Internal medicine and cardiovascular research
Bertil Hood (1917-1991) was one of Sweden's leading twentieth century figures in internal medicine. During his era, which spanned several decades, he strongly influenced cardiovascular research—especially hypertension. For many years he was affiliated with the University Hospital in Lund and Malmö General Hospital (MAS), now known as Malmö University Hospital (MAS). Many doctors will have encountered Professor Hood in one of his numerous roles as teacher, clinician, scientist, and administrator. For some he was a groundbreaking source of inspiration; others saw him as an obstinate professor, with rigid ideas and opinions. Who was he, and how did he come to assume such an important role in hypertension research in Sweden?
Born in Malmö
Professor Hood was born on 4 February 1917, in Malmö, where his father was a teacher. He eventually returned to the city after holding a number of posts elsewhere in Sweden. After completing his schooling in Malmö in 1935, he began to study medicine in Lund and eventually moved to Göteborg, where he was awarded a PhD in 1950. His thesis dealt with the effects of carbon dioxide inhalation on the kidneys in different types of patients, including hypertensives (1). Two years later he became Associate Professor of Internal Medicine at this same university. Dr. Hood's clinical years took him to various cities including Borås, Falun, Jönköping, and Lund. Between 1944 and 1946 he held short temporary positions as city medical officer and rural district medical officer in the Falun region, where he carried out the experiments leading to his dissertation. From 1954 to 1971 he was assistant senior physician at the Department of Internal Medicine at Sahlgrenska Hospital in Göteborg. In the early 1970s he spent a few years in Uppsala, eventually settling in Lund as Professor of Nephrology and shortly thereafter as Professor of Internal Medicine in nearby Malmö, where he remained active until his retirement.
Focusing on hypertension
Professor Hood's scientific and clinical contributions evolved through a number of phases. His background was in nephrology and the world of metabolism, the many facets of which he mastered better than the majority of his contemporaries. His first great interest was renal blood flow and circulation, an interest that progressed toward high blood pressure and the various forms of primary and secondary hypertension and their treatment. It should be remembered that as recently as the 1940s and 1950s, severely elevated blood pressure—known as malignant hypertension—often resulted in sequelae such as major cerebral hemorrhage and cardiac insufficiency. Professor Hood's research led to several decades of work focusing on the diagnosis and treatment of hypertension as well as hypertension-related damage to various organ systems, especially the heart, brain, and kidneys. Professor Hood is remembered as the first doctor in Sweden to treat hypertension with medications, in October 1950 at the Department of Internal Medicine, Sahlgrenska Hospital, in Göteborg. At that time, the only drugs available were sympatholytic ganglion blockers (hexamethonium), which acted on the autonomic nervous system. Although they did lower blood pressure, they had extensive side effects, particularly dizziness. Gradually, as treatment advanced, diuretics (thiazides) and vasodilators (hydralazine) with blood-pressure lowering effects became available. However, it would take until the early 1970s before modern beta-receptor blockers came on the scene, facilitating a more versatile and controllable treatment.
Back in Malmö
While active in Malmö, Professor Hood had considerable influence not only on research at the Department of Internal Medicine, but also on clinical rounds and at meetings. His contemporaries will recall occasions when they were "Hooded" - cornered in a corridor and drawn into a scientific discussion that would end with a suggestion for a new project based on Bertil Hood's latest brainstorm. Some of these ideas proved viable and advanced to become thesis projects; others were more transient and soon forgotten.
Malmö Preventive Medicine
One of Professor Hood's most enduring contributions to medicine came in 1974, when he planned and launched a major health study in Malmö, the "Malmö Preventive Medicine" project. The idea was to summon men and women of specific age groups in Malmö for examination and offer medical assistance to those found to have cardiovascular risk factors or hidden alcohol abuse. The latter would be revealed through specific questions supplemented with a liver blood test, gamma-glutamyltransferase (GT). Initially, several age groups of men (N= 22,000) and later on, women (N= 11,000) were invited. In all, an extremely large number of individuals was examined and about 20% of them received treatment based on their risk factors or hidden alcohol abuse. Several studies of the results of this large-scale health project were later conducted. The experiment was most effective in countering alcohol abuse. Its impact on reducing cardiovascular disease was more modest as compared with other age groups that never participated in the project. The Malmö Preventive Medicine study was carried out between 1974 and 1992 and this year thus marks the 30th anniversary. Individuals once screened at the initiative of Professor Hood are now being re-examined at the Internal Medicine Clinical Research Unit in Malmö. To date, just over 4,000 people have had a fresh health checkup. The project is being led by Professor Göran Berglund and Associate Professor Peter Nilsson, both from the Department of Internal Medicine, University Hospital MAS.
The future of cardiovascular medicine
It is intriguing to read how Dr. Hood viewed the future of cardiovascular medicine. Today, some of his beliefs seem dated, but others are still valid: for example, the debate on establishing priorities between interventions for ordinary medical conditions afflicting the many versus interventions for more serious conditions afflicting only the few.
When Professor Hood fell ill with cancer, he was forced to slow down and cut back on his interests. He died in 1991, but to this day is remembered for his trailblazing initiatives in Swedish clinical hypertension research and his tremendous enthusiasm for health check-ups and preventive measures. Professor Hood was not an uncomplicated person and some of his co-workers found it difficult to keep up with him, but without his contributions we could not have accumulated the vast experience necessary to accomplish the advances made in these medical fields. Today, health exams and hypertensive treatment are very different from Professor Hood's day; the wheel of progress keeps turning and one day our own approach will also seem dated and inadequate.
Text: Dr. Peter Nilsson
All references are available upon request.