Correction. Renal control of calcium, phosphate, and magnesium homeostasis

Association between serum phosphorus and mortality in NHANES 2003-2006: the effect of gender and renal function

BACKGROUND

The impact of high serum phosphorus in the general population is still debated. Studies are heterogeneous, most lack an adjustment for parathyroid hormone, vitamin D and phosphorus intake and the effect might differ by gender and renal function. We investigated the association between serum phosphorus and mortality in American adults.

METHODS

We prospectively analyzed 5698 non-pregnant and non-CKD adults from the National Health and Nutrition Examination Survey (NHANES) 2003-2006. Serum phosphorus and potential confounders including parathyroid hormone, 25(OH)vitamin D and phosphorus intake were evaluated. All-cause, cardiovascular- and cancer-related deaths were recorded through December 31st, 2015. Sex-specific terciles of serum phosphorus were used to fit adjusted Cox proportional hazard models for mortality. Analysis was stratified by gender and renal function.

RESULTS

A total of 590 deaths were recorded over a median follow-up of 81 months. Women showed higher serum phosphorus than men. The adjusted hazard ratio (HR) for all-cause mortality was 1.35 (95% CI 1.08-1.58) (p = 0.033) for the third tercile (versus second tercile). This increased risk was present in participants with estimated glomerular filtration rate (eGFR) below 90 ml/min/1.73 m² but not above, although interaction was not significant (p = 0.12). Interaction by gender, phosphorus intake, PTH and fasting time was also not detected. For cardiovascular and cancer mortality, the adjusted HR was 0.81 (95% CI 0.33-2.00) (p = NS) and 1.45 (95% CI 0.77-2.72) (p = NS), respectively.

CONCLUSIONS

We demonstrated that the highest tercile of serum phosphorus is associated with increased all-cause mortality, irrespective of PTH, 25(OH)vitamin D or phosphorus intake. This association may differ by gender and renal function, but larger studies testing for effect modification are needed.

Proteinuria in relation to age-dependent changes in the plasma and urine concentrations of some electrolytes and hematological indices in Wistar rats

The study was carried out to determine the influence of proteinuria on plasma and urine concentrations of electrolytes and hematological indices in Wistar rats of different age groups. Eighty Wistar rats of both sexes were used for this study. Groups 1 and 2 each consisted of 8 one month old male and female rats; 3 and 4 had 8 three month old rats; 5 and 6 had 8 six month old rats; 7 and 8 had 8 nine month old rats; 9 and 10 had 8 twelve month old rats. The plasma sodium, potassium and calcium concentrations of 3 month old rats were significantly lower when compared with 1, 6, 9 and 12 months of age. Similarly, rats aged 3 months had significantly lower urine concentrations of sodium, potassium and calcium than rats of other age groups. A strong correlation was observed between the urine protein and urine sodium of the female rats at ages 3, 9 and 12 months but it was only significant at age 12 months (p = 0.105 and p = 0.021, respectively). Also, the female rats aged 3 and 12 months had a strong correlation between their urine protein and urine calcium (p = 0.002 and p = 0.131, respectively). The red blood cells, lymphocyte and monocyte counts of the rats increased gradually and peaked at age 9 months with a subsequent decline at 12 months of age. It was concluded that the influence of proteinuria on electrolytes was least observed in the rats aged 3 months, since they had reduced and consistent plasma and urine concentrations of electrolytes measured when compared with other age groups. This implies that long-term renal studies involving the use of rats must be carefully interpreted because of the changes in plasma and urine concentrations of electrolytes as the rats age.

Effect of tramadol addiction alone and its co-abuse with cannabis on urinary excretion of Copper, Zinc, and Calcium among Egyptian addicts

BACKGROUND

The use of illicit drugs has become a worldwide health problem. Substances with the potential to be abused may have direct or indirect effects on physiologic mechanisms that lead to organ system dysfunction and diseases.

OBJECTIVE

The present study aims to investigate the structural and reabsorption integrity of the nephron among Egyptian addicts of tramadol alone and coabused with cannabis.

METHODS

Sixty-five males were included in the study, they were classified into control group (G1=19), tramadol addicts group (G2=18), and tramadol coabused with cannabis addicts group (G3=28). Parameters investigated for structural integrity were urinary levels ofleucineaminopeptidase and N-acetyl-β-D-glucosaminidase, and urinary parameters for reabsorption integrity were levels of copper and zinc as well as calcium, also urinary creatinine was measured. In addition, urinary levels of tramadol and tetrahydrocannabinol were estimated.

RESULTS

Among the two addicted groups, all measured parameters were not significantly different in comparison with the control group except for urinary calcium excretion which was found to be significantly increased among the two addicted groups.

CONCLUSION

Both tramadol addiction alone or coabused with cannabis causes increased urinary excretion of calcium, indicating reabsorption dysfunction of calcium without affecting structural integrity along the nephron.