The relationship of plasma pyridoxine to psychological functioning, cognition, and immune functioning in HIV-1-infected and at-risk homosexual men

Date of Award




Degree Name

Doctor of Philosophy (Ph.D.)

First Committee Member

Karl Goodkin - Committee Chair

Second Committee Member

Mike Antoni - Committee Member


This study examined the relationship of pyridoxine status (deficient vs. adequate) to psychological, cognitive, and immunological functioning at a baseline measurement and longitudinally. Subjects included 84 HIV-1+ and 63 HIV-1-recently bereaved homosexual men. At baseline, subjects completed a psychosocial questionnaire, physical examination, and blood draw. Subjects were randomly assigned to either a ten week bereavement intervention group or a community comparison control group, and then completed a second assessment after the ten weeks were completed. At baseline, pyridoxine deficiency was a significant predictor of psychological distress, controlling for life stressors, social support, coping style, and HIV-1 serostatus. In post hoc analyses, pyridoxine status was associated with depressed, anxious, fatigued, and confused mood states. Longitudinally, change in pyridoxine status did not significantly predict change in psychological distress; however, when examining specific mood states in post hoc analyses, being pyridoxine deficient over time was associated with decreased vigorous mood and improvement in pyridoxine status from deficient to adequate was associated with increased anxious mood. Pyridoxine status was not significantly related to performance on the cognitive measures in this investigation at baseline or longitudinally. Pyridoxine deficiency at baseline was related to higher CD4 cell counts and tended to be related to lower natural killer cell cytotoxicity (NKCC), after controlling for HIV-1 serostatus and disease progression markers, as well as psychosocial variables. Normalization of pyridoxine status longitudinally was associated with increased total lymphocyte count and yielded a trend toward higher NKCC. Change from pyridoxine adequacy to pyridoxine deficiency was associated with greater lymphocyte proliferation to PHA. 5-HIAA levels were positively associated with natural killer cell kinetic lytic units at baseline, suggesting a possible role for serotonin as a mediating mechanism for the relationship between pyridoxine deficiency and alterations in immune functioning. Although associated in the predicted direction, 5-HIAA levels failed to achieve a significant relationship with the psychological distress variables or the other immune variables. The implications of the findings of the relationship between pyridoxine status and psychological and immune functioning for HIV-1 seropositive and seronegative individuals are discussed.


Health Sciences, Nutrition; Psychology, Clinical; Health Sciences, Immunology; Psychology, Physiological

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