Occupational quartz and particle exposure affect systemic levels of inflammatory markers related to inflammasome activation and cardiovascular disease

Table 5 Mixed model analysis on the effect of respiratory dust or quartz exposure on selected inflammatory markers

Inflammatory marker	Sample data	Exposure	P value	R² adj	Direction	Other variables included
Inflammasome-related cytokines
IL-1β	Morning	Quartz	0.15	0.047	Down	Infection
	Shift difference	Quartz	0.0039	0.25	Down	Age, workplace, smoking, stress
IL-18	Shift difference	Quartz	0.014	0.29	Down	Age
	Morning	Quartz	0.049	0.32	Down	Age, BMI, stress, infection
IL-1ra		N/S by AIC
*Caspase-1 ex vivo* activation in monocytes**
Caspase-1 LPS act	Morning	Resp. dust	0.052	0.54	Down	Workplace, stress infection
Caspase-1 LPS act	Shift difference	Resp. dust	0.0036	0.24	Down	BMI, workplace, stress
Caspase-1 ATP act	Morning	Quartz	2.76 × 10^–5	0.47	Down	Age, BMI
Caspase-1 ATP act	Shift difference	Quartz, Resp. dust	0.0028 0.16	0.44	Down Up	Pre-shift value, age, BMI, workplace
Caspase-1 LPS + ATP act	Morning	Quartz	1.90 × 10^–6	0.61	Down	Age, BMI, workplace, smoking
Caspase-1 LPS + ATP act	Shift difference	Quartz	9.63 × 10^–5	0.45	Down	Age, BMI, smoking
Other inflammatory mediators significantly correlated with exposure using Pearson or Kendall \({\varvec{\uptau}}\)
CXCL8	Shift difference	Resp. dust	0.060	0.15	Up	BMI
	Morning	Resp. dust	0.028	0.20	Up	BMI
SAA		N/S by AIC
sST2	Morning	Quartz	0.0047	0.27	Down	Workplace
	Shift difference	Quartz	0.020	0.13	Down	BMI, workplace
		Resp. dust	0.029		Up

Mixed model analysis performed on inflammasome-related markers and inflammatory markers which significantly correlated with exposure using Pearson or Kendall \(\uptau\). The Akaike information criteria was used to select models, by testing the variables respiratory quartz exposure, respiratory dust exposure, BMI, age, smoking status, symptoms of infection last two weeks, mental stress, and workplace (foundry A or B). For the over-shift difference data, the pre-shift inflammatory marker levels were also included as a variable. For the morning samples, the inflammatory marker data from the second sampling and the average exposure for each individual was included in the analyses. For the over-shift differences, the biomarker data and exposure data from both sampling occasions were included in the analyses. The R² adj. value was adjusted for the number of parameters included in the model
N/S Not selected, act. Activated, resp. Respirable

ISSN: 1476-069X