INS and Insulin resistance: Duran et al. [32] further note that at two months post-parathyroidectomy, there is a reduction in insulin resistance (HOMA-IR) (p = 0.003) and serum insulin (p = 0.003), in addition to noting a positive correlation between pre-operative calcium and both pre-operative insulin (r = 0.480, p = 0.028) and HOMA-IR (r = 0.478, p = 0.028).