Prevalence and Characteristics of Self-Harm in Adolescents: Meta-Analyses of Community-Based Studies 1990-2015

OBJECTIVE

To provide meta-analytic estimates of self-harm from all community-based studies of adolescents from 1990 through 2015, estimates of suicidal risk, and characteristics including age profile, frequency, types, seeking help, and reasons.

METHOD

Databases, bibliographies, and the internet were searched for cross-sectional and cohort studies of 12- to 18-year-olds. Meta-analytic estimates of the prevalence and characteristics of self-harm, risk of suicidal behaviors, and rates comparing different methods were calculated.

RESULTS

One hundred seventy-two datasets reporting self-harm in 597,548 participants from 41 countries were included. Overall lifetime prevalence was 16.9% (95% CI 15.1-18.9), with rates increasing to 2015. Girls were more likely to self-harm (risk ratio 1.72, 95% CI 1.57-1.88). The mean age of starting self-harm was 13 years, with 47% reporting only 1 or 2 episodes and cutting being the most common type (45%). The most frequent reason was relief from thoughts or feelings. Slightly more than half sought help, but for most this was from a friend. Suicidal ideation (risk ratio 4.97) and attempts (risk ratio 9.14) were significantly higher in adolescents who self-harmed, but this was higher with more frequent self-harm. Methodologic factors also were associated with higher rates of self-harm.

CONCLUSION

Interventions that can lower suicidal risk should be made available to adolescents who self-harm frequently as soon as possible. Preventative interventions that help adolescents deal with negative feelings should be instituted at the onset of puberty. Because friends are frequently asked for support, interventions also should be developed for peer groups.

Biomarkers of Inflammation and Immune Function and Risk of Colorectal Cancer

A substantial number of prospective epidemiological studies have been conducted to investigate the association between biomarkers of inflammation and immune function and risk of colorectal cancer. Although pre-diagnostic concentrations of these biomarkers, especially C-reactive protein, have been associated with a higher risk of colorectal cancer in some studies, this association does not seem to have a robust support without hints of bias. Future prospective studies should evaluate multiple inflammatory biomarkers with longitudinal measures over the follow-up taking advantage of new multiplex cytokine quantification arrays and use more sophisticated joint or biomarker pattern statistical approaches to capture the complex and dynamic interplay between biomarkers and risk of colorectal cancer. Large collaborative consortia and Mendelian randomization studies should be encouraged to diminish the threat of biases and improve the reliability of this literature.

Plasma non-esterified fatty acid levels in children and their relationship with sex steroids

OBJECTIVE

Puberty is associated with decreased insulin sensitivity. Sexual hormones have been related with the onset of insulin resistance, but their relationship with non-esterified fatty acids (NEFA) remains unexplored. The aim of this study was to evaluate circulating NEFA levels in population-based samples of prepubertal children and adolescents and to analyze the association of NEFA with obesity, insulin resistance, and sexual hormones in adolescents.

EXPERIMENTAL

The studied population included 854 randomly selected 6-8-year-old children and 822 children aged 12-16years. NEFA levels were determined using a commercial kit. Testosterone and estradiol levels were determined by RIA, and insulin and sex hormone binding protein by IRMA. HOMA was calculated as an indicator of insulin resistance.

RESULTS

NEFA levels were lower in adolescents than in 6-8-year-old children, and decreased progressively with age between 12-year-olds and 16-year-olds. No significant differences in NEFA levels were observed between obese and non-obese adolescents. NEFA were not correlated with insulin or HOMA in 12-16-year-old girls, and appear negatively correlated with these variables in boys. Insulin and HOMA were negatively correlated with SHBG levels in both sexes adjusting by age but NEFA levels were not.

CONCLUSIONS

NEFA levels decrease with age in adolescents and are not significantly increased in obese children, supporting the fact that the decreased insulin sensitivity at this age is not affecting NEFA metabolism. Although SHBG is related to insulin and HOMA independently of age in both sexes, SHBG levels are not associated with NEFA.

Relationship of adiponectin with sex hormone levels in adolescents

BACKGROUND/AIMS

Adiponectin is an adipose tissue-derived adipocytokine which, starting at puberty, is present in lower levels in males than in females. In adults, a relationship between adiponectin levels and sexual hormones has been suggested, but this association remains unclear in children. Our study aimed to analyze the relationship of adiponectin with dehydroepiandrosterone sulfate, testosterone, estradiol, and sex hormone-binding globulin (SHBG) in adolescents.

METHODS

The population-based sample included 785 healthy 12- to 16-year-old children. Testosterone, estradiol, and dehydroepiandrosterone sulfate levels were assessed by radioimmunoassay. SHBG was measured by immunoradiometric assay. Adiponectin concentrations were measured by ELISA.

RESULTS

Adiponectin levels were positively correlated with SHBG and negatively correlated with the free androgen index independently of body mass index (BMI) and fat mass. No significant correlations were observed between adiponectin and total testosterone or estradiol. Multiple linear regression analysis showed that, after adjustment for BMI, SHBG appears as the primary predictor of adiponectin levels in both sexes, accounting for 5.7% of the variation in adiponectin levels in boys and 7.5% in girls.

CONCLUSION

Adiponectin is related to free androgen index and SHBG levels in adolescents after adjusting for BMI and fat mass, thus suggesting an association between adiponectin levels and androgen bioavailability that would explain the sex-based differences in adiponectin levels through life.