Evaluation of factors associated with cadmium exposure and kidney function in the general population

Abstract

Cadmium (Cd) is a nonessential toxic metal which is widely distributed in the environment. The general population is exposed to low levels of Cd and the kidney is the organ most sensitive to Cd toxicity. This study was performed to simultaneously evaluate Cd exposure, kidney function, and oxidative stress biomarkers in the general population. A total of 643 adults were interviewed to document demographic characteristics, lifestyles, past-medical history, and diet during the last 24 h. We estimated daily Cd intake based on the diet of study subjects who had not been exposed to Cd occupationally. Whole blood and urine samples were collected and analyzed to determine Cd concentrations and kidney function indices (β₂ -microglobulin [β₂-MG], N-acetyl-β-D-glucosaminidase [NAG], metallothionein [MT]). The oxidative stress index (malondialdehyde [MDA]) was determined from the urine. The daily Cd intake from diet was established as 7.07 μg/day. The mean concentration of Cd measured in the blood was 1.22 μg/L and urine was 0.95 μg/g creatinine. The concentrations of Cd in blood and urine were higher in females than in males. The blood levels of Cd were affected by sex, age, and smoking, and urine Cd was influenced by sex, age, and blood Cd. The urine Cd was positively correlated with MT, NAG activity, and MDA in females, but with NAG only in males. The blood Cd was associated with MT in males. Increased NAG activity was observed when Cd in urine reached 1.0 μg Cd/g creatinine and was also affected by age, hypertension, and diabetes mellitus. Urinary MT only responded to Cd in urine or blood. In summary, exposure to Cd in the general population was influenced by various factors including sex, age, and smoking habits. Such exposure might eventually cause tubular damage in the kidneys through the oxidative stress mechanism, and females might be more susceptible than males to Cd exposure under the environment.

Reference values of cadmium, arsenic and manganese in blood and factors associated with exposure levels among adult population of Rio Branco, Acre, Brazil

“…Additional risk factors for Cd exposure in the present study were age, non-white ethnicity and low education. The observed increase in Cd blood levels with age is in agreement with other studies (Forte et al, 2011;Gil et al, 2011;Bjermo et al, 2013;Huang et al, 2013;Khlifi et al, 2014) and reflects the well-known capacity of metals to accumulate in the body. Thus, blood levels of Cd might be indicative of both recent and past exposure to this metal.…”

“…Reports from Spain and the Czech Republic also found significantly higher Cd blood levels in men (Lustigová and Puklová, 2006;Gil et al, 2011), whereas other studies did not find gender differences (CDC, 2005;Khlifi et al, 2014;Kuno et al, 2013) or revealed higher levels in females than males (Wennberg et al, 2006;Forte et al, 2011;Huang et al, 2013). Because men are more likely to smoke and to be occupationally exposed to metals, these divergent findings may be explained by the different composition of the study populations, which include occupational exposed individuals, people from the general population, smokers and non-smokers, or only non-smokers.…”

Cadmium exposure in inhabitants living in non-polluted area

“…I also appreciate the precise information on the smoking duration and the daily number of cigarettes by Adams and Newcomb for the comparability of the results. There was no difference in the blood Cd levels between never smokers and former smokers in the Korean study, especially in subjects under 50 years old, 6 which was the same as the result reported by Adams and Newcomb.…”

Deleterious effects of incense smoke exposure on kidney function and architecture in male albino rats

“…Several of the incense smoke constituents such as PAHs, heavy metals and particulate fractions are also present in the established environmental pollutants wherein they are shown to exert oxidative stress in kidney. For example, exposure of heavy metals such as lead and cadmium from the polluted water and air is shown to modify the oxidative stress markers in human kidney (Garçon et al, 2007;Huang et al, 2013). Rats exposed to industrial dust fiber amosite exhibited increased oxidative stress and renal fibrosis (Boor et al, 2009).…”