Global arginine bioavailability ratio is decreased in patients with major depressive disorder

Abstract

IntroductionThe global arginine bioavailability ratio (GABR) is used to estimate arginine supply. Arginine is precursor to nitric oxide (NO) that has been suggested to play a role in major depressive disorder (MDD). NO also participates in neuronal, inflammatory and cardioprotective functions.ObjectivesTo compare GABR between:– D patients and non-depressed controls;– remitted and non-remitted MDD patients;– baseline and follow-up within remitted and non-remitted MDD groups.AimsTo investigate the role of NO production in MDD.MethodsThe sample comprised 99 MDD patients and 253 non-depressed controls (Beck Depression Inventory scores < 10) aged 20–71 years. Altogether, 78 patients returned for the follow-up; 33 were remitted and 45 non-remitted. GABR was calculated from serum levels of arginine, citrulline and ornithine, which were analysed using ultra-performance liquid chromatography. Differences between the study groups were examined using logistic regression adjusted for age, gender, smoking, alcohol use, physical exercise and glycated haemoglobin. The follow-up regression analyses were adjusted for age, gender and physical exercise.ResultsLowered GABR was associated with belonging to the MDD group (OR 0.13, 95% CI 0.03–0.50). Exclusion of participants using anti-depressants that were associated with measured metabolites did not change the results. Over the follow-up period, the remitted and non-remitted groups both showed an increase in GABR (Z = –.53, P < 0.001 and Z = –3.00, P = 0.003, respectively).ConclusionsDecreased GABR may characterise MDD. This could affect neuronal, immunological and cardioprotective functions of NO.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Arginine deficiency measured by global arginine bioavailability ratio in patients with acute coronary syndrome

“…The global L-arginine bioavailability ratio (GABR), defined as the ratio of the level of L-arginine to the sum of its major metabolite levels (L-arginine/[L-citrulline + Lornithine]), has been reported as an index of arginine bioavailability in various clinical settings [9][10][11][12][13][14] , including stable coronary artery disease (CAD) 15,16) . In acute coronary syndrome (ACS), GABR was reported to be lower in patients with cardiogenic shock due to acute myocardial infarction than in patients with stable CAD 17) .…”

A Low Arginine/Ornithine Ratio is Associated with Long-Term Cardiovascular Mortality

“…This phenomenon has been termed the "arginine paradox" 15) . The global l-arginine bioavailability ratio (GABR) 16) , defined as the ratio of l-arginine levels to the sum of its major metabolite levels (l-arginine / [l-citrulline＋ l-ornithine]), is an important indicator in a variety of clinical situations, including stable coronary artery disease (CAD) [17][18][19][20][21][22][23][24] . Patients with cardiogenic shock due to acute myocardial infarction (AMI) have been reported to have a lower GABR compared with patients with stable CAD 25) .…”