Insulin resistance in bipolar disorder: A systematic review of illness course and clinical correlates

Prevalence of insulin resistance and its associated factors in drug-naïve patients with bipolar disorder among Han Chinese population

BACKGROUND

Metabolic syndrome (Mets) is commonly seen in bipolar disorder (BD). As the key component and early biological index of Mets, insulin resistance (IR) among BD has received more and more attention. However, little is known about the prevalence of IR and its associated factors in drug-naïve patients with (BD), especially among Han Chinese population.

METHODS

A cross-sectional study was conducted on 125 drug-naïve patients with bipolar disorder (BD) and 85 healthy controls (HC). The Homeostatic Model Assessment of insulin resistance (HOMA-IR) was calculated, and IR was defined as HOMA-IR greater than the 75th percentile value for health controls (2.35). Clinical characteristics of BD were collected through semi-structural interview performed by a trained interviewer with background of psychiatric education.

RESULTS

Among the measured anthropocentric variables including BMI, waist circumference, abdomen circumference, hipline, and hip-waist ratio, waist circumference was found to be the most closely related to IR (0R = 1.070, 95%CI = 1.031-1.110, P < 0.001). Male was another factor that was associated with IR (OR = 2.281, 95%CI = 1.107-4.702, P = 0.025). After adjusted for gender and waist circumference, the risk of IR was significantly higher in bipolar disorder than in healthy controls (OR = 2.66, 95%CI = 1.364-5.214, P = 0.004). No significant association was found between IR and any of the observed physical and mental comorbidities, any characteristic of illness course including age onset, number of mixed episodes, types of current state, duration of current episode, duration of illness course, rapid cycling, number of mood episodes, and subgroup of BD. Hypersomnia was the only symptomatic feature that was significantly associated with IR (OR = 0.316, 95%CI = 0.124-0.803, P = 0.016).

CONCLUSIONS

Bipolar disorder increases two-to-three-fold risk of IR, both circumference and male are the risk factors of IR but hypersomnia act as a protective factor.

Clinical and genetic contributions to medical comorbidity in bipolar disorder: a study using electronic health records-linked biobank data

Bipolar disorder is a chronic and complex polygenic disease with high rates of comorbidity. However, the independent contribution of either diagnosis or genetic risk of bipolar disorder to the medical comorbidity profile of individuals with the disease remains unresolved. Here, we conducted a multi-step phenome-wide association study (PheWAS) of bipolar disorder using phenomes derived from the electronic health records of participants enrolled in the Mayo Clinic Biobank and the Mayo Clinic Bipolar Disorder Biobank. First, we explored the conditions associated with a diagnosis of bipolar disorder by conducting a phenotype-based PheWAS followed by LASSO-penalized regression to account for correlations within the phenome. Then, we explored the conditions associated with bipolar disorder polygenic risk score (BD-PRS) using a PRS-based PheWAS with a sequential exclusion approach to account for the possibility that diagnosis, instead of genetic risk, may drive such associations. 53,386 participants (58.7% women) with a mean age at analysis of 67.8 years (SD = 15.6) were included. A bipolar disorder diagnosis (n = 1479) was associated with higher rates of psychiatric conditions, injuries and poisonings, endocrine/metabolic and neurological conditions, viral hepatitis C, and asthma. BD-PRS was associated with psychiatric comorbidities but, in contrast, had no positive associations with general medical conditions. While our findings warrant confirmation with longitudinal-prospective studies, the limited associations between bipolar disorder genetics and medical conditions suggest that shared environmental effects or environmental consequences of diagnosis may have a greater impact on the general medical comorbidity profile of individuals with bipolar disorder than its genetic risk.

Current Status and Treatment of Rapid Cycling Bipolar Disorder

BACKGROUND

Rapid cycling (RC) at least 4 recurrent episodes per year in bipolar disorder (BD) has been recognized since the 1970s. We now comment on our recent review of the topic and extensive RC analysis in a large clinical cohort, emphasizing therapeutics research.

COMMENTS

Prevalence of RC-BD averages 36% for any year versus 22% in the preceding year. Rapid cycling is not a consistent feature over many years, although average long-term, annual recurrence rates are greater in RC-BD patients. Risk of RC may be somewhat greater among women and with older ages. It is also associated with cyclothymic temperament, prominent depression, and mood-switching with antidepressant treatment and is associated with increased suicidal risk. Treatment of individual episodes in RC-BD and effective long-term prevention remain inadequately studied, although antidepressant treatment can worsen RC. Some research supports treatment with aripiprazole, lamotrigine, and lithium, and interest in second-generation antipsychotics is emerging. All such options are used in various inadequately evaluated combinations.

CONCLUSIONS

Rapid cycling is prevalent among BD patients but seems to vary in risk over time without evidence of progressive worsening. Treatment of acute episodes in RC-BD patients and effective long-term preventive management require much more intensive investigation.

The relationship between peripheral insulin resistance and social cognitive deficits among euthymic patients with bipolar disorder

BACKGROUND

Despite extensive literature documenting emotion-related social-cognitive deficits in euthymic patients with bipolar disorder (BD), the factors contributing to these deficits have not been definitively established. To address this gap, the present study aimed to examine the association between peripheral insulin resistance (IR) and emotion-related social-cognitive abilities in BD patients and controls.

METHOD

Sixty-five BD patients and 38 non-psychiatric controls were recruited, and their social cognitive ability and IR were measured using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) and the homeostasis model assessment of insulin resistance (HOMA-IR), respectively.

RESULTS

The study found that the BD patients scored significantly lower than the non-psychiatric controls in the task of emotional management. The BD patients had a higher mean HOMA-IR value as compared with the controls but this result was not statistically significant (p = 0.051). The interaction between BD diagnosis and HOMA-IR value was significant on the MSCEIT Facilitating emotions branch and Facilitation subscale (p = 0.024, p = 0.010), and post-hoc analyses revealed that the BD patients in the higher HOMA-IR group had significantly lower scores than BD patients in the lower HOMA-IR group and the non-psychiatric controls in the higher HOMA-IR group on both the MSCEIT Facilitating emotion branch and Facilitation subscale.

LIMITATIONS

Due to the cross-sectional nature of the study, causality could not be inferred. The study did not examine potential mediators or moderators between IR and social cognition.

CONCLUSIONS

The results suggested that BD patients with IR experience additional impairment in specific domains of social cognition.

The association between insulin resistance and depressive symptoms - A national representative cross-sectional study

OBJECTIVE

Increasing evidence suggests a positive association between insulin resistance (IR) and depression. However, whether sex-or body mass index-specific differences exist remains controversial, and only few studies have analyzed specific symptom domains. Thus, the present study aimed to analyze the association between IR and depressive symptom domains and to clarify the effects of sex and body mass index.

METHODS

The study sample comprised 4007 participants, aged 19-79, from the Korea National Health and Nutrition Examination Study 2020. Participants completed health interviews and examinations, providing data on circulating insulin and glucose levels, the Patient Health Questionnaire-9 (PHQ-9), and related covariates. IR was calculated using the homeostasis model assessment of insulin resistance. Associations between IR and PHQ-9 were analyzed using negative binomial regression with adjustments for the complex survey design.

RESULTS

The association between log-transformed IR and PHQ-9 total scores was statistically significant (incidence rate ratio [IRR] = 1.17, 95% confidence interval [CI] = 1.07-1.29, p = 0.001). Only body mass index specific differences were statistically significant, as the association was only significant in those without obesity (IRR = 1.21, 95% CI = 1.06-1.38, p = 0.005). IR was associated with cognitive/affective (IRR = 1.23, 95% CI = 1.08-1.41, p = 0.002) and somatic (IRR = 1.14, 95% CI = 1.04-1.25, p = 0.005) depressive symptom domains. Sensitivity analyses revealed similar results.

CONCLUSIONS

IR was positively associated with cognitive/affective and somatic depressive symptoms in non-obese individuals.

Association Between Maternal Mood Disorders and Schizophrenia and the Risk of Type 1 Diabetes in Offspring: A Nationwide Cohort Study

Objective

Our study aimed to determine whether mothers with bipolar disorder, major depressive disorder, schizophrenia, or schizoaffective disorder affected the risk of type 1 diabetes (T1D) in their offspring.

Methods

We conducted a nationwide cohort study by using data from Taiwan's National Health Insurance Research Database and the Maternal and Child Health Database from 2004 to 2018. A total of 2,556,640 mother-child pairs were identified. Cox proportional hazards models were used to compare the risk of T1D between children born to mothers with mood disorders and schizophrenia and those without.

Results

No significant difference in risk of T1D was observed between the offspring of mothers with major psychiatric disorders and those without (adjusted hazard ratio (aHR) of 0.86 with a 95% confidence interval (CI) of 0.58-1.24). In subgroup analysis, we found an aHR of 1.81 with a 95% CI of 0.83-3.82 in the maternal bipolar disorder on the risk of T1D in offspring and an aHR of 0.87 (95% CI: 0.59-1.25) in maternal major depressive disorder. In the schizophrenia/schizoaffective disorder group, aHR cannot be obtained due to lesser than three events in the analysis.

Conclusion

The risk of T1D in offspring of mothers with mood disorders and schizophrenia was not significant. However, children born to mothers with bipolar disorder may have a tendency to develop T1D. The relationship between maternal psychiatric disorders and the risk of T1D in offspring warrants further investigation in studies with longer follow-up periods.