Derangement of glucose metabolism in hyperparathyroidism

Abstract

The derangement of glucose metabolism is found frequently in all forms of hyperparathyroidism. Both in primary (PHPT) and secondary hyperparathyroidism (SHPT) PTH excess is thought to be involved in deteriorating insulin sensitivity and secretion though their different clinical and pathophysiological conditions. In PHPT these abnormalities are related to a high frequency of Type 2 diabetes mellitus and also impaired glucose tolerance according to recent clinical studies, without differences between symptomatic and asymptomatic clinical presentation. In chronic renal failure (CRF), the disorders of glucose metabolism due to SHPT do not bear an increased risk for diabetes whereas they seem to be involved in the progression of atherosclerotic vascular damage which connotes CRF. Moreover, clinical and experimental studies have shown that vitamin D deficiency associated with glucose metabolism abnormalities favors the development of the metabolic syndrome. The potential for metabolic and cardiovascular harm related to hyperparathyroidism, especially PHPT, is the most interesting issue for clinical endocrinologists. This short review of the clinical and pathophysiological data of literature on glucose homeostasis disorders in hyperparathyroidism focuses on its potential clinical and therapeutic impact, particularly in the management of PHPT.

Vitamin D and type 2 diabetes mellitus: Where do we stand?

“…The relationship between vitamin D, Ca and insulin was elucidated in 1967, when Milner and Hales [17] showed that, in animals, Ca and magnesium (tightly regulated by the VTD system) were essential for insulin secretion. Also, having an inadequate VTD status may play a role in insulin resistance [18][19][20][21]: indeed, VTD has a direct effect on insulin action, as it stimulates the expression of the insulin receptor and, thus, enhances responsiveness for glucose transport [22]. Vitamin D also has indirect (Ca-mediated) effects on insulin action: Ca is tightly regulated, and intracellular Ca 2+ concentrations must be kept within an extremely narrow range for the optimal action of insulin on different insulin-responsive tissues, such as skeletal muscle and fat tissue [23][24][25].…”

Hyperparathyroidism and New Onset Diabetes After Renal Transplantation

“…A higher prevalence of DM has been detected in patients with pHPT. 10,13,15 Reports on the effect of parathyroidectomy (PTX) on DM in patients with pHPT are contradictory. Some studies have shown a beneficial effect, 15,32 one no benefit 33 and one partial improvement.…”

“…3,4 The ensuing hypercalcemia can lead to interstitial calcification in the allograft with graft dysfunction 5,6 and soft tissue calcification. 7,8 Primary hyperparathyroidism (pHPT) 9,10 and sHPT 11,12 are both associated with abnormalities in glucose metabolism, such as glucose intolerance and insufficient insulin release. Furthermore, a higher prevalence of diabetes mellitus (DM) has been reported in patients with pHPT.…”

Association of serum vitamin D and parathormone levels in patients of type 2 diabetes mellitus with diabetic retinopathy

“…It is shown through different studies that parathormone excess can reduce glucose tolerance 16 and induce inflammatory cytokines like IL-6 and its soluble receptor (IL-6sR) 17 and thereby may contribute to development and progression of diabetic retinopathy.…”