Timothy L Middleton1,2, Jencia Wong3,2, Lynda Molyneaux3, Belinda A Brooks3,4, Dennis K Yue3,2, Stephen M Twigg3,2, Ted Wu3. 1. Diabetes Centre, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia timothy.middleton@sswahs.nsw.gov.au. 2. Department of Medicine, University of Sydney, Sydney, New South Wales, Australia. 3. Diabetes Centre, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia. 4. School of Nursing, University of Sydney, Sydney, New South Wales, Australia.
Abstract
OBJECTIVE: To determine the effect of sulfonylurea-related hypoglycemia on cardiac repolarization and ectopy in the setting of well-controlled type 2 diabetes. RESEARCH DESIGN AND METHODS: Thirty subjects with sulfonylurea-treated type 2 diabetes underwent 48 h of concurrent continuous glucose monitoring and ambulatory electrocardiography. Ventricular repolarization (QTc) and QT dynamicity were analyzed during periods of hypoglycemia (<3.5 mmol/L for >20 min) and compared with periods of euglycemia and hyperglycemia combined. Cardiac ectopy rates during hypoglycemia were compared with ectopy rates when blood glucose was 4-10 mmol/L. RESULTS: Mean HbA1c was 6.9% (52 mmol/mol). Hypoglycemia was detected in 9 of 30 subjects (30%); episodes were typically nocturnal (67%) and asymptomatic (73%). Hypoglycemia-associated QTc prolongation was seen in five of nine subjects with a large variation in individual response. Higher QT dynamicity, a poor prognostic factor in cardiac disease, was seen in subjects who experienced hypoglycemia compared with subjects who did not (0.193 vs. 0.159 for the nocturnal period; P = 0.01). This finding persisted after the hypoglycemic event. The rates of ventricular and supraventricular ectopy demonstrated a nonsignificant trend toward an increase during hypoglycemia (median rate ratio 1.58 and 1.33, respectively). Similar, nonsignificant results were observed in a separate insulin-treated cohort. CONCLUSIONS: Hypoglycemia, often unrecognized, is a frequent finding in well-controlled sulfonylurea-treated type 2 diabetes. It is associated with the novel finding of increased QT dynamicity and QTc prolongation in some individuals. Our findings suggest sulfonylurea-related hypoglycemia can have detrimental cardiovascular sequelae. Similar effects are also seen in the setting of insulin therapy.
OBJECTIVE: To determine the effect of sulfonylurea-related hypoglycemia on cardiac repolarization and ectopy in the setting of well-controlled type 2 diabetes. RESEARCH DESIGN AND METHODS: Thirty subjects with sulfonylurea-treated type 2 diabetes underwent 48 h of concurrent continuous glucose monitoring and ambulatory electrocardiography. Ventricular repolarization (QTc) and QT dynamicity were analyzed during periods of hypoglycemia (<3.5 mmol/L for >20 min) and compared with periods of euglycemia and hyperglycemia combined. Cardiac ectopy rates during hypoglycemia were compared with ectopy rates when blood glucose was 4-10 mmol/L. RESULTS: Mean HbA1c was 6.9% (52 mmol/mol). Hypoglycemia was detected in 9 of 30 subjects (30%); episodes were typically nocturnal (67%) and asymptomatic (73%). Hypoglycemia-associated QTc prolongation was seen in five of nine subjects with a large variation in individual response. Higher QT dynamicity, a poor prognostic factor in cardiac disease, was seen in subjects who experienced hypoglycemia compared with subjects who did not (0.193 vs. 0.159 for the nocturnal period; P = 0.01). This finding persisted after the hypoglycemic event. The rates of ventricular and supraventricular ectopy demonstrated a nonsignificant trend toward an increase during hypoglycemia (median rate ratio 1.58 and 1.33, respectively). Similar, nonsignificant results were observed in a separate insulin-treated cohort. CONCLUSIONS:Hypoglycemia, often unrecognized, is a frequent finding in well-controlled sulfonylurea-treated type 2 diabetes. It is associated with the novel finding of increased QT dynamicity and QTc prolongation in some individuals. Our findings suggest sulfonylurea-related hypoglycemia can have detrimental cardiovascular sequelae. Similar effects are also seen in the setting of insulin therapy.
Authors: Sridharan Raghavan; Wenhui G Liu; David R Saxon; Gary K Grunwald; Thomas M Maddox; Jane E B Reusch; Seth A Berkowitz; Liron Caplan Journal: BMJ Open Diabetes Res Care Date: 2018-06-15
Authors: Andreas Andersen; Jonatan I Bagger; Samuel K Sørensen; Maria P A Baldassarre; Ulrik Pedersen-Bjergaard; Julie L Forman; Gunnar Gislason; Tommi B Lindhardt; Filip K Knop; Tina Vilsbøll Journal: Cardiovasc Diabetol Date: 2021-12-24 Impact factor: 9.951