Positive association between the plasma levels of 5-hydroxyindoleacetic acid and the severity of depression in patients with chronic obstructive pulmonary disease

Table 2 Correlations between plasma monoamines levels and lung function, arterial blood gas parameters, and total SGRQ scores in the patients with COPD

	%FVC, %	%FEV₁, %	PaO₂, Torr	PaCO₂, Torr	Total SGRQ, units
5-HIAA, ng/mL	−0.36 (0.002)	−0.40 (<0.001)	−0.38 (<0.001)	0.26 (0.031)	0.33 (0.006)
5-HT, μg/mL	−0.09 (NS)	−0.08 (NS)	−0.17 (NS)	0.06 (NS)	0.10 (NS)
HVA, ng/mL	−0.36 (0.002)	−0.49 (<0.001)	−0.39 (<0.001)	0.09 (NS)	0.26 (0.029)
MHPG, ng/mL	−0.21 (NS)	−0.46 (<0.001)	−0.41 (<0.001)	0.25 (0.036)	0.40 (<0.001)

All correlation coefficients were expressed as r (p value).
Post-bronchodilator data for %FVC and %FEV₁ were used.
5-HIAA, 5-hydroxyindoleacetic acid; 5-HT, 5-hydroxytryptamine; HVA, homovanillic acid; MHPG, 3-methoxy-4-hydroxyphenylglycol; FVC, forced expiratory capacity; FEV₁, forced expiratory volume in 1 second; PaO₂, partial pressure of oxygen; PaCO₂, partial pressure of carbon dioxide; SGRQ, St. George’s Respiratory Questionnaire.

ISSN: 1471-244X