Can long‐term exposure to chromium improve insulin sensitivity in chromium mine workers?

Abstract

The purpose of this work was to evaluate insulin sensitivity in chromium mine workers exposed to chromium chronically. Body mass index, waist circumference, fat mass and percent, lipid levels, serum glucose, insulin, leptin and chromium levels, HOMA (%S), and HOMA (%B) values were measured in 93 male workers and 94 age-and body mass index-matched healthy controls. Fat mass and fat percent of workers were higher than control subjects (P < 0.01 and P < 0.0001, respectively). Mean insulin level of the workers was lower than control subjects (6.2 ± 4.9 lU/mL and 9.38 ± 5, respectively, P < 0.0001). Mean serum leptin levels was also lower than the control group (8.47 ± 6.5 ng/mL and 19.0 ± 10.8, respectively, P < 0.0001). Serum chromium was higher than the control subjects (407.7 ± 224.2 nmol/L and 4.45 ± 3.9, respectively, P < 0.00001). Mean HOMA (%S) index of workers was higher than control subjects (114.4 ± 55.6 and 55.7 ± 40.6, P < 0.001). Serum high-density lipoprotein cholesterol levels of the workers were significantly higher than the control group (P < 0.02). In conclusion, long-term exposure to chromium may improve insulin sensitivity and b-cell function. This improvement appears to be a result of low body fat mass and fat percent in body composition. In addition, chromium usage may have useful effects in the insulin sensitivity and therefore in development of type 2 diabetes mellitus.

Chromium as an essential nutrient: a review

“…The lack of Cr deficiency or some other etiological factors may provide an explanation. A number of human studies (Anderson, 2000;Tuzcu et al, 2004), studies on pigs (Wenk et al, 1995), horses (Pagan et al, 1995;Ott and Kivipelto, 1999), cattle and rats (Kim et al, 2004) have confirmed the possibility of influencing glucose tolerance and insulin resistance by Cr supplementation.…”

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“…38 Daily mean intake for chromium has been reported to be around approximately 33 μg. 39 Previous studies have suggested the possibility of chromium supplementation in influencing glucose tolerance and insulin resistance in humans, 40,41 and rats. 42 In vitro experiments showed that chromium and insulin supplementation to animal tissues resulted in increased glucose oxidation to carbon dioxide and water, increased glycogenesis and conversion of glucose to lipids, as well as increased glucose utilization.…”

Occupational chemical exposure and diabetes mellitus risk

“…When glucose metabolism was assessed in workers employed in this occupational setting, Cr exposure seemed to exert significant beneficial effects improving glucose tolerance with respect to unexposed controls (Wrobel et al, 1999), particularly in the older, even more obese worker subgroups (Stupar et al, 1999). Comparably, significant Cr beneficial effects on insulin sensitivity, cell function and insulin levels were reported by Tuzcu et al (2004) in mine workers exposed to the metal compared to controls. The authors suggested that this may be due to a Crinduced lower fat mass or to an increase in the number and activation of insulin receptors (Davis and Vincent, 1997;Morris, 1999).…”