Lithotripsy Linked to Diabetes and Hypertension Risk
By Judith Groch, MedPage Today Staff Writer
Reviewed by Robert Jasmer, MD; Assistant Professor of Medicine, University
of California, San Francisco
April 10, 2006
MedPage Today Action Points
Explain to patients that although the authors of this study warn about the
adverse effects associated with shockwave lithotripsy, they note that other
methods also have risks.
Urologists are advised to discuss the risks, benefits, and alternatives of
shockwave treatment with individual kidney stone patients.
Review
ROCHESTER, Minn., April 10 - Shockwave lithotripsy for renal stones
increased the risk of diabetes almost four-fold and that of hypertension
significantly compared with medical treatment, according to a 19-year
follow-up study at the Mayo Clinic.
To our knowledge, this is the longest follow-up of patients treated with
shockwave lithotripsy and the only study to demonstrate an association with
diabetes, said Amy Kranbeck, M.D., and colleagues in an April 10 online
report by the Journal of Urology.
In a chart review of 630 patients with renal and proximal ureteral calculi
treated with shockwave lithotripsy at Mayo in 1985, questionnaires were sent
to 578 patients alive in 2004. Respondents (288) were matched by age,
gender, and year of presentation with a cohort of nephrolithiasis patients
managed non-surgically.
Almost two decades later, multivariate analysis, controlling for change in
BMI, found that the risk of developing diabetes was 3.75 times that of
patients treated medically (95% CI 1.56, 9.02; P=0.003). Development of
diabetes was related to the number of shocks (P=0.005) and total intensity
of treatment (P=0.007). In the shock-wave group, 16.8% developed diabetes.
The risk of developing hypertension, after excluding patients with
pre-existing hypertension, was 1.47 times that of patients treated medically
(95% CI 1.03, 2.10; P=0.034). The development of hypertension correlated
strongly with bilateral treatments (P=0.033), but not with the total number
of shocks (P=0.620), average intensity (P=0.464), or total intensity
(P=0.693), the researchers said.
Diabetes in this group could be a result of damage to pancreatic islet
cells, a previously known risk of lithotripsy. The pancreas is in the blast
path of the lithotriptor, the researchers said, noting that advanced imaging
modalities have demonstrated microvascular damage to pancreatic tissue and
small hematomas after lithotriptor treatment.
The researchers speculated that the hypertension risk might be related to
parenchymal or vascular changes in the kidneys with the risk exacerbated by
bilateral treatments.
Hypertension following shockwave lithotripsy has been the subject of an
ongoing controversy since the late 1980s, Dr. Krambeck said, but subsequent
studies with follow-ups shorter than five years could not demonstrate these
effects on blood pressure.
Patients were treated with the Dornier HM3 lithotriptor, introduced in the
U.S. in 1984, and still considered the "gold standard," the researchers
said. Further studies with other lithotriptors should be done to determine
their respective long-term adverse medical effects, the researchers
suggested.
Co-author Joseph Segura, M.D., said that the Mayo urologists continue to use
shockwave treatment, among other alternative treatments, which also have
risks. These include percutaneous stone removal or ureteroscopy with laser
or ultrasound to break up the stones. About a million people in the U.S.
have had shockwave lithotripsy, he said.
"Despite the risks, shockwave therapy still can save the day for patients,
and it would be a mistake to put it on the shelf," Dr. Segura said. He
stressed the need for kidney stone patients and their physicians to weigh
the pros and cons of lithotripsy according to individual situations.
Primary source: Journal of Urology
Source reference:
Amy Krambeck, et al, "Diabetes Mellitus and Hypertension Associated with
Shock Wave Lithotripsy of Renal and Proximal Ureteral Stones at 19 Years
Followup," Journal of Urology, 2006, 4/10 online.
Regards,
Catherine
"Every science touches art at some points while
every art has its scientific side; the worst man
of science is he who is never an artist, and the
worst artist is he who is never a man of science."
[Armand Trousseau]
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