimens (HRT) on depressive symptoms in postmenopausal women. In this prospective-randomized, placebo-controlled, double-blind study, 286 women in menopause were divided into four groups according to therapeutic regimens they received; 1) Conjugated equine estrogen (CEE) of 0.625 mg plus medroxyprogesterone acetate (MPA) of 2.5 mg (n = 79), 2) CEE (0.625 mg) plus MPA of 5 mg (n = 77), 3) tibolone of 2.5 mg (a selective tissue estrogenic activity regulator) (n = 76), and 4) Calcium (Ca) of 1,000 mg (n = 54). Beck Depression Inventory (BDI), and serum levels of lipoprotein lipids were assessed before and after 12-months of treatment with oral continuous HRT and Ca supplementation. BDI scores in the study groups were not correlated with lipid profiles. We compared two subgroups of patients with initial BDI scores 0-14 (normal mood scores) in order to asses for the possible relation between the lipid profile and mood. Following treatment, first subgroup had increased scores to 15-30 (mildly depressed women, n = 27) and the second subgroup preserved BDI scores of 0-14 (normal mood scores, n = 23). Serum levels of total cholesterol, high-density lipoprotein, low-density lipoprotein and body mass index were found to be similar between these two groups. BDI scores decreased significantly in all HRT groups after 12 months of treatment, compared to Ca group (p < 0.05). We did not observe any correlation between BDI scores and lipid profiles before and following continuous HRT or Ca supplementation. Continuous combined hormone replacement regimens, CEE + MPA and tibolone, have superior long-term effects on mood scores in menopause and should be considered during the decision process for use of HRT due to menopausal symptoms.

Lipid and lipoprotein levels in depressive disorders with melancholic feature or atypical feature and dysthymia

The purpose of the present study was to explore the relationship between serum lipid and lipoprotein levels and clinical subtypes in patients with depressive disorders. A total of 207 patients who were admitted for general health screening were assessed by using the semistructured clinical interview for Diagnostic and Statistical Manual of Mental Disorders (4th edn; DSM-IV) criteria for the possibility of having depressive disorders. Blood and physical examinations were done to rule out systemic diseases. A total of 142 patients without systemic diseases was recruited for further analysis, including dysthymia (n = 35), major depressive disorder with melancholic feature (n = 22), major depressive disorder with atypical feature (n = 46) and normal controls (n = 39). Analysis of covariance after age adjustment reveals significant differences in patients with melancholic feature and patients with atypical feature in serum concentrations of triglyceride (TG) and very-low-density-lipoprotein cholesterol (VLDL) in men, and high-density-lipoprotein cholesterol (HDL) in women. This suggests that the TG, VLDL and HDL levels might be used as biological markers to differentiate between major depressive patients with melancholic feature or atypical feature.