Effect of parathyroid hormone on serum magnesium levels: the neglected relationship in hemodialysis patients with secondary hyperparathyroidism

Abnormalities of serum magnesium levels in dialysis patients undergoing parathyroidectomy

In primary hyperparathyroidism, postoperative hypocalcemia can be exacerbated by magnesium deficiency. However, the significance of magnesium homeostasis in surgery for secondary hyperparathyroidism is unknown. In this study, 268 consecutive adult patients on renal replacement therapy who underwent parathyroidectomy for secondary hyperparathyroidism were included for analysis. We found that about one fifth presented with hypomagnesemia (5.6%) or hypermagnesemia (14.6%). Hypomagnesemia was associated with lower calcium levels and longer postoperative hospital stays. Hypermagnesemia was associated with higher calcium-phosphorus products and lower parathyroid hormone levels. In multivariate analysis, patient age, alkaline phosphatase, and osteocalcin were independent predictors of prolonged stay after parathyroidectomy. There was a positive correlation between serum magnesium levels and severity of itching in these patients. Calcium-phosphorus products and serum magnesium levels were independently associated with pruritus. In conclusion, magnesium abnormalities play a minor role in hungry bone syndrome after parathyroidectomy for secondary hyperparathyroidism. Patients with higher serum magnesium levels had greater severity of pruritus.

Impact of Subtotal Parathyroidectomy on Clinical Parameters and Quality of Life in Hemodialysis Patients with Secondary Hyperparathyroidism

BACKGROUND

Impairment of quality of life (QOL) is a key clinical characteristic of patients with end-stage renal disease (ESRD), and can be especially severe in the presence of secondary hyperparathyroidism (SHPT). Despite the proven success of parathyroidectomy (PTX) in controlling biochemical parameters in patients with severe SHPT, evidence is lacking regarding the effects of PTX on various clinical outcomes, including QOL.

METHODS

Twenty ESRD patients on maintenance hemodialysis with SHPT who underwent subtotal PTX were included in an observational longitudinal study. All studied patients underwent history-taking, clinical examinations, and laboratory investigations, including a complete blood count and measurements of serum calcium, phosphorus, magnesium, parathyroid hormone (PTH), and albumin levels preoperatively and at 3 months postoperatively. QOL was assessed before surgery and at 3 months after surgery using the Kidney Disease Quality of Life 36-Item Short-Form instrument.

RESULTS

After PTX, significant decreases in serum PTH and phosphorus levels were observed, as well as a significant increase in serum magnesium levels. Significant weight gain and improvements of QOL were also detected postoperatively.

CONCLUSION

Subtotal PTX seems to be an efficient alternative to medical management in uncontrolled cases of SHPT, as it is capable of controlling the biochemical derangements that occur in hyperparathyroidism. Furthermore, PTX had a beneficial effect on clinical outcomes, as shown by weight gain and improvements in all QOL scales.

Combined use of a nanocarbon suspension and 99mTc-MIBI for the intra-operative localization of the parathyroid glands

OBJECTIVE

To investigate the combined use of a nanocarbon (NC) suspension and low-dose ^99mTc-MIBI for parathyroid localization during surgery in patients with secondary hyperparathyroidism (sHPT).

METHODS

Between March 2010 and September 2015, 40 patients with sHPT were enrolled in this study and were randomized to receive either low-dose ^99mTc-MIBI+NC (group I) or low-dose ^99mTc-MIBI (group II). Pre- and post-operative serum levels of intact PTH (iPTH), calcium and phosphorus between groups were compared and the intra-operative radioactive counts of the parathyroid glands were measured.

RESULTS

The post-operative iPTH level was significantly lower in patients of group I (24.2±31ng/L) than in those of group II (106±155ng/L) (P=0.03) while there were no significant differences in intra-operative parathyroid gland radioactive counts between the groups. The duration of the surgical procedure was shorter for patients of group I than patients of group II. There were no serious intra-operative or post-operative complications.

CONCLUSION

The combined use of an NC suspension and ^99mTc-MIBI for patients with sHPT is strongly recommended for the localization of parathyroid glands during surgery and is likely to improve clinical outcomes for patients.

Serum Magnesium Abnormality and Influencing Factors of Serum Magnesium Level in Peritoneal Dialysis Patients: A Single-Center Study in Northern China

Background/Aims: Both hypomagnesemia and hypermagnesemia have been associated with cardiovascular diseases, bone diseases, and mortality in dialysis patients. We aimed to investigate the prevalence of and influencing factors for abnormal serum Mg levels in patients on peritoneal dialysis (PD). Methods: A cross-sectional study in Peking University People’s Hospital recorded the demographic information, clinical characteristics, and laboratory data. Data were assessed and compared with the results from 2 other studies in China. Results: Of 180 enrolled PD patients, the primary diseases were glomerulonephritis (38.3%) and diabetic nephropathy (38.3%). Mean serum Mg concentration was 1.02 ± 0.16 mmol/L; 67% had normal serum Mg concentrations, and 33% had hypermagnesemia. Conclusions: Hypermagnesemia is likely to occur in patients with higher serum phosphate, lower intact parathyroid hormone, and lower high-sensitivity C-reactive protein levels. Serum Mg level distributions in PD patients vary throughout China, may have different potential causes (such as geographical location and dietary habits) and should be further studied.

Magnesium disorders can cause calcium pyrophosphate deposition disease: A case report and literature review

Calcium pyrophosphate deposition (CPPD) disease, also known as pseudogout, is one of the most common forms of inflammatory arthritis. A variety of comorbidities and metabolic conditions have been recognized to predispose to CPPD. We describe here a patient with chronic CPP arthritis due to hypomagnesemia, which is one of the metabolic etiologies associated with CPPD, especially in younger patients. We also performed a literature search and reviewed all reported cases of CPPD disease associated with hypomagnesemia. All cases of hypomagnesemia and its etiologies leading to CPP arthropathy identified in the literature by this systematic search are summarized in this paper.