The Effect of Parathyroidectomy on Insulin Sensitivity in Patients with Primary Hyperparathyroidism – an never Ending Story?

Abstract

Previous studies demonstrated insulin resistance and increased prevalence of impaired glucose tolerance and type 2 diabetes mellitus in patients with primary hyperparathyroidism (PHPT). The effect of curative parathyroidectomy on insulin sensitivity was associated with conflicting results depending on which method for measuring the insulin sensitivity has been used. There was no improvement using HOMA and QUICKI while minimal model demonstrated significant improvement in insulin sensitivity. The aim of our study was to evaluate the insulin sensitivity before and after parathyroidectomy in patients with PHPT using a euglycemic clamp. 44 patients with PHPT and 11 age and body mass index matched healthy controls participated in study protocol. Before surgery M values and HOMA IR suggest insulin resistance in patients with PHPT. There was no difference in M index (3.74±1.89 vs. 4.62±2.27, p>0.05), HOMA IR (2.94±1.39 vs. 3.29±0.81, p>0.05), AUC glucose (863.0±261.3 vs. 842.3±165.5, p>0.05), AUC insulin (7068.7±4159.0 vs. 7229.6±2581.7, p>0.05), ISI (4.73±2.77 vs. 4.25±2.94, p>0.05) and AIR (47.89±32.05 vs. 38.96±21.20, p>0.05) between patients with PHPT and HC. There was significant improvement in insulin sensitivity after parathyroidectomy but both preoperative and postoperative M values were not significantly different in comparison to HC. There were no significant changes in HOMA IR, AUC glucose, AUC insulin, ISI and AIR before and after therapy. In conclusion, we observed significant improvement in insulin sensitivity after parathyroidectomy in patients with PHPT. There was no difference in parameters of insulin secretion before and after parathyroidectomy in patients with PHPT.

Parathyroid hormone stimulates adipose tissue browning

“…Another potential interaction between the development of insulin resistance and PTH is that patients with primary hyperparathyroidism are at high risk for developing type 2 diabetes or insulin resistance [13]: insulin sensitivity improves with parathyroidectomy [13]. This association is relevant because type 2 diabetes does not stimulate WAT browning nor does it increase Ucp1 but it does cause muscle wasting [8].…”

Effect of curative parathyroidectomy on insulin resistance

“…There are few studies, which demonstrated the improvement of IR after CPTX in patients with PHPT. [910] But at the same time, few studies showed that there was no improvement in IR and metabolic risk factors after CPTX in patients with PHPT. [111213] The present study was designed to observe the effect of CPTX on peripheral IR in patients with PHPT of varying severity.…”

Rising Glucagon-Like Peptide 1 Concentrations After Parathyroidectomy in Patients With Primary Hyperparathyroidism

“…42 Previous large-scale observational and epidemiologic results also indicate that increased PTH concentrations are positively associated with abnormal glucose metabolism. 10,43 In an epidemiologic study (n ¼ 1071; 40-65 y), serum PTH was positively correlated with fPG. 43 Despite the fact that available evidence suggests a solid pathophysiological background associating PHPT with impairment of glucose homeostasis, potential beneficial effects of PTX on glucose homeostasis remain controversial.…”

“…[6][7][8][9] Several studies implicated both hypercalcemia and increased PTH concentration with impairment of glucose sensitivity and an increase in insulin resistance (IR), in normoglycemic patients with PHPT. 3,[10][11][12] However, the exact pathophysiological pathways of these biophenomena have not been elucidated, so far. Moreover, hypovitaminosis D, which is highly prevalent in asymptomatic PHPT, has been also hypothesized to be involved in the impairment of glucose homeostasis in people with asymptomatic PHPT.…”