Liu G, et al. - This study investigated the link between exposure to perchlorate, nitrate and thiocyanate and risk of developing diabetes in humans. Independent of traditional risk factors, an association of elevated urinary perchlorate levels with an increased prevalence of diabetes mellitus was reported.

Methods

• Researchers measured urinary perchlorate, nitrate and thiocyanate among 11 443 participants (mean age 42.3 years) from the National Health and Nutritional Examination Survey 2001–14, using ion chromatography coupled with electrospray tandem mass spectrometry.
• Diabetes was defined as self-reported doctor diagnosis, use of oral hypoglycaemic medication or insulin, fasting plasma glucose ≥ 126 mg/dl or glycated haemoglobin A1c (HbA1c) ≥ 6.5%.

Results

• Findings showed that the median (interquartile range) levels of urinary perchlorate, nitrate and thiocyanate were 3.32 (1.84, 5.70) μg/l, 46.4 (27.9, 72.0) mg/l and 1.23 (0.59, 2.78) mg/l, respectively.
• Researchers observed that higher levels of urinary perchlorate were associated with elevated levels of fasting glucose, HbA1c, insulin and homeostatic model assessment of insulin resistance (all P_trend < 0.001).
• They also noted that after multivariate adjustment including urinary creatinine, smoking status and body mass index (BMI), higher urinary perchlorate, but not nitrate or thiocyanate, was associated with an increased prevalence of diabetes mellitus.
• Data revealed that comparing extreme quintiles, the odds ratio (95% confidence interval) of diabetes was 1.53 (1.21, 1.93;P_trend < 0.001) for perchlorate, 1.01 (0.77, 1.32; P_trend = 0.44) for nitrate and 0.98 (0.73, 1.31; P_trend= 0.64) for thiocyanate.
• Researchers found that, when urinary perchlorate, nitrate and thiocyanate were further mutually adjusted, the outcomes did not materially change.
• In addition, similar results were observed when analyses were stratified by smoking status, as well as by age, gender, kidney function and BMI.