Tryptophan Intake and Metabolism in Older Adults with Mood Disorders.

Cezary Chojnacki,Tomasz Popławski,Paulina Konrad,Janusz Blasiak,Michał Fila,Jan Chojnacki

doi:10.3390/nu12103183

Abstract

The role of serotonin in the pathogenesis of depression is well-documented, while the involvement of other tryptophan (TRP) metabolites generated in the kynurenine pathway is less known. The aim of this study was to assess the intake and metabolism of TRP in elderly patients with mood disorders. Ninety subjects in three groups, 30 subjects each, were enrolled in this study: controls (healthy young adults, group I) and elderly individuals without (group II) or with (group III) symptoms of mild and moderate depression, as assessed by the Hamilton Depression Rating Scale (HAM-D) and further referred to as mood disorders. The average TRP intake was evaluated with the nutrition calculator. Urinary levels of TRP, 5-hydroxyindoleacetic acid (5-HIAA), L-kynurenine (KYN), kynurenic acid (KynA), xanthurenic acid (XA), and quinolinic acid (QA) were determined by liquid chromatography with tandem mass spectrometry and related to creatinine level. The average daily intake of TRP was significantly lower in group III than the remaining two groups, but group III was also characterized by higher urinary levels of KYN, KynA, XA, and QA as compared with younger adult individuals and elderly patients without mood disorders. Therefore, mild and moderate depression in the elderly may be associated with a lower intake of TRP and changes in its kynurenine metabolic pathway, which suggests a potential dietary TRP-based intervention in this group of patients.

Highlights

The process of aging influences structural, functional, biochemical, molecular, and genetic characteristics in many cells and tissues, affecting several individual somatic and behavioral features [1].The elderly often have sleep disorders and the pathogenesis of these syndromes can be related to various factors, including the use of caffeine, tobacco, and alcohol, sleep habits, and comorbid diseases [2].Older adults often suffer from mood disorders and possible causes include sociopsychological factors, such as weakening of family and social ties and feeling of loneliness [3]
We investigated the association of the occurrence of mood disorders with tryptophan intake and metabolism in the elderly in comparison with younger and older adults without such disorders
Mood disorders are relatively frequent in older adults and become a major public health problem [16]

Summary

Introduction

The process of aging influences structural, functional, biochemical, molecular, and genetic characteristics in many cells and tissues, affecting several individual somatic and behavioral features [1].The elderly often have sleep disorders and the pathogenesis of these syndromes can be related to various factors, including the use of caffeine, tobacco, and alcohol, sleep habits, and comorbid diseases [2].Older adults often suffer from mood disorders and possible causes include sociopsychological factors, such as weakening of family and social ties and feeling of loneliness [3]. The process of aging influences structural, functional, biochemical, molecular, and genetic characteristics in many cells and tissues, affecting several individual somatic and behavioral features [1]. The elderly often have sleep disorders and the pathogenesis of these syndromes can be related to various factors, including the use of caffeine, tobacco, and alcohol, sleep habits, and comorbid diseases [2]. Older adults often suffer from mood disorders and possible causes include sociopsychological factors, such as weakening of family and social ties and feeling of loneliness [3]. Aging may affect all internal organs, including the brain. Multi-causal, accumulating organic damage could contribute to behavioral and mood disorders and a range of affective problems in elderly patients. The activity of digestive and endocrine glands decreases with aging [4]

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