Blood cadmium in Chinese adults and its relationships with diabetes and obesity

Abstract

The aim of this study is to evaluate blood cadmium levels (BCLs) in Chinese adults and explore whether blood cadmium is associated with diabetes or obesity. This study included 5544 adults from a cross-sectional SPECT-China study. BCL and blood lead level (BLL) was measured by atomic absorption spectrometry. Fasting plasma glucose (FPG) was used to define prediabetes and diabetes. Overweight and obesity were defined by body mass index (BMI). The associations of BCL with prediabetes, diabetes, overweight, and obesity were analyzed by multinomial logistic regression analyses. Medians (interquartile range) of BCL were 1.97 μg/L (0.60-3.82) in men and 1.59 μg/L (0.54-3.51) in women. Subjects in low-economic-status areas and urban areas had significantly higher BCL. BCL in current smokers was significantly higher than in current non-smokers. In the adjusted model, a mild positive relationship between BCL and FPG was found. Meanwhile, the prevalence of prediabetes was increased according to the increase in BCL tertiles. Surprisingly, BCL had a negative relationship with prevalence of overweight. In conclusion, BCL in Chinese adults was much higher than in other developed countries and was influenced by gender, smoking, and residential area. BCL was positively related to prediabetes while negatively related to overweight.

Kidney Cadmium Toxicity, Diabetes and High Blood Pressure: The Perfect Storm

“…The U.S. population studies show that blood Cd level as low as 0.4 µg/L is associated with an increased risk of hypertension in Caucasian women (OR 1.54, 95% CI 1.08-2.19) and in Mexican-American women (OR 2.38, 95% CI 1.28-4.40) and that the prevalence of hypertension in Black, Caucasian and Mexican-American women (men) in the U.S. NHANES 1999-2006 was 40.7 (30.1), 32.2 (36.2) and 19.4 (16.7) %, respectively. Increased diabetic risk by Cd exposure has been reported for the Korean population (Son et al 2015), Chinese population (Nie et al 2016) and the U.S. population (Schwartz et al 2003;Wallia et al 2014). In the Chinese study, a synergistic effect of Cd exposure and obesity on diabetic risk has also been noted (Nie et al 2016).…”

“…Increased diabetic risk by Cd exposure has been reported for the Korean population (Son et al 2015), Chinese population (Nie et al 2016) and the U.S. population (Schwartz et al 2003;Wallia et al 2014). In the Chinese study, a synergistic effect of Cd exposure and obesity on diabetic risk has also been noted (Nie et al 2016). Diabetes and hypertension are associated with an increased risk of albuminuria, stage 3 or stage 4 CKD among NHANES 1999NHANES -2004 participants, aged between 20 and ≥ 70 yrs, with a stronger association in younger ages (Islam et al 2009).…”

“…The Canadian Health Survey 2007-2011 has reported also that non-smokers with higher BMI had lower blood and urinary Cd levels (Garner and Levallois 2016). In a Chinese study (Nie et al 2016), urinary Cd levels ≥ 2.95 µg/g creatinine were associated with lowered risk of overweight. Son et al (2015) observed an inverse association between blood Cd levels and BMI in Korean men (40-70 yrs) with mean blood Cd of 1.7 μg/L, and mean urinary Cd of 2.13 μg/g creatinine.…”

“…Mitochondrial effects of in lowdose Cd exposure have also been noted in a Swedish study (Ellis et al 2012), showing a positive correlation between urinary Cd levels and urinary excretion of the mitochondrial metabolites such as citrate, 3-hydroxyisovalerate, and 4-deoxy-erythronic acid. Intriguingly, risk of overweight is lower in Chinese subjects with higher Cd exposure (Nie et al 2016), while an inverse association between Cd exposure levels and central obesity and BMI has been noted in the U.S. (Padilla et al 2010;Jain 2013) and Canada (Garner and Levallois 2016) populations. These findings are consistent with reduction in weight after renal glucose reabsorption is diminished through administration of SGLT2 inhibitors (Vallon 2015).…”

“…These observations may explain lower mortality among diabetic obese people, compared with diabetic lean persons (Engelmann et al 2016). In a Chines population study (n = 5,544), Nie et al (2016) observed risk of pre-diabetes increases with Cd exposure in a dosedependent manner (OR 1.19, 95% CI 1.01-1.40 and OR 1.37, 95% CI 1.14-1.63), comparing blood Cd 0.81-2.94, ≥ 2.95 vs. ≤ 0.80 µg/L. As can be expected, a synergy between obesity and high Cd exposure levels is evident from this Chinese study, showing higher risk of pre-diabetes in obese Chinese (OR 2.33, 95% CI 1.10-4.94), compared with non-obese Chinese with similarly high blood Cd levels (OR 1.44, 95% CI 1.15-1.82).…”