Multiple chemical sensitivity described in the Danish general population: Cohort characteristics and the importance of screening for functional somatic syndrome comorbidity-The DanFunD study.

Thomas Meinertz Dantoft,Torben Jørgensen,Linus Andersson,Sine Skovbjerg,Marie Weinreich Petersen,Steven Nordin

doi:10.1371/journal.pone.0246461

Abstract

BackgroundMultiple chemical sensitivity (MCS) is characterized by widespread symptoms attributed to exposure to airborne chemicals. MCS is categorized as a functional somatic syndrome (FSS), and MCS cases often meet the criteria for other types of FSS, e.g. fibromyalgia. The primary aim was to characterize MCS regarding symptom triggers, symptoms, lifestyle and describe demographics, socioeconomics and lifestyle factors associated with MCS. A secondary aim was to examine the implication of FSS comorbidity.MethodsData were derived from a random sample of the Danish adult population enrolled in the Danish Study of Functional Disorders (DanFunD; n = 9,656). Questionnaire data comprised information used to delimit MCS and four additional types of FSS, as well as data on demographics, socioeconomics and lifestyle. MCS cases (n = 188) was stratified into subgroups; MCS only (n = 109) and MCS with comorbid FSS (n = 73). Information regarding FSS comorbidities were missing for six MCS cases. MCS subgroups and controls without FSS comorbidities (n = 7,791) were compared by means of logistic regression analyses, adjusted for age and sex.ResultsMCS was associated with female sex, not being in occupation and low social status, but not with age or education. MCS cases reported normal dietary intake and smoking habits and lower alcohol consumption. Additional associations were found between MCS and low rate of cohabitation, sedentarism, daily physically limitations, and poor quality of sleep. However, subgroup analysis revealed that these findings were primarily associated with MCS with comorbid FSS.ConclusionsMCS was associated with lower socioeconomic status, physically inactivity and poor quality of sleep. Subgroup analysis revealed that several associations was explained by FSS comorbidity, i.e. MCS cases with no comorbid FSS showed normal rate of cohabitation and did not report physical limitations or difficulties sleeping. Overall, our findings emphasise the importance of screening MCS cases for FSS comorbidity both in epidemiological and clinical settings.

Highlights

Most people are on a regular basis exposed to a range of airborne chemicals that they may notice, but do not pay much attention to
Multiple chemical sensitivity described in a general Danish population: The Danish Study of Functional Disorders (DanFunD) study obtained in accordance with the guidelines stated by the Danish Data Protection Agency: http://www. datatilsynet.dk/english
We found no difference between participants with MCS and the controls in regard to daily dietary intake, smoking habits or alcohol consumption, except for a Multiple chemical sensitivity described in a general Danish population: The DanFunD study higher percentage of MCS cases not consuming any alcohol (Table 3)

Summary

Introduction

Most people are on a regular basis exposed to a range of airborne chemicals that they may notice, but do not pay much attention to Such exposures can be perfumed products, car exhaust, organic solvents and cooking fumes as some common examples [1,2]. For some individuals, these common airborne chemical exposures that most people consider to be benign, are associated with recurrent disabling physical reactions [4,5,6]. This condition, by the patients attributed to an acquired increase in sensitivity to airborne chemical, is often referred to as multiple chemical sensitivity (MCS). A secondary aim was to examine the implication of FSS comorbidity

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