Shock-wave lithotripsy increases diabetes/hypertension risk

Caroline Cassels

April 11, 2006

April 11, 2006

Rochester, MN - Shock-wave lithotripsy (SWL), the preferred treatment for patients with renal calculi, significantly increases the risk of diabetes and hypertension, a new study has found [ 1 ].

Results from a retrospective study of 630 patients by researchers at the Mayo Clinic shows a more-than-threefold increased risk of diabetes and a 1.5-fold increased risk of hypertension among patients who underwent SWL 19 years previously compared with a cohort of matched, conservatively treated, nephrolithiasis patients.

"This is a completely new finding," said the study's lead author, Dr Amy Krambeck, in a Mayo Clinic statement. "It opens the eyes of the world of urology to the fact that hypertension and diabetes are potential side effects. We can't say with 100% certainty that shock-wave treatment for the kidney stones caused diabetes and hypertension, but the association was very strong."

The study is published in the May 2006 issue of the Journal of Urology.


In the blast path

The authors note there has been conflicting research over the link between SWL and hypertension?with one study reporting an association while two others found none.

"Lithotripsy is a relatively new treatment, and as a result, long-term studies on its potential effects have not been [done]. So this is what sparked our interest. We basically looked at every organ in the blast path of the machine and questioned the development of a potential disease process related to those specific organs 20 years after these patients were treated," Krambeck told renal wire .

The researchers conducted retrospective chart reviews on 630 patients who underwent SWL between January 1, 1985 to December 31, 1985 with a Dornier HM3 lithotriptor, a 1985 machine that is considered the gold standard in SWL but is not widely used today.

Median patient age was 52 and ranged from 18 to 90 years. The study included 218 females and 404 males. Stone location was 384 left, 295 right, and 57 bilateral. There were 541 renal solitary locations, 27 multiple locations, and 114 proximal ureteral stones. Questionnaires were sent to 578 SWL patients who were alive in 2004. The response rate was 58.9%. Preexisting diabetes, hypertension, and obesity were present in eight (2.8%), 28 (9.7%), and 74 (25.7%) patients, respectively.

Among the 288 controls, stone location was 148 left, 127 right, 232 renal, and 54 ureteral. In the control group, preexisting hypertension, diabetes, and obesity was found in 48 (16.7%), nine (3.1%), and 100 (35.3%) patients, respectively.

They report that the risk for both hypertension and diabetes was increased significantly among those treated with SWL.

Prevalence of diabetes and hypertension in SWL patients vs controls


Condition
Odds ratio
95% CI
p
Diabetes
3.23
1.73-6.02
<0.001
Hypertension
1.47
1.03-2.10
0.0034



To download table as a slide, click on slide logo below



Diabetes risk was related to the intensity of treatment and the number of administered shocks, whereas hypertension risk was related to bilateral treatment.


Don't throw baby out with the bathwater

Krambeck speculated that the association between SWL and diabetes may be due to soft-tissue damage to the pancreas. "It is possible the pancreas is catching some of the impact of the shock waves and sustaining some damage, which, in the long run, could lead to problems with insulin secretion and the development of diabetes. But at this point, this is only a theory," she said.

According to the researchers, the association between SWL and hypertension could be that "renal parenchymal or vascular changes related to SWL could contribute to the development of hypertension in the SWL group. This effect may be exacerbated by bilateral SWL treatments," they write.

At this point, said Krambeck, it would be a mistake to renounce SWL as a treatment modality. Clinicians, she said, should be aware of the study's findings and discuss the risks and benefits with their patients. In addition, she said, physicians whose patients opt for SWL should monitor them for early signs of diabetes and hypertension.

Click here to download the Powerpoint presentation.

Source

  1. Krambeck AE, Gettman MT, Rohlinger AL, et al. Diabetes mellitus and hypertension associated with shock wave lithotripsy of renal and proximal ureteral stones at 19-year follow-up. J Urol 2006; 175:1742-1747. Abstract

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