Multiple chemical sensitivity: Genotypic characterization, nutritional status and quality of life in 52 patients

Abstract

Background and objectives

Multiple chemical sensitivity (MCS) is a chronic, multisystem syndrome of unknown etiology. The aim of the present study was to describe the nutritional status and quality of life of patients suffering from MCS, as well as to identify potential polymorphisms associated with this illness.

Patients and methods

A cross-sectional, descriptive study was performed on patients with a diagnosis of MCS. Data on anthropometric and body composition variables, hand muscle strength and quality of life were collected. The selection of single nucleotide polymorphisms (SNPs) was based on genes previously associated with MCS and genes involved in inflammatory and oxidative stress pathways.

Results

A total of 52 patients (93.2% female), with a mean age of 50.9 (10.3) years were included in the study. Among them, based on their BMI, 48% had an inadequate nutritional status (17% were underweight and 32% were overweight or obese). Thirty percent of patients had a low muscle mass for their age, 84% had muscle strength below the tenth percentile, and 51.8% had a high fat mass percentage. Regarding quality of life, all median scores were lower than those of other illnesses assessed for every subscale assessed. Statistically significant differences between patient cases and controls were found with respect to rs1801133 (MTHFR), rs174546 (FADS1) and rs1801282 (PPARγ) polymorphisms.

Conclusion

A high percentage of patients had a poor nutritional status, low muscle strength and decreased muscle mass. These facts exacerbate the already-lower quality of life of these patients. Specific genetic polymorphisms associated with the syndrome or its pathogenesis was not identified.

Resumen

Antecedentes y objetivos

La sensibilidad química múltiple (SQM) es un síndrome multisistémico y crónico, de etiología desconocida. El objetivo de este estudio fue describir el estado nutricional y la calidad de vida, así como identificar posibles polimorfismos asociados al síndrome o a su patogenia.

Pacientes y métodos

Estudio epidemiológico, descriptivo y transversal en pacientes con diagnóstico de SQM. Se recogieron datos antropométricos, composición corporal, fuerza muscular y calidad de vida. La selección de single nucleotide polymorphisms (SNP, «polimorfismos de un solo nucleótido») se centró en genes asociados previamente a la SQM y genes que participan en rutas de estrés oxidativo e inflamación.

Resultados

Se incluyeron 52 pacientes (93,2% del sexo femenino), con una edad media de 50,9 (10,3) años. Respecto a su estado nutricional (IMC), un 48% estaba fuera de rangos de normalidad (17% desnutrición y 32% sobrepeso y obesidad). Un 30% presentó masa muscular por debajo de la referencia para la edad, un 84% una fuerza muscular inferior al percentil 10 y un 51,8% un porcentaje de masa grasa elevado. Respecto a la calidad de vida, las puntuaciones medias estuvieron por debajo de las de otras enfermedades en todas las subescalas evaluadas. Se observaron diferencias significativas en las frecuencias encontradas entre casos y controles para los SNP rs1801133 (MTHFR), rs174546 (FADS1) y rs1801282 (PPARγ).

Conclusión

Un elevado porcentaje de pacientes presentó un estado nutricional anormal con masa y fuerza muscular disminuidas, lo que reduce la calidad de vida de estos pacientes, ya mermada por la sintomatología. No se identificaron polimorfismos genéticos específicos asociados al síndrome o a su patogenia.