PTH and Hypocalcemia: When taking them together, a mean reduction of PTH levels of 73 ± 11 per cent was observed in the patient cohort that developed hypocalcaemia, whereas the group of patients with a mean reduction of PTH levels of 39.5 ± 7.3 per cent had no hypocalcaemia in the following course (P < 0.0001; Fig. 6).