Renal arteriosclerosis increases the risk for both renal composite and cardiovascular events in Japanese adults with type 2 diabetes and diabetic nephropathy regardless of the presence of hypertension, according to findings published in the Journal of Diabetes Investigation.
Miho Shimizu , MD, PhD, of the division of nephrology at Kanazawa University Hospital in Japan, and colleagues conducted a retrospective study of 185 adults with type 2 diabetes and diabetic nephropathy (mean age, 59 years; 32.4% women) who were diagnosed at Kanazawa University Hospital or Kanazawa Medical Center in Japan between 1985 and 2017.
Renal biopsies were performed at baseline to determine renal arteriosclerosis, which was scored for severity (0-2 with increasing severity). Additional baseline measurements included serum creatinine, estimated glomerular filtration rate, and systolic and diastolic blood pressure.
Four groups were established based on renal arteriosclerosis severity score and hypertension presence. Most participants were categorized by a score of at least 1 and hypertension (n = 103), followed by those with a score of at least 1 and normal-range BP (n = 68), those with no renal arteriosclerosis and normal-range BP (n = 9) and those with no renal arteriosclerosis and hypertension (n = 5). The group with no renal arteriosclerosis and normal-range BP was used as reference in comparisons.
During follow-up, the researchers were concerned with two primary outcomes: renal events and CV events. Renal events occurred when a participant needed dialysis or experienced a 30% drop in eGFR. CV events included CV death, nonfatal myocardial infarction, coronary intervention and nonfatal stroke.
There were 129 renal composite events and 55 CV events during an average follow-up of 7.6 years. Renal arteriosclerosis was found in 95.4% of participants with hypertension and 88.3% of participants with normal-range BP.
Among participants with renal arteriosclerosis, renal composite event incidence was higher for those with vs. without hypertension (P < .01). However, incidence of renal events was not significantly different for participants with no renal arteriosclerosis regardless of hypertension status.
Participants with renal arteriosclerosis and hypertension were at greater risk for renal events compared with the reference group (adjusted HR = 4.99; 95% CI, 1.98-12.54). Greater risk for renal events was also found for participants with renal arteriosclerosis and normal-range BP compared with the reference group (aHR = 3.21; 95% CI, 1.27-8.14).
No difference was found for participants with no renal arteriosclerosis and either normal-range BP or hypertension when it came to CV events. However, among those with a renal arteriosclerosis, hypertension was associated with a higher incidence of CV events than normal-range BP (P < .05).
The risk for a CV event was higher for participants with renal arteriosclerosis and hypertension (aHR = 10.02; 95% CI, 1.92-52.39) compared with the reference group and the group with a renal arteriosclerosis and normal-range BP (HR = 6.06; 95% CI, 1.24-29.61).
“These findings suggest that renal [arteriosclerosis] is not only directly associated with renal outcomes, but also with cardiovascular outcomes,” Shimizu and colleagues wrote. “The high prevalence of advanced renal [arteriosclerosis] among normal-range BP as well as [hypertension] highlights the importance of taking renal [arteriosclerosis] status into consideration when trying to reduce the burden of renal and cardiovascular outcomes in type 2 diabetes patients with diabetic nephropathy.” – by Phil Neuffer
Disclosures: The authors report no relevant financial disclosures.