PTH and type 2 diabetes mellitus: Primary hyperparathyroidism (PHPT), the third most common endocrine disease, after type 2 diabetes (T2D) and thyroid disorders (prevalence 1–3:1000 in the general population, up to 20:1000 in postmenopausal women) [100,101]; the hallmark features are hypercalcemia and increased or inappropriately normal levels of PTH [102].