Manganese intake may reduce risk of incident kidney stones
A recent study has found that zinc and iron intake is not associated with the risk of kidney stones, copper intake may be associated with a higher risk in some individuals, while higher total manganese intake is associated with a reduced risk but not with traditional 24-hour urinary composite markers of stone risk.
No significant association existed between total and dietary intakes of zinc and iron and incident stones after multivariable adjustment. On the other hand, higher manganese intake correlated with a lower risk of stones. The highest quintile of total manganese intake vs the lowest quintile had a pooled hazard ratio (HR) of 0.82 (95 percent CI, 0.68–0.98; p=0.02).
Moreover, there was a marginal association between total but not dietary copper intake and greater risk of stones (pooled HR, 1.14; 1.02–1.28; p=0.01). Total intake of manganese and copper was not statistically associated with urinary supersaturation.
“Further research is needed to elucidate the mechanisms by which manganese may reduce kidney stone formation,” the authors said.
A prospective analysis was performed on 193,551 participants in the Health Professionals Follow-up Study and the Nurses’ Health Study I and II. A total of 6,576 incident stones were recorded during a follow-up of 3,316,580 person-years.
The authors used multivariate regression models to identify associations of the intake of zinc, iron, copper and manganese with the risk of stones. They also examined the association between the intake of trace metals and urine composition in a subgroup of participants with 24-hour urine collections.