Background: Currently, there is no specific therapy for chronic pancreatitis (CP). The treatment
of micronutrient antioxidant therapy for painful CP has been sporadically used for more than 30
years, however, its efficacy are still poorly understood.
Objective: The purpose of this meta-analysis is to investigate the safety and efficacy of
antioxidant therapy for pain relief in patients with CP.
Setting: University Hospital in China
Study Design: Systematic review and meta-analysis
Methods: Two authors independently reviewed the search results and extracted data and
disagreements were resolved by discussion. Effects were summarized using standardized mean
differences (SMDs), weighted mean differences, or odds ratio (OR) according to the suitable effect
model. MEDLINE, PsycINFO, Scopus, EMBASE, and the Cochrane Central Register of Controlled
Trials were searched from 1980 through December 2012. Randomized controlled trials (RCTs)
that studied antioxidant supplementation for pain relief in patients with CP were analyzed.
Results: Nine randomized controlled trials (RCTs) involving 390 patients were included. Overall,
there was no association of antioxidant therapy with pain reduction in CP patients (SMD, −0.55;
95% CI, −1.22 to 0.12; P = 0.67). However, antioxidant therapy significantly increased blood
levels of antioxidants in CP patients versus the placebo group (SMD, 1.08; 95% CI, 0.74 to 1.43;
P < 0.00001). Interestingly, combined antioxidant (selenium, β-carotene, vitamin C, vitamin E,
methionine) therapy was found to be associated with pain relief (SMD, -0.93; 95% CI, -1.72 to
-0.14; P = 0.02), while the trials in which a single antioxidant was used revealed no significant
pain relief (SMD, -0.12; 95% CI, -1.23 to 0.99; P = 0.83) in CP patients. Strong evidence was
obtained that the antioxidants increased adverse effects (OR, 6.09; 95% CI, 2.29 to 16.17, P <
0.01); nevertheless, none was serious.
Limitations: Because of the small sample, a consolidated conclusion cannot be reached based
on current RCTs. Large-sample RCTs are needed to clarify the analgesic effect of antioxidants in
CP patients.
Conclusions: Combined antioxidant therapy seems to be a safe and effective therapy for pain
relief in CP patients. Measures of total antioxidant status may not help to monitor the efficacy of
antioxidant therapy for patients with CP.
Key words: Antioxidant, pain, chronic pancreatitis, meta-analysis
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