In sickness and in health: diabetic treatments need an
injection of common sense
Animal insulins can suit diabetic patients far better than human insulin,
says Dr James Le Fanu.
Medicine is, for the most part, a sane and scientific enterprise but it can be
surprisingly intolerant of even the most well-intentioned criticism.
Thus, some of those with diabetes find that modern regimes of treatment can cause,
perhaps paradoxically, severe problems - but their difficulties have fallen on deaf
ears, with serious implications.
Since the discovery of the life-saving potential of insulin in 1921, diabetics have
successfully controlled the level of sugar in their blood by regularly injecting
themselves with the hormone, derived from pigs and cows. This is cheap,
plentiful and highly effective.
Then, in the early 1980s, scientists managed to produce human insulin by the
revolutionary process of genetic engineering. They inserted the relevant gene into a
bacterium that reproduced billions of times, producing the hormone in prodigious
In practical terms, the chemistry of human insulin is virtually identical to the animal
varieties, but it seemed obvious that the human form must be "better" and doctors
accordingly advised their patients that they should switch.
Some found, quite unexpectedly, that their previously well-controlled diabetes
suddenly went haywire, as the levels of sugar in the blood oscillated wildly. Matthew
Kiln, a family doctor, found that he could no longer anticipate the potentially serious
state when his blood sugar fell too low - known as a "hypo" - which must be
promptly corrected before coma supervenes. His personality changed, too, and he
became uncharacteristically more irritable and argumentative, with unfortunate
consequences for his personal and professional life.
Surveys revealed that about one in four diabetics were experiencing similar
difficulties. No one could come up with a satisfactory explanation but most were
able, albeit with some difficulty, to persuade their doctors to do the sensible thing
and switch them back to the animal-based insulins.
Dr. Kiln and his contemporaries had realised that there was something wrong
because they knew, from personal experience, how the control of their diabetes had
deteriorated. This opportunity is, however, denied to those who have come after
them, and who are routinely started on the genetically engineered human form.
No doubt, this works for many but certainly not for all, as revealed by the experience
of another doctor-cum-diabetic, Ann Robinson, a 46-year-old psychiatrist.
Dr. Robinson discovered that she had diabetes a couple of years ago, but expected
to be back at work in no time. Her human insulin injections, as intended, kept the
levels of sugar in her blood within the normal range, but she felt terrible. "I did not
feel like me with an illness. I felt like someone else," she says. "I became a zombie. I
could not concentrate for more than a few minutes and, whenever I took the least
exercise such as going for a walk, my blood sugar went right through the floor."
The months went by and her perplexed consultant changed Dr. Robinson's regime
of injections no less than five times, but to no avail. She realised eventually that
there was no alternative but to take early retirement on medical grounds.
Then, one evening in July, while idly flipping through a medical journal, she chanced
upon an article by Dr. Kiln that rang a peal of bells with her. She rushed round to her
family doctor, brandishing Dr. Kiln's article, and persuaded him to switch her from
human to pig insulin. Within a couple of days, her life changed.
"I woke feeling hungry for the first time in two years," she says, as if, once again, her
body's metabolism was working as it should. Her intellect emerged from the twilight
as she found she could concentrate once more, her joints loosened up and her
personality returned. "I was me again," she says.
Dr. Robinson wonders how many others there are like her: children, for example,
whose behavioral and learning problems are blamed on their reaction to being
diagnosed as having diabetes, but who will become their sunny selves again simply
by switching to pig insulin. But how are they (or their parents) to know?
And there's the rub. Ten years ago, Dr. Kiln helped set up the Insulin Dependent
Diabetes Trust to promote research and publicize this important issue - but,
astonishingly, no one really seems to want to know. It is scarcely revolutionary to
propose that some of those with diabetes might do better with animal-based insulins
- but, for many and complex reasons, neither the diabetes specialists nor the drug
companies are prepared to give them a sympathetic hearing.
Indeed, it remains an uphill struggle to ensure that the animal insulins are even
available. This is perhaps not unrelated to the fact that they are far less profitable to
the drug companies than the much more expensive human forms. Enough said.