The Effects of Soy Protein on Post-thoracotomy Pain

The Effects of Soy Protein Supplementation on Post-thoracotomy Pain

This study seeks to determine whether soy protein supplements reduce the pain that often occurs following surgery for a lung tumor. Patients are randomized to receive either soy protein or milk protein prior to and following a thoracotomy for a lung tumor. We are especially interested in pain severity and pain medication use following surgery and will measure function and quality of life.

Study Overview

• Status: Withdrawn
• Conditions: Pain; Thoracotomy
• Intervention / Treatment: Procedure: Soy protein

Detailed Description

Preclinical studies indicate that soy-containing diets suppress the development of pain behaviors and hyperalgesia seen following nerve injury and recent data indicate a similar protective effect of a diet high in soy protein in inflammatory and bone cancer pain models. These studies further indicate that soy exposure is only protective when administered in the period immediately preceding injury. Very few studies have directly studied the effects of soy-containing diets on pain sensitivity in humans, but one recent randomized clinical trial suggests that dietary soy supplementation may reduce pain due to osteoarthritis. The proposed study will examine whether a soy protein supplement reduces the pain commonly experienced following thoracotomy for lung surgery. This is a useful clinical model for studying the effects of soy protein supplementation on pain because the pain associated with surgery is quite severe and is one of the greatest concerns patients have about undergoing surgery. The growing recognition that greater acute pain leads to persistent pain following tissue healing underscores the importance of identifying viable strategies, including both non-pharmacological as well as pharmacological, for reducing the acute pain associated with surgery. Using a 2 group (soy protein supplementation vs. matched milk placebo supplementation) design, patients undergoing elective major open thoracotomy for segmentectomy, lobectomy, or bilobectomy will be randomly assigned to one of these two treatment groups. Patients will begin taking the soy/placebo supplement 2-3 days prior to thoracotomy and continue daily consumption of the supplement for an additional period following surgery. The feasibility/pilot study will examine the effects of soy supplementation on outcome measures during three post-operative time periods: 1) the immediate post-operative period; 2) during 2-12 weeks following surgery; and 3) during 14-24 weeks following surgery. Pain is the primary outcome domain of interest in this pilot study and measures will include pain severity ratings and pain medication use. Function and quality of life are the secondary outcome domains of interest and measures will include pain-related interference with daily activities, sleep, and health-related quality of life. Outcome measures will be collected bi-weekly throughout the study. The study aims to determine the feasibility and acceptability of soy supplementation in the period surrounding thoracotomy, determine level of adherence to soy supplementation over the 6-month period of follow-up, and estimate the effect size of soy supplementation relative to placebo in reducing significant pain following thoracotomy. The proposed study will provide the necessary groundwork to move towards such a larger randomized trial to evaluate the pain-reducing effects of soy protein supplementation following thoracotomy.

• Study Type: Interventional
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21205
      • Johns Hopkins Medical Institutions

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion criteria: 1) undergoing major elective thoracotomy through a classic incision, including segmentectomy, lobectomy, or wedge resection, 2) for women, a negative mammogram within the past year; 3) for women using oral contraceptives or hormone replacement therapy, the agreement to hold steady dosing of these medications for the duration of the study; and 4) ability to comprehend the consent information and to complete all study assessments.

Exclusion criteria: 1) age less than 18 years, 2) current alcohol or substance abuse/dependence; 3) delirium, dementia, or cognitive impairment (MMSE < 24; (23)); 4) use of analgesics (other than aspirin or non-steroidal anti-inflammatories) for a condition other than the reason for surgery; 5) milk or soy allergy; 6) lactose intolerance; 7) pre-operative chest pain; 8) women with a history of breast cancer; or 9) [use of an antibiotic within 3 months prior to surgery.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

What is the study measuring?

Primary Outcome Measures

Outcome Measure
pain severity
pain medication use

Secondary Outcome Measures

Outcome Measure
function
health-related quality of life

Collaborators and Investigators

• Sponsor: National Center for Complementary and Integrative Health (NCCIH)
• Investigators: Principal Investigator: Jennifer A. Haythornthwaite, Ph.D., Johns Hopkins University

Study record dates

Study Major Dates

• Study Start: March 1, 2006
• Primary Completion (Actual): March 1, 2010
• Study Completion (Actual): March 1, 2010

Study Registration Dates

• First Submitted: June 23, 2006
• First Submitted That Met QC Criteria: June 23, 2006
• First Posted (Estimate): June 26, 2006

Study Record Updates

• Last Update Posted (Estimate): March 22, 2013
• Last Update Submitted That Met QC Criteria: March 21, 2013
• Last Verified: March 1, 2013

More Information

Terms related to this study

• Keywords: pain; thoracotomy; soy protein
• Other Study ID Numbers: R21 AT003613