Dr. Ron’s Research Review – September 28, 2016

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This week’s research review focuses on Cyclooxygenase Inhibitors and B6

 

A study found that the clinical use of cyclooxygenase inhibitors impairs vitamin B-6 metabolism. (Chang et al., 2013)

The cross-sectional study involved 150 rheumatoid arthritis patients, with and without cyclooxygenase inhibitor treatments. Patients who were taking cyclooxygenase inhibitors had lower circulating pyridoxal-5'-phosphate, especially those taking NSAIDs >6 mo.

 

 

Plasma vitamin B-6 RA-COX, no use
(n = 26)
RA+COX ≤ 6 mo
(n=32)
RA+COX > 6 mo
(n=89)
PLP (nM) 42.3 (39.6, 73.8) 35.1 (34.5, 64.9) 29.1 (33.9, 44.9)
Pyridoxal (nM) 15.1 (12.3, 19.8) 17.1 (16.3, 33.7) 15.9 (15.9, 26.1)
PLP:pyridoxal 3.21 (2.80, 4.39) 2.32 (1.97, 3.43) 2.02 (2.12, 2.84)
Homocysteine (mM) 6.67 (6.50, 8.74) 6.45 (6.15, 8.19) 6.48 (6.47, 7.62)


This study further raises concerns about the long-term clinical use of antiinflammatory NSAIDs in humans. Vitamin B-6 status should be carefully monitored in long-term NSAID users.

 

 

Dr. Ron


 

Articles

Clinical use of cyclooxygenase inhibitors impairs vitamin B-6 metabolism.
            (Chang et al., 2013) Download
BACKGROUND:  A low circulating vitamin B-6 concentration, which is an independent risk factor for cardiovascular disease, is commonly seen in human inflammation. OBJECTIVE:  We investigated whether cyclooxygenase inhibitors alter vitamin B-6 metabolism. DESIGN:  To investigate whether subjects taking a cyclooxygenase inhibitor had an altered vitamin B-6 profile, we conducted a cross-sectional study that involved 150 rheumatoid arthritis patients, with and without cyclooxygenase inhibitor treatments. C57BL/6J mice and hyperlipidemic Syrian hamsters received drug regimens that reflected clinical nonsteroidal antiinflammatory drug (NSAID) uses in treating human inflammation. The impact of long-term physiologic use of selective and nonselective cyclooxygenase inhibitors on vitamin B-6 metabolism was systematically investigated in these independent in vivo models. RESULTS:  Patients who were taking cyclooxygenase inhibitors had lower circulating pyridoxal-5'-phosphate, especially those taking NSAIDs >6 mo. Long-term celecoxib and naproxen use reduced hepatic pyridoxal-5'-phosphate in mice. Nonselective cyclooxygenase inhibitor naproxen significantly decreased vitamin B-6 vitamers in the kidney. CONCLUSIONS:  To our knowledge, we show novel findings that long-term physiologic doses of cyclooxygenase inhibitor may impede the synthesis of the coenzymatically active form of vitamin B-6. Because the cause of vitamin B-6 depletion in inflammation remains unknown, this study provides a potential mechanism that could account for the poor vitamin B-6 status in human inflammation. Moreover, this study further raises concerns about the long-term clinical use of antiinflammatory NSAIDs in humans. Vitamin B-6 status should be carefully monitored in long-term NSAID users. Future randomized placebo-controlled studies are needed to determine the impacts of antiinflammatory cyclooxygenase inhibitor use on vitamin B-6 metabolism in humans.

 

References

Chang, HY, et al. (2013), ‘Clinical use of cyclooxygenase inhibitors impairs vitamin B-6 metabolism.’, Am J Clin Nutr, 98 (6), 1440-49. PubMed: 24153347