Prevalence and possible mechanisms of reactive hypoglycemia in polycystic ovary syndrome

STUDY QUESTION: What is the prevalence of reactive hypoglycemia (RH) in polycystic ovary syndrome (PCOS) versus age-and body mass index (BMI)-matched healthy controls. SUMMARY ANSWER: The prevalence of RH was increased in PCOS versus controls. WHAT IS KNOWN ALREADY: Previous studies suggested an increased prevalence of RH in PCOS. STUDY DESIGN, SIZE, DURATION: Cross-sectional study of 88 women with PCOS and 34 healthy age-and BMI-matched controls. PARTICIPANTS/MATERIALS, SETTING, METHODS: Eighty-eight women with PCOS and 34 age-and BMI-matched controls were included. The study was conducted at Odense University Hospital, Denmark. Participants underwent 5 h oral glucose tolerance test (5 h OGTT). Indices of insulin resistance, beta-cell function, and area under the curve (AUC) for glucose, insulin and C-peptide were calculated. Insulin clearance was estimated as 5 h AUC C-peptide/insulin. RH was defined as blood glucose <= 3.3 mmol/l during 5 h OGTT. MAIN RESULTS AND THE ROLE OF CHANCE: RH occurred in 15/88 (17%) women with PCOS versus 0/34 controls (P = 0.01). Nine out of 15 women with RH were obese and 6 were lean (P = 0.42). Obese patients with RH had significantly higher 5 h AUC sinsulin and C-peptide compared with lean patients with RH (P = 0.02 and 0.04, respectively). Obese patients with RH had significantly lower 5 h AUC C-peptide/insulin versus obese patients without RH (P = 0.02). In lean patients with RH, 5 h AUCs insulin and C-peptide were similar to lean controls. LIMITATIONS, REASONS FOR CAUTION: The 5 h OGTT was used to diagnose RH and may be a limitation of the study. Although the 5 hOGTTis the most widely accepted method, no gold standard exists in terms of diagnosing RH. The 5 hOGTT was suggested to over-estimate the incidence of RH compared with meal test. WIDER IMPLICATIONS OF THE FINDINGS: The study supports previous suggestions of increased prevalence of RH in women with PCOS compared with controls. STUDY FUNDING/COMPETING INTERESTS: This study was funded by Jacob Madsen's and Olga Madsen's Foundation, Institute of Clinical Research, Odense University Hospital, Kolding Hospital, AP Moller's Foundation, Bernhard and Marie Kleins Foundation, The Novo Nordisk Foundation, and The Danish Medical Association. The authors declare no conflict of interest.