noise pollution is reported to be associated with diabetes, but few studies have elucidated the associations between noise frequency characteristics. We aimed to evaluate the relationships between different noise frequency components and incident hyperglycaemia. An industry-based cohort of 905 volunteers was enrolled and followed up to 2012. Octave-band frequencies of workstation noise and individual noise levels were measured in 2012 to classify subjects' exposures retrospectively. We applied Cox regression models to estimate the relative risk (RR) of hyperglycaemia. An increased RR for hyperglycaemia of 1.80 (95% confidence interval [CI]: 1.04, 3.10) was found among subjects exposed to ≥ 85 A-weighted decibels (dBA) compared with those exposed to < 70 dBA. The highexposure groups at frequencies of 31.5, 63, 125, 250, 500, 1000, and 2000 Hz had a significantly higher risk of hyperglycaemia (all p values < 0.050) than the low-exposure groups. A 5-dB increase in noise frequencies at 31.5, 63, 125, 250, 500 Hz, and 1000 Hz was associated with an elevated risk of hyperglycaemia (all p values < 0.050), with the highest value of 1.27 (95% CI: 1.10, 1.47) at 31.5 Hz (p = 0.001). Occupational noise exposure may be associated with an increased incidence of hyperglycaemia, with the highest risk observed at 31.5 Hz. Growing numbers of field studies have reported an association between occupational noise exposure and cardiovascular disease (CVD) morbidity and mortality 1-10. In 2019, the World Health Organization (WHO) and the International Labour Organization (ILO) provided a joint methodology (WHO/ILO joint methodology) for estimating the work-related burden of CVD and injury due to workplace noise exposure 11. Noise exposure is regarded as an environmental stressor through direct (i.e., sleep disturbance) and indirect (i.e., annoyance) pathways that pose adverse health effects. Acute noise exposure may activate the hypothalamus-pituitary-adrenal axis and the sympathetic-adrenal-medulla axis to elevate the levels of stress hormones, including cortisol, catecholamine, adrenalin, and noradrenalin. Repeated and chronic stimuli may cause overproduction of stress hormones (e.g., cortisol) that increase the levels of fatty acids and glucose to partially restore homeostasis. In addition, catecholamines also boost the energy supply by breaking down triacylglycerol. Such increases in stress hormones may lead to pathophysiologic alterations in blood pressure, blood lipids, blood viscosity, and blood glucose, which promote the development of hypertension, arteriosclerosis, and CVD 12-14. Because the overproduction of cortisol may inhibit pancreatic insulin secretion and reduce insulin sensitivity in the liver, skeletal muscles, and adipose tissue 14 , it is plausible that long-term noise exposure may produce adverse changes in blood glucose. Noise pollution has been reported to be associated with diabetes in many animal and environmental epidemiological studies; however, few studies have elucidated the relationship between noise fre...