Both Obesity and Bipolar Disorders in 2249 Individuals Show White Matter Microstructure Abnormalities
Lorielle Dietze of Dalhousie University “obtained body mass index (BMI) and diffusion tensor imaging derived fractional anisotropy (FA) values from 930 individuals with bipolar disorders (BD), and 1319 control individuals from 20 cohorts in the ENIGMA-BD Working Group.”
They “found that lower FA was associated with both BD and BMI, in five white matter tracts, including the corpus callosum and thalamic radiation. Nine ROIs were correlated with only BD, while higher BMI was uniquely correlated with lower FA in four white matter ROIs.”
They concluded: “For the first time we showed that both obesity and BD demonstrated lower FA in some of the same regions. The impact of obesity may be greater in some tracts in BD individuals.”
Obesity is associated with reduce cortical thickness in bipolar disorders
Sean R. McWhinney et al reported in Psychological Medicine (2023) that obesity was associated with reduced cortical thickness (but not surface area) in most areas of the brain in 2832 participants.
Editors Note: Patients and clinicians should try to prevent and reduce weight gain using the best tolerated medications from the outset and helping with weight loss by various measures. These can include the anticonvulsants topiramated and zonisamine, the combination of bupropion and naltrexone, and the use of new anti-diabetic drugs such as Jardiance and Farxiga that have weight loss (greater than with metformin) as a side effect. Prescribing a good diet and regular exercise is also indicated. Reducing obesity will likely make you live longer and maybe could even make you smarter.
Adiposity and Cognitive Function Are Bidirectionally Related
Sakib et al reported in JAMA New Open that ” In this cohort study that included 11,103 adolescents, executive function and episodic memory were bidirectionally associated with adiposity, and this association was statistically mediated through the morphology of the lateral prefrontal cortex. Obesity (BMI) was associated worse executive functioning, episodic memory, and task performance. Thus preserving cognition is another reason beyond physical health to follow a good diet, get exercise, and use medications for weight loss if obesity is a problem.”
Cold Water Immersion Can Have Benefits
From:
Medscape Staff, December 08, 2022
“Bathing in cold water or ice may cut “bad” body fat and reduce the risk of disorders such as diabetes, but other claims of health benefits are less defined, according to researchers from the Arctic University of Norway and the University Hospital of North Norway.
WHAT TO KNOW:
- Immersion in cold water has a major impact on the body. It elevates the heart rate and has positive effects on brown adipose tissue, a type of “good” body fat that is activated by cold and may protect against obesity and cardiovascular disease.
- Exposure to cold water or cold air also appears to increase the production of the protein adiponectin by adipose tissue. Adiponectin plays a key role in protecting against insulin resistance, diabetes, and other diseases.
- Repeated cold-water immersions by inexperienced as well as experienced swimmers during the winter months significantly increased insulin sensitivity and decreased insulin concentrations.
- Numerous health and well-being claims from regular exposure to the cold, such as weight loss, better mental health, and increased libido, may be explained by other factors, including an active lifestyle, trained stress handling, social interactions, as well as a positive mindset.
- Those seeking to voluntarily practice cold-water emersion need to be educated about possible health risks associated with taking a dip in icy water, which include the consequences of hypothermia, and of heart and lung problems, which are often related to the shock from the cold.”
Links Between Mixed Depression, Insulin Resistance, Inflammation, and Cognitive Deficits
At the 2019 meeting of the International Society for Bipolar Disorders, researcher Roger McIntyre discussed links between obesity, diabetes, and cardiovascular problems; increased inflammation; and decreased functioning of the neural networks involved in cognition.
He and his colleagues analyzed 121 studies that included empirical research and meta-analyses. McIntyre and colleagues found that patients with higher levels of inflammatory markers have more insulin resistance and cognitive dysfunction. A meta-analysis revealed that the inflammatory markers IL-6, TNF alpha, and CRP were significantly elevated in people with bipolar disorder compared to normal controls, while IL-1B was not.
People with depression who had a few manic traits (mixed depression) were particularly likely to have insulin resistance and elevated levels of pro-inflammatory markers.
People with mixed depression have increases in inflammation and increased incidence of cardiovascular disorder. People experiencing a first episode of mixed depression who are overweight show increased signs of brain aging.
In studies McIntyre and colleagues analyzed, diabetes or pre-diabetes occurred in 50% of depressed patients, and these patients had the greatest amount of cognitive dysfunction.
Treatment
McIntyre noted that taking the antipsychotic drug lurasidone for bipolar depression worked best in both adults and children who had elevated levels of CRP at baseline. The fast-acting antidepressant ketamine also works well in those who show baseline inflammation .
The anti-diabetes drug liraglutide (Victoza, Saxenda) improves mixed depression symptoms and cognition in obesity, diabetes, and mixed depression. Liraglutide belongs to a class of drugs called glucagon-like peptide-1 (GLP-1) receptor agonists or incretin mimetics. They work by increasing insulin release from the pancreas and decreasing excessive glucagon release.
McIntyre now routinely uses liraglutide for cognitive deficits in patients with obesity or diabetes, including patients with mixed depression. It is injected under the skin at 0.6 mg daily, then the dosage is increased to 1.2 mg and then 1.8 mg. Victoza reduces major cardiovascular events in those with type 2 diabetes. The higher-dose Saxenda (3mg) can be used for weight control.
Another anti-diabetes drug, pioglitazine, has also been reported to be helpful in bipolar depression.
McIntyre found that the antibody infliximab, which can be used as an intravenous treatment for chronic inflammation and works by blocking the effects of TNF-alpha, did not improve depression, but did improve cognition.
McIntyre also supports the use of acetyl-L-carnitine, a potential adjunctive treatment that can reverse the insulin resistance that often occurs with obesity and thus could theoretically improve cognition.
McIntyre described preliminary literature suggesting the effectiveness of drugs such as statins, calcium channel blockers, and biguanides such as the diabetes treatment metformin in reducing inflammation.
Bariatric surgery to reduce the size of the stomach was another option discussed by McIntyre. He said the intervention is safe for patients with bipolar disorder and can help them recover cognitive function.
McIntyre noted that offspring of a mother with obesity have decreased response to sensory cues, reward preference, cognitive control, and motor control. Obesity and the inflammation that goes along with it apparently affect offspring via epigenetic mechanisms, meaning obesity may change the structure of inherited DNA (without changing its sequence).
Obesity Associated with Inflammation and Brain Abnormalities
At the 2019 meeting of the International Society for Bipolar Disorders, researcher David J. Bond reviewed the data on the multiple adverse effects of obesity in patients with bipolar disorder. These include increased cardiovascular risk, poorer response to treatment, brain abnormalities, and decreased cognitive function, which is correlated with the degree of overweight.
Editor’s Note: These data emphasize the importance of starting a nutritious diet early in life and sustaining it through adulthood, avoiding the drugs most associated with weight gain such as clozapine and olanzapine, and facilitating weight loss with drugs. There are several treatments that can aid in weight loss. One is the diabetes treatment metformin, starting at a high dose of 500mg twice daily, and increasing to 1000mg twice daily if tolerated. The anticonvulsants topiramate or zonisamide also promote weight loss. The most effective option is a combination of the antidepressant bupropion sustained release (at a dose of 150–300mg) plus the anti–substance abuse drug naltrexone (50mg). This combination was associated with a loss of 10% of body weight over 12 weeks in women with diabetes.
Adipokines May Be the Link Between Mood Disorders and Obesity
Researchers David J. Bond and Lakshmi Yatham think they may have identified why bipolar disorder and obesity occur so often together. In North America, more than 60% of people with bipolar disorder are overweight or obese, and obesity rates are 60% higher in people with bipolar disorder than in people without bipolar disorder.
Bond and Yatham hypothesized that adipokines might be responsible for both bipolar disorder and obesity. Adipokines are cell signaling proteins that regulate both mood and appetite. Abnormal levels of adipokines in blood could cause both mood episodes and weight gain.
The researchers measured blood levels of five adipokines (leptin, adiponectin, resistin, adipsin, and lipocalin-2) in 53 young people with bipolar disorder. They found three interesting links between adipokines, mood, weight, and medications, which they reported in the Journal of Clinical Psychiatry in 2017.
The first finding was that low levels of leptin and adiponectin (adipokines with antidepressant properties) predicted a greater risk of depressive relapse over a 12-month period. The second finding was that high levels of leptin and adipsin predicted greater weight gain over a 12-month period. The third finding was that treatment with second-generation antipsychotics, which often leads to weight gain and other metabolic side effects, was associated with higher levels of resistin, an adipokine linked to type 2 diabetes.
The findings about leptin were particularly interesting, because leptin’s appetite-regulating effects change with a person’s weight. In the study, low leptin predicted depression, while high leptin predicted weight gain. In people of normal weight, low leptin predicts weight gain, while in overweight or obese people, high leptin predicts weight gain. Bond and Yatham suggest that leptin’s mood-regulating effects may be more consistent, with low leptin increasing depression risk regardless of weight.
These findings may help researchers find ways of treating mood episodes that do not encourage weight gain.
Child Abuse Linked to Adolescent Obesity
New research clarifies how trauma in early life can lead to obesity in adolescence. In a study of 160 young people between the ages of 9 and 15, researcher Janitza Montalvo-Ortiz and colleagues identified seven sites in the genome where DNA methylation predicted body mass index (BMI) in adolescence. The researchers also collected information on family traumas that occurred during the participants’ childhoods and found that DNA methylation and family trauma such as child abuse interacted to predict BMI.
Epigenetics describes the ways life experiences can change how easily DNA is turned on or off. While the genes coded by DNA sequences one inherits from one’s parents never change, the structure of DNA can change. DNA methylation is one type of epigenetic change that refers to the addition of methyl groups to promoter regions of DNA in response to life events.
In this research, which was presented at the 2016 meeting of the Society of Biological Psychiatry, Montalvo-Ortiz and colleagues found that the site of DNA methylation with the strongest link to BMI in adolescence was a gene called MAP2K3. This gene had previously been linked to obesity, but this is the first time DNA methylation at this site has been linked to both obesity and childhood trauma. Other relevant gene sites where DNA methylation occurred include ANKRD2, CPXM2, NUBPL, and RFK.
Weight Gain is a Common Issue with Antidepressants, But Buproprion is an Exception
A 2016 study by researcher David Arterburn and colleagues in the Journal of Clinical Medicine suggests that taking an antidepressant for two years is associated with an increase in body weight. Luckily, bupropion (trade name Wellbutrin) is an exception that may be a good choice for obese or overweight patients.
The researchers analyzed links between which antidepressants patients in a large health system in Washington State were prescribed and their body weight two years later.
The researchers used fluoxetine (Prozac) as a reference. Most antidepressants did not differ significantly from fluoxetine in terms of the weight gain experienced by people taking the drug.
There were a few exceptions. Compared to non-smoking fluoxetine users, who gained an average of 4.6 pounds in two years, non-smoking bupropion users actually lost weight—an average of 2.4 pounds. (Smokers taking bupropion still gained an average of 6.9 pounds.)
Sertraline (Zoloft) was another exception. Sertraline users gained more than users of other antidepressants—an average of 10.5 pounds over two years.
Bad Habits May Reduce Brain Volumes, May Cause Dementia
Smoking, alcohol use, obesity, and diabetes aren’t just harmful to the body. They may actually lead to dementia.
Behavioral risk factors for cardiovascular disease like those listed above have been linked to reduced volume in the brain as a whole and several brain regions, including the hippocampus, precuneous, and posterior cingulate cortex. A 2015 study by researcher Kevin King and colleagues found that these reduced brain volumes are early indicators of cognitive decline.
King and colleagues analyzed data on 1,629 participants in the long-term Dallas Heart Study. Their cardiovascular risk factors were assessed when they began the study, and their brain volume and cognitive function were measured seven years later.
Alcohol use and diabetes were associated with lower total brain volumes, while smoking and obesity were linked to low volumes in the posterior cingulate cortex.
Low hippocampal volume was linked to past alcohol use and smoking, while lower precuneous volume was linked to alcohol use, obesity, and blood glucose levels.King and colleagues suggested that subtle differences in brain volumes in midlife are the first sign of developing dementia in participants who were still younger than 50 years of age.
