Diligence associated with better cardiovascular outcomes in type 2 diabetes patients

People with type 2 diabetes, who display lower levels of diligence, may have a significantly higher risk of developing cardiovascular disease with which diabetes is strongly associated, finds research published in the open access journal BMJ Open Diabetes Research & Care.

While certain personality traits may influence cardiovascular disease risk, adopting a healthy lifestyle is still beneficial, irrespective of diligence level, the findings show.

Effective management of type 2 diabetes requires keeping up healthy lifestyle behaviors and following a strict medication regimen, so the influence of personality traits on cardiovascular disease risk might therefore be considerable, suggest the researchers.

To explore this further, they tracked the health of 8794 people with type 2 diabetes, who had enrolled in the UK Biobank study between 2006 and 2010, until the end of 2021.

Participants' personalities and psychological disposition were assessed using the Big Five traits of: extraversion; agreeableness; conscientiousness; openness; and neuroticism. 

As the UK Biobank study doesn't collect data on direct measures of these traits, proxies were created using self-reported information on mental health, psychological factors, and social support. These proxies were sociability, warmth, diligence, curiosity, and nervousness.

During an average monitoring period of around 13 years, 2110 people developed cardiovascular disease. 

Diligence was associated with a significantly lower risk of developing any type of cardiovascular disease, even after accounting for potentially influential factors. People displaying this trait were 7% less likely to experience any kind of cardiovascular event during the tracking period. 

And they were 10% less likely to have a heart attack, 17% less likely to have a stroke caused by a blood clot (ischaemic stroke), 8% less likely to have atrial fibrillation (irregular heart rhythm), and 16% less likely to develop heart failure.

They were also more likely to have a healthy lifestyle than those who didn't display this trait. But irrespective of diligence level, those with healthy lifestyle behaviors had better cardiovascular outcomes than those with unhealthy lifestyle behaviors.

Diligence is a proxy for conscientiousness and characterized by resourceful, disciplined, and organized behavior, which is reflected in several traits such as orderliness and industriousness. Previously published studies have suggested that people with this trait are less likely to smoke and are more likely to be physically active, explain the researchers.

This is an observational study, and as such, can't establish cause and effect. The researchers also acknowledge various limitations to their findings. For example, psychological factors, such as depression and anxiety, are known to be associated with cardiovascular disease, but their role couldn't be comprehensively evaluated in this study. 

And information wasn't available on potentially influential lifestyle factors, such as alcohol consumption, diet, and sleep patterns, or on rates of treatment compliance. Participants in the UK Biobank study are also predominantly White so the findings may not be applicable to other ethnicities.

Nevertheless, the researchers conclude: "Among personality traits, a lower diligence level was significantly associated with a higher risk of cardiovascular diseases, including myocardial infarction [heart attack], ischaemic stroke, atrial fibrillation, and heart failure, in patients with type 2 diabetes."

They add: "Unhealthy lifestyle behaviors were more prevalent in patients with low than high diligence scores. However, healthy lifestyle factors had a protective association with cardiovascular diseases in both groups of patients. 

"These findings highlight the importance of assessing personality traits for cardiovascular risk prediction and modifying lifestyle factors as preventive strategies for patients with type 2 diabetes."