Depression and heart disease – at first glance, they may seem like two very different health issues. But a growing body of research suggests that these conditions are more closely connected than we once thought. A recent study from Finland has taken a deep dive into the complex relationship between depression and cardiovascular health, and the findings are shedding new light on how our genes may be the key to unlocking this mystery.
The study, published in the journal Frontiers in Psychiatry, analyzed data from nearly 900 participants in the Young Finns Study, a long-term research project that has followed the health of Finnish children and adolescents since 1980. Now in their 30s and 40s, these participants provided a unique opportunity for scientists to examine the genetic underpinnings of both mental and cardiovascular health.
So how exactly did the researchers go about this? They started by looking at two specific markers: the Beck’s Depression Inventory (BDI-II) score, which measures symptoms of depression, and the American Heart Association’s cardiovascular health (CVH) metrics, which take into account factors like smoking, diet, physical activity, body mass index, blood pressure, cholesterol, and blood sugar. By analyzing the participants’ whole blood transcriptome – essentially, a snapshot of which genes are turned “on” or “off” at a given time – the scientists were able to identify patterns of gene expression that were linked to both depression and cardiovascular health.
Imagine your genes as a vast library, with each book containing the instructions for a specific protein in your body. The transcriptome is like a catalog of which books are currently being read and used to make those proteins. By comparing the transcriptomes of people with different BDI-II scores and CVH metrics, the researchers were able to pinpoint a specific “gene module” – a group of genes that work together – that was significantly associated with both depression and cardiovascular health.
This gene module, dubbed the “darkred” module by the researchers (a name automatically assigned by the analysis software), contained 256 genes that were co-expressed, meaning they tended to be turned on or off together. Interestingly, many of these genes are involved in processes that have been previously linked to brain disorders like Alzheimer’s, Parkinson’s, and Huntington’s disease, as well as inflammation and energy production in cells.
Among the top genes in the module were YOD1, RBX1, and LEPR. YOD1 and RBX1 are part of the ubiquitin-proteasome system, which acts as the cell’s waste disposal, breaking down and recycling damaged or unneeded proteins. Dysregulation of this system has been implicated in neurodegeneration and inflammation. LEPR, on the other hand, encodes the receptor for the hormone leptin, which plays a key role in regulating appetite, metabolism, and immune function. Leptin resistance has been linked to obesity, diabetes, and cardiovascular disease, as well as depression.
“The top three genes from this gene module are known to be associated with neurodegenerative diseases, bipolar disorder, and depression. Now we have shown that they are associated with poor cardiovascular health as well,” says first study author Dr. Binisha H Mishra, a postdoctoral researcher at Tampere University, in a media release.
So what does all of this mean for the average person? While more research is needed to fully understand the implications of these findings, they suggest that there may be shared biological pathways underlying both depression and cardiovascular disease. This could potentially lead to new ways of predicting, preventing, and treating these conditions.
For example, if we can identify people who are genetically predisposed to both depression and heart disease, we may be able to intervene earlier with lifestyle changes, medications, or other therapies to reduce their risk. On the flip side, treating depression could potentially have benefits for cardiovascular health as well.
“We can use the genes in this module as biomarkers for depression and cardiovascular disease,” concludes Dr. Mishra. “Ultimately, these biomarkers may facilitate the development of dual-purpose preventative strategies for both the diseases.”
Of course, our genes are just one piece of the puzzle. Environmental factors like stress, diet, and physical activity also play a significant role in both mental and cardiovascular health. But by understanding the complex interplay between our genes and our environment, we can begin to develop a more holistic approach to health and wellbeing.
