The Relationship between Plasma Erythropoietin Levels and Symptoms of Attention Deficit Hyperactivity Disorder

Serum Erythropoietin and Ischemic-Modified Albumin Levels in Adolescents with Obsessive-Compulsive Disorder

Erythropoietin (EPO) has neuroprotective effects by increasing oxidative stress resistance and stabilizing redox balance. Ischemic-modified albumin (IMA) is a product of protein oxidation, and recent evidence suggests that IMA can be used as an indicator of oxidative damage. This study aimed to investigate serum EPO and IMA levels in obsessive-compulsive disorder (OCD) patients and to investigate the relationship between EPO and IMA levels and clinical variables such as disease duration and disease severity. A total of 68 adolescents (11-18 years old), including 35 OCD patients (18 males/17 females) and 33 healthy controls (14 males/19 females) without comorbid disorders matched for age, gender, and BMI, were included in the study. The enzyme-amplified chemiluminescence technique determined serum EPO levels, and serum IMA levels were determined by the spectrophotometric method. Serum EPO levels were lower in OCD patients compared to healthy controls (p = 0.002; Z =  - 3.123), and serum IMA levels (ABSU) were significantly higher in the OCD group (p = 0.005). A significant positive correlation was found between IMA levels and the duration of OCD symptoms (p = 0.015, r = 0.409). The study's findings contribute to the growing body of evidence implicating inflammatory and oxidative processes in the pathogenesis of OCD. The potential of EPO and IMA levels as diagnostic biomarkers for OCD aligns with the ongoing efforts to identify reliable biological markers for the disorder. The positive correlation of IMA levels with the duration of OCD shows the importance of early detection of oxidative damage.

Association of Endogenous Erythropoietin Levels and Iron Status With Cognitive Functioning in the General Population

Background

Emerging data suggest that erythropoietin (EPO) promotes neural plasticity and that iron homeostasis is needed to maintain normal physiological brain function. Cognitive functioning could therefore be influenced by endogenous EPO levels and disturbances in iron status.

Objective

To determine whether endogenous EPO levels and disturbances in iron status are associated with alterations in cognitive functioning in the general population.

Materials and Methods

Community-dwelling individuals from the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study, a general population-based cohort in Groningen, Netherlands, were surveyed between 2003 and 2006. Additionally, endogenous EPO levels and iron status, consisting of serum iron, transferrin, ferritin, and transferrin saturation were analyzed. Cognitive function was assessed by scores on the Ruff Figural Fluency Test (RFFT), as a reflection of executive function, and the Visual Association Test (VAT), as a reflection of associative memory.

Results

Among 851 participants (57% males; mean age 60 ± 13 years), higher endogenous EPO levels were independently associated with an improved cognitive function, reflected by RFFT scores (ß = 0.09, P = 0.008). In multivariable backward linear regression analysis, EPO levels were among the most important modifiable determinants of RFFT scores (ß = 0.09, P = 0.002), but not of VAT scores. Of the iron status parameters, only serum ferritin levels were inversely associated with cognitive function, reflected by VAT scores, in multivariable logistic regression analysis (odds ratio, 0.77; 95% confidence interval 0.63–0.95; P = 0.02 for high performance on VAT, i.e., ≥11 points). No association between iron status parameters and RFFT scores was identified.

Conclusion

The findings suggest that endogenous EPO levels and serum ferritin levels are associated with specific cognitive functioning tests in the general population. Higher EPO levels are associated with better RFFT scores, implying better executive function. Serum ferritin levels, but not other iron status parameters, were inversely associated with high performance on the VAT score, implying a reduced ability to create new memories and recall recent past. Further research is warranted to unravel underlying mechanisms and possible benefits of therapeutic interventions.

Prevalence and Comorbidities of Attention Deficit Hyperactivity Disorder Among Adults and Children/Adolescents in Korea

OBJECTIVE

This study investigated the prevalence and comorbidities of attention deficit hyperactivity disorder (ADHD) among adults and children/adolescents in Korea.

METHODS

This study used data from the Korea Health Insurance Review and Assessment Service collected from 2008 to 2018. Study participants comprised patients with at least one diagnosis of ADHD (International Statistical Classification of Diseases and Related Health Provisions, 10th revision code F90.0). Prevalence rates and psychiatric comorbidities were also analyzed.

RESULTS

We identified 878,996 patients diagnosed with ADHD between 2008 and 2018. The overall prevalence rate of diagnosed ADHD increased steeply from 127.1/100,000 in 2008 to 192.9/100,000 in 2018; it increased 1.47 times in children/adolescents (≤ 18 years) and 10.1 times in adults (＞ 18 years) during this period. Among adult and children/ adolescent ADHD patients, 61.84% (95% confidence interval [95% CI] 61.74-61.93) and 78.72% (95% CI 78.53- 78.91) had at least one psychiatric comorbidity, respectively.

CONCLUSION

Our results showed that the prevalence rate of diagnosed ADHD has increased in Korea; however, it is lower than the global average. Further studies are required to identify and treat vulnerable populations appropriately.