Occupational determinants of cryptogenic polyneuropathy.
OBJECTIVE
The aim was to investigate different occupational and leisure time exposures as determinants for cryptogenic polyneuropathy.


METHODS
A case-referent study was conducted in Sweden including 232 cases of cryptogenic polyneuropathy 40-79 years of age at diagnosis who were enrolled from the out-patient neurology departments of 3 hospitals. From the population register 853 referents were randomly selected. Information on occupational and leisure time exposure was obtained from a postal questionnaire. The response rate was 71% for cases and for referents. Crude odds ratios (CORs) and logistic regression odds ratios (LORs) were calculated for exposures with 5 or more exposed cases and referents taken together. The reference category was defined as individuals unexposed to any of the occupational or leisure time risk factors in the questionnaire.


RESULTS
As expected, male sex and increasing age were significant determinants for cryptogenic polyneuropathy. Occupational exposures in men to Stoddard solvent, petrol exhausts, herbicides or hand and foot vibrations generated significantly increased CORs. LORs >3.50 were found in men for occupational exposure to sulphur dioxide, xylene, methyl ethyl ketone, herbicides and in women for occupational exposure to lead, nitrous oxide and insecticides. Only solvent exposure in leisure time remained significant in the regression analysis indicating that not only occupational exposures were of importance. Interactions between occupational and leisure time exposure were seen for several agents.


CONCLUSIONS
Several known determinants for polyneuropathy, from animal studies and case reports, were confirmed. New determinants were also indicated, i.e. sulphur dioxide, xylene and methyl ethyl ketone.
Division of Occupational and Environmental Medicine, Department of Molecular and Clinical Medicine, Faculty of Health Sciences, Linkoping University, Sweden. Martin.Tondel@lio.se
Martin
M
Tondel
Jonas
J
Lindh
Pia
P
Jonsson
Magnus
M
Vrethem
Bodil
B
Persson
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015984:Causality; D004781:Environmental Exposure / Q000009:adverse effects; D006801:Humans; D007899:Leisure Activities; D016015:Logistic Models; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D016017:Odds Ratio; D011115:Polyneuropathies / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D013223:Statistics as Topic; D013548:Sweden