Associations of Iron Intake, Serum Iron and Serum Ferritin with Bone Mineral Density in Women: The National Health and Nutrition Examination Survey, 2005-2010.

The relationship between iron and bone mineral density (BMD) is still poorly understood. We investigated the associations of iron intake, serum iron and serum ferritin with BMD. This cross-sectional study identified 4000 females aged 12 to 49 years with complete and valid data on iron intake, serum iron, serum ferritin, and femoral neck and lumbar spine BMD from the National Health and Nutrition Examination Survey 2005-2010. Daily iron intake was the mean intake of iron nutrient ascertained from two consecutive 24-h dietary recalls; serum iron and serum ferritin were directly measured with established methods. Femoral neck and lumbar spine BMD were measured by Dual-energy X-ray absorptiometry (DXA). After adjusting for multiple covariates (i.e., age, body mass index and race), we used linear regression and generalized additive models (GAMs) to test the linear and non-linear associations of iron intake, serum iron and serum ferritin with BMD. The mean age of this study was 27.70 years (SD = 11.88 years). Higher serum ferritin was associated with lower femoral neck and lumbar spine BMD (all adjusted P < 0.05); iron intake and serum iron were not associated with femoral neck and lumbar spine BMD. Similar results were found when iron levels were classified as iron deficiency, normal iron and iron overload. There were no obvious non-linear relationships between the above three iron variables and BMD in the GAM analyses. There was a negative and linear association between serum ferritin and BMD; iron intake and serum iron were not associated with BMD. Serum ferritin appeared to be a better iron variable than iron intake and serum iron in relation to BMD.

The Study on the Correlation Between Six Kinds of Mineral Elements and Diabetes.

The study aimed to explore the relationship of six kinds of mineral elements and diabetes among adults in northeast China. A cross-sectional survey was conducted in Jilin Province, northeast China. A total of 366 males and 204 females aged 18 ~ 77 years from Jingyu town, Dongliao town, and Changling town were included using a multistage stratified random cluster sampling design. Data was obtained from face to face interview, physical examination, and laboratory measurement. We defined the normal people (3.9 ~ 6.0 mmol/L), impaired fasting glucose (IFG) individuals (6.1 ~ 6.9 mmol/L), and diabetes mellitus (DM) (> 7.0 mmol/L) according to the WHO diagnostic criteria. Kruskal-Wallis test, Spearman rank correlation, as well as binary logistic regression were used to analyze influencing factors. lg(Cu/Zn)was correlated with DM (OR 8.390; 95% CI of OR 1.272-55.347). The specific mineral elements such as Zn, Ca, as well as Cu/Zn ratio may be the potential risk factors for diabetes. So, the supplement or reduction of these elements is supposed to be told to IFG to prevent or delay the occurrence of diabetes or DM to avoid its complication.