Harold Himsworth was born in Huddersfield, Yorkshire. He won a scholarship to the local grammar school but was forced to leave at 16 to work in a woollen mill. Undeterred, he studied at night school before gaining entrance to University College, London in 1924. He was the first member of his family either to leave Yorkshire or to attend university, and it was difficult for him to find his feet. He kept such a low profile as a medical student that the examiners needed to send for his photograph when he won the University Gold Medal in 1929, but no such problem existed when he followed this up by achieving a Gold Medal for his MD thesis two years later. A spell in the laboratory of C. R. (later Sir Charles) Harington, who had just determined the structure of thyroxine, inspired the young doctor to a career in research. University College Hospital was then the foremost clinical academic centre in Britain and did much to establish the new style of clinical research as a discipline in the UK. The brightest young doctors from Britain and the Commonwealth were attracted to work in this stimulating environment. “Harry”, as he was known to his contemporaries and students, stood out even against this competition, becoming Deputy Director in 1936 and Professor of Medicine in 1939.
Every thoughtful person whose life depends on insulin tries to work out how much is needed to bring about a given reduction in blood glucose, or to balance a given quantity of food. This apparently simple challenge, the source of untold frustration over the years, was taken up with enthusiasm by clinicians early in the insulin era. What they sought was “the glucose equivalent of insulin”. Their problem was that the effect of insulin varies widely from patient to patient, and also varies according to the level of glucose in the blood at the time insulin is given. Harry studied carbohydrate metabolism and the actions of insulin in the laboratory, in normal volunteers and in patients. He demonstrated the effects of high and low carbohydrate diets on the glucose tolerance test in normal subjects, and went on to show that the hypoglycaemic effect of administered insulin is reduced by dietary carbohydrate restriction. He then followed up the work of Wilhelm Falta in Vienna, who had attempted to correlate glucose tolerance with insulin sensitivity. Harry devised a standardised insulin–glucose tolerance test, the forerunner of modern glucose–insulin clamp techniques, and used this to distinguish between “insulin-sensitive” and “insulin-insensitive” types of diabetes. He observed that “insulin-sensitive” patients did not differ from healthy controls in their sensitivity to insulin and were liable to develop ketoacidosis, whereas “insulin-insensitive” patients did not. From this he inferred that “insulin-sensitive” patients lacked the capacity to produce insulin whereas “insulin-insensitive” patients could not respond fully to their own insulin. This classic observation, although not followed up for many years, established the scientific basis for the subsequent distinction between type 1 and type 2 diabetes. He summarised his research in his 1939 Goulstonian Lectures  and noted the association of obesity, hypertension and arteriosclerosis with “insulin-insensitive” diabetes.
With the onset of World War Two he embarked on a new programme of research in an attempt to understand why workers in munitions factories were prone to acute or chronic liver failure. By combining laboratory and clinical research with careful observation of patients, Harry shifted the focus of attention from the end result, cirrhosis, to the initiating damage to the hepatocyte . His academic leadership and breadth of clinical and scientific knowledge and insight were recognised when he was appointed Secretary (Chief Executive) of the UK Medical Research Council in 1949. He was perfectly suited to exploit the increasing resources for medical research voted by parliament over the next twenty years. He had a vision of, and a responsibility for, the entire range of biomedical research from molecular biology through clinical medicine to the social sciences. He was able to communicate this vision and to work with scientists and clinicians, the universities, hospitals and the National Health Service, as well as with politicians and civil servants, to achieve much of what he envisaged. Harry maintained his interest in diabetes throughout his long retirement, and was both amused and delighted to meet with Dr Reaven fifty years after his own studies had ended and to discuss the expanded concept of type 2 diabetes.
Institute of Public Health
University of Cambridge, UK
1 Himsworth HP (1939) Mechanism of diabetes mellitus (The Goulstonian Lectures). Lancet 65: 118–171
2 Himsworth HP (1947) The liver and its diseases. Blackwell Scientific Publications, Oxford