Endocrine Abstracts

Introduction: Differential diagnosis of hypocalcaemia is extensive, and careful diagnostic algorithm should be performed to adequately treat hypocalcaemic disorders.

Case report: Two female patients with hypocalcaemia are presented. The first one was 49 years old, admitted to hospital due to weakness, hampered mobility and bone pain (hips, thorax). Six years ago she was hospitalized due to chronic renal failure, osteoporosis, fractures of hip neck and both pubic bones, but did not take any medication. Current diagnostic procedures revealed several rib fractures (X-ray), and laboratory tests showed: iron deficiency, urea and creatinine increased, high alkaline phosphatase (297 U/l), low total serum (1.8 mmol/l) and ionizing calcium (0.56 mmol/l), low urinary calcium, low serum phosphate, low vitamin D (34 nmol/l) and vitamin B12 values, and high PTH (44.3 pmol/l) and bone markers. Densitometry (DXA) showed characteristics for severe osteoporosis. The diagnosis of osteomalacia was made, and therapy with calcitriol (2×0.25 μg/day), calcium (CaCO₃ 3×1 g), vitamin B12 and folate was introduced, with significant clinical improvement. Other patient was 39 years old, admitted due to chronic bone pain and suspected bone metastases on scintigraphy. Medical history revealed cerebral palsy, epilepsy and chronic gastritis. Diagnostic evaluation did not confirmed malignant disease, but hypocalcemia (1.97 mmol/l) and hypophosphatemia (0.46 mmol/l) were found. TSH (7.72 mIU/l) and PTH (21.3 pmol/l) were increased, with low vitamin D (9.3 nmol/l) and high alkaline phosphatase (360 U/l). DXA showed low bone mineral density. Final discharge diagnosis were osteomalacia, hypothyroidism and megaloblastic anemia. Calcium (CaCO₃ 1 g) and vitamin D replacement therapy (4000–6000 drops/day) were started, with clinical and laboratory tests improvement.

Conclusion: Calcium, PTH and vitamin D disorders require detailed medical history, diagnostic evaluation and differential diagnosis. Adequate therapy, monitoring and follow up guarantee well treated and satisfied patient.