Novo Nordisk has criticised as insufficient a recent study suggesting that people using Ozempic or Wegovy for treating obesity or type 2 diabetes may have an increased risk of developing a rare form of blindness.
Forbes reports that the study – of nearly 1 700 patients who either used semaglutide, the active ingredient in Ozempic and Wegovy, or another drug for treating type 2 diabetes or obesity – suggested a possible link between semaglutide and non-arteritic anterior ischaemic optic neuropathy (NAION), according to the Harvard-led research team.
Semaglutide is associated with a four times higher risk of NAION when used for treating type 2 diabetes and a seven times higher risk when used for obesity, they wrote in JAMA Ophthalmology.
Among the 710 patients with type 2 diabetes, the rate of developing NAION was 8.9% for those taking semaglutide, compared with 1.8% for patients taking other medications.
Patients who were prescribed semaglutide for weight loss treatment developed NAION at a rate of 6.7%, while patients taking other medications had a rate of 0.8%.
Semaglutide has “provided very significant benefits in many ways, but future discussions between a patient and their physician should include NAION as a potential risk”, Medscape reports study leader Joseph Rizzo, MD, with Massachusetts Eye and Ear and Harvard Medical School, as saying.
“It is important to appreciate, however, that the increased risk relates to a disorder that is relatively uncommon.”
“Given the numbers of participants who have been recruited to clinical trials and the large number of people globally who use GLP-1 RAs, we should be confident that if corroborated, the absolute risk of developing NAION in direct relation to taking semaglutide must indeed be rare,” Susan Mollan, MBcHP, of University Hospitals Birmingham NHS Foundation Trust, in England, wrote in a commentary published with the study.
Novo Nordisk said in a statement that the study lacked sufficient data to establish an association between semaglutide and NAION, adding that the disorder is “not an adverse drug reaction” for publicly available forms of the drug.
The Danish pharmaceutical firm also said the study’s design was limited because it was not conducted as a randomised controlled trial, in which patients are randomly assigned to one or two groups before being compared to a control group.
NAION is a rare form of blindness that largely affects older adults, according to the American Academy of Ophthalmology.
It occurs from a lack of sufficient blood flow to the eye’s optic nerve, which connects the brain to the eye. The disorder is found in about 10 in every 100 000 people over 50 in the US, and people with cardiovascular disease, diabetes, obstructive sleep apnoea or high cholesterol have an increased risk.
Researchers have studied the possible risks associated with Ozempic, Wegovy and other similar drugs as they’ve increased in popularity.
A study published last month suggested the drugs could result in reduced hip and spine bone mineral density when used without exercise, adding to concerns patients could lose muscle mass while taking GLP-1 drugs for weight loss.
Both the US Food and Drug Administration and European medical officials have also denied claims Ozempic could result in an increased risk of suicidal thoughts.
The FDA has said it was evaluating other possible side effects for the drug, including hair loss and aspiration, while some complaints suggest it could cause digestive issues like stomach paralysis, pancreatitis and bowel obstructions.
Study details
Risk of Nonarteritic Anterior Ischaemic Optic Neuropathy in Patients Prescribed Semaglutide
Jimena Tatiana Hathaway, Madhura Shah, David Hathaway, et al.
Published in JAMA Ophthalmology on 3 July 2024
Abstract
Importance
Anecdotal experience raised the possibility that semaglutide, a glucagon-like peptide 1 receptor agonist (GLP-1 RA) with rapidly increasing use, is associated with nonarteritic anterior ischaemic optic neuropathy (NAION).
Objective
To investigate whether there is an association between semaglutide and risk of NAION.
Design, Setting, and Participants
In a retrospective matched cohort study using data from a centralised data registry of patients evaluated by neuro-ophthalmologists at 1 academic institution from December 1, 2017, through November 30, 2023, a search for International Statistical Classification of Diseases and Related Health Problems, Tenth Revision code H47.01 (ischaemic optic neuropathy) and text search yielded 16 827 patients with no history of NAION. Propensity matching was used to assess whether prescribed semaglutide was associated with NAION in patients with type 2 diabetes (T2D) or overweight/obesity, in each case accounting for covarying factors (sex, age, systemic hypertension, T2D, obstructive sleep apnoea, obesity, hyperlipidemia, and coronary artery disease) and contraindications for use of semaglutide. The cumulative incidence of NAION was determined with the Kaplan-Meier method and a Cox proportional hazards regression model adjusted for potential confounding comorbidities. Data were analysed from 1 December 2017 until 30 November 2023.
Exposures
Prescriptions for semaglutide vs non–GLP-1 RA medications to manage either T2D or weight.
Main Outcomes and Measures
Cumulative incidence and hazard ratio of NAION.
Results
Among 16 827 patients, 710 had T2D (194 prescribed semaglutide; 516 prescribed non–GLP-1 RA antidiabetic medications; median [IQR] age, 59 [49-68] years; 369 [52%] female) and 979 were overweight or obese (361 prescribed semaglutide; 618 prescribed non–GLP-1 RA weight-loss medications; median [IQR] age, 47 [32-59] years; 708 [72%] female). In the population with T2D, 17 NAION events occurred in patients prescribed semaglutide vs 6 in the non–GLP-1 RA antidiabetes cohort. The cumulative incidence of NAION for the semaglutide and non–GLP-1 RA cohorts over 36 months was 8.9% (95% CI, 4.5%-13.1%) and 1.8% (95% CI, 0%-3.5%), respectively. A Cox proportional hazards regression model showed higher risk of NAION for patients receiving semaglutide (hazard ratio [HR], 4.28; 95% CI, 1.62-11.29); P < .001). In the population of patients who were overweight or obese, 20 NAION events occurred in the prescribed semaglutide cohort vs 3 in the non–GLP-1 RA cohort. The cumulative incidence of NAION for the semaglutide vs non–GLP-1 RA cohorts over 36 months was 6.7% (95% CI, 3.6%-9.7%) and 0.8% (95% CI, 0%-1.8%), respectively. A Cox proportional hazards regression model showed a higher risk of NAION for patients prescribed semaglutide (HR, 7.64; 95% CI, 2.21-26.36; P < .001).
Conclusions and Relevance
This study’s findings suggest an association between semaglutide and NAION. As this was an observational study, future study is required to assess causality.
Medscape article – Semaglutide Linked to Cause of Vision Loss (Open access)
Forbes article – Using Ozempic Or Wegovy Could Raise Risk For Rare Form Of Blindness, Study Suggests
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