麻豆传媒

BOSTON -- Patients with diabetic nephropathy who had been using statins over the long term saw an increased risk of complications, according to research here, but important questions about their study remain.

Researchers analyzed data from more than 600 patients with type 2 diabetic nephropathy -- 190 of them on statin therapy -- in a hospital in Saudi Arabia, and found that those on statins were more likely to have one of four conditions versus those not on statins:

• Myocardial infarction: 31.1% versus 22.1% (P=0.0215)
• Cardiovascular accident: 22.6% versus 15.4% (P=0.0397)
• Background retinopathy: 30% versus 20.5% (P=0.0138)
• Cataracts: 46.3% versus 36.7% (P=0.0257)

"The present study reveals that long-term use of statin was associated with an increase incidence of diabetic complications in diabetic nephropathy patients," wrote authors , of King Saud University and , of King Khalid University Hospital, both in Riyadh. Their findings were presented in a poster presentation at the National Kidney Foundation meeting. "Further prospective randomized controlled trials are desired to see the long-term outcome of statin therapy," they added.

However, the results should be viewed with caution, according to , of the University of Alabama at Birmingham School of Medicine. She wrote in an email to 麻豆传媒 that the results came as a surprise because "statins have significant cardiovascular preventive benefits, and in this study, they did not confer any mortality benefit and, if anything, were associated with a higher risk of cardiovascular accidents." Rizk was not involved with the study.

At baseline, those on statins were less likely than those not on statins to be male (42.1% versus 50.8%, P=0.04), to have a longer duration of diabetes (16.6 years versus 15.02, P=0.0123), and to have a higher body mass index.

"The data should be interpreted with caution, of course, for its retrospective nature, but more importantly, for the fact that the two groups were not matched at baseline (with the higher BMI and longer duration of diabetes mellitus in the statin group making them a higher risk group)," Rizk pointed out.

A 2014 study found that statins were not associated with an increased risk of microvascular complications in diabetes patients, and might actually reduced microvascular complications. In addition, other research has shown that pretreatment with a statin was associated with a decreased risk of nephropathy in acute coronary syndrome patients.

All of the participants were nephropathy patients at some point from 1989 to 2006 at Security Forces Hospital in Saudi Arabia. The mean age of those on statins was 67, and they had an average BMI of 30 kg/m². The average duration of disease 16.6 years and the average duration of follow-up of 10.6 years.

The researchers also analyzed four other factors in statin and nonstain users, but the results were not statistically significant:

• Mortality: 14.2% versus 13.8% (P=0.8948)
• Foot infections: 7.4% versus 7.6% (P=0.9303)
• Neuropathy: 26.8% versus 25.1% (P=0.657)
• Proliferative retinopathy: 13.7% versus 11.7% (P=0.4954)

Other study limitations included the lack of clarity on how the authors defined diabetic nephropathy, Rizk noted. In addition, "proteinuria is a known risk factor for cardiovascular disease and should be accounted for in this analysis," she said.

There was also a lack of data on key factors that could have been relevant, including diabetes control and estimated glomerular filtration rate at baseline, "making this study flawed with potential bias," Rizk stated.

"In my mind, this study does not have the rigorous design of a retrospective study to raise concerns about statin use yet," he said. Al Wakeel did not respond to email requests from 麻豆传媒 for comment.

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