Table 3.
Association of Gulf War illness with exposures with potential cholinergic effects, by butyrylcholinesterase genetic subgroup
| Butyrylcholinesterase genetic subgroup | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| U/U homozygotes (n = 89 GWI cases, 100 controls) | U/K heterozygotes (n = 41 GWI cases, 46 controls) | Less common BChE variants (K/K, U/AK, U/A, A/F, AK/F) (n = 14 GWI cases, 14 controls) | |||||||
| Experience/exposure | % cases exposed | % controls exposed | OR * (95% C.I.) | % cases exposed | % controls exposed | OR * (95% C.I.) | % cases exposed | % controls exposed | OR * (95% C.I.) |
| Took PB (pyridostigmine bromide) pills | 67% | 48% | 2.25 (1.23–4.11) | 74% | 41% | 3.98 (1.57–10.1) | 92% | 23% | 40.0 ↑ (3.58–447) |
| Wore uniforms treated with pesticides | 22% | 8% | 3.07 (1.27–7.44) | 37% | 11% | 4.92 (1.59–15.2) | 29% | 8% | 4.80 (0.46–50.2) |
| Used pesticide cream or spray on skin | 55% | 31% | 2.75 (1.50–5.02) | 62% | 28% | 4.23 (1.71–10.5) | 50% | 43% | 1.33 (0.31–5.91) |
| Living area sprayed with pesticides | 21% | 18% | 1.23 (0.59–2.57) | 24% | 17% | 1.47 (0.51–4.29) | 21% | 14% | 1.64 (0.23–11.7) |
| Heard chemical alarms sounded | 57% | 57% | 1.02 (0.57–1.82) | 62% | 44% | 2.00 (0.84–4.79) | 64% | 50% | 1.80 (0.40–8.18) |
BChE = butyrylcholinesterase, GWI = Gulf War illness, OR = prevalence odds ratio, C.I. = confidence interval.
*OR compares GWI cases with controls within each genetic subgroup.
↑OR for veterans with less common BChE variant genotypes differs significantly from OR for veterans with U/U and U/K genotypes, p = 0.019.