Cyclic nucleotides and catecholamines in rheumatoid arthritis

Area of Science:

• Biochemistry
• Rheumatology
• Endocrinology

Background:

• Rheumatoid arthritis (RA) is a chronic inflammatory disease.
• The metabolic effects of fasting on RA patients are not fully understood.
• Cyclic nucleotides and catecholamines play roles in inflammatory processes.

Purpose of the Study:

• To investigate the impact of total fasting on urinary cyclic nucleotide and catecholamine excretion in female RA patients.
• To correlate these biochemical changes with clinical improvements in RA symptoms.

Main Methods:

• A controlled cross-over study involving 12 female RA patients.
• Two periods: a control period (hospitalization with food) and a fasting period (7 days total fast).
• Daily monitoring of urinary cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), epinephrine (E), and norepinephrine (NE); clinical assessment using Ritchie's index every two days.

Main Results:

• Clinical and laboratory measures of inflammation improved significantly during fasting.
• Urinary cAMP levels decreased, while E and NE levels increased significantly during fasting.
• Urinary cGMP initially decreased but returned to pre-fasting levels; the cAMP/cGMP ratio increased, peaking on days 2-3 of the fast, coinciding with maximal clinical improvement.

Conclusions:

• Total fasting positively impacts clinical status and inflammatory markers in RA patients.
• Fasting induces significant changes in cyclic nucleotide and catecholamine excretion patterns.
• The observed biochemical alterations may contribute to the anti-inflammatory and clinical benefits of fasting in RA.