Vascular Complications Big Contributor to Diabetes Deaths

SEATTLE -- There's been an uptick in diabetes-related deaths due to certain vascular complications over the past two decades, according to late-breaking findings presented here.

According to National Vital Statistics System data from 2001 to 2020, there were a total of 4,957,211 diabetes-related deaths among U.S. adults, said Omolara Adeniran, MD, of SUNY Downstate Medical Center University Hospital in New York City.

Of these deaths, more than 38% -- representing over 1.9 million deaths -- were attributed to micro- or macro-vascular complications, Adeniran said at the American Association of Clinical Endocrinology (AACE) annual meeting.

These fatal vascular complications have only become more common in recent years. In fact, there was a 6.8% (95% CI 3.8-9.8, P<0.0001) increase in the annual average percentage change (AAPC) in vascular complications over these two decades.

This was largely driven by the upswing in renal complications, Adeniran pointed out, which included diabetic nephropathy, intracapillary glomerulonephritis, and Kimmelstiel-Wilson syndrome. Of deaths due to vascular complications, 71.1% had renal complications, representing over 1.3 million cases.

Between 2001 and 2020, there was a 14.9% increase in AAPC each year in nephropathy-related death. When broken down by years, there was a slow but significant uptick seen between 2001 and 2009 (8.8% AAPC), followed by a "drastic increase" between 2009 and 2013, marked by a 62.5% annual percent change. But after 2013, nephropathy deaths steadied, with only a small and insignificant increase each year through 2020.

"It's still gradually increasing," Adeniran warned. "It hasn't dropped yet. Even though it did not spike like during the period of 2009 to 2013."

Although it looks relatively stable over the past few years, she added: "In what direction this is going to take? We do not know. We hope that it's going to come down."

"This is a wake-up call that we should focus and we should monitor patients who are diabetic and have elevated microalbuminuria or they have high blood pressure," Adeniran recommended, underscoring the importance of specifically monitoring the kidneys. "End-stage renal disease has been seen as also one of the common causes of death in [patients with diabetes]."

"The increased trend of diabetic nephropathy-related deaths may partly be explained by the growing prevalence of diabetes," she said, adding that about 40% of patients with diabetes go on to develop kidney disease.

Peripheral circulatory complications were the second most common vascular-related cause of death in people with diabetes, accounting for 27.1% of cases (515,293 cases). These included things like gangrene, peripheral angiopathy, and ulcers. Cases of peripheral circulatory complications steadily declined throughout the past two decades, significantly dropping by 3.1% (95% CI -3.7 to -2.6%, P<0.0001) every year.

Far less common were deaths due to diabetic neuropathy (1.5% of deaths, 28,697 cases) or diabetic retinopathy (0.3% of deaths, 5,751 cases).

Cases of diabetic-related neuropathy were generally stable leading up to 2005, but then started on a steady and significant incline through 2020 (4.7% annual percent change, P<0.0001). These included amyotrophy, autonomic neuropathy, mononeuropathy, and polyneuropathy.

And following a similar pattern, cases of diabetic retinopathy were generally stable from 2001 to 2007, but started to take a significant step up thereafter through 2020 (6.2% annual percent change, P<0.0001). This included cases of retinopathy and cataracts related to diabetes.

Diabetes mortality and subsequent vascular complications were accounted for using ICD-10 codes. People with all forms of diabetes were included: type 2 diabetes (29.7% of cases), type 1 diabetes (4.2%), malnutrition-related diabetes (0.02%), and unspecified (66.1%).

Some limitations included an inability to separate out age, sex, and racial differences among vascular complications and deaths, though Adeniran said future studies should look at this.

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