Severe Mental Illness and the Risk of Diabetes Complications: A Nationwide, Register-based Cohort Study

Cardiovascular risk management among individuals with type 2 diabetes and severe mental illness: a cohort study

AIMS/HYPOTHESIS

The aim of this study was to compare cardiovascular risk management among people with type 2 diabetes according to severe mental illness (SMI) status.

METHODS

We used linked electronic data to perform a retrospective cohort study of adults diagnosed with type 2 diabetes in Scotland between 2004 and 2020, ascertaining their history of SMI from hospital admission records. We compared total cholesterol, systolic BP and HbA1c target level achievement 1 year after diabetes diagnosis, and receipt of a statin prescription at diagnosis and 1 year thereafter, by SMI status using logistic regression, adjusting for sociodemographic factors and clinical history.

RESULTS

We included 291,644 individuals with type 2 diabetes, of whom 1.0% had schizophrenia, 0.5% had bipolar disorder and 3.3% had major depression. People with SMI were less likely to achieve cholesterol targets, although this difference did not reach statistical significance for all disorders. However, people with SMI were more likely to achieve systolic BP targets compared to those without SMI, with effect estimates being largest for schizophrenia (men: adjusted OR 1.72; 95% CI 1.49, 1.98; women: OR 1.64; 95% CI 1.38, 1.96). HbA1c target achievement differed by SMI disorder and sex. Among people without previous CVD, statin prescribing was similar or better in those with vs those without SMI at diabetes diagnosis and 1 year later. In people with prior CVD, SMI was associated with lower odds of statin prescribing at diabetes diagnosis (schizophrenia: OR 0.54; 95% CI 0.43, 0.68, bipolar disorder: OR 0.75; 95% CI 0.56, 1.01, major depression: OR 0.92; 95% CI 0.83, 1.01), with this difference generally persisting 1 year later.

CONCLUSIONS/INTERPRETATION

We found disparities in cholesterol target achievement and statin prescribing by SMI status. This reinforces the importance of clinical review of statin prescribing for secondary prevention of CVD, particularly among people with SMI.

Trends in Incidence of Hospitalization for Hypoglycemia and Diabetic Ketoacidosis in Individuals With Type 1 or Type 2 Diabetes With and Without Severe Mental Illness in Denmark From 1996 to 2020: A Nationwide Study

OBJECTIVE

To examine trends in incidence of acute diabetes complications in individuals with type 1 or type 2 diabetes with and without severe mental illness (SMI) in Denmark by age and calendar year.

RESEARCH DESIGN AND METHODS

We conducted a cohort study using nationwide registers from 1996 to 2020 to identify individuals with diabetes, ascertain SMI status (namely, schizophrenia, bipolar disorder, or major depression) and identify the outcomes: hospitalization for hypoglycemia and diabetic ketoacidosis (DKA). We used Poisson regression to estimate incidence rates (IRs) and incidence rate ratios (IRRs) of recurrent hypoglycemia and DKA events by SMI, age, and calendar year, accounting for sex, diabetes duration, education, and country of origin.

RESULTS

Among 433,609 individuals with diabetes, 8% had SMI. Risk of (first and subsequent) hypoglycemia events was higher for individuals with SMI than for those without SMI (for first hypoglycemia event, IRR: type 1 diabetes, 1.77 [95% CI 1.56-2.00]; type 2 diabetes, 1.64 [95% CI 1.55-1.74]). Individuals with schizophrenia were particularly at risk for recurrent hypoglycemia events. The risk of first DKA event was higher in individuals with SMI (for first DKA event, IRR: type 1 diabetes, 1.78 [95% CI 1.50-2.11]; type 2 diabetes, 1.85 [95% CI 1.64-2.09]). Except for DKA in the type 2 diabetes group, IR differences between individuals with and without SMI were highest in younger individuals (<50 years old) but stable across the calendar year.

CONCLUSIONS

SMI is an important risk factor for acute diabetes complication and effective prevention is needed in this population, especially among the younger population and those with schizophrenia.

The Fusion Clinic: Integrating the care of people with severe mental illness and diabetes

AIM

People with coexisting severe mental illness (SMI) and type 2 diabetes have a shorter life expectancy and poorer diabetes outcomes than those without SMI. This is partly explained by the separate treatment of diabetes and SMI, which occurs in parallel silos in many healthcare systems. The Steno Diabetes Center Sjaelland and Region Zealand established the Fusion Clinic to offer combined psychiatric and diabetes care delivered by both diabetes and mental healthcare professionals. This study describes how the clinic was established and the initial diabetes outcomes.

METHODS

The Fusion Clinic was co-designed by people with diabetes and SMI and healthcare professionals to improve the care of adults with diabetes and SMI. The clinic approach utilised the F-ACT model. The 63 people referred to the Fusion Clinic between 01.02.2020 and 01.01.2022 who attended the clinic for more than 6 months were included in this study. Diabetes outcomes were recorded in the electronic medical records (Sundhedsplatformen EPIC).

RESULTS

There was a high prevalence of diabetes complications at baseline. Furthermore, 70% had one or more additional concomitant diseases, as well as SMI and diabetes. Assessment of diabetes complications and measurements of HbA1c and lipid profile improved after referral to the clinic. HbA1c declined during the first 6 months of attendance at the clinic.

CONCLUSIONS

This model of service delivery has the potential to improve the quality of care for people with SMI and type 2 diabetes.

The development of type 2 diabetes management in people with severe mental illness in the Capital Region of Denmark from 2001 to 2015

BACKGROUND

Type 2 diabetes (T2D) treatment has changed markedly within the last decades. We aimed to explore whether people with severe mental illness (SMI) have followed the same changes in T2D treatment as those without SMI, as multiple studies suggest that people with SMI receive suboptimal care for somatic disorders.

METHODS

In this registry-based annual cohort study, we explored the T2D treatment from 2001 to 2015 provided in general practices of the Greater Copenhagen area. We stratified the T2D cohorts by their pre-existing SMI status. T2D was defined based on elevated glycated hemoglobin (≥48 mmol/mol) or glucose (≥11 mmol/L) using data from the Copenhagen Primary Care Laboratory Database. Individuals with schizophrenia spectrum disorders (ICD-10 F20-29) or affective disorders (bipolar disorder or unipolar depression, ICD-10 F30-33) were identified based on hospital-acquired diagnoses made within 5 years before January 1 each year for people with prevalent T2D or 5 years before meeting our T2D definition for incident patients. For comparison, we defined a non-SMI group, including people who did not have a hospital-acquired diagnosis of schizophrenia spectrum disorders, affective disorders, or personality disorders. For each calendar year, we assembled cohorts of people with T2D with or without SMI. We used Poisson regression to calculate the rates per 100 person-years of having at least one biochemical test (glycated hemoglobin, low-density lipoprotein cholesterol, estimated glomerular filtration rate, and urine albumin-creatinine ratio), having poor control of these biochemical results, taking glucose-lowering or cardiovascular medications, or experiencing a clinical outcome, including all-cause mortality and cardiovascular mortality. Three outcomes (cardiovascular events, cardiovascular mortality, and all-cause mortality) were additionally examined and adjusted for age and sex in a post hoc analysis.

RESULTS

From 2001 to 2015, 66,914 individuals were identified as having T2D. In 2015, 1.5% of the study population had schizophrenia spectrum disorder and 1.4% had an affective disorder. The number of people who used biochemical tests or had poor biochemical risk factor control was essentially unrelated to SMI status. One exception was that fewer LDL cholesterol tests were done on people with affective disorders and schizophrenia spectrum disorders at the beginning of the study period compared to people in the non-SMI group. This difference gradually diminished and was almost nonexistent by 2011. There was also a slightly slower rise in UACR test rates in the SMI groups compared to other people with T2D during the period. Throughout the study period, all groups changed their use of medications in similar ways: more metformin, less sulfonylurea, more lipid-lowering drugs, and more ACEi/ARBs. However, people with schizophrenia disorder consistently used fewer cardiovascular medications. Cardiovascular events were more common in the affective disorder group compared to the non-SMI group from 2009 to 2015 (rate ratio 2015 : 1.36 [95% CI 1.18-1.57]). After adjustment for age and sex, all-cause mortality was significantly higher among people with a schizophrenia spectrum disorder each year from 2003 to 2015 compared to the non-SMI group (rate ratio 2015 : 1.99 [95% CI 1.26-3.12]).

CONCLUSION

Persons with schizophrenia or affective disorders demonstrated the same treatment changes for T2D as those without SMI in general practice. The lower use of most types of cardiovascular medications among people with schizophrenia disorders indicates potential undertreatment of hypertension and dyslipidemia and remains throughout the study period. Cardiovascular events were most common among people with affective disorders, but this was not reflected in a higher proportion using cardiovascular preventive medications. This knowledge should be considered in the management of this vulnerable patient group.

Association between depression and macrovascular disease: a mini review

Depression and macrovascular diseases are globally recognized as significant disorders that pose a substantial socioeconomic burden because of their associated disability and mortality. In addition, comorbidities between depression and macrovascular diseases have been widely reported in clinical settings. Patients afflicted with coronary artery disease, cerebrovascular disease or peripheral artery disease exhibit an elevated propensity for depressive symptoms. These symptoms, in turn, augment the risk of macrovascular diseases, thereby reflecting a bidirectional relationship. This review examines the physiological and pathological mechanisms behind comorbidity while also examining the intricate connection between depression and macrovascular diseases. The present mechanisms are significantly impacted by atypical activity in the hypothalamic-pituitary-adrenal axis. Elevated levels of cortisol and other hormones may disrupt normal endothelial cell function, resulting in vascular narrowing. At the same time, proinflammatory cytokines like interleukin-1 and C-reactive protein have been shown to disrupt the normal function of neurons and microglia by affecting blood-brain barrier permeability in the brain, exacerbating depressive symptoms. In addition, platelet hyperactivation or aggregation, endothelial dysfunction, and autonomic nervous system dysfunction are important comorbidity mechanisms. Collectively, these mechanisms provide a plausible physiological basis for the interplay between these two diseases. Interdisciplinary collaboration is crucial for future research aiming to reveal the pathogenesis of comorbidity and develop customised prevention and treatment strategies.

Type 2 Diabetes and Its Association With Psychiatric Disorders in Young Adults in South Korea

Importance

Because type 2 diabetes (T2D) has become increasingly prevalent among young adults, the study of the association of T2D with psychiatric disorders in young adults is important for early detection and timely intervention.

Objective

To determine whether a diagnosis of a psychiatric disorder is associated with increased risk of developing T2D in young adults.

Design, Setting, and Participants

This large-scale prospective cohort study used data collected by the South Korean National Health Insurance Service between 2009 and 2012, representing 97% of the South Korean population. Young adults aged 20 to 39 years with and without diagnoses of psychiatric disorders were included in the study. Young adults with missing data and those with a history of T2D were excluded from the study. The cohort was followed up to monitor development of T2D until December 2018. Data were analyzed from March 2021 to February 2022.

Exposure

Diagnosis of 1 of 5 psychiatric disorders, including schizophrenia, bipolar disorder, depressive disorder, anxiety disorder, and sleep disorder.

Main Outcomes and Measures

The primary outcome was newly diagnosed T2D during a follow-up period of 7.59 years. The incidence rate of T2D was calculated as the number of new cases per 1000 person-years during the follow-up period. The Cox proportional hazards regression model was used to estimate the hazard ratios (HRs) and 95% CIs for T2D incidence. Exploratory analyses were performed for subgroups stratified by age and sex.

Results

In total, 6 457 991 young adults (mean [SD] age, 30.74 [4.98] years; 3 821 858 men [59.18%]) were followed up, including 658 430 individuals with psychiatric disorders. The cumulative incidence of T2D differed significantly between individuals with and without psychiatric disorders (log-rank test, P < .001). Incidence rates of T2D for individuals with and without psychiatric disorders were 2.89 and 2.56 per 1000 person-years, respectively. Individuals with a diagnosis of any psychiatric disorder showed a higher risk of developing T2D than those without a diagnosis (adjusted HR, 1.20; 95% CI, 1.17-1.22). The adjusted HRs for T2D were 2.04 (95% CI, 1.83-2.28) for individuals with schizophrenia, 1.91 (95% CI, 1.73-2.12) for individuals with bipolar disorder, 1.24 (95% CI, 1.20-1.28) for individuals with depressive disorder, 1.13 (95% CI, 1.11-1.16) for individuals with anxiety disorder, and 1.31 (95% CI, 1.27-1.35) for individuals with sleep disorder.

Conclusions and Relevance

In this large-scale prospective cohort study of young adults, 5 psychiatric disorders were significantly associated with an increased risk of developing T2D. Young adults with schizophrenia and bipolar disorder in particular were at a higher risk of T2D. These results have important implications for early detection of and timely intervention in T2D for young adults with psychiatric disorders.

Indicators of quality of diabetes care in persons with type 2 diabetes with and without severe mental illness: a Danish nationwide register-based cohort study

BACKGROUND

This study aims to examine quality of diabetes care in persons with type 2 diabetes with and without severe mental illness (SMI).

METHODS

In a nationwide prospective register-based study, we followed persons with type 2 diabetes in Denmark with and without SMI including schizophrenia, bipolar disorder, or major depression. Quality of care was measured as receipt of care (hemoglobin A1c, low-density lipoprotein-cholesterol and urine albumin creatinine ratio assessment and eye and foot screening) and achievement of treatment targets between 2015 and 2019. Quality of care was compared in persons with and without SMI using generalized linear mixed models adjusted for key confounders.

FINDINGS

We included 216,537 persons with type 2 diabetes. At entry 16,874 (8%) had SMI. SMI was associated with lower odds of receiving care, with the most pronounced difference in urine albumin creatinine ratio assessment and eye screening (OR: 0.55, 95% CI: 0.53-0.58 and OR: 0.37 95% CI: 0.32-0.42, respectively). Among those with an assessment, we found that SMI was associated with higher achievement of recommended hemoglobin A1c levels and lower achievement of recommended low-density lipoprotein-cholesterol levels. Achievement of recommended low-density lipoprotein-cholesterol levels was similar in persons with versus without schizophrenia.

INTERPRETATION

Compared to persons without SMI, persons with SMI were less likely to receive process of care, with the most pronounced differences in urine albumin creatinine ratio assessment and eye screening.

FUNDING

This study was funded by Steno Diabetes Center Copenhagen through an unrestricted grant from Novo Nordisk Foundation.

Association of comorbid mental disorders with cardiovascular disease risk in patients with type 2 diabetes: A nationwide cohort study

OBJECTIVE

To examine the association between comorbid mental disorders and cardiovascular disease (CVD) risk among patients with type 2 diabetes.

METHOD

This retrospective cohort study was conducted using the claims data of 2,227,394 South Korean patients with type 2 diabetes. We analyzed the occurrence of CVD including myocardial infarction (MI) and ischemic stroke, CVD-specific mortality, and all-cause mortality according to comorbid mental disorders including depressive disorders, bipolar and related disorders, schizophrenia spectrum disorders, insomnia, and anxiety disorders.

RESULTS

Among the patients, 9.1% had a comorbid mental disorder. The adjusted hazard ratios (aHR) for MI, ischemic stroke, CVD-specific mortality, and all-cause mortality in patients with any mental disorder were 1.20 (95% CI, 1.17-1.24), 1.13 (95% CI, 1.11-1.16), 1.16 (95% CI, 1.12-1.20), and 1.21 (95% CI, 1.19-1.23), respectively. Each mental disorder increased the risk of all outcomes, particularly bipolar and related disorders and schizophrenia spectrum disorders.

CONCLUSION

Comorbid mental disorders increased the CVD risk in patients with type 2 diabetes, with significantly increased risks associated with schizophrenia spectrum disorders (aHR: 1.27 for MI and 1.50 for ischemic stroke) and bipolar and related disorders (aHR: 1.27 for MI and 1.45 for ischemic stroke).

Severe mental illness and quality of care for type 2 diabetes: A retrospective population-based cohort study

AIMS

To compare quality of care for type 2 diabetes in people with severe mental illness (SMI) versus no mental illness.

METHODS

We used routinely collected linked data to create a retrospective cohort study. We included 158,901 people diagnosed with type 2 diabetes in Scotland during 2009-2018 of whom 1701 (1%), 768 (0.5%) and 5211 (3%) had a prior hospital admission record for schizophrenia, bipolar disorder, and major depression, respectively. We compared recording of HbA1c, cholesterol, creatinine, blood pressure, urinary albumin, foot examination, retinopathy screening, body mass index and smoking during the first year after diabetes diagnosis using logistic regression and recording of HbA1c and retinopathy screening over longer follow-up using generalised linear mixed effects model, adjusting for confounding factors.

RESULTS

Receipt of care during the first year was generally similar, or better, for people with each SMI than for people without any mental illness. During mean follow up of 4.8 (SD 2.5) years, depression and bipolar disorder were associated with lower odds of receiving retinopathy screening.

CONCLUSIONS

Receipt of diabetes care was similar or better among people with SMI versus without SMI. However, mechanisms to support improved retinopathy screening for people with SMI are needed.