Body Mass Index and Suicide

Association between body mass index and suicide attempts in Chinese patients of a hospital in Shanxi district with first-episode drug-naïve major depressive disorder

OBJECTIVE

In patients with major depressive disorder (MDD), the relationship between body mass index (BMI) and risk of suicide attempts (SA) remains unclear, and findings are controversial. The aim of this study was to investigate the relationship between BMI and SA in a Chinese population with first-episode drug-naïve (FEDN) MDD.

METHODS

A total of 1718 patients with FEDN MDD were enrolled in this cross-sectional study. Their socio-demographic characteristics as well as anthropometric data were collected. The 17-item Hamilton Rating Scale (HAMD-17) and Hamilton Anxiety Scale (HAMA) were used to assess the severity of depression and anxiety symptoms in all participants. Thyroid hormones, lipid profile, and fasting blood glucose (FBG) were measured. A history of suicide attempts was verified based on medical records and interviews with patients and their family members. Multiple logistic regression analysis was used to estimate the association between BMI and the risk of SA. Threshold effects were examined by a two-piecewise logistic regression model.

RESULTS

Multiple logistic regression analysis showed that BMI was independently and negatively correlated with SA (OR = 0.91, 95%CI: 0.85 to 0.98, P = 0.01) in patients with FEDN MDD after adjusting for covariates. Smoothing plots also revealed a non-linear (L-shaped) relationship between BMI and SA, and a two-piecewise logistic regression model was used to calculate the inflection point of BMI as 22.1 kg/m2. On the left of the inflection point, a negative association between BMI and SA was detected (OR = 0.54, 95%CI: 0.42 to 0.70, P < 0.001), while no significant association was observed on the right side of the inflection point (OR = 1.01, 95%CI: 0.93 to 1.10, P = 0.75).

CONCLUSIONS

Our results suggest that lower BMI is associated with a higher risk of recent SA in Chinese patients with FEDN MDD, especially in those with BMI below 22.1 kg/m2.

Gender differences in the association between body mass index and recent suicide attempts in Chinese patients with first-episode drug-naïve major depressive disorder

Controversial evidence exists on the relationship between body mass index (BMI) and suicide attempts (SA) in patients with major depressive disorder (MDD). This cross-sectional study aimed to explore the association between BMI and SA in first-episode drug-naïve (FEDN) MDD patients in China. The study was conducted from 2016 to 2018 in Taiyuan, China. Univariate and multivariate logistic regression analyzed the BMI-SA association, with subgroup analysis for gender. Threshold effects were examined using two-piecewise regression. In males, BMI was significantly associated with SA (OR = 0.84, 95% CI 0.74-0.94, P = 0.003) after full adjustment, but not in females (OR = 0.97, 95% CI 0.89-1.06, P = 0.541). The interaction with gender was significant (P for interaction < 0.05). Smoothing plots revealed an L-shaped BMI-SA relationship in both genders, with BMI inflection points at 27.3 kg/m2 in males and 21.4 kg/m2 in females. Below the inflection points, BMI is negatively associated with SA in males (OR = 0.75, 95% CI 0.66-0.86, P < 0.001) and females (OR = 0.48, 95% CI 0.32-0.72, P < 0.001). Above the inflection points, no association existed for both genders (all P > 0.05). Results showed an L-shaped nonlinear BMI-SA relationship in FEDN MDD patients but differing BMI inflection points between genders, thus contributing to effective prevention programs for suicide.

Body mass index weight categories in adults who died by suicide: An observational study

BACKGROUND

There is conflicting evidence about the relationship between body mass index (BMI) and suicide death. This study aimed to characterize and compare suicide deaths by weight using BMI weight categories.

METHODS

We examined suicide deaths in adults in the city of Toronto (2009-2015); grouped them by BMI categories (underweight, normal weight, overweight, and obese) and compared groups based on demographics, clinical variables and method of suicide death.

RESULTS

Suicide decedents' (n = 1429) mean age was 48.6 years (SD = 17.4) and mean BMI was 25.5 (SD = 5.4). Underweight decedents were more likely to be female and to have cancer while obese decedents were more likely to have diabetes. Underweight decedents were more likely to have an identified history of any medical condition. Obese and overweight decedents were significantly more likely to have an identified history of any psychiatric condition. Non-violent methods (e.g., self-poisoning) were used at a higher proportion by people with obesity and by people who were underweight.

LIMITATIONS

Psychological autopsies were not available and it was not possible to assess for change in or stability of BMI over time.

CONCLUSIONS

These findings add to our understanding of the relationship between suicide and weight. A higher prevalence of females as well as those with a history of cancer and any medical condition in underweight decedents was noteworthy and of potential clinical significance.

Body Mass Index and Saltwater Drowning

Comparison of body mass index (BMI) was undertaken between 30 cases of salt water drowning and 30 age- and sex-matched controls randomly selected from the autopsy files of Forensic Science SA, Adelaide, Australia, during the period 2000 to 2017. The age range of drowning cases and controls was 18 to 80 (average, 49) years, with a male to female ratio of 19:11. The BMIs of the drowning cases ranged from 15.5 to 37.5 (average, 25.4; median, 23). The control cases had higher BMIs ranging from 22.9 to 44.3 (average, 29.2; median, 25). The number of obese (BMI, ≥30) decedents in the drowning group was 5 (17%) and in the controls was 9 (30%). Individuals who drown in the sea may regularly swim, and thus be fitter and therefore slimmer than more sedentary controls. However, it is also possible that greater amounts of adipose tissue may be protective against drowning, as increased fat stores could improve buoyancy. Thinner individuals with denser body mass may have to struggle more to avoid submersion. It could be that a low BMI is an underappreciated finding that may increase the risk of lethal immersion along with alcohol intoxication and poor swimming skills.

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.

Body mass index and suicide methods

Overweight and obesity is associated with lower rates of suicide. However, little is known about the association with different suicide methods. We studied the association between groups of body mass index and suicide methods. We identified all medicolegal autopsy cases with a cause of death due to external causes in Sweden during 1999-2013 (N = 39,368) and included 11,715 suicides and 13,316 accidents or homicides as controls. We applied multinomial regression models adjusted for age, sex, year and season of death. Obesity was associated with suicidal intoxication, OR 1.15 [95% confidence interval (CI) 1.02, 1.30] and negatively associated with all other suicide methods studied. Underweight showed a negative association with suicidal drowning and there was an indication towards a negative association with hanging in men OR 0.81 (95% CI 0.65, 1.01). We conclude that body mass index (BMI) is associated with the choice of suicide method. This may be of importance in a public health perspective, e.g. potential for prevention of intoxications. In the practice of forensic medicine, the physician's level of suspicion may rise if the apparent suicidal method is less common for the individual characteristics of the deceased, such as BMI.

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

BACKGROUND

Suicide is among the leading causes of death worldwide. Suicide attempts and suicidal ideation are more common than completed suicide and are associated with psychological distress. These behaviors are considered risk factors of completed suicide. Considering the psychosocial stigma and medical comorbidities associated with obesity, an accumulating body of studies have investigated body mass index (BMI) as a potential risk factor of suicide. However, several cohort studies have demonstrated an inverse relationship between BMI and completed suicide, suggesting a protective effect of increasing BMI against completed suicide. The association between BMI and attempted suicide is more equivocal, with several studies reporting both positive and negative relationships between BMI and attempted suicide. The primary objective of this study is to systematically review the literature to determine the association between BMI and suicidal behavior (including completed suicide, attempted suicide, suicidal ideation) in an adult population (18 years and older). The secondary objective is to explore whether sex, age, and the method used in suicide modify the relationship between BMI and suicidal behavior.

METHODS/DESIGN

An electronic search will be conducted using PubMed/MEDLINE, PsycINFO, CINAHL, and EMBASE using a predefined search strategy; databases will be searched from their inception. Two authors (SP and RE) will independently screen articles using predefined inclusion and exclusion criteria and will extract pertinent data using a pilot tested extraction form. At all levels of screening, discrepancies between the two authors will be resolved by consensus, and in the case of disagreement, by consulting a third author (ZS). The primary outcomes include the association between BMI and completed suicide, attempted suicide, and suicidal ideation. If appropriate, a meta-analysis will be conducted. Risk of bias and quality of evidence will be assessed.

DISCUSSION

The results of this systematic review will inform health care professionals and researchers about whether BMI has a significant role in suicidal behavior and psychological well-being.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42014014739 .

Inverse association between obesity predisposing FTO genotype and completed suicide

The A allele of rs9939609 in the FTO gene predisposes to increased body mass index (BMI) and obesity. Recently we showed an inverse association between the obesity related A allele of rs9939609 and alcohol dependence which was replicated by others. Since this finding raises a possibility that FTO may be associated with other psychiatric phenotypes, we aimed to examine association of rs9939609 with completed suicide. We genotyped rs9939609 in 912 suicide victims and 733 controls using TaqMan approach. We observed an inverse association between suicide and the rs9939609 A allele (OR = 0.80, P = 0.002, P_cor = 0.006) with genotype distribution suggesting a co-dominant effect. Given the link between alcoholism and suicide under influence of alcohol reported in Polish population, confounding by alcohol addiction was unlikely due to apparently similar effect size among cases who were under influence of ethanol at the time of death (OR = 0.76, P = 0.003, N = 361) and those who were not (OR = 0.80, P = 0.007, N = 469). The search for genotype-phenotype correlations did not show significant results. In conclusion, our study proves that there is an inverse association between rs9939609 polymorphism in FTO gene and completed suicide which is independent from association between FTO and alcohol addiction.