Congenital hyperinsulinism: 2026 so far

Evidence broadened from small series to larger surgical outcomes.

In the months covered, new reports added more concrete, center-based information about what can happen when CHI is treated with surgery, and outcomes differed strongly between focal and diffuse disease. In focal CHI, minimally invasive and targeted resections were often followed by cure and stopping hypoglycemia medicines. Even so, small comparisons still reported incomplete resections and second procedures. In diffuse CHI, results were more variable. Some series reported higher cure rates with near-total versus subtotal pancreatectomy (surgery removing most of the pancreas). Others emphasized postoperative hyperglycemia and longer-term risks like diabetes after extensive resection. This means surgery conversations are increasingly organized around whether CHI is focal or diffuse, and around balancing hypoglycemia control against later glucose complications.

Research covered in: January 2026, March 2026, April 2026, June 2026, July 2026, September 2026

Reports added longer follow-up and gene-linked response patterns.

So far in 2026, treatment reports more often described CHI as having different medication pathways rather than one standard step-by-step course. Genetic cause and CHI type often lined up with diazoxide responsiveness (whether diazoxide keeps blood sugar stable). Single-center cohorts described that some children did well on diazoxide alone, others needed added octreotide, and some proceeded to surgery. One cohort linked ABCC8/KCNJ11 variants with poorer diazoxide response, while HK1 variants were more often diazoxide responsive. For diazoxide-unresponsive children, a real-world series reported that most achieved normoglycemia (blood sugar in the usual range) on long-acting octreotide (octreotide-LAR) over multi-year follow-up. Gallstones and temporary liver enzyme elevations were the main reported side effects. In practice, families may face longer periods of medical management, including long-acting formulations, when diazoxide fails, while the evidence remains observational and not comparative against other options.

Research covered in: February 2026, March 2026, June 2026, August 2026, September 2026

More real-world detail emerged on feeding and perioperative needs.

Reports from the months covered added more day-to-day detail about supportive care in infancy and around surgery. One infant cohort reported that breastfeeding on demand could continue during diazoxide treatment and during dose reductions without increased hypoglycemic episodes. No fluid overload or diazoxide-related adverse effects were observed during the treatment period. Separate cohorts highlighted that many infants with CHI required IV dextrose (sugar given through a vein) and/or parenteral nutrition (nutrition given through a vein) at diagnosis. They also reported that exclusive oral feeding by 6 months was less common in CHI than in transient hyperinsulinism (temporary over-release of insulin). Around pancreatectomy, reports emphasized large intraoperative glucose swings and frequent ICU-level postoperative care in some series. As a result, feeding plans and close hospital monitoring often come up repeatedly in early CHI care, especially when surgery is part of treatment.

Research covered in: March 2026, April 2026, June 2026, September 2026

Testing broadened to mosaic and non-coding causes, with limits.

So far in 2026, several reports showed that a genetic explanation for CHI can sometimes be found even after earlier negative testing. Examples included low-level mosaic variants detectable in blood and non-coding variants such as HK1 intron 2 changes. Re-screening studies reported that repeat testing could yield informative or definite diagnoses in a subset of previously unexplained cases. Specialized approaches, including long-read sequencing (a method that reads long stretches of DNA), were used to clarify syndromic diagnoses (a broader genetic condition with multiple features) in small numbers of children with hyperinsulinism. At the same time, reports highlighted limits. Very low-level mosaic signals sometimes failed confirmation testing. In small series and case reports, ABCC8-related disease did not consistently map onto focal versus diffuse patterns or predictable diazoxide response. In real care, families may be offered updated or confirmatory genetic testing over time, but the results may not fully predict subtype or treatment response on their own.

Research covered in: January 2026, March 2026, April 2026, May 2026, July 2026, September 2026

Follow-up reports broadened focus to neurologic and metabolic outcomes.

In the available months, follow-up research often tracked outcomes beyond immediate hypoglycemia control. This included neurodevelopment (how the brain and skills develop), seizures/epilepsy (repeated seizures) in specific syndromic forms, and later shifts toward hyperglycemia or diabetes in some post-surgical or genetic contexts. Single-center surgical follow-up described mixed long-term paths after pancreatectomy, including later diabetes or recurrent hypoglycemia in some. Registry-based follow-up after extensive diffuse-CHI surgery reported ongoing glucose variability plus diabetes and exocrine pancreatic insufficiency (not enough digestive enzymes from the pancreas) in many participants. One small cohort report described thrombosis (blood clots) in nearly half of children with persistent CHI at that center, including non-catheter-related clots, with recurrent hypoglycemia more frequent in those with thrombosis. This framing means long-term monitoring in CHI is often discussed as covering metabolic, neurologic/developmental, and complication surveillance, even though causality and individual risk remain uncertain in these data sources.

Research covered in: March 2026, April 2026, July 2026