Sanjay Kalra ( Department of Endocrinology, Bharti Hospital & BRIDE, Karnal, India. )
Jacko Abodo ( Centre Hospitalier et Universitaire de Yopougon, Service d'endocrinologiediabétologie,Abidjan, Côte d'Ivoire, )
Eugene Sobngwi ( Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1; Yaoundé Central Hospital; RSD Institute, Yaoundé, Cameroon, )
Mahamane Sani MA ( Department of Endocrinology, Diabetes and Nutrition, Reference General hospital of Niamey, Niamey, Niger Republic, )
Douglas Villaroel ( Diabetes Unit, Medical Center. Santa Cruz, Bolivia, )
Nitin Kapoor ( Department of Endocrinology, Diabetes and Metabolism, Christian Medical College & Hospital, Vellore, Tamil Nadu,India, Nossal Institute for Global Health, Melbourne School of Population and Global Health, Faculty of Medicine, Dentistry and Health Science, The University of Melbourne, Australia, )
Rakesh Sahay ( Department of Endocrinology, Osmania Hospital, Hyderabad, India )
There are multiple insulin preparations, and strengths, available in various delivery devices. Modern insulin analogues are characterised by better safety and tolerability, and are increasingly being used across much of the world. Does there still exist a role for human insulin? This brief communication explores the potential indications for human insulin, while discussing the concerns and caveats related to its use, and suggesting ways of safe and smart use of human insulin.
Keywords: Diabetes, Hypoglycaemia, Human insulin, Insulin, Lipoatrophy, Insulin technique, Person centred care. Corticosteroid induced hyperglycaemia.
Insulin, a 51 amino acid long dipeptide, has been used for the management of diabetes for a century now. The last three decades have witnessed the development and widespread use of insulin analogues, which have been shown to have lower rates of hypoglycaemia.1 A Cochrane review, however, has pointed out that the efficacy of insulin analogues remains similar to that of human insulin.2
Human insulin is available as prandial, basal and premixed formulations. The premixed preparations can be in ratios of 25:75, 30:70 and 50:50 bolus: basal depending upon the manufacturer. These preparations can be used as part of basal, basal plus, basal bolus, prandial and premixed insulin regimens. The convenience of modern insulin delivery devices, that was limited to certain insulin analogues, has now been extended to human insulins as well. Human insulins are packaged at 40 IU/ml, 100 IU/ml and 200 IU/ml strengths (in different countries), and can be injected through syringes, disposable pens, reusable pens or even insulin pumps.3,4
Advantages of Human Insulin
Human insulin remains the most economical insulin worldwide, and its affordability is a big advantage, especially in pay-from-pocket countries.
The longer duration of action of regular human insulin (as opposed to prandial analogues like lispro, aspart and glulisine) makes it a better choice for person with long inter-meal gaps, especially if they are regular with their inter-meal small snacks. Examples include children and workers who have an early breakfast before they go to school or work, and take a late lunch after returning late in the afternoon. This pharmacokinetic property is also advantageous in persons with corticosteroid-induced hyperglycaemia, where short acting analogues may not be able to cover the evening surge in glucose.
NPH (neutral protamine Hagedorn) insulin can be used once or twice daily to manage corticosteroid- induced hyperglycaemia as well.5 Its peak of action coincides with the peak of action of prednisolone and methylprednisolone, and thus offers an effective way of ensuring glucose control.
A 24-hour glucose profile may reveal situations which can benefit from human insulin. Examples include persons with pre meal hyperglycaemia, and midnight hyperglycaemia. Shift workers who change times of work, and meal pattern frequently, may benefit from an NPH-based regimen, rather than detemir or glargine U-100. It must be noted however, than second generation basal analogues such as degludec offer the flexibility of changing timing of administration of insulin.6
Yet another potential indication for human insulin is persons who take high protein, high fat or complex carbohydrate-rich meals. The area under curve of rapid acting insulins is more concordant with the glycaemic rise that is expected with meals of high or moderate glycaemic index. If the meal is rich in complex carbohydrates, proteins or fats, a slower but more sustained rise of insulin concentrations, as seen with human insulin, will be preferred.7
People who require rapid resolution of hyperglycaemia, in order to manage concomitant medical, surgical or obstetric illness, may respond better to as basal bolus regimen including one or two doses of NPH. This is because NPH has a shorter half-life, and will take lesser time to achieve steady state, as compared to longer-acting basal analogues. Patient preference is another indication for human insulin, if the patient prefers to use a syringe and vial, or a particular insulin concentration. Table lists the potential advantages of human insulin, using the biopsychosocial model to enhance understanding.
Moreover, cost of conventional insulins is also lower than analogues. This makes it more usable in lower middle-income countries and facilitates compliance in cost restrained settings.8