Pain intensity, illness duration, and protein catabolism in temporomandibular disorder patients with chronic muscle pain.

Abstract

AIMS:

To investigate whether the duration of chronic pain in temporomandibular disorder (TMD) patients is associated with a net depletion of amino acids, and a distinct process from pain intensity.

METHODS:

Twenty-nine patients defined by the research diagnostic criteria/TMD as having Type 1a muscle pain (TMD1A group), and 34 age- and sex-matched control subjects, were assessed for variation in urinary organic and amino acid excretion by gas chromatography-mass spectrometry.

RESULTS:

The TMD1A patients' mean pain intensity, assessed on a visual analog scale (VAS), was 5.4 (95% confidence limits: 4.5 to 6.3), TMD1A illness duration was 5.0 +/- 1.2 (SD) years, number of body areas with pain/subject was 6.3 +/- 2.4 (range 0 to 10), and symptom prevalence from the Symptom Check List-90-Revised (SCL-90-R) was 25.5 +/- 11.3 symptoms/subject, which was higher than the controls (5.2 +/- 5.0 symptoms/subject, P < .001). TMD1A patient illness duration was positively correlated with symptom prevalence and body pain distribution, and all were independent of pain intensity. The TMD1A patients had: (1) and increased tyrosine:leucine ratio; and (2) reduced leucine concentrations (both P < .001), which suggests deregulated catabolism. Pain intensity was associated with: (1) changes in the multivariate urinary metabolite excretion patterns (P < .001); (2) reduced leucine concentrations (P < .001); and (3) increases in total urinary metabolites (P < .04), and in 2 unidentified molecules, UM28 (P < .001) and CFSUM1 (P < .002). TMD1A illness duration was associated with lower (1) urinary metabolite concentrations and (2) succinic acid and combined glutamine + glutamic acid levels, suggesting a progressive depletion of metabolite reserves.

CONCLUSION:

In TMD1A patients, total amino acid excretion was positively correlated with pain intensity and negatively correlated with illness duration, which indicated that illness duration was associated with a different set of metabolic anomalies compared with those identified for pain intensity.

• Authors: Neil R McGregor, Mariann Zerbes, Suzanne H Niblett, R Hugh Dunstan, Timothy K Roberts, Henry L Butt, Iven J Klineberg
• Journal: Journal of orofacial pain (J Orofac Pain) Vol. 17 Issue 2 Pg. 112-24 ( 2003) ISSN: 1064-6655 [Print] United States
• PMID: 12836499 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Amino Acids
• Glutamine
• Glutamic Acid
• Tyrosine
• Succinic Acid
• Leucine

Topics

• Adult
• Amino Acids (urine)
• Case-Control Studies
• Chi-Square Distribution
• Chronic Disease
• Cohort Studies
• Confidence Intervals
• Facial Pain (metabolism, physiopathology)
• Female
• Gas Chromatography-Mass Spectrometry
• Glutamic Acid (urine)
• Glutamine (urine)
• Humans
• Leucine (urine)
• Male
• Pain Measurement
• Protein Denaturation
• Succinic Acid (urine)
• Temporomandibular Joint Disorders (metabolism, physiopathology)
• Time Factors
• Tyrosine (urine)