Abstract:
Background Diabetes is resulted from the interaction between environment and organism, and fasting blood glucose is an early indicator for screening diabetes. In recent years, researchers have focused on the associations of diabetes with exposure to polychlorinated dibenzo-dioxins and polychlorinated dibenzo-furans (PCDD/Fs) and blood glucose level changes, but the results are inconsistent.
Objective This study measures the exposure levels of PCDD/Fs in workplaces and living environments in a city of Hubei Province, and investigates the correlation between PCDD/Fs exposure and fasting blood glucose levels.
Methods A cross-sectional study in Hubei Province was conducted in August 2013 and September 2014. The participants consisted of 381 incineration workers or foundry workers in a solid waste incinerator and a steel plant as the occupational exposure group, and 381 residents living 5 km away as the control group. Questionnaire data were collected and fasting blood glucose levels were measured. PCDD/Fs exposure levels through inhalation and food intake were summed up to represent individual PCDD/Fs exposure level. Generalized linear regression models were used to examine the correlation between PCDD/Fs exposure and fasting blood glucose levels, and interaction tests were performed with considering selected influencing factors of fasting blood glucose.
Results The PCDD/Fs exposure levelM (P25-P75) in the occupational exposure group0.22 (0.13-0.48) pg TEQ/(kg·d) was significantly higher than that in the control group0.09 (0.05-0.10) pg TEQ/(kg·d) (P < 0.05), and so was the fasting blood glucose level(5.15±0.62) and (4.90±0.71) mmol/L, respectively, P < 0.05. The results of generalized linear regression model showed that there was a significant positive correlation between PCDD/Fs exposure level and fasting glucose level (Ptrend < 0.05), after adjusting for age, gender, body mass index, smoking, drinking, exercise, diabetes prevalence, and family history of diabetes. Each 1-unit increase in ln-transformed PCDD/Fs exposure level was associated with 0.10 mmol/L increase of fasting glucose level. Exercise or age had interaction with PCDD/Fs exposure level (Pinteraction < 0.05), as in those without exercise (b=0.178, 95%CI:0.096-0.260) or aged < 40 years (b=0.080, 95%CI:0.015-0.145), fasting blood glucose level increased with higher PCDD/Fs exposure level, and in those with exercise or aged < 40 years the associations were not significant.
Conclusion PCDD/Fs exposure level is positively correlated with fasting blood glucose level, and exercise can moderately attenuate this effect.