Tag: chemical sensitivity

A 2-day cardiopulmonary exercise test in chronic fatigue syndrome patients who were exposed to humidifier disinfectants

Abstract:

Some survivors of humidifier disinfectants (HDs) complain of chronic, inexplicable fatigue, and post-exertional malaise (PEM). Two-day cardiopulmonary exercise tests (CPETs) performed 24 hours apart (2-day CPET protocol) are increasingly employed to evaluate PEM and related disabilities among individuals with chronic fatigue syndrome (CFS). The purpose of this study was to assess the reproducibility of CPET variables in individuals who had been exposed to HD and to show that 2-day CPET is an objective means of differentiating between fatigue conditions in people with CFS symptoms who have been exposed to HDs.

Twenty-nine HD survivors with CFS symptoms were enrolled in this study. To document and assess PEM in CFS, a 2-day CPET was conducted to measure baseline functional capacity (CPET1) and provoke PEM. Twenty-four hours later, a second CPET assessed changes in related variables, focusing on PEM effects on functional capacity. This CPET also measured changes in energy production and physiological function, objectively documenting PEM effects.

In the 2-day CPET, the peak oxygen consumption (VO2peak), VO2 at ventilatory threshold (VO2@VT), time to reach VO2peak, and time to reach VO2@VT were significantly decreased (p<0.001). The peak O2 pulse and O2 pulse at VT also decreased significantly (p<0.001). A 6-minute walk test revealed significantly decreased distance (p<0.01). This is the first study to conduct a 2-day consecutive CPET in previously exposed HD participants with CFS symptoms.

Our results confirm previous work that demonstrated abnormal responses to PEM in CFS patients. Therefore, a 2-day CPET is an objective measure to differentiate fatigue conditions in people with CFS symptoms who have been exposed to HDs.

Source: Leem JH, Jeon HE, Nam H, Kim HC, Joa KL. A 2-day cardiopulmonary exercise test in chronic fatigue syndrome patients who were exposed to humidifier disinfectants. Environ Anal Health Toxicol. 2022 Dec;37(4):e2022033-0. doi: 10.5620/eaht.2022033. Epub 2022 Nov 3. PMID: 36916046; PMCID: PMC10014750. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10014750/ (Full text)

Illness from low levels of environmental chemicals: relevance to chronic fatigue syndrome and fibromyalgia

Abstract:

This article summarizes (1) epidemiologic and clinical data on the symptoms of maladies in association with low-level chemicals in the environment, i.e., environmental chemical intolerance (CI), as it may relate to chronic fatigue syndrome (CFS) and fibromyalgia; and (2) the olfactory-limbic neural sensitization model for CI, a neurobehavioral synthesis of basic and clinical research. Severe CI is a characteristic of 20-47% of individuals with apparent CFS and/or fibromyalgia, all patients with multiple chemical sensitivity (MCS), and approximately 4-6% of the general population.

In the general population, 15-30% report at least minor problems with CI. The levels of chemicals reported to trigger CI would normally be considered nontoxic or subtoxic. However, host factors–e.g., individual differences in susceptibility to neurohormonal sensitization (amplification) of endogenous responses–may contribute to generating a disabling intensity to the resultant multisystem dysfunctions in CI.

One site for this amplification may be the limbic system of the brain, which receives input from the olfactory pathways and sends efferents to the hypothalamus and the mesolimbic dopaminergic [reward] pathway. Chemical, biologic, and psychological stimuli can initiate and elicit sensitization. In turn, subsequent activation of the sensitized limbic and mesolimbic pathways can then facilitate dysregulation of behavioral, autonomic, endocrine, and immune system functions.

Research to date has demonstrated the initiation of neurobehavioral sensitization by volatile organic compounds and pesticides in animals, as well as sensitizability of cardiovascular parameters, beta-endorphin levels, resting EEG alpha-wave activity, and divided-attention task performance in persons with CI. The ability of multiple types of widely divergent stimuli to initiate and elicit sensitization offers a new perspective on the search for mechanisms of illness in CFS and fibromyalgia with CI.

 

Source: Bell IR, Baldwin CM, Schwartz GE. Illness from low levels of environmental chemicals: relevance to chronic fatigue syndrome and fibromyalgia. Am J Med. 1998 Sep 28;105(3A):74S-82S. http://www.ncbi.nlm.nih.gov/pubmed/9790486

 

Serum neopterin and somatization in women with chemical intolerance, depressives, and normals

Abstract:

The symptom of intolerance to low levels of environmental chemicals (CI, chemical intolerance) is a feature of several controversial polysymptomatic conditions that overlap symptomatically with depression and somatization, i.e., chronic fatigue syndrome, fibromyalgia, multiple chemical sensitivity, and Persian Gulf syndrome. These syndromes can involve many somatic symptoms consistent with possible inflammation. Immunological or neurogenic triggering might account for such inflammation.

Serum neopterin, which has an inverse relationship with l-tryptophan availability, may offer a marker of inflammation and macrophage/monocyte activation. This study compared middle-aged women with CI (who had high levels of affective distress; n = 14), depressives without CI (n = 10), and normals (n = 11).

Groups did not differ in 4 p.m. resting levels of serum neopterin. However, the CI alone had strong positive correlations between neopterin and all of the scales measuring somatization. These preliminary findings suggest the need for additional research on biological correlates of ‘unexplained’ multiple somatic symptoms in subtypes of apparent somatizing disorders.

 

Source: Bell IR, Patarca R, Baldwin CM, Klimas NG, Schwartz GE, Hardin EE. Serum neopterin and somatization in women with chemical intolerance, depressives, and normals. Neuropsychobiology. 1998;38(1):13-8. http://www.ncbi.nlm.nih.gov/pubmed/9701717

 

Neurasthenic fatigue, chemical sensitivity and GABAa receptor toxins

Abstract:

Following observation of fatigue syndromes in people who have been occupationally exposed to pesticides and insecticides which exert their toxicity through the GABAa receptor, we have formulated the hypothesis that fatigue syndromes in general may be secondary to altered sensitivity of the GABAa receptor. We discuss the possible involvement of organochlorine compounds which are widespread in the environment. Organophosphate compounds may have similar toxic effects through damaged cholinergic input to the dentate gyrus of the hippocampus where cholinergic and GABAergic transmission are closely linked.

 

Source: Corrigan FM, MacDonald S, Brown A, Armstrong K, Armstrong EM. Neurasthenic fatigue, chemical sensitivity and GABAa receptor toxins. Med Hypotheses. 1994 Oct;43(4):195-200. http://www.ncbi.nlm.nih.gov/pubmed/7838000

 

Chronic fatigue syndrome

Note: This letter was written in response to a letter published in the Canadian Medical Association Journal on May 1, 1989. You can read Holland’s letter here:  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1268972/pdf/cmaj00190-0022b.pdf

 

It is regrettable that the publication of an earlier letter from one of us (G.H.R.) and Dr. Jean A. Monro (Can Med Assocj 1989; 140: 361) generated surprise (and apparent disapproval of CMAJ’s action) on the part of Dr. Ray Holland (ibid 1016).

In expressing his disagreement with the use of the term “chronic fatigue syndrome” Holland also appears to be at odds with the US Centers for Disease Control (CDC), whose case definition for this condition (1) was the main point of the earlier letter. We have no disagreement with Holland that “there are also primary psychologic causes of chronic fatigue”. However, the CDC case definition specifically calls for the exclusion of clinical conditions, including psychiatric disease, that may produce similar symptoms.

The whole issue of what triggers psychologic symptoms or illness, however, is an important related matter. Holland reports, quite rightly, that panic disorder appears to be increasingly common. As physicians we have been led to assume that panic disorder has a psychologic origin rather than identifiable extrinsic causes. At the Environmental Health Center – Dallas we have confirmed that panic attacks and other emotional responses may be reproducibly triggered by double-blind testing for sensitivities to foods, inhalants and chemicals. (2)

Similar behavioural effects have been seen in pesticide poisoning (3) and with exposure to other environmental toxins. (4) Specifically, panic attacks have been cited in the psychiatric literature as being triggered by solvent exposure. (5’6)

Being unable to find physical diagnoses for chronic fatigue does not necessarily mean that psychologic illness is the cause. It may simply be that our understanding of the factors precipitating the illness is far from complete. Medical history teaches us that once physical causes for “psychologic” symptoms are discovered the condition moves, as if by magic, from the psychiatric to the medical realm. A good example of this is the relief of behavioural symptoms by correction of thiamin (7) or cobalamin (8) deficiency.

It is our experience that a substantial percentage of chronic fatigue cases (not a minuscule percentage, as Holland suggests) may arise from or be worsened by adverse reactions to components of the patient’s total environment, such as food, inhalants and chemicals.

~Gerald H. Ross, MD, CCFP Fellow in environmental medicine

~William J. Rea, MD, FACS, FAAEM Medical director

~Alfred R. Johnson, DO, FAAEM Environmental Health Center – Dallas; Dallas, Texas

References

1. Holmes GP, Kaplan JE, Gantz NM et al: Chronic fatigue syndrome: a working case definition. Ann Intern Med 1988; 108: 387-389
2. King DS: Can allergic exposure provoke psychological symptoms? A double-blind test. Biol Psychiatry 1981; 16:3-19
3. Rea Wl, Butler JR, Laseter JL et al: Pesticides and brain function changes in a controlled environment. Clin Ecol 1984; 2:145-150
4. Fein GG, Schwartz PM, Jacobson SW et al: Environmental toxins and behavioral development: a new role for psychological research. Am Psychologist 1983; 38: 1188-1197
5. Dager SR, Holland JP, Cowley DS et al: Panic disorder precipitated by exposure to organic solvents in the work place. Am I Psychiatry 1987; 144:1056-1058
6. Lindstrom K, Ruhimake H, Hamminen K: Occupational solvent exposure and neuropsychiatric disorders. Scand J Work Environ Health 1984; 10: 321-323
7. McLaren DS: Clinical manifestations of nutritional disorders. In Shils ME, Young VR (eds): Modem Nutrition in Health and Disease, Lea and Febiger, Philadelphia, 1988: 733-745
8. Lindenbaum J, Healton EB, Savage DG, et al: Neuropsychiatric disorders caused by cobalamin deficiency in the absence of anemia or macrocytosis. N EnglJ Med 1988; 318: 1720-1729

 

Source: G H Ross, W J Rea, and A R Johnson. Chronic fatigue syndrome. CMAJ. 1989 Jul 1; 141(1): 11–12. PMCID: PMC1269261  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1269261/