Association between body mass index and suicidal behaviors: a systematic review protocol

A scoping review shows that no single existing risk of bias assessment tool considers all sources of bias for cross-sectional studies

OBJECTIVES

Different tools to assess the potential risk of bias (RoB) for cross-sectional studies have been developed, but it is unclear whether all pertinent bias concepts are addressed. We aimed to identify RoB concepts applicable to cross-sectional research validity and to explore coverage for each in existing appraisal tools.

STUDY DESIGN AND SETTING

This scoping review followed the Joanna Briggs Institute methodology. We included records of any study design describing or reporting methods, concepts or tools used to consider RoB in health research reported to be descriptive/prevalence survey or analytic/association (cross-sectional) study designs. Synthesis included quantitative and qualitative analysis.

RESULTS

Of the 4556 records screened, 90 were selected for inclusion; 67 (74%) described the development of, or validation process for, appraisal tools, 15 (17%) described methodological content or theory relevant to RoB for cross-sectional studies and 8 (9%) records of methodological systematic reviews. Review of methodological reports identified important RoB concepts for both descriptive/prevalence and analytic/association studies. Tools identified (n = 64 unique tools) were either intended to appraise quality or assess RoB in multiple study designs including cross-sectional studies (n = 21; 33%) or cross-sectional designs alone (n = 43; 67%). Several existing tools were modified (n = 17; 27%) for application to cross-sectional studies. The RoB items most frequently addressed in the RoB tools were validity and reliability of the exposure (53%) or outcome (65%) measurement and representativeness of the study population (59%). Most tools did not consider nonresponse or missingness appropriately or at all.

CONCLUSION

Assessing cross-sectional studies involve unique RoB considerations. We identified RoB tools designed for broad applicability across various study designs as well as those specifically tailored for cross-sectional studies. However, none of the identified tools comprehensively address all potential biases pertinent to cross-sectional studies. Our findings indicate a need for continued improvement of RoB tools and suggest that the development of context-specific or more precise tools for this study design may be necessary.

Association between a changeable lifestyle, sedentary behavior, and suicide risk: A systematic review and meta-analysis

BACKGROUND

Suicide and self-injury have become increasingly serious public health crises. Yet current evidence about the association between sedentary behavior (SB) and suicide is inconclusive. We explore the relationship between SB and suicide behavior to provide intervention measures to change the risk factors of the latter.

METHODS

We searched PubMed, Embase, Cochrane Library, and Web of Science from database inception to September 10, 2023. Adjusted odds ratios (ORs) with 95 % confidence intervals (CIs) were used as effect measures. Subgroup analysis was conducted based on gender, regions and countries, age, and study type.

RESULTS

A total of 13 studies were included. According to the meta-analysis of suicide type, compared with individuals without sedentary behavior, individuals with sedentary behavior have a higher risk of suicide attempt (OR = 1.23, 95%CI: 1.15-1.37, p < 0.001), suicide ideation (OR = 1.47, 95%CI:1.28-1.68, p < 0.001) and suicide plan (OR = 1.30, 95%CI:1.16-1.44, p < 0.001). We conducted multiple subgroup analyses for different suicidal behaviors. The analysis found that SB can increase the risk of suicide attempt in different subgroups of different genders, different research centers, Africa, and adolescents; SB can increase the risk of suicide ideation in the subgroups of different genders and ages, different research centers, Asia and Africa; SB can increase the risk of suicide plan in the subgroups of different genders, multi-center study, Africa, and adolescents.

LIMITATIONS

Future research should focus on objective SB measurement and explore its dose-response relation and time limit.

CONCLUSION

A sedentary lifestyle is associated with suicide behavior risk, with varying effects across age groups and regions, as evidenced in both single-center and multi-center studies.

Incidence and prevalence of neurological disorders in the United Arab Emirates: a systematic review

BACKGROUND/OBJECTIVES

The United Arab Emirates (UAE) is a rapidly developing country. With the increase in average life-expectancy, high rates of consanguinity, and the adoption of a Western lifestyle, the burden of neurological disorders is expected to increase over the next few decades. Despite the importance of neurological disorders, there has not been a systematic review of published studies on the epidemiology of neurological disorders in the UAE.

METHODS

We searched for studies of incidence and/or prevalence of neurological disorders in the UAE published in English in MEDLINE, Google Scholar, Embase, and Scopus databases with no date restrictions up until 01 October 2023. Two authors independently assessed abstracts and full texts of possibly relevant papers, followed by data extraction from studies satisfying the eligibility criteria.

RESULTS

Eight articles (N = 2067 patients) were included, half reported incidence and prevalence of multiple sclerosis, with an average crude prevalence 56/100,000 and related demyelinating disorders. Others were related to headache, meningitis, cerebral venous thrombosis, and brain tumours.

CONCLUSION

There is a distinct lack of data on the epidemiology of different neurological diseases in the UAE. Large population-based studies, ideally longitudinal, are required to provide accurate and reliable estimates of the incidence and prevalence of neurological disorders to help inform healthcare capacity planning.

An investigation of the relationships between suicidal ideation, psychache, and meaning in life using network analysis

BACKGROUND

Previous studies have investigated the relationships between psychache or meaning in life and suicidal ideation based on sum score of corresponding scale. However, this practice has hampered the fine-grained understanding of their relationships. This network analysis study aimed to conduct a dimension-level analysis of these constructs and the relationships among them in a joint framework, and identify potential intervention targets to address suicidal ideation.

METHODS

Suicidal ideation, psychache, and meaning in life were measured using self-rating scales among 738 adults. A network of suicidal ideation, psychache, and meaning in life was constructed to investigate the connections between dimensions and calculate the expected influence and bridge expected influence of each node.

RESULTS

"Psychache" was positively linked to "sleep" and "despair", while "presence of meaning in life" had negative associations with "psychache", "despair", and "pessimism". The most important central nodes were "sleep" and "despair", and the critical bridge nodes were "presence of meaning in life" and "psychache".

CONCLUSION

These preliminary findings uncover the pathological pathways underlying the relationships between psychache, meaning in life, and suicidal ideation. The central nodes and bridge nodes identified may be potential targets for effectively preventing and intervening against the development and maintenance of suicidal ideation.

Body Mass Index (BMI): A Screening Tool Analysis

Body mass index (BMI), a measurement based on a person’s height and weight, allows the classification of individuals into categories such as obese or overweight. With these classifications, we can assess risk for hypertension, diabetes, cancer, hypercholesterolemia, and other chronic diseases. Furthermore, childhood BMI serves as a prediction method for health and disease later in life. Along with BMI, researchers also study waist circumference and waist-to-hip ratio in correlation with the above-mentioned chronic illnesses. This brief review explores the associations between body mass index, waist circumference, and the waist-hip ratio as measurements and their capability as predictors for persistent conditions like diabetes and hypertension.

An Exploratory Analysis of Predictors of Youth Suicide-Related Behaviors in Autism Spectrum Disorder: Implications for Prevention Science

Although autism spectrum disorder (ASD) is associated with significant mental health concerns, little is known about suicidality, particularly among youth. To address this critical gap in the literature, the current study examined the predictive validity of (1) demographics, (2) core autism symptoms, (3) cognitive abilities and adaptive behavior, (4) comorbid psychopathology, and (5) medical problems, for suicide-related behaviors among autistic youth (N = 481; M_age = 11.56 years). As indices of suicide-related behaviors, parents reported on whether the child had ever (1) talked about killing themselves, and (2) engaged in deliberate self-harm or attempted suicide. These two suicide-related outcomes had distinct clinical correlates, including child age, parental education, restricted and repetitive behaviors, IQ and adaptive behavior, affective and conduct problems, and medical concerns.

Association of macro-level determinants with adolescent overweight and suicidal ideation with planning: A cross-sectional study of 21 Latin American and Caribbean Countries

BACKGROUND

Adolescents and young people (10-24 years old) in the Latin America and the Caribbean (LAC) region represent approximately 25% of the region's population. Since the 2008 global economic crisis, the pace of reduction in poverty and income inequality in the LAC region has stalled. The region is characterised by high levels of inequities and is also vulnerable to many natural disasters. Food systems are changing with increased availability and marketing of packaged and fast foods and sugar-sweetened drinks. Adolescence is a formative phase of the life course with multiple physical, emotional and social changes which can make them vulnerable to health problems. We assess the potential impact of macro-determinants, human and economic development as well as income inequality, on 2 top-ranking regional priorities for adolescent nutrition and mental health, using measures of overweight and suicidal ideation and planning which some have shown to be associated.

METHODS AND FINDINGS

The Global School-based Health Survey (GSHS) is a nationally representative self-administered, school-based survey. We examined overweight/obesity and suicidal ideation with planning by gross domestic product (GDP) per capita or human development index (HDI) in 10-19-year-old adolescents from 21 LAC countries between 2009 and 2013. Sample sizes varied from 943 in Anguilla to 27,988 in Argentina. A total of 55,295 adolescents had a measure of overweight/obesity status, and 59,061 adolescents reported about suicidal ideation with planning. There was equal representation by sex in the surveys (52% girls and 48% boys). A total of 28.8% of boys and 28.1% of girls had overweight/obesity, and 7.5% of boys and 17.5% of girls reported suicidal ideation with planning over the last 12 months. Adjusted for individual socioeconomic and risk behaviours, and relative to the highest GDP per capita tertile, the middle tertile was associated with 42% (95% confidence interval (CI) 59% to 17%, p = 0.003) and 32% (95% CI 60% to 5%, p = 0.023), and the lowest tertile with 40% (95% CI 55% to 19%, p = 0.001) and 46% (95% CI 59% to 29%, p < 0.001) lower chances of overweight/obesity for girls and boys, respectively. A similar positive effect was seen with HDI, with lowest chances of overweight in the lowest tertile compared with the highest tertile for both sexes. Overweight/obesity was positively related with suicidal ideation with planning for girls (odds ratio (OR) 1.12, 95% CI 1.02 to 1.22, p = 0.009) and weakly related for boys (OR 1.09, 95% CI 0.96 to 1.24, p = 0.182). In contrast to overweight/obesity status, suicidal ideation with planning was not related to macro-level indices despite both outcomes sharing common individual socioeconomic and risk behaviour correlates. Limitations include the dominance of Argentinians in the sample (40%), the exclusion of vulnerable adolescents who dropped out of school, and reporting bias due to stigma of mental health-related issues.

CONCLUSIONS

This study shows that economic and human development were positively associated with adolescent overweight/obesity but not with suicidal ideation with planning. We also observed an interconnectedness between overweight/obesity and suicide ideation with planning among girls. These findings highlight the importance of strategies that engage with both upstream and downstream determinants to improve adolescent nutrition and mental health.

Impact of physical activity and exercise on bone health in patients with chronic kidney disease: a systematic review of observational and experimental studies

Background

Chronic Kidney Disease (CKD) patients frequently develop life-impairing bone mineral disorders. Despite the reported impact of exercise on bone health, systematic reviews of the evidence are lacking. This review examines the association of both physical activity (PA) and the effects of different exercise interventions with bone outcomes in CKD.

Methods

English-language publications in EBSCO, Web of Science and Scopus were searched up to May 2019, from which observational and experimental studies examining the relation between PA and the effect of regular exercise on bone-imaging or -outcomes in CKD stage 3–5 adults were included. All data were extracted and recorded using a spreadsheet by two review authors. The evidence quality was rated using the Cochrane risk of bias tool and a modified Newcastle-Ottawa scale.

Results

Six observational (4 cross-sectional, 2 longitudinal) and seven experimental (2 aerobic-, 5 resistance-exercise trials) studies were included, with an overall sample size of 367 and 215 patients, respectively. Judged risk of bias was low and unclear in most observational and experimental studies, respectively. PA was positively associated with bone mineral density at lumbar spine, femoral neck and total body, but not with bone biomarkers. Resistance exercise seems to improve bone mass at femoral neck and proximal femur, with improved bone formation and inhibited bone resorption observed, despite the inconsistency of results amongst different studies.

Conclusions

There is partial evidence supporting (i) a positive relation of PA and bone outcomes, and (ii) positive effects of resistance exercise on bone health in CKD. Prospective population studies and long-term RCT trials exploring different exercise modalities measuring bone-related parameters as endpoint are currently lacking.

Determinants of Suicidality in the European General Population: A Systematic Review and Meta-Analysis

Close to one million people commit suicide each year, with suicidal attempts being the main risk factor for suicide. The aim of this systematic review and meta-analysis is to achieve a greater understanding of suicidality in the general population of Europe by studying associated factors and their statistical significance with suicidality, as well as the effect of the temporal moment in which suicidality is observed in a relationship. A search strategy was carried out in electronic databases: Proquest's Psychology Database, Scopus, PsycINFO, Medline and Embase. Odds ratios (ORs), publication bias, influential studies on heterogeneity and analysis moderators were calculated. Twenty-six studies were included after meeting the inclusion criteria. Factors statistically associated with suicidality are female gender, age over 65 years, unemployment, low social support, adulthood adversity, childhood adversity, family history of mental disorder, any affective disorder, major depression, anxiety/stress/somatoform disorders, tobacco and substance use, any mental disorder and body mass index. As a limitation, a high heterogeneity between studies was found. Factors associated with suicidality in the general population are relevant for understanding the suicidal phenomenon.

Health Behaviors among Male and Female University Students in Cambodia: A Cross-Sectional Survey

Students go through a transition when they enter university, which involves major individual and contextual changes in every domain of life that may lead to several behavioral and health problems. This study examined a wide range of health behaviors and practices among 1,359 male and female students recruited from two public universities in Cambodia using a multistage cluster sampling method. Health-related information in different domains were collected using a structured questionnaire. We compared the variables in male and female students. Of the total, 50.8% were male and the mean age was 21.3 (SD = 2.3) years. The majority (79.5%) reported not having any vigorous-intensity activities, 25.9% not having moderate-intensity activities, and 33.5% not having walked continuously for 10 min over the last week. More than one-third (38.3%) reported drinking alcohol, 1.1% smoking tobacco, and 0.4% using an illicit drug in the past 12 months. About one in ten (10.6%) reported having sexual intercourse; of whom, 42.4% reported not using a condom in the last intercourse, and the mean number of sexual partners was 2.1 (SD = 2.4) in the past 12 months. Only 7.1% reported having been diagnosed with a sexually transmitted infection (STI) in the past 12 months; of whom, 60% sought for treatment for the most recent STI. About one-third (33.6%) reported eating fast food at least once over the last week. More than half (55.6%) had one to two servings of fruits or vegetables daily, and 9.9% did not eat any fruits or vegetables over the last week. Gender differences were observed in physical activities, dietary intakes, cigarette smoking, alcohol drinking, and sexual behaviors. Findings from this study indicate that public health and education policies should promote healthy behaviors among university students. The interventions may take advantage of and expand upon the positive health behaviors and consider gender differences.

Family-based analyses reveal novel genetic overlap between cytokine interleukin-8 and risk for suicide attempt

BACKGROUND

Suicide is major public health concern. It is imperative to find robust biomarkers so that at-risk individuals can be identified in a timely and reliable manner. Previous work suggests mechanistic links between increased cytokines and risk for suicide, but questions remain regarding the etiology of this association, as well as the roles of sex and BMI.

METHODS

Analyses were conducted using a randomly-ascertained extended-pedigree sample of 1882 Mexican-American individuals (60% female, mean age = 42.04, range = 18-97). Genetic correlations were calculated using a variance components approach between the cytokines TNF-α, IL-6 and IL-8, and Lifetime Suicide Attempt and Current Suicidal Ideation. The potentially confounding effects of sex and BMI were considered.

RESULTS

159 individuals endorse a Lifetime Suicide Attempt. IL-8 and IL-6 shared significant genetic overlap with risk for suicide attempt (ρg = 0.49, pFDR = 7.67 × 10-03; ρg = 0.53, pFDR = 0.01), but for IL-6 this was attenuated when BMI was included as a covariate (ρg = 0.37, se = 0.23, pFDR = 0.12). Suicide attempts were significantly more common in females (pFDR = 0.01) and the genetic overlap between IL-8 and risk for suicide attempt was significant in females (ρg = 0.56, pFDR = 0.01), but not in males (ρg = 0.44, pFDR = 0.30).

DISCUSSION

These results demonstrate that: IL-8 shares genetic influences with risk for suicide attempt; females drove this effect; and BMI should be considered when assessing the association between IL-6 and suicide. This finding represents a significant advancement in knowledge by demonstrating that cytokine alterations are not simply a secondary manifestation of suicidal behavior, but rather, the pathophysiology of suicide attempts is, at least partly, underpinned by the same biological mechanisms responsible for regulating inflammatory response.

Association between body weight status and suicidal ideation among Chinese adolescents: the moderating role of the child's sex

PURPOSE

Suicidality (ranging from suicidal ideation to suicidal attempts and completed suicide) is a major and preventable public health concern, and body weight is considered a modifiable factor which might be helpful to the early risk assessment of suicidal ideation. This study aimed to comprehensively evaluate the association of body weight status with suicidal ideation across sex among Chinese adolescents.

METHODS

Data were drawn from the 2015 National School-based Chinese Adolescents Health Survey, and 54,640 students' questionnaires were completed and qualified for the survey. Body mass index z scores were calculated and categorized into four levels: underweight (less than the 5th percentile for sex and age), normal weight (between the 5th and 85th percentile), overweight (between the 85th and 95th percentile), and obese (above the 95th percentile).

RESULTS

Of the total sample, 47.3% (25,852) were boys. The weighted prevalence of suicidal ideation among Chinese adolescents is 15.7% (14.6% in boys and 17.3% in girls). After adjusting for demographics, smoking, drinking, and depressive symptoms, our final multivariate logistic regression models demonstrated that only boys identified as underweight (Adjusted odds ratio [AOR] = 1.23, 95% CI = 1.06-1.44) or obese (AOR = 1.19, 95% CI = 1.02-1.38) were at a higher risk of suicidal ideation. Additionally, the association between weight status and suicidal ideation among boys might be moderated by academic pressure, smoking, and depressive symptoms.

CONCLUSIONS

There was a significant J-shaped association between relative body weight and suicidal ideation in boys. The child's sex should be taken into consideration when developing interventions against unhealthy weight and suicidal ideation.

Psychosomatic and Psychosocial Questions Regarding Bariatric Surgery: What Do We Know, or What Do We Think We Know?

SUBJECT

In view of the epidemic increase in severe obesity and the ineffectiveness of conservative weight-loss interventions, bariatric surgery delivers compelling results for patients with class II (BMI ≥ 35 kg/m²) and class III obesity (BMI ≥ 40 kg/m²), not only in reducing weight over the long term, but also in reducing obesity-related somatic comorbidity and improving psychosocial functioning and quality of life. Investigations into the psychosocial aspects of obesity surgery have proliferated over the last 15 years, providing a huge amount of essential research data. Yet the results are partly contradictory and highly dependent on the duration of follow-up.

METHODS

Based of a narrative review, this article provides an overview of the current status and recent developments of the reciprocal effects between bariatric surgery and psychosocial functioning. The review focused on eight domains representing important psychosomatic and psychosocial aspects of bariatric surgery.

RESULTS

Especially in cases of class II and III obesity, bariatric surgery is the only means to reduce bodyweight significantly and permanently, though they carry with them the associated risk factors of metabolic, cardiovascular, and oncological diseases.With regard to psychosocial and psychosomatic aspects, studies with a short-term catamnesis (approx. 3 years) speak in favor of an improvement in the quality of life including mental disorders. If we consider studies with longer follow-ups, however, the results are not as uniform. In particular, we observe an increase in harmful alcohol consumption, self-harm behavior, and suicide risk.

CONCLUSIONS

In light of mental well-being and thus also quality of life, bariatric surgery would appear to convey an elevated risk for a minority of patients.Yet identifying these patients before surgery has so far been insufficient.

Night noise exposure and risk of death by suicide in adults living in metropolitan areas

BACKGROUND

Noise is defined as "sound that is unwanted, unpleasant, or harmful to health." It may induce negative emotions and mental health problems and even may leads to increased suicide risk. Little attention has been paid so far to a potential link between noise and suicide. We investigated the association between nighttime environmental noise and suicide death in adults in the Republic of Korea.

METHODS

We analyzed the data from the National Health Insurance Service-National Sample Cohort, with a 4-year baseline (2002-2005) and an 8-year follow-up (2006-2013) assessment. A total of 155,492 adults constituted the study sample: younger adults (20-54 years, n = 124,994), or older adults (≥55 years, n = 30,498), and adults with mood and anxiety disorders (n = 34,615). Suicide death was defined as per International Classification of Diseases-10 code X60-X84. Data on nighttime noise were obtained from the National Noise Information System.

RESULTS

During the study period, 315 (0.2%) died of suicide. The incidence of suicide per 100,000 person-years was 25.71. With interquartile range increases in nighttime noise, the adjusted hazard ratio (HR) for suicide death was significantly increased: 1.32 (95% confidence interval [CI]: 1.02-1.70) for younger adults, 1.43 (95% CI: 1.01-2.02) for older adults, and 1.55 (95% CI: 1.10-2.19) for adults with mental illness. In the penalized regression spline models, the HRs for suicide death were gradually increased with environmental noise levels, and the risk was the highest for adults with mental illness.

CONCLUSIONS

We found a significant association between exposure to nighttime noise and the risk of suicide death in adults in the Republic of Korea.

Longitudinal risk factors for suicidal thoughts in depressed and non-depressed young adolescents

OBJECTIVE

Evidence regarding the role of risk factors in the longitudinal course of suicidal ideation among young adolescents is lacking. We aimed to assess the effects of a range of risk factors, including obesity, academic performance, child-parent relationship, physical maltreatment, and depressive symptoms, on the development of suicidal ideation in young adolescents.

METHODS

A school cohort of seventh and eighth graders was followed for 1 year and differences in the risk factors distributions were examined between depressed and non-depressed adolescents. We further examined risk factors for newly developed suicidal ideation and persistent suicidal ideation in the groups of adolescents based on the presence of suicidal ideation at baseline.

RESULTS

A total of 1710 young adolescents were recruited, among whom 8.2% were categorised as having clinically significant depression. For depressed adolescents, being obese was associated with a three-fold increased risk of having suicidal ideation. For non-depressed adolescents, physical maltreatment, a feeling of not being cared about and sub-threshold depressive symptoms were the risk factors. The latter two remained robust in predicting newly developed suicidal ideation.

CONCLUSION

The current study may shed light on the differential strategies to address suicidal thoughts in depressed and non-depressed adolescents. We emphasise the importance of recognition and management of sub-threshold depressive symptoms and the relevance of obesity, physical maltreatment and a feeling of not being cared about to suicide prevention programmes in early adolescence.

Is cardiac autonomic function associated with cardiorespiratory fitness and physical activity in children and adolescents? A systematic review of cross-sectional studies

BACKGROUND

Heart rate variability (HRV) is considered to explain improvements in cardiovascular health accrued by physical activity (PA) and cardiorespiratory fitness (CRF) over and above traditional cardiovascular risk factors.

OBJECTIVE

To systematically address associations between HRV, PA and CRF in children and adolescents.

DATA SOURCES

Medline, EMBASE, SportDISCUS and CINAHL Plus were searched on 5th September 2015 and updated on 4th August 2016.

ELIGIBILITY CRITERIA

Observational studies comparing HRV in different groups of PA and CRF, and/or studies investigating associations between PA, CRF and HRV. Sports practices and PA intensities were also included. The square root of the mean of the sum of the squares of differences between adjacent RR intervals (RMSSD), the spectral density in the high (HF) and low (LF) frequency, and the LF/HF ratio were included. Risk of bias was assessed using the adapted Newcastle-Ottawa Scale (NOS).

RESULTS

Heterogeneity exists in the assessment of the exposures and outcomes, and sample characteristics. Risk of bias (NOS) was observed in most of the studies. Studies with low risk of bias showed positive associations between moderate-to-vigorous PA and RMSSD. The evidence for the associations between PA and frequency indices is weak. Similarly, the evidence for the association between CRF and HRV is weak.

CONCLUSIONS

Despite the heterogeneity in the studies, moderate-to-vigorous PA is positively associated with RMSSD, but less clear are the associations between CRF and HRV, as well as other PA intensities. Further research is needed to clarify the role of PA and CRF on HRV in children and adolescents.

Body Mass Index Is an Important Predictor for Suicide: Results from a Systematic Review and Meta-Analysis

Public health concerns for the independent management of obesity and suicidal behavior are rising. Emerging evidence suggests body weight plays an important role in quantifying the risk of suicide. In light of these findings, we aimed to clarify the association between body mass index (BMI) and suicidal behavior by systematically reviewing and evaluating the literature. Studies were identified by searching MEDLINE, EMBASE, PsycINFO, and CINAHL from inception to January 2015, supplemented by hand and grey literature searches. Study screening, data extraction, and risk of bias assessment were conducted in duplicate. We included 38 observational studies. Meta-analyses supported an inverse association between BMI and completed suicide. Pooled summary estimates demonstrated that underweight was significantly associated with an increased risk of completed suicide (HR = 1.21, 95% CI 1.07 to 1.36, p = .002), and obesity (HR = 0.71, 95% CI 0.56 to 0.89, p = .003) and overweight (HR = 0.78, 95% CI 0.75 to 0.82, p < .0001) were significantly associated with a decreased risk of completed suicide relative to normal weight. A qualitative summary of the literature demonstrated conflicting evidence regarding the association between BMI and attempted suicide and revealed no association between BMI and suicidal ideation. BMI may be used to aid the assessment of suicide risk, especially that of completed suicide. However, unmeasured confounders and systematic biases of individual studies limit the quality of evidence.

Effect of sex and age on the association between suicidal behaviour and obesity in Korean adults: a cross-sectional nationwide study

OBJECTIVES

To examine the hypothesis that the relationship between obesity and the risk of suicidal behaviour would differ according to sex and age.

SETTING

Data from the 2007-2012 Korean National Health and Nutrition Examination Survey (KNHANES) were used.

PARTICIPANTS

36 211 adults with body mass index (BMI) data were included and the mean age was 49.6 years.

INDEPENDENT VARIABLE

BMI.

PRIMARY AND SECONDARY OUTCOME MEASURES

Suicide ideation and attempts.

DESIGN AND ANALYSIS

A cross-sectional study was performed. Multiple logistic regressions after controlling for socioeconomic variables and concomitant diseases were applied to see the relationship between obesity level and suicidal ideation or attempt.

RESULTS

Women with severe obesity had the highest prevalence of suicide attempts and ideation, whereas among males, underweight men had the highest prevalence. After adjustment, obese men had a lower OR for suicide ideation (OR=0.87, 95% CI 0.76 to 1.00). Among women, the ORs of severely obese and underweight women were 1.27 (95% CI 1.06 to 1.52) and 1.24 (95% CI 1.06 to 1.45), respectively. When grouped by age category, the ORs for suicide ideation in severely obese women aged 18 to <30 years or attempts in severely obese women aged 30 to <50 years were 2.30 (95% CI 1.36 to 3.89) and 3.07 (95% CI 1.50 to 6.31), respectively. However, overweight and obese women aged more than 50 years exhibited significantly less ORs of suicide ideation, when compared with counterparts of normal weight.

CONCLUSIONS

The association between obesity and suicidal behaviour exhibited a different pattern by sex and age in South Korea. In particular, severely obese young women had a substantial risk of suicidal behaviour. Our study results highlighted the importance of obesity management in the prevention of suicide among young women, and may be helpful for the drafting of the health agenda in Asian countries with an obesity prevalence and culture similar to those in Korea.

Neutrophil-to-lymphocyte ratio predicting suicide risk in euthymic patients with bipolar disorder: Moderatory effect of family history

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) has been independently related to bipolar disorder (BD) and factors associated with suicidal risk. The aim of our study was to explore the relationship between NLR and suicide risk in euthymic BD patients. We also sought to propose a model of interaction between NLR and stress-diathesis factors, leading to suicidal risk in BD.

METHODS

The study group consisted of 83 patients diagnosed with BD (36 suicide attempters; 47 suicide non-attempters), compared to the healthy control group (n=73) and matched according to age, gender, and body mass index (BMI). NLR was measured according to the complete blood count. Mood symptoms have been assessed by Young Mania Rating Scale and Montgomery-Asberg Depression Rating Scale. Early trauma and acute stress were evaluated by Early Trauma Inventory Self Report-Short Form and List of Threatening Experiences Questionnaire, respectively. Suicide risk has been assessed by Suicide Behaviors Questionnaire-Revised (SBQ-R).

RESULTS

Significant correlation was found between NLR and SBQ-R score. The main effects of suicide attempts on NLR, after covarying for confounders, were observed, indicating increased NLR in BD suicide attempters compared to healthy controls. We found significant moderatory effects of family history on NLR relationship to suicidal risk, with NLR being significant positive predictor of suicidal risk only in the patients with positive family history of suicide attempts.

CONCLUSIONS

The results suggest an enhancing effect of positive family history of suicide attempts on predictive effect of NLR on suicide risk. Our data support the idea that immune markers can predict suicide attempt risk in BD, but only in the subpopulation of BD patients with family history of suicide attempts. This could lead to prevention in suicide behavior in the patient population at particular risk of suicide.

Prevalence and influence factors of suicidal ideation among females and males in Northwestern urban China: a population-based epidemiological study

Background

Suicide is an urgent public health challenge for China. This study aims to examine the prevalence, influence factors, and gender differences of suicidal ideation among general population in Northwestern Urban China.

Methods

Data used in this study were derived from the third wave of a cohort study of a randomized community sample with 4291 participants (≥20 years) in 2008 in Lanzhou City and Baiyin City, Gansu Province. Data were collected via face-to-face interview by the trained interviewers. Descriptive analyses, chi-square tests and multivariate logistic regressions were performed by using Stata 12.0, as needed.

Results

The prevalence of 12-month suicidal ideation was 4.29 %, there was no significant difference between males and females [5.04 % vs 3.62 %, Adjusted Odds Ratio (AOR) = 0.83, p = 0.351]. Several risk factors for suicidal ideation were confirmed, including being unmarried (AOR = 1.55, p = 0.030), having depression symptoms (AOR = 2.33, p < 0.001), having other insurance (AOR = 1.83, p = 0.01) or no insurance (AOR = 1.73, p = 0.024). In addition, several influence factors were significantly different in males and females, such as being currently married (unmarried vs married, AOR = 1.84, p = 0.027, for females; no difference for males), feeling hopeless (hopless vs hopeful, AOR = 1.92, p = 0.06, for females; no difference for males), having other insurances (having other insurances vs having basic employee medical insurance, AOR = 1.92, p = 0.044, for males; no difference for females), having debts (having debts vs no debts, AOR = 2.69, p = 0.001, for males; no difference for females), currently smoking (smoking vs nonsmoking, AOR = 3.01, p = 0.019 for females, no difference for males), and currently drinking (drinking vs nondrinking, AOR = 2.01, p = 0.022, for males; no difference for females).

Discussion and conclusion

These findings suggested that comprehensive suicide prevention strategies should be developed or strengthened in order to prevent suicide ideation in China, and the gender-specific differences need to be explored through further researches.