Association between first-line monotherapy with metformin and the risk of atrial fibrillation (AMRAF) in patients with type 2 diabetes.

BACKGROUND: Type 2 diabetes (T2D) has a strong association with atrial fibrillation (AF) which increases risk of thromboembolic events, heart failure, and frequent hospitalizations. Metformin is the first-line medication for T2D with proposed anti-inflammatory, pro-metabolic, and cardio-protective benefits. Our objective was to investigate if initial therapy with metformin is associated with reduced incidence of AF in comparison to other non-insulin anti-hyperglycemic agents in patients with newly diagnosed T2D. METHODS: This retrospective cohort analysis included adults with a new diagnosis of T2D who were started on monotherapy (except insulin) between 2007 and 2017, without prior anti-hyperglycemic agent use, history of arrhythmias, or estimated GFR (eGFR) ≤ 30 ml/min. A multivariate analysis was performed using a fine-gray regression competing risk analysis to control for confounding variables after which pooled hazard ratios and 95 % confidence intervals were reported. Patients were followed until the end of study date, development of AF, addition of more anti-hyperglycemic agents, or death, whichever occurred first. RESULTS: Among 4584 metformin initiators compared to 1080 non-metformin monotherapy initiators, 10-year cumulative incidence of AF in metformin group was 5.2 % as compared to 8.1 % with other agents which was not statistically significant. Competing risk analysis did not demonstrate reduced rates of AF with metformin use (HR 0.92, 95 % CI 0.69 to 1.21; P = 0.55). Increased age and the presence of congestive heart failure were associated with significantly higher risk of AF in both groups (HR: 1.29, 95 % CI: 1.21 to 1.37; P ≤ 0.001; HR: 2.73, 95 % CI: 1.62 to 4.61; P ≤ 0.001, respectively). CONCLUSION: Initiation of metformin as a first line monotherapy for T2D, when compared to other non-insulin monotherapies, was not associated with decreased risk of developing AF in this retrospective observational study.

Early Post-Renal Transplant Hyperglycemia.

CONTEXT: Though posttransplant diabetes mellitus (PTDM, occurring > 45 days after transplantation) and its complications are well described, early post-renal transplant hyperglycemia (EPTH) (< 45 days) similarly puts kidney transplant recipients at risk of infections, rehospitalizations, and graft failure and is not emphasized much in the literature. Proactive screening and management of EPTH is required given these consequences. OBJECTIVE: The aim of this article is to promote recognition of early post-renal transplant hyperglycemia, and to summarize available information on its pathophysiology, adverse effects, and management. METHODS: A PubMed search was conducted for "early post-renal transplant hyperglycemia," "immediate posttransplant hyperglycemia," "post-renal transplant diabetes," "renal transplant," "diabetes," and combinations of these terms. EPTH is associated with significant complications including acute graft failure, rehospitalizations, cardiovascular events, PTDM, and infections. CONCLUSION: Patients with diabetes experience better glycemic control in end-stage renal disease (ESRD), with resurgence of hyperglycemia after kidney transplant. Patients with and without known diabetes are at risk of EPTH. Risk factors include elevated pretransplant fasting glucose, diabetes, glucocorticoids, chronic infections, and posttransplant infections. We find that EPTH increases risk of re-hospitalizations from infections (cytomegalovirus, possibly COVID-19), acute graft rejections, cardiovascular events, and PTDM. It is essential, therefore, to provide diabetes education to patients before discharge. Insulin remains the standard of care while inpatient. Close follow-up after discharge is recommended for insulin adjustment. Some agents like dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists have shown promise. The tenuous kidney function in the early posttransplant period and lack of data limit the use of sodium-glucose cotransporter 2 inhibitors. There is a need for studies assessing noninsulin agents for EPTH to decrease risk of hypoglycemia associated with insulin and long-term complications of EPTH.

Insulinoma With Concomitant Insulin Antibodies.

OBJECTIVE: The coexistence of insulinoma and insulin antibodies is extremely rare. The aim of this novel case report is to inform physicians of the possibility of an insulinoma with concomitant insulin antibodies. METHODS: In this report, we describe a patient with symptomatic hypoglycemia confirmed with a 72-hour fast, who was subsequently found to have an insulinoma with concomitant elevation in his immunoglobulin G insulin antibody titer. RESULTS: The patient presented with initial symptoms of diaphoresis, confusion, and disorientation and was found unresponsive by a bystander. He had a fingerstick blood glucose of 36 mg/dL (reference 74-99 mg/dL), without exogenous insulin or sulfonylurea use. His symptoms resolved with administration of glucose. He was subsequently admitted for a 72-hour fast in which he developed neuroglycopenic symptoms 4 hours into the fast with fingerstick glucose of 47 mg/dL and serum glucose of 44 mg/dL (reference 74-99 mg/dL), C-peptide of 10.8 ng/mL (reference 0.5-2.7 ng/mL), insulin level of 106 µIU/mL (reference <25 µIU/mL), and a proinsulin level of 675 pmol/mL (reference <22 pmol/mL). His insulin-to-C-peptide ratio was 0.20, in which a ratio <1 is indicative of an insulinoma. Endoscopic ultrasound demonstrated a 16 x 11 mm biopsy-proven neuroendocrine tumor. He was found to have a high titer insulin antibody titer at 2.4 U/mL (reference <0.4 U/mL), was started on prednisone, and underwent successful radiofrequency ablation. He was able to be successfully tapered off steroids without recurrence. CONCLUSION: The coexistence of insulinoma with insulin antibodies is novel, and to our knowledge, has never been published.