Endocrinologists are challenging the long-standing use of sliding scale insulin, arguing it reflects outdated understanding amid calls for more personalised and carbohydrate-aware approaches to diabetes management.
Sliding scale insulin, a habit that has survived almost a century of diabetes care, is drawing fresh criticism from endocrinologists who say it reflects an outdated understanding of how insulin should be matched to meals. In the lead article on KevinMD, endocrinologist Michael Duben argues that dosing a pre-meal insulin shot solely from the blood glucose reading before eating ignores what actually matters: how much carbohydrate is on the plate. He says the approach is especially ill-suited to modern hospital care, where patients may be eating very different meals from one day to the next.
The critique is not new. A series of papers over the past two decades has repeatedly questioned whether sliding scale insulin does any meaningful good for inpatients. A 2004 review in the Journal of Family Practice called it an antiquated approach, while later papers in 2007 and 2010 described it as reactive, physiologically unsound and prone to poor control. A 2015 meta-analysis found no clear advantage over other insulin regimens and reported more hyperglycaemic events, adding to the argument that the practice persists more from habit than evidence.
Duben places the modern debate in historical context, tracing sliding scale insulin back to Elliott Joslin and the era when insulin was still new and urine testing was the practical tool available. He argues that the method made sense only within the very low-carbohydrate diets common at the time, not in today’s hospital wards or outpatient clinics. He also says broad nutritional advice has long pushed patients towards higher carbohydrate intake, making a glucose-based meal dose even less likely to line up with what is actually eaten. That mismatch, he says, helps explain why sliding scale dosing can underdose some meals and overdose others.
The alternative, in his view, is to reduce the carbohydrate load rather than try to fine-tune an inherently blunt insulin guess. He says that for many people with type 2 diabetes, lowering carbohydrate intake can eliminate the need for mealtime insulin, while those with type 1 diabetes still need bolus insulin but can often manage with smaller, more predictable doses. He also warns that any major carbohydrate reduction should be paired with prompt medication review, particularly for people taking insulin, sulfonylureas or sodium-glucose cotransporter-2 inhibitors, because of the risk of hypoglycaemia or euglycaemic ketoacidosis.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
