Denosumab-induced hypocalcemia post bariatric surgery-a severe and protracted course: a case report.

BACKGROUND: Denosumab is known to cause abnormalities in calcium homeostasis. Most of such cases have been described in patients with underlying chronic kidney disease or severe vitamin D deficiency. Previous bariatric surgery could also contribute to hypocalcemia and deterioration in bone health. CASE PRESENTATION: We present a case of a 61-year-old Malay female with worsening bilateral limb weakness, paresthesia, and severe carpopedal spasm a week after receiving subcutaneous denosumab for osteoporosis. She had a history of gastric bypass surgery 20 years ago. Post gastric bypass surgery, she was advised and initiated on lifelong calcium, vitamin D, and iron supplementations that she unfortunately stopped taking 5 years after surgery. Her last serum blood tests, prior to initiation on denosumab, were conducted in a different center, and she was told that she had a low calcium level; hence, she was advised to restart her vitamin and mineral supplements. Laboratory workup revealed severe hypocalcemia (adjusted serum calcium of 1.33 mmol/L) and mild hypophosphatemia (0.65 mmol/L), with normal magnesium and renal function. Electrocardiogram showed a prolonged QTc interval. She required four bolus courses of intravenous calcium gluconate, and three courses of continuous infusions due to retractable severe hypocalcemia (total of 29 vials of 10 mL of 10% calcium gluconate intravenously). In view of her low vitamin D level of 33 nmol/L, she was initiated on a loading dose of cholecalciferol of 50,000 IU per week for 8 weeks. However, despite a loading dose of cholecalciferol, multiple bolus courses, and infusions of calcium gluconate, her serum calcium hovered around only 1.8 mmol/L. After 8 days of continuous intravenous infusions of calcium gluconate, high doses of calcitriol 1.5 µg twice daily, and 1 g calcium carbonate three times daily, her serum calcium stabilized at approximately 2.0 mmol/L. She remained on these high doses for over 2 months, before they were gradually titrated down to ensure sustainability of a safe calcium level. CONCLUSION: This case report highlights the importance of screening for risk factors for iatrogenic hypocalcemia and ensuring normal levels before initiating denosumab. The patient history of bariatric surgery could have worsened the hypocalcemia, resulting in a more severe presentation and protracted response to oral calcium and vitamin D supplementation.

Abnormal glucose tolerance in women with prior gestational diabetes mellitus: a 4-year follow-up study.

BACKGROUND: Adoption of the International Association of Diabetes and Pregnancy Study Group (IADPSG) criteria for diagnosis of gestational diabetes mellitus (GDM) varies worldwide. Early detection of women at increased risk of developing type 2 diabetes mellitus (T2DM) following GDM enables initiation of measures to delay disease onset. OBJECTIVES: To determine the 4-year cumulative incidence and risk factors for developing abnormal glucose tolerance (AGT) among women with previous GDM using modified IADPSG criteria. Additionally, to review post-natal attendance at diabetes screening and the impact of post-partum lifestyle modifications and breastfeeding on the risk of T2DM development. METHODS: Four hundred twenty-six women with a prior history of GDM were invited to participate in the study, 4 years after the index pregnancy. The following were completed: body measurements, oral glucose tolerance test (OGTT), glycated haemoglobin (HbA1c), vitamin D, and other biochemistry measurements. Participants also completed a lifestyle questionnaire. RESULTS: Of the 74 women who participated, 15 (20%) had AGT. Predictive factors for AGT development were as follows: fasting glucose levels (p = 0.004), HbA1c (p = 0.008) at GDM diagnosis, and early pregnancy BMI (p = 0.001). Thirty-three (45%) women had not attended their postnatal screening. The odds ratio of the association between breastfeeding and AGT development was 0.16 (95% CI: 0.05 to 0.53). CONCLUSION: The proportion of women who develop AGT after a diagnosis of GDM remains high. The factors associated with progression to AGT are available at GDM diagnosis. Preventing AGT in this group is possible by supporting breastfeeding. Attendance at post-natal screening should also be encouraged.