008–17-year-3-Month-Old Female with CF and Hypoglycemia

Abstract

Patient Demographics: Patient is a 17-year-3-month-old Caucasian female Clinical Presentation: Patient presented to clinic with post prandial hypoglycemia without the use of exogenous insulin. Relevant Past History: She has a history of hypothyroidism, impaired glucose tolerance, cystic fibrosis (CF) diagnosed at birth due to meconium ileus, and celiac disease. Weight 45.6 kg (42%) and height 1.48m (1%). Family history includes brother with CF, mother with hypothyroidism, and father with hypertension. Evaluation: Workup included oral glucose tolerance test (OGTT), HgbA1c, diabetes autoimmune panel, and thyroid studies. OGTT was remarkable for fasting BG=95, 1 hr BG= 309, 2 hr= 248. HgbA1c 6.1%. All other labs were normal. Continuous glucose monitoring (CGM) revealed postprandial hyperglycemia after meals with overcorrection causing lows (60’s) without exogenous insulin use. Interventions: Management of CFRD is best with a team approach including patient, family, pulmonary and endocrine teams. Management includes blood glucose monitoring, nutritional counseling, and insulin. Patient and family completed diabetes education training with a CDE and RD, and were taught to monitor postprandial blood sugar 1-2 hours after meals and to carbohydrate count. Patient was started on 2 units Lantus insulin daily and Novolog insulin prior to all meals/snacks. Patient returned 3 months later and postprandial hypoglycemia was eliminated with initiation of pre-meal insulin. Discussion/Recommendations: CFRD is the most common co-morbidity in CF. The average age of onset is 18-21 years, affecting 20% of adolescents and 40-50% of adults. With a combination of insulin deficiency and insulin resistance, CFRD worsens the prognosis of CF and is associated with worsening pulmonary function, increased infections, nutritional decline, and increased mortality. Postprandial and OGTT-related hypoglycemia is common in CF. Postprandial hypoglycemia is associated with early glucose dysregulation (higher peak plasma glucose) and arises from late secretion of endogenous insulin. Administration of insulin at meals may prevent hyperglycemia excursions and blunt post-prandial hypoglycemia events. CFRD should always be a differential diagnosis for any patient who presents to endocrine clinic with postprandial hypoglycemia. Endocrine nurses are in an important position to educate patients regarding symptomatology, pathophysiology, and treatment of CFRD.