Multi-metal exposure ups diabetes mellitus risk

Exposure to different metals, particularly cadmium, iron, zinc, copper, and lead, appears to aggravate the risks of impaired fasting glucose (IFG) and diabetes mellitus, reports a recent China study.

The study included 250 adults (mean age 57.98 years, 60 percent women) who resided in a cadmium-polluted area, in whom blood and urine metal levels were measured using inductively coupled argon plasma mass spectrometry. A parallel group of 204 controls (mean age 58.5 years, 56.86 percent women) who lived in an unpolluted area was also included.

Logistic regression analysis revealed that in participants who lived in unpolluted areas, blood cadmium was negatively associated with the prevalence of IFG (odds ratio [OR], 0.780, 95 percent confidence interval [CI], 0.655–0.928; p=0.005) and diabetes mellitus (OR, 0.506, 95 percent CI, 0.288–0.888; p=0.018).

Urinary zinc had a similar inverse correlation with IFG (OR, 0.622, 95 percent CI, 0.465–0.831; p=0.001) and diabetes mellitus (OR, 0.609, 95 percent CI, 0.395–0.939; p=0.025) when looking at participants who lived in polluted areas.

On the other hand, urinary iron (OR, 1.876, 95 percent CI, 1.290–2.778; p=0.001) significantly aggravated the risk of IFG. Blood iron (OR, 1.008, 95 percent CI, 1.001–1.014; p=0.0019) and urinary lead (OR, 1.185, 95 percent CI, 1.022–1.376; p=0.025) had similar effects on diabetes mellitus.

“The underlying mechanisms regarding such an interaction are perhaps related to similar biotransportation ways, signaling pathways or other competitive/synergistic action of metals,” the researchers said. “Future research should explore the effects and mechanisms of metal-to-metal interactions on the aetiology of diabetes mellitus.”