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Tag: diabetes

The Impact of Major Depressive Disorder on Cardiometabolic Disease Risk

Driven by a widespread change in lifestyle factors, such as dietary patterns and physical activity levels, as well as heightened stress levels, the global prevalence of cardiometabolic disease continues to rise. A burgeoning body of evidence suggests the potential impact of mental health factors, specifically the presence of major depressive disorder (MDD) on the development of cardiometabolic conditions. Affecting an estimated 322 million people, MDD has a high comorbidity rate with other medical disorders and in particular, type 2 diabetes. Although the mechanisms underlying the potential causal associations between the two are unknown, both cardiometabolic disease and major depressive disorder place a significant burden on population health.

Past observational studies have reported an association between MDD and an increased risk for type 2 diabetes, caused by biological alterations – such as elevated counter-regulatory hormone release and activity – as well as poor lifestyle factors, including smoking and alcohol consumption. Research has shown that brain regions involved in mood regulation also control metabolism, hypothalamic-pituitary-adrenal (HPA) axis, inflammatory responses, and autonomic nervous system (ANS) thus, controlling heart rate and blood pressure. These factors may influence the relationship between MDD and certain cardiometabolic conditions, however, evidence remains limited.

Adding to the growing body of evidence, a recent bidirectional Mendelian randomization study published in Diabetologia aimed to assess the causal relationships between major depressive disorder, type 2 diabetes, coronary artery disease, and heart failure to further elucidate the connections.

MDD and Cardiometabolic Disease

A team of researchers utilized the Mendelian randomization method – used for assessing causal inference of exposures on outcomes based on genetic variants as instrumental variables for exposures – to diminish chances of residual confounding and eliminate reverse causality due to the fixed nature of genetic variants regardless of disease progression or development.

In conducting their investigation, researchers extracted summary-level data for MDD, T2D, CAD, and heart failure from corresponding large genome-wide association studies; they used 96 single-nucleotide polymorphisms (SNPs) for MDD, 202 SNPs for type 2 diabetes, 44 SNPs for CAD, and 12 SNPs for heart failure. To perform their main analyses, the random-effects inverse-variance weighted method used.

Impact of MDD on Cardiometabolic Risk

Overall, the study’s authors found that the genetic liability to MDD was significantly associated with type 2 diabetes and coronary artery disease; they also found a suggestive association between MDD and heart failure. In examining the causal relationship, the research team found limited evidence in support of the causal effects of cardiometabolic disease on MDD risk, indicating that the presence of these conditions may not increase the likelihood of major depressive disorder.

However, meta-analyses did prove that the presence of MDD had an impact on type 2 diabetes development with the potential to increase risk by up to 60%. Additionally, the team found evidence of MDD having a causal association with the risk of CAD and HF. As diabetes and CAD have been known risk factors for HF and CAD may explain over 60% of heart failure cases, the relationship between major depressive disorder and heart failure may possibly be mediated via type 2 diabetes and coronary artery disease.

The latest findings further validate previous evidence that MDD is a potential risk factor for both type 2 diabetes and CAD, however, additional research needs to be conducted to determine whether MDD is causally related to heart failure. Future studies are likely to continue investigating the correlation to determine the significance of the impact of MDD on cardiometabolic health as well as to assess potential therapeutic interventions.

Due to the high disease burden related to causal association, the study’s authors recommend “that MDD prevention, management, and treatment should be enhanced for type 2 diabetes prevention.” Implications for the clinical practice may include more targeted strategies for the prevention and treatment of cardiometabolic diseases in the future with an increased focus on the mental health of patients.

 

Latest Statistics: 34 Million Americans Have Diabetes

Previous data indicates that diabetes is the leading risk factor for hospitalizations across the United States, with a total of 7.8 million hospital discharges reporting the condition as any of the listed diagnoses among adult patients aged 18 or older. Although incidence rates have slowed in recent years, approximately 34 million adults in the United States have type 1 or type 2 diabetes today. Of those, about 7.3 million meet laboratory criteria for diagnosed diabetes, however, are unaware or do not report having the disease. 

In a recent attempt to calculate the national estimated disease burden and prevalence of diabetes, the Centers for Disease Control and Prevention released the 2020 National Diabetes Statistics Report, which can be accessed in full here. Their findings indicate a decrease in the number of newly diagnosed diabetes cases in recent years among most – but not all – demographics and highlight the importance of more targeted prevention methods focused on adolescents specifically. 

Data for the report were derived from the National Health and Nutrition Examination Survey, the National Health Interview Survey, the Indian Health Service (IHS), National Data Warehouse, the Behavioral Risk Factor Surveillance System, the U.S. Diabetes Surveillance System, and the U.S. resident population estimates. Researchers established diagnosed diabetes status based on self-reported patient information; undiagnosed diabetes was determined by fasting plasma glucose measures or HbA1c levels.

Current Estimates

In 2018, new cases of diagnosed diabetes grew by 1.5 million, equivalent to about 6.9 diagnosed patients per 1,000 persons, similar to 2006 incidence rates. That year an estimated 88 million adults had prediabetes, although many of them may have been unaware of their condition.

Currently, adults aged. between 18 to 44 years experience lower diabetes rates than those aged between 45 and 65 as well as those aged above 65 years. However, younger demographics are increasingly at risk for developing the condition.

Incidence of New Cases in Youth

Per the latest statistics, the number of new diabetes cases decreased throughout the past decade in the United States with one exception – the overall incidence of type 1 diabetes significantly increased among children and adolescents between 2002 and 2015. The largest change was observed among children of Hispanic descent. In addition, the prevalence of type 2 diabetes also increased in this age demographic with changes consistent across all racial groups.

Prevalence and Risk Factors

Despite the decreased incidence of new cases in adults, the latest data from the Centers for Disease Control and Prevention reveal that the age-adjusted prevalence of total diabetes increased among adults between 1999 and 2016 – up from 9.5% in 1999-2002 to 12% in 2013-2016. These results held steady in 2018 at 6.7 per 1,000 adults compared with 2000 data, which reported a rate of 6.2 per 1,000 persons. 

Meanwhile, the age-adjusted results for 2017-2018 found the prevalence of diagnosed diabetes was highest among Native Americans and Alaskan Natives, Hispanic adults, and African Americans.

“Among adults, prevalence varied significantly by education level, which is an indicator of socioeconomic status,” the report explains. “Specifically, 13.3% of adults with less than a high school education had diagnosed diabetes vs. 9.7% of those with a high school education and 7.5% of those with more than a high school education.”

Common risk factors for diabetes-related complications showed that about 22% of diagnosed adults were tobacco users, 15% reported current smoking, and 36.4% had quit smoking. Furthermore, 89% of those with diagnosed diabetes were overweight or had obesity while 38% were physically inactive. 

Implications

As current literature proves, diabetes has a significant burden on population health and outcomes, contributing to increased risks of comorbid cardiometabolic conditions as well as adverse complications. The growing number of newly diagnosed cases in children and adolescents indicates an urgent need for age-specific prevention and management protocols as well as increased efforts to combat the disease in younger populations as early onset diabetes tends to predispose patients to poorer outcomes. 

The CDC’s latest report outlining trends in prevalence and estimates of diabetes burden can be accessed here.