Application for inclusion of amorphous 100% porcine insulin zinc suspension in the Model List of Essential Medicines, (Professor A Teuscher et al)
Comment from Dr G. Roglic Diabetes Team (WHO/MNC/DIA)
This is an application to include amorphous 100% porcine insulin zinc suspension, an intermediate-acting insulin, in the Model List of Essential Medicines. The WHO Model List already includes intermediate-acting insulin, but does not specify its origin/species (human, bovine, porcine) nor its type (zinc suspension, isophane suspension).
The applicants base their request on the premise that human insulin has been introduced without rigorous trials of its efficacy and side-effect profile; and they claim that semi-synthetic/biosynthetic human insulin leads to a higher rate of severe hypoglycaemia, as well as chronic complications, in comparison to porcine insulin. I agree that human insulin was introduced without proof of being superior to animal insulin. However, it has neither been proven inferior in efficacy and short-term side-effects. The available evidence does not indicate any substantial difference between insulin species regarding acute complications (hypoglycaemia). Contrary to the applicants' claim, there are no studies of late complications, long-term morbidity and mortality and quality of life that would compare animal insulin to semi-synthetic/biosynthetic human insulin.
The applicants do not adequately justify the singling out of porcine semilente insulin as the insulin to be specifically recommended in the Model List of Essential Medicines. Its superiority to isophane porcine insulin (NPH) is unsubstantiated. It is also not clear why regular porcine insulin is omitted from the application, although similar arguments could be used for its inclusion.
The arguments regarding the cost of animal vs. synthetic human insulin are unlikely to hold for long, given technological progress. Semi-synthetic/biosynthetic human insulin is likely to become cheaper than animal insulin. Table 2 is too simplistic to be meaningful.
The application is based mostly on an over-enthusiastic interpretation of the results of one methodologically sound study and a few studies that do not withstand rigorous scrutiny. More research is needed to justify the decision to single out any species-specific insulin, and particularly an insulin that would not be used by most of the world's Moslem population.
References
Richter B, Nieses G. "Human" insulin versus animal insulin in people with diabetes mellitus. The Cochrane Database of Systematic Reviews, Issue 4, 2002.
AireyCM et al. Hypoglycaemia induced by exogenous insulin - "human" and animal insulin compared. Diabetic Medicine 2000;17:416-432.