Correlation analysis of cancer stem cell marker CD133 and human endogenous retrovirus (HERV)-K env in SKOV3 ovarian cancer cells.

BACKGROUND: Human endogenous retrovirus (HERV)-K is a type of retrovirus that is present in the human genome, and its expression is usually silenced in healthy tissues. The precise mechanism by which HERV-K env influences cancer stemness is not fully understood, but it has been suggested that HERV-K env may activate various signaling pathways that promote stemness traits in cancer cells. OBJECTIVE: To establish the connection between HERV-K env expression and cancer stemness in ovarian cancer cells, we carried out correlation analyses between HERV-K env and the cancer stem cell (CSC) marker known as the cluster of differentiation 133 (CD133) gene in SKOV3 ovarian cancer cells. METHOD: To perform correlation analysis between HERV-K env and CSCs, ovarian cancer cells were cultured in a medium designed for cancer stem cell induction. The expression of HERV-K env and CD133 genes was verified using quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot analyses. Additionally, the expression of stemness-related markers, such as OCT-4 and Nanog, was also confirmed using RT-qPCR. RESULTS: In the stem cell induction medium, the number of tumorsphere-type SKOV3 cells increased, and the expression of CD133 and HERV-K env genes was up-regulated. Additionally, other stemness-related markers like OCT-4 and Nanog also exhibited increased expression when cultured in the cancer stem cell induction medium. However, when HERV-K env knockout (KO) SKOV3 cells were cultured in the same cancer stem cell induction medium, there was a significant decrease in the number of tumorsphere-type cells compared to mock SKOV3 cells subjected to the same conditions. Furthermore, the expression of CD133, Nanog, and OCT-4 did not show a significant increase in HERV-K env KO SKOV3 cells compared to mock SKOV3 cells cultured in the same cancer stem cell induction medium. CONCLUSION: These findings indicate that the expression of HERV-K env increased in SKOV3 cells when cultured in cancer stem cell induction media, and cancer stem cell induction was inhibited by KO of HERV-K env in SKOV3 cells. These results suggest a strong association between HERV-K env and stemness in SKOV3 ovarian cancer cells.

Association of metabolic syndrome and its components with the risk of depressive symptoms: A systematic review and meta-analysis of cohort studies.

BACKGROUND: The purpose of this meta-analysis was to quantitatively analyze the association between metabolic syndrome (MetS) and the risk of depressive symptoms. METHODS: Three electronic databases (PubMed, Embase, and PsycINFO) were searched for articles published through February 15, 2022. Cohort studies evaluating the association between MetS and depressive symptoms were selected for inclusion in this study. A random-effects model was used to evaluate the pooled estimates of MetS, including each of its components, associated with depressive symptoms. RESULTS: A total of 11 cohort studies were selected including >2.65 million participants. There was a significant association between MetS and depressive symptoms risk, albeit with a high degree of heterogeneity (relative risk = 1.29, 95 % confidence interval: 1.12-1.48; I2 = 79.3 %). This association was consistently significant in Western countries, but it was not significant in Asian countries. When stratified by sex, age, and geographical region, MetS and its components exhibited varying degrees of association with depressive symptoms. CONCLUSIONS: MetS is a risk factor for depressive symptoms. Further large-scale prospective cohort studies are required to confirm our findings.

Impact of sarcopenia and phase angle on mortality of the very elderly.

BACKGROUND: Sarcopenia is a major component of geriatric syndrome and associated with poor clinical outcomes and mortality. However, diagnosing sarcopenia in the very elderly is difficult, and data on its epidemiology and devastating effects in this group are scarce. Phase angle (PA) is measured using bioimpedance spectroscopy and known to reflect cellular integrity and health. This study aimed to clarify the impact of sarcopenia and PA on mortality risk in very elderly people living in long-term care facilities. METHODS: This prospective cohort study enrolled elderly residents living in nine long-term care facilities. We collected the participants' data, such as body mass index (BMI), comorbidities and laboratory data, from September to October 2017 and mortality data until October 2019. Nutritional status was evaluated using the Mini Nutritional Assessment (MNA) score, and multifrequency bioimpedance spectroscopy was used to assess body composition including PA. Appendicular skeletal muscle mass was calculated using the body composition monitor-derived equation of Taiwan's researchers. Sarcopenia was diagnosed using the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) definition (sarcopenia vs. normal group). We divided the participants into two groups according to the median PA value of 3.65° (high vs. low group) and performed multivariate regression analyses to verify the association with mortality risk according to sarcopenia diagnosis or PA group. RESULTS: A total of 279 elderly participants were enrolled; of them, 238 (85.3%) were diagnosed with sarcopenia according to EWGSOP2 guidelines. The median patient age was 83 years, 211 (75.6%) were female and the median BMI was 20.4 kg/m2 . The sarcopenia group was older than the normal group (84 vs. 81 years; P = 0.002), had a lower mean BMI (19.8 vs. 26.6 kg/m2 , P < 0.001) and had a lower MNA score (9 vs. 12 points, P < 0.001). Sarcopenia was associated with a higher mortality risk after the adjustment for age, sex and diabetes mellitus (hazard ratio [HR], 3.744; 95% confidence interval [CI], 1.155-12.134; P = 0.028). A low PA was associated with sarcopenia, older age, female sex, low MNA score and overhydration volume; it was also a significant predictor of mortality after the adjustment for age, sex, diabetes mellitus and MNA score (HR, 0.593; 95% CI, 0.420-0.837; P = 0.003). CONCLUSIONS: Sarcopenia is prevalent among the very elderly patients in long-term care facilities. Sarcopenia and low PA are significantly associated with higher mortality risk.

Stent-based electrode for radiofrequency ablation in the rat esophagus: a preliminary study.

Endoluminal radiofrequency (RF) ablation has been widely used as a safe and effective treatment for Barrett's esophagus. However, inadequate RF ablation may occur due to insufficient contact between the electrode and target tissues. Herein, a stent-based monopolar RF electrode (SE) was developed to evenly deliver RF energy to the inner wall of the rat esophagus. The optimal RF parameters were evaluated in the exposed rat esophagus. The temperature in the rat esophagus reached 70 â„ƒ in 89 s at 30 W, 59 s at 40 W, and 34 s at 50 W. The technical feasibility and efficacy of RF ablation using SE were evaluated based on changes in histological transformation and immunohistochemical parameters of tissues compared at immediately, 1 and 2 weeks after the procedure. The degrees of inflammatory cell infiltration, fibrotic changes, TUNEL, and HSP70 in the RF-ablated rat esophagus were significantly higher than compared with sham control (all p < 0.05). TUNEL-positive deposition gradually decreased, but HSP 70-positive deposition maintained a similar level for 2 weeks. The stent-based RF ablation was technically feasible and effective in evenly inducing thermal damages to the rat esophagus. The RF ablation system using the SE may represent a promising treatment for endoluminal malignancies.

Resting Heart Rate and Cognitive Decline: A Meta-Analysis of Prospective Cohort Studies.

BACKGROUND AND PURPOSE: Several previous meta-analyses have identified an association between cognitive decline and heart rate variability, which reflects autonomic nerve activity. This systematic review and meta-analysis investigated the impact of increased resting heart rate (RHR) on the incidence of cognitive decline, including dementia. METHODS: The PubMed, Embase, and PsycInfo databases were searched for relevant prospective cohort studies published before April 18, 2022. A methodological quality assessment of the included studies was conducted using the Newcastle-Ottawa Scale. Summary estimates of the incidence of cognitive decline, including dementia, were generated using a random-effects model. Potential publication bias was evaluated using Begg's funnel plots and Egger's regression tests. RESULTS: The meta-analysis included 7 prospective cohort studies comprising 53,621 participants. A weak significant association was observed between RHR and the risk of cognitive decline, although the analysis indicated high heterogeneity among the studies (relative risk=1.18, 95% confidence interval=1.04-1.33, I²=82.5%). Significant associations were determined between RHR and all combined types of dementia except for Alzheimer's disease and mild cognitive impairment. There was also a dose-response association between increased RHR and cognitive decline. The meta-estimate of the cognitive decline risk associated with a 10 beat-per-minute increase in RHR was 1.06, and it was 1.10 for dementia. CONCLUSIONS: This study found that a higher RHR was associated with an increased cognitive decline risk. Due to study limitations such as publication bias and high heterogeneity, additional studies are required to validate this finding. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number CRD42021282912.

High-Frequency Pulsed Electric Field Ablation in Beagle Model for Treatment of Prostate Cancer.

Conventional irreversible electroporation (IRE) with low-frequency pulsed electric field (LF-PEF) is used to induce cell death; however, it has several disadvantages including a long procedure time and severe muscle contraction due to high-voltage electric field. This study investigates a novel IRE protocol with high-frequency pulsed electric field (HF-PEF) of 500 Hz repetition to ablate the prostate tissue in beagles for treatment of prostate cancer. A finite element analysis was performed to validate optimal electrical field strength for the procedure. In total, 12 beagles received HF-PEF of 500 Hz and were sacrificed at 4 h, 4 days, and 28 days (3 each). The remaining three beagles underwent sham procedure. The outcomes of HF-PEF were assessed by histological responses. HF-PEF successfully decellularized the prostate tissues 4 h after the treatment. The prostate glands, duct, and urethra were well preserved after IRE with HF-PEF. The ablated prostatic tissues were gradually regenerated and appeared similar to the original tissues 28 d after IRE with HF-PEF. Moreover, electrocardiography and hematology demonstrated that IRE with HF-PEF did not seriously affect the cardiac tissue. HF-PEF was effective and safe in the beagle prostate and effectively induced the ablation and gradually recovered with cellular regeneration.

Effect of human endogenous retrovirus-K env gene knockout on proliferation of ovarian cancer cells.

BACKGROUND: Among various human endogenous retroviruses (HERVs), the HERV-K (HML-2) group has been reported to be highly related to cancer. In pancreatic cancer cells, shRNA-mediated downregulation of HERV-K env RNA decreases cell proliferation and tumor growth through the RAS-ERK-RSK pathway; in colorectal cancer, CRISPR-Cas9 knockout (KO) of the HERV-K env gene affects tumorigenic characteristics through the nupr-1 gene. OBJECTIVE: The effect of HERV-K env KO has not been studied in ovarian cancer cell lines. In this study, we analyzed the tumorigenic characteristics of ovarian cancer cell lines, including cell proliferation, migration, and invasion, and the expression patterns of related proteins after CRISPR-Cas9 KO of the HERV-K env gene. METHODS: The HERV-K env gene KO was achieved using the CRISPR-Cas9 system in ovarian cancer cell lines SKOV3 and OVCAR3. Tumorigenic characteristics including cell proliferation, migration, and invasion were analyzed, and related protein expression was investigated by western blot analysis. RESULTS: The expression of the HERV-K env gene in KO cells was significantly reduced at RNA and protein levels, and tumorigenic characteristics including cell proliferation, migration, and invasion were significantly reduced. In HERV-K env KO SKOV3 cells, the expression of the RB protein was significantly up-regulated and the cyclin B1 protein level was significantly reduced. In contrast, in HERV-K env KO OVCAR3 cells, the level of phospho-RB protein was significantly reduced, but other protein levels were not changed. CONCLUSION: The results of this study showed that HERV-K env gene KO affects cell proliferation, invasion, and migration of ovarian cells through RB and Cyclin B1 proteins, but the specific regulation pattern can differ by cell line.

Acid suppressant use in association with incidence and severe outcomes of COVID-19: a systematic review and meta-analysis.

PURPOSE: Several observational studies have presented conflicting results on the association between the use of proton pump inhibitors (PPIs) or histamine H2 receptor antagonist (H2RA) and the risk of coronavirus disease 2019 (COVID-19). This systematic review and meta-analysis aimed to examine this association. METHODS: In July 2021, PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science were searched for articles investigating the relationship between the two main acid suppressants and COVID-19. Studies showing the effect estimates as hazard ratio (HR) for severe outcomes or incidence of COVID-19 were evaluated using a random-effects model. RESULTS: A total of 15 retrospective cohort studies with 18,109 COVID-19 cases were included in the current meta-analysis. PPI use was significantly associated with severe outcomes of COVID-19 (hazard ratio [HR] = 1.53; 95% confidence interval [CI]: 1.20-1.95) but not with the incidence of COVID-19, whereas H2RA use was significantly associated with decreased incidence (HR = 0.86, 95% CI: 0.76-0.97). For subgroup analyses of PPIs, increased severe outcomes of COVID-19 were observed in < 60 years, active use, in-hospital use, and Asians. For subgroup analyses of H2RAs, decreased severe outcomes of COVID-19 were observed in > 60 years, while in-hospital use and use in Asia were associated with higher disease severity. CONCLUSIONS: Close observation can be considered for COVID-19 patients who use PPIs to prevent severe outcomes. However, caution should be taken because of substantial heterogeneity and plausible protopathic bias.

Evaluation of electroporated area using 2,3,5-triphenyltetrazolium chloride in a potato model.

Irreversible electroporation (IRE) is a tissue ablation method, uses short high electric pulses and results in cell death in target tissue by irreversibly permeabilizing the cell membrane. Potato is commonly used as a tissue model for electroporation experiments. The blackened area that forms 12 h after electric pulsing is regarded as an IRE-ablated area caused by melanin accumulation. Here, the 2,3,5-triphenyltetrazolium chloride (TTC) was used as a dye to assess the IRE-ablated area 3 h after potato model ablation. Comparison between the blackened area and TTC-unstained white area in various voltage conditions showed that TTC staining well delineated the IRE-ablated area. Moreover, whether the ablated area was consistent over time and at different staining times was investigated. In addition, the presumed reversible electroporation (RE) area was formed surrounding the IRE-ablated area. Overall, TTC staining can provide a more rapid and accurate electroporated area evaluation.

Effects of thymosin ß4-derived peptides on migration and invasion of ovarian cancer cells.

BACKGROUND: Thymosin ß4 (Tß4) is a highly conserved actin binding protein associated with the metastatic potential of tumor cells by stimulating cell migration. The role of Tß4 and its derived fragment peptides in migration of ovarian cancer cells has not been studied. OBJECTIVE: To analyze the effects of Tß4 and its derived fragment peptides on ovarian cancer cell migration and invasion, we applied Tß4 and three Tß4-derived synthetic peptides to SKOV3 ovarian cancer cells. METHOD: The migration and invasion of SKOV3 cells treated with Tß4(1-43), Tß4(1-15), Tß4(12-26), Tß4(23-), and untreated control were analyzed by in vitro migration and invasion assay with transwell plate. Cell proliferation assay was conducted to identify the effect of Tß4 and its derived peptide on SKOV3 cell proliferation. The expression of Tß4 related proteins related with cell proliferation was analyzed by Western blot after treatment with Tß4 and its derived peptides. RESULTS: Cell migration and invasion were significantly increased in Tß4 peptide-treated SKOV3 cells compared with untreated control. All three Tß4-derived fragment peptides including those without an actin binding site significantly stimulated migration and invasion of SKOV3 cells. Tß4 and its derived peptide significantly stimulated SKOV3 cell proliferation and up-regulated the expression of RACK-1 protein. CONCLUSIONS: The Tß4 peptide and all of its derived fragment peptides including those without an actin binding motif stimulate migration and invasion of SKOV3 ovarian cancer cells. All peptides significantly increased RACK-1 expression and cell proliferation of SKOV3 cells. These results suggest that Tß4 stimulates migration and invasion of SKOV3 cells by stimulation of cell proliferation through up-regulation of RACK-1 protein.

Association between sunlight exposure and risk of prostate cancer: a systematic review and meta-analysis.

BACKGROUND: The prevalence of prostate cancer (PC) is increasing worldwide. An association between sunlight exposure and PC risk has been described by a previously published meta-analysis, although the level of statistical significance was not reached. We have, therefore, performed an updated systematic review and meta-analysis to further elucidate this potential connection. METHODS: To identify relevant articles, we conducted an in-depth search of 4 electronic databases (PubMed, Embase, the Web of Science and Scopus) for manuscripts published prior to March 2021. A random-effects model was used to compute a meta-estimate of the effects of sunlight exposure on risk of PC. RESULTS: Of the 5680 articles that were initially identified in our search, 12 observational epidemiological studies encompassing 29 282 cases of PC were selected for inclusion in the qualitative systematic review. Of these, two case-control studies were excluded from the meta-analysis. Comparing highest-to-lowest exposure, personal sunlight exposure was significantly associated with a decreased risk of PC [odds ratio (OR) = 0.67, 95% CI: 0.57-0.78] in a random-effects meta-analysis; however, high heterogeneity was present (I2 = 85.9%). Comparing moderate-to-lowest exposure, there was a non-significant relationship between personal sunlight exposure and the risk of PC (OR = 0.87, 95% CI: 0.68-1.10; I2 = 74.0%). CONCLUSIONS: Our findings indicate that exposure to sunlight may protect against PC. The limitations of our research are occurrence of publication bias and a substantial heterogeneity due to a diversity of criteria for measuring sunlight exposure.

Calcium Supplements and Risk of Cardiovascular Disease: A Meta-Analysis of Clinical Trials.

BACKGROUND: Recent systematic reviews and meta-analyses of randomized, double-blind, placebo-controlled trials (double-blind, placebo-controlled RCTs) have reported controversial findings regarding the associations between calcium supplements on the risk of cardiovascular disease (CVD). This meta-analysis aimed to investigate the association between them. METHODS: We searched PubMed, EMBASE, the Cochrane Library, and the bibliographies of relevant articles for double-blind, placebo-controlled RCTs in November, 2020. Relative risks (RRs) with 95% confidence intervals (CIs) for the risk of cardiovascular disease were calculated using a random effects model. The main outcomes were CVD, coronary heart disease (CHD), and cerebrovascular disease. RESULTS: A total of 13 double-blind, placebo-controlled RCTs (n = 28,935 participants in an intervention group and 14,243 in a control group)) were included in the final analysis. Calcium supplements significantly increased the risk of CVD (RR 1.15, 95% CI 1.06-1.25], I2 = 0.0%, n = 14) and CHD (RR 1.16, 95% CI 1.05-1.28], I2 = 0.0%, n = 9) in double-blind, placebo-controlled RCTs, specifically in healthy postmenopausal women. In the subgroup meta-analysis, dietary calcium intake of 700-1000 mg per day or supplementary calcium intake of 1000 mg per day significantly increased the risk of CVD and CHD. CONCLUSIONS: The current meta-analysis found that calcium supplements increased a risk of CVD by about 15% in healthy postmenopausal women.

Sunlight exposure in association with risk of lymphoid malignancy: a meta-analysis of observational studies.

PURPOSE: Several observational studies have shown contradictory results regarding the association between sunlight exposure and the risk of malignant lymphoma. Thus, we aimed to systematically determine the association between sunlight exposure and lymphoid malignancy risk through a meta-analysis. METHODS: A thorough search of four electronic databases (PubMed, Embase, Web of Science, and Scopus) was performed to identify eligible studies until 13 August 2020. A random-effects model was used to calculate risk estimates of sunlight exposure. The main outcome measure was the risk of lymphoid malignancy subtypes with odds ratios (ORs) and 95% confidence intervals (CIs) according to various forms of solar ultraviolet radiation. RESULTS: In total, 17 case-control studies and 9 cohort studies including 216,285 non-Hodgkin lymphoma (NHL) and 23,017 Hodgkin's lymphoma (HL) patients were included in the final analysis. Personal sunlight exposure was significantly associated with a decreased risk of HL (OR 0.77; 95% CI 0.68-0.87) and NHL (OR 0.81; 95% CI 0.71-0.92), including all subtypes except T-cell lymphoma. Ambient sunlight exposure at residence was associated with a reduced risk of HL (OR 0.88; 95% CI 0.81-0.95) and all NHL subtypes (OR 0.84; 95% CI 0.73-0.96), except for chronic lymphocytic leukemia/small lymphocytic lymphoma. As the number of sunburns and sunbaths increased, the risk of NHL tended to decrease. CONCLUSION: While there was an observed protective effect both from case-control and prospective studies, substantial heterogeneity was found in the current study. Thus, more evidence is required to confirm that promoting sunlight exposure can prevent the development of lymphoid neoplasia.

Analysis of KAP1 expression patterns and human endogenous retrovirus Env proteins in ovarian cancer.

BACKGROUND: Human endogenous retroviruses (HERVs) constitute around 8% of the human genome and have important roles in human health and disease, including cancers. Previous studies showed that HERV envelope (Env) proteins are highly expressed in cancer tissues and co-related with cancer progression. KAP1 has been reported to play a key role in regulating retrotransposons, including HERV-K, through epigenetic silencing. OBJECTIVE: The relationship between KAP-1 and HERV Envs expressions was analyzed only in tumor cell lines and has not yet been studied in cancer tissues. In this study, we analyzed the expression patterns and relationship between KAP1 and HERV Env proteins in ovarian cancer tissues. METHOD: The expression patterns of KAP-1 and HERV Env proteins, including HERV-K and HERV-R, were analyzed in ovarian cancer tissue microarrays that contained 80 surgical specimens, including normal ovary and malignant ovarian cancers. RESULTS: The expression of HERV-R Env and KAP1 proteins is significantly higher in ovarian cancer compared with normal ovary tissues. However, the expression of HERV-K Env did not change significantly in cancer tissues. The expression patterns of HERV-K Env and HERV-R Env significantly increased in early stages of cancer and KAP1 expression was higher in certain stage and types of cancers. However, the expression of HERV-K Env, HERV-R Env, and KAP1 did not change in different age groups. The correlation between the expression of KAP1 and HERV-Env, including HERV-K and HERV-R, was not significantly correlated. CONCLUSIONS: The results of this study showed that there was no significant correlation between the expression of KAP1 and HERV Env proteins in ovarian cancer tissues, unlike studies with cell lines in vitro. These results suggest that the actual expression of HERV Env proteins in ovarian cancer tissues may be regulated through various complex factors as well as KAP1.

Classification of cervical neoplasms on colposcopic photography using deep learning.

Colposcopy is widely used to detect cervical cancers, but experienced physicians who are needed for an accurate diagnosis are lacking in developing countries. Artificial intelligence (AI) has been recently used in computer-aided diagnosis showing remarkable promise. In this study, we developed and validated deep learning models to automatically classify cervical neoplasms on colposcopic photographs. Pre-trained convolutional neural networks were fine-tuned for two grading systems: the cervical intraepithelial neoplasia (CIN) system and the lower anogenital squamous terminology (LAST) system. The multi-class classification accuracies of the networks for the CIN system in the test dataset were 48.6 ± 1.3% by Inception-Resnet-v2 and 51.7 ± 5.2% by Resnet-152. The accuracies for the LAST system were 71.8 ± 1.8% and 74.7 ± 1.8%, respectively. The area under the curve (AUC) for discriminating high-risk lesions from low-risk lesions by Resnet-152 was 0.781 ± 0.020 for the CIN system and 0.708 ± 0.024 for the LAST system. The lesions requiring biopsy were also detected efficiently (AUC, 0.947 ± 0.030 by Resnet-152), and presented meaningfully on attention maps. These results may indicate the potential of the application of AI for automated reading of colposcopic photographs.

A simple segmentation and quantification method for numerical quantitative analysis of cells and tissues.

BACKGROUND: Microscopic image analysis based on image processing is required for quantitative evaluation of decellularization. Existing methods are not widely used because of expensive commercial software, and machine learning-based techniques lack generality for decellularization because many high-resolution image data has to be processed. OBJECTIVE: In this study, we developed an image processing algorithm for quantitative analysis of tissues and cells in a general microscopic image. METHODS: The proposed method extracts the color images obtained by the microscope into reference images consisting of grayscale, red (R), green (G), and blue (B) information and transforms each into a binary image. The transformed images were extracted by separating the cells and tissues through outlier noise elimination, logical multiplication and labeling. In order to verify the method, decellularization of porcine arotic valve was performed by the electrical method. Slice samples were obtained by time and the proposed method was applied. RESULTS: The experimental results show that the segmentation of cells and tissues, and quantitative analysis of the number of cells and changes in tissue area during the decellularization process was possible. CONCLUSIONS: The proposed method shows that cell and tissue extraction and quantitative numerical analysis were possible in different brightness of microscopic images.

The association between aspirin use and depression: a systematic review and meta-analysis of observational studies.

PURPOSE: Many clinical trials and observational studies have been conducted under the premise that the anti-inflammatory effect of aspirin may prevent depression. These studies, however, showed inconsistent results. To inspect the association between aspirin use and depression, we conducted a meta-analysis of observational studies. METHODS: In August 2019, two authors independently searched PubMed, EMBASE, and PsycINFO to retrieve observational epidemiological studies presenting an association between aspirin use and depression. Case-control and cohort studies were included, and odds ratios (ORs) or relative risks (RRs) with 95% confidence intervals (CIs) for the risk of depression were estimated using a random-effects model. In addition, number needed to harm (NNH) was calculated to measure the rates of depression. RESULTS: In total, 12 observational studies-five case-control studies and seven prospective cohort studies-were included in this meta-analysis. The random-effects model demonstrated a significant association between aspirin use and depression (OR/RR 1.10; 95% CI: 1.05-1.16) with insignificant heterogeneity (I2 = 23.3%). The risk estimates of depression from prospective cohort studies were similar (RR 1.11; 95% CI: 1.08-1.14), and heterogeneity was not observed (I2 = 0.0%). In the subgroup meta-analysis, a duration of aspirin use ≥5 years and a dosage ≥500 mg daily were also associated with depression. The NNH for depression with aspirin use >5 years was 103 (95% CI 91-111) indicating that observed event is rare. CONCLUSIONS: Aspirin use was associated with depression in the present meta-analysis. One of the major limitations is the lack of detail and consistency with respect to exposure verification in the included papers. Another limitation is the lack of randomized controlled studies and prospective cohort studies.

Association between anaemia and adult depression: a systematic review and meta-analysis of observational studies.

BACKGROUND: Several observational studies have been conducted to investigate the link between anaemia and adult depression but have shown inconsistent results. This systematic review and meta-analysis was performed to investigate this association. METHODS: A comprehensive search of four electronic databases (PubMed, EMBASE, PsycINFO and the Cochrane Library) was conducted to identify relevant papers published up to November 2019 for the systematic review and meta-analysis. The Newcastle-Ottawa Scale was used to assess the methodological quality of selected studies. A random-effects model was used to draw metaestimates of the relationship between anaemia and adult depression. RESULTS: A total of 9706 papers were retrieved, and 14 observational epidemiological studies (9 case-control studies and 5 prospective cohort studies) comprising 10 764 cases of depression were finally included in this meta-analysis. The mean age of the participants ranged from 38.4 to 75.0 years. A significant association was identified between low haemoglobin levels and adult depression (OR or relative risk 1.43; 95% CI 1.23 to 1.65). Subgroup analyses according to study design, mean age, diagnostic criteria of anaemia, geographical region, number of participants, methodological quality and adjustment for various confounding factors such as education, smoking, comorbid disorders, physical activity, alcohol intake and medication use showed similar results. CONCLUSIONS: The current study showed that anaemia was related to an increased risk of adult depression. One of the important limitations of our study was a moderate degree of heterogeneity due to the variety of assessment tools used to identify depression and the existence of publication bias. Another limitation of this meta-analysis was the lack of prospective cohort studies.