Deployment stressors and a chronic multisymptom illness among Gulf War veterans

Saudi Arabia-United States collaboration in health research: a formula for success

The aim of this article is to share our experiences from an international collaborative effort to study health outcomes among Saudi Arabian National Guard (SANG) soldiers following the 1991 Gulf War. By paying particular attention to distinct social and religious customs, geopolitical differences, and unique aspects of the health care system, we achieved a successful international collaboration in health research.

Blunted circadian variation in autonomic regulation of sinus node function in veterans with Gulf War syndrome

PURPOSE

To test the hypothesis that subtle abnormalities of the autonomic nervous system underlie the chronic symptoms reported by many Gulf War veterans, such as chronic diarrhea, dizziness, fatigue, and sexual dysfunction.

METHODS

Twenty-two ill Gulf War veterans and 19 age-, sex-, and education-matched control veterans underwent measurement of circadian rhythm of heart rate variability by 24-hour electrocardiography, ambulatory blood pressure recording, Valsalva ratio testing, sympathetic skin response evaluation, sweat imprint testing, and polysomnography. Investigators were blinded to case- or control-group status.

RESULTS

High-frequency spectral power of heart rate variability increased normally 2.2-fold during sleep in controls but only 1.2-fold in ill veterans (P <0.0001). In ill veterans as compared with controls, it was lower at night (P = 0.0006), higher during the morning (P = 0.007), but no different during the rest of the day (P = 0.8). The mean heart rate of ill veterans also declined less at night (P = 0.0002), and their corrected QT intervals tended to be longer over the full 24 hours (P = 0.07), particularly at night (P = 0.03). Blunting of the nocturnal heart rate dip in ill veterans was confirmed by 24-hour automatic ambulatory blood pressure monitoring (P = 0.05) and polysomnography (P = 0.03). These differences remained significant after adjusting for potential confounders. Cases and controls were similar on measures of sympathetic adrenergic and sudomotor function, sleep architecture, respiratory function, and circadian variation in blood pressure and body temperature.

CONCLUSION

Some symptoms of Gulf War syndrome may be due to subtle autonomic nervous system dysfunction.

Regional prevalence of fatiguing illnesses in the United States before and after the terrorist attacks of September 11, 2001

OBJECTIVE

Stress or emotional traumas are considered risk factors for unexplained fatiguing illnesses. From July to December 2001, the Centers for Disease Control and Prevention conducted a multigeographical pilot study to test the feasibility of a survey to estimate the prevalence of fatiguing illnesses in the United States. We used data obtained during this survey to estimate the effect of the coincidentally occurring terrorist attacks of September 11, 2001, on the regional prevalence of fatiguing illnesses.

METHODS

Identified by random-digit dialing, 2,728 households in eight regional strata were interviewed, and 7,317 respondents were screened for severe fatigue of at least 1 month duration. Identified fatigued people of age 18 to 69 years (N = 440) and a sample of nonfatigued people of the same age range (N = 444) were interviewed in detail concerning fatigue, other symptoms, and medical and psychiatric histories.

RESULTS

Weighted prevalence estimates based on interviews performed after the attacks were significantly lower compared with estimates based on interviews performed before the attacks (prolonged fatigue: 5,450 vs. 1,530/100,000, p =.010; chronic fatigue: 18,510 vs. 10,070/100,000, p =.002; chronic fatigue syndrome-like illness: 2,510 vs. 960/100,000, p =.014).

CONCLUSION

Our findings suggest decreased regional prevalence of fatiguing illnesses in the aftermath of the terrorist attacks. The causes of this effect are unknown but might involve acute psychological and physiological adaptations that modify the perception or manifestation of fatigue. Future studies should be specifically designed to scrutinize the relationship between stress and fatiguing illnesses and the mediating mechanisms of such a relationship.

Reported Exposures, Stressors, and Life Events Among Gulf War Registry Veterans

We investigated the association of 15 exposures, 10 stressors, and 18 life events with illness symptoms reported by 978 veterans who believe they suffer from Gulf War-related illnesses. A mail survey was completed by veterans (60% response rate) from the Gulf War Health Registry. Variables most associated with high symptom group membership were reported chemical/biologic warfare (CBW), concerns with infection and faulty equipment, feelings of mistrust in the military, and disability leading to work stoppage within 2 years after the war. These data suggest that belief in CBW exposure, and the experience of war stress and serious negative life events after the war, are important concomitants of Gulf War illness. Models seeking to explain Gulf War symptoms need to incorporate a range of exposure and psychosocial factors to fully account for important influences.

Epidemiology of fibromyalgia

Chronic widespread pain, the cardinal symptom of fibromyalgia (FM), is common in the general population, with comparable prevalence rates of 7.3% to 12.9% across different countries. The prevalence of FM in the general population was reported to range from 0.5% to 5% and up to 15.7% in the clinic. The common association of FM with other rheumatic disorders, chronic viral infections, and systemic illnesses has been well documented in several studies. Up to 65% of patients with systemic lupus erythematosus meet the criteria for FM. FM is considered a member of the family of functional somatic syndromes. These syndromes are very common and share a similar phenomenology, epidemiologic characteristics, high rates of occurrence, a common pathogenesis, and similar management strategies. A high prevalence of FM was demonstrated among relatives of patients with FM and it may be attributed to genetic and environmental factors.

Applying exercise to the management of fibromyalgia

Fibromyalgia, chronic fatigue syndrome, and related illnesses fall under the spectrum of chronic multisymptom illnesses (CMI). This constellation of syndromes often is defined by chronic pain, unremitting fatigue, cognitive difficulties, and various other symptoms. In treating these illnesses, pharmacotherapy generally is the mode of choice, with exercise being overlooked often. However, research has shown that exercise is quite beneficial in reducing pain and fatigue in this population and should be included as part of a multimodal therapy regimen. This article reviews the exercise and CMI literature and provides a model for applying these evidence-based guidelines to a clinical population.

Combined forced running stress and subclinical paraoxon exposure have little effect on pyridostigmine-induced acute toxicity in rats

Pyridostigmine is a short-acting inhibitor of cholinesterase (ChE) used as a pretreatment against potential nerve agent exposure during the Persian Gulf War. As pyridostigmine contains a quaternary ammonium group, it is generally believed to elicit changes in the peripheral nervous system function only. It has been hypothesized, however, that the neurotoxicity of pyridostigmine may be altered by either stress or combined exposures to other toxicants. We evaluated the effects of forced running stress, exposure to the organophosphate anticholinesterase paraoxon, or a combination of both on the acute neurotoxicity of pyridostigmine. ChE (blood, diaphragm, and selected brain regions) and carboxylesterase (CE; liver, plasma) inhibition was also evaluated. Young adult male Sprague-Dawley rats were either given vehicle or paraoxon (0.1 mg/kg, i.m.) and subsets placed in their home cage or forced to run on a treadmill for 60 min. Pyridostigmine (0, 10 or 30 mg/kg, p.o.) was given 60 min after paraoxon dosing and rats were evaluated for cholinergic toxicity just prior to sacrifice 60 min later. No signs of toxicity were noted following paraoxon exposure while both dosages of pyridostigmine (10 and 30 mg/kg, p.o.) elicited signs of functional toxicity. Toxicity was not different with combined paraoxon-pyridostigmine exposures and forced running did not influence toxicity under any conditions. Paraoxon (0.1 mg/kg, i.m.) caused moderate (23-46%) ChE inhibition in blood, diaphragm and brain 2 h after exposure. Pyridostigmine (10 or 30 mg/kg, p.o.) caused extensive inhibition of blood (88-94%) and diaphragm (75-85%) ChE activity but no significant effect on brain regional ChE activity. Forced running stress did not influence the degree of tissue ChE inhibition following either paraoxon, pyridostigmine or paraoxon-pyridostigmine combined exposures. CE activities were inhibited (26-43%) in plasma and liver by paraoxon but inhibition was not influenced by either stress or combined paraoxon-pyridostigmine exposures. These results suggest that subclinical paraoxon exposure and forced running stress, by themselves or in combination, have little effect on acute pyridostigmine toxicity in rats.

Neurobehavioral effects of pesticides: state of the art

The authors have reviewed the literature on neurobehavioral toxicity of pesticides to assess the status of knowledge on this matter. Some data suggest that exposure to DDT and fumigants may be associated with permanent decline in neurobehavioral functioning and increase in psychiatric symptoms, but, due to the limited number of studies available and the scarce knowledge on exposure levels, no firm conclusion can be drawn. Data on subjects acutely poisoned with organophosphorous compounds suggest that an impairment in neurobehavioral performance and, in some cases, emotional status may be observed as a long-term sequela, but the possibility still remains that these effects were only an aspecific expression of damage and not of direct neurotoxicity. Studies carried out on subjects chronically exposed to organophosphates, but never acutely poisoned, do not provide univocal results but the slight changes consistently observed in sheep dippers suggest the need of focusing on activities characterized by relatively higher exposure levels. In general, the main limits of existing knowledge are the variability of the testing methods used, which makes it difficult to compare the results of single studies, and the scarce knowledge on exposure levels. A promising approach may be the conduction of prospective longitudinal or cohort studies, where exposure and dose assessment can be more easily controlled, or the evaluation of cohorts of workers a priori selected for the availability of environmental and biological monitoring data. The follow up of the populations under study may give an answer at the problem of the prognostic significance of the observed changes. Also the protocols used to assess neurobehavioral functioning need to be standardized.

Pyridostigmine bromide and the long-term subjective health status of a sample of over 700 male Reserve Component Gulf War era veterans

Data from a 1996-1997 survey of approximately 700 Reserve Component male veterans indicate that the consumption of pyridostigmine bromide pills, used as a pretreatment for potential exposure to the nerve agent Soman, was a significant predictor of declines in reported subjective health status after the war, even after controlling for a number of other possible factors. Reported reactions to vaccines and other medications also predicted declines in subjective health. While higher military rank generally predicted better health during and after the war, educational attainment, minority status, number of days in theater, and age generally did not predict changes in subjective health. Although servicemembers were directed to take three pills a day, veterans reported a range of compliance--less than a fourth (24%) followed the medical instructions compared to 61% who took fewer than three pills daily and 6% who took six or more pills a day. Implications for use of pyridostigmine bromide are discussed.

Treatment of fatigue in fibromyalgia

Clearly, fatigue is a large and challenging problem for those suffering from fibromyalgia. It adds greatly to the morbidity and disability associated with the disease. In the management of this specific symptom in fibromyalgia, attention should first be focused on identifying comorbidities that may be present and contribute to fatigue. As with other symptoms of fibromyalgia, education is a critical component of management. This can be done by the practitioner, with available free resources, or with specialized cognitive behavioral programs. This education process can be augmented with a variety of other nonpharmacologic therapies, especially very gradually increasing, low-impact, aerobic exercise programs. Numerous pharmacologic therapies may also be helpful as an adjunct to treatment. Classes of compounds that raise central levels of norepinephrine or dopamine appear to be the most specific for management of fatigue. There are also many medications used to combat fatigue in other disorders that have not yet been adequately explored as to the possible benefits in alleviating the fatigue of fibromyalgia. Advances in the management of fatigue in fibromyalgia are likely to come from a variety of directions. Easier access to well designed nonpharmacologic therapies is essential, because these treatments are underutilized in clinical practice at present. Improvements in pharmacologic therapies will come from new insights into mechanisms, especially those that might only be present in subsets of patients and would respond to more targeted therapies.

Risk factors for multisymptom illness in US Army veterans of the Gulf War

This research study examined the prevalence of symptoms and identified risk factors for reported symptoms among a group of Army Gulf War (GW) veterans. A survey was mailed to all members of the Ft. Devens cohort in 1997, representing the third assessment of a group that consisted of 2949 US Army soldiers deployed to the Gulf, and was studied initially in 1991. A total of 1290 subjects responded to the mailed survey; aggressive follow-up methods to address non-response bias were employed. Subjects were classified as having multisymptom illness if they reported symptoms from at least two of three symptom categories (fatigue, mood-cognition, musculoskeletal). Sixty percent of the respondents met criteria for multisymptom illness. Female gender, lower levels of education, psychological symptoms, self-reported use of a medical clinic in the Gulf, ingestion of anti-nerve gas pills (pyridostigmine bromide), anthrax vaccination, tent heaters, exposure to oil fire smoke, and chemical odors were significantly related to multisymptom illness in logistic regression analyses. Analyses in which subjects were stratified by level of psychological symptoms revealed different sets of GW-service environmental exposures and suggest that subgroups of GW veterans may have different sets of risk factors.

An interdisciplinary therapeutic approach for dealing with patients attributing chronic fatigue and functional memory disorders to environmental poisoning--a pilot study

Nonspecific symptoms and a general feeling of ill health that is difficult to objectify are the commonest health problems with which patients present to an Environmental Medicine Outpatient Department (OPD). Of this group, a great proportion meets the classification criteria for Chronic Fatigue Syndrome (CFS) or Functional Memory Disorders in association with Idiopathic Chronic Fatigue (FMD-ICF). This is a longitudinal study of the OPD of Environmental Medicine, Freiburg University Hospital, Germany, to determine the feasibility and impact of an interdisciplinary therapeutic approach (self-help program, acupuncture, psychosomatic support by group interventions) in 8 patients with CFS, FMD-ICF, or CFS in association with self-reported Multiple Chemical Sensitivities (sr-MCS). The intervention took into consideration the patients' need for treatment of physical aspects of their disease. This is an important step to motivate patients into required psychosomatic support. Although none of the patients was willing to accept psychosomatic support or psychotherapy at study outset, acceptance of psychosomatic group interventions was high during the study course. Additionally five patients started with personal counseling at the Psychosomatic Clinic, and, without feeling stigmatized, 4 patients started with specific psychotherapy. The patients' quality of life showed no increase after four months, but, as shown by the Sum-Score of SF-36, it had improved significantly at the end of the study, which covered eight months' treatment (p = 0.015). Two follow-up investigations showed that this improvement probably persisted in part (mainly in the dimensions mental health, social function, physical role function, and vitality). In conclusion our interdisciplinary therapeutic approach indicates successful treatment of patients attributing CFS, CFS/sr-MCS, and FMD-ICF to environmental poisoning. We now plan to conduct a randomized controlled trial in the future.

The combined effects of pyridostigmine and chronic stress on brain cortical and blood acetylcholinesterase, corticosterone, prolactin and alternation performance in rats

Thousands of soldiers who served in the Gulf War have symptoms that have been collectively termed Gulf War Illness (GWI). It has been suggested that a combination of operational stress and pyridostigmine, a drug given as a pretreatment to protect soldiers against the effects of exposure to nerve agents, might have had unexpected adverse health effects causing these symptoms. Our laboratory has previously modeled operational stress in rats using a paradigm of around-the-clock intermittent signalled footshock. In the present studies, this model was used to investigate the potential synergistic effects of chronic stress and pyridostigmine on physiology and behavior. Seventy-two rats were trained to perform an alternation lever pressing task to earn their entire daily food intake. The rats were then implanted with osmotic minipumps containing vehicle, pyridostigmine (25 mg/ml pyridostigmine bromide) or physostigmine (20 mg/ml eserine hemisulfate). The pumps delivered 1 microl/h, which resulted in a cumulative dosing of approximately 1.5 mg/kg/day of pyridostigmine or 1.2 mg/kg/day of physostigmine, equimolar doses of the two drugs. The rats were then returned to their home cages where performance continued to be measured 24 h/day. After 4 days, 24 of the 72 rats were trained to escape signalled footshock (avoidance-escape group) and 24 other rats (yoked-stressed group) were each paired to a rat in the avoidance-escape group. The remaining 24 rats were not subjected to footshock (unstressed group). Shock trials were intermittently presented in the home cage 24 h/day for 3 days, while alternation performance continued to be measured. Since only 12 test cages were available, each condition was repeated to achieve a final n of six rats per group. Pyridostigmine and physostigmine each decreased blood acetylcholinesterase levels by approximately 50%. Physostigmine also decreased brain cortical acetylcholinesterase levels by approximately 50%, while pyridostigmine had no effect on cortical acetylcholinesterase activity. Alternation performance was impaired on the first day of stress and then recovered. Neither pyridostigmine nor physostigmine affected performance in the absence of stress or increased the effects of stress alone. Corticosterone was significantly increased in the yoked stress group compared to unstressed controls. These data suggest that pyridostigmine does not exacerbate the effects of stress on performance or levels of stress hormones. Furthermore, these data do not suggest that stress enables pyridostigmine to cross the blood brain barrier.