Cardiorenal Outcomes Differ Between Type 1 and Type 2 Diabetes

Sara Freeman

October 26, 2021

While type 2 diabetes is associated with a greater risk for cardiovascular events than type 1 diabetes, the latter is more associated with chronic kidney complications, according to data from a French observational study.

That's not to say that type 1 diabetes isn't also associated with poor heart health that is of concern, according to Denis Angoulvant, MD, of Tours (France) Regional University Hospital and Trousseau Hospital in Paris.

"The difference is that, in the middle or older ages, we suddenly see a surge of cardiovascular events in type 1 diabetic patients," he said at the annual meeting of the European Association for the Study of Diabetes. "As a cardiologist, I must say that we are barely seeing these patients ahead of those complications, so we advocate that there's a gap to be filled here to prevent these events in these patients."

Few studies have looked at the comparative risks for cardiovascular and renal outcomes between patients with type 1 and type 2 diabetes, Angoulvant said, so the aim of the study he presented was to look at this in more detail.

Comparing Cardiovascular and Renal Outcomes

Data from the French hospital discharge database (PMSI), which covers more than 98% of the country's population, were used to find all adults with type 1 or type 2 diabetes who had at least 5 years of follow-up data starting from 2013.

Not surprisingly, there were eight times as many individuals with type 2 diabetes (425,207) than those with type 1 diabetes (50,623), and patients with type 2 diabetes tended to be older than those with type 1 diabetes (mean age, 68.6 vs. 61.4 years).

There were many significant differences between the two groups of patients in terms of clinical variables, such as patients with type 2 diabetes having more cardiovascular risk factors or preexisting heart problems, and those with type 1 diabetes more likely to have diabetic eye disease.

Indeed, Angoulvant pointed out that those with type 2 diabetes were significantly more likely (all P < .0001) than those with type 1 diabetes to have: hypertension (70.8% vs. 50.5%), heart failure (35.7% vs. 16.4%), valvular heart disease (7.2% vs. 3.5%), dilated cardiomyopathy (5.5% vs. 2.7%), coronary artery disease (27.6 vs. 18.6%), previous MI (3.0% vs. 2.4%), peripheral vascular disease (22.0% vs. 15.5%), and ischemic stroke (3.3 vs. 2.2%).

"Regarding more specific microvascular diabetic complications, we had a higher incidence of chronic kidney disease in type 2 diabetes patients [10.2% vs. 9.1%], but a higher incidence of diabetic retinopathy in type 1 diabetes patients [6.6% vs. 12.2%]," Angoulvant said.

Considering more than 2 million person-years of follow-up, the annual rates of MI, new-onset heart failure, ischemic stroke, and chronic kidney disease for the whole study population were respective 1.4%, 5.4%, 1.2%, and 3.4%. The annual rate for death from any cause was 9.7%, and for a cardiovascular reason was 2.4%.

Cardiovascular Disease Prevalence and Event Rates

The mean follow-up period was 4.3 years, and over this time the age- and sex-adjusted prevalence of cardiovascular disease was found to be highest in individuals with type 2 diabetes, especially after the age of 40 years.

Looking at the rates of different cardiovascular events showed that both younger (18-29 years) and older (60+ years) people with type 1 diabetes had a 1.2-fold higher risk for MI than similarly aged individuals with type 2 diabetes.

Furthermore, younger and older type 1 diabetes individuals had a 1.1- to 1.4-fold greater risk of new-onset heart failure than those with type 2 diabetes.

"Interestingly, regarding the incidence of ischemic stroke in our population, we found no significant difference between patients with type 1 diabetes, and patients with type 2 diabetes," Angoulvant said.

Chronic Kidney Disease and Risk for Death

Chronic kidney disease was most common in individuals with type 1 diabetes who were aged between 18 and 69 years, with a greater prevalence also seen in those with type 2 diabetes only after age 80.

The risk of new chronic kidney disease was significantly increased in patients with type 1 diabetes, compared with patients with type 2 diabetes, with a 1.1- to 2.4-fold increase seen, first in individuals aged 18-49 years, and then again after the age of 60 years.

Angoulvant reported that the risk of dying from any cause was 1.1-fold higher in people with type 1 diabetes, compared with those with type 2 diabetes, but after the age of 60 years.

The risk of death from cardiovascular events was also increased in people with type 1 diabetes, but between the ages of 60 and 69 years.

Asked what his take-home message might be, Angoulvant stressed the importance of heart failure, in all patients with diabetes but particularly in those with type 1 diabetes.

"I think there is room for improvement in terms of assessing who is going to have heart failure, how to assess heart failure, and more importantly, how to prevent heart failure," perhaps by "introducing those drugs that have shown tremendous benefit regarding hospitalization, such as [sodium-glucose transporter 2] inhibitors" in patients with type 1 diabetes ahead of the events, he said.

Angoulvant had no conflicts of interest to disclose.

This article originally appeared on, part of the Medscape Professional Network.


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