At the Dutch Endocrine Meeting in Eindhoven, Layal Chaker was recently voted onto the board of the Dutch Association for Endocrinology. She has been coming to the conference for years. While pursuing her PhD, she presented a poster at the conference with details about her research. Later on, she was invited to give a talk at the young investigators session. Now she sits on the board. Chaker says it is ‘an honour’. “I get to be involved with the ins and outs of the association.” It is an additional responsibility alongside her work as a clinical epidemiologist, on the one hand, and as a doctor of internal medicine and endocrinologist on the other. “Someone once gave me the advice that if my work wasn’t also slightly my hobby, I’d better find a different job”, Chaker says of about her busy schedule, “but I enjoy it enough to be able to do it with complete and utter conviction.”
Gradually, Chaker discovered that internal medicine is where her true passion lies. Initially, she wanted to become an ophthalmologist, but choosing that path would not have benefited either her or her patients: “I’ve got two left hands. You don’t want me touching your eyes.” During her medical internships, a colleague pointed out to her that she was a classic internal medicine type. “That’s someone who likes complex phenomena; a nerd who likes to do thorough research and talk to people. I didn’t see it as clearly myself, but that colleague turned out to be right: I am a nerd.”
Number of books a year: 4
Last book read: Leaders Eat Last by Simon Sinek
Favourite genre: “Realism, not absurdism or science fiction. And I love Russian literature, which has a nice slow pace.”
Principal motivation: These days, being able to implement things in daily life and work. It used to be reading about other people and cultures. Reading helps us understand people and empathise better.
Complexity, please
Somehow, Chaker knew she enjoyed complexity. It became clear to her at grammar school while reading the Cairo Trilogy by the Nobel laureate Naguib Mahfouz. The story consists of three books (Palace Walk, Palace of Desire and Sugar Street) that follow the family of a wealthy patriarch in pre-World War II Egypt. The trilogy is both a personal portrait of a family and a story about the sociopolitical life of three generations in Egypt. The themes are expansive. “It’s about the British pulling out of Egypt and the influence of the West in the Middle East – something that’s equally relevant now. It deals with the relationship between religion and science, women’s rights and colonialism, with universal themes of maternal love, family and sibling relationships also coming into play.”
The Cairo Trilogy gave Chaker insight into her own nature. “While reading, I realised I wasn’t the kind of person who enjoyed reading a straightforward book on the beach. The book made me realise, even more so than when I read Harry Mulisch’s The Discovery of Heaven, that I revel in layers and complexity.”
And if any topic is complex, it is hormones, an endocrinologist’s area of focus. “Hormones are produced somewhere in the body and then enter your bloodstream, so they get everywhere else. They have effects throughout your body, but what those effects are is different for everyone”, Chaker says, briefly providing a summary of the endocrine system.
The unknown territory of the thyroid
In her research, she specialised in the thyroid, where thyroid hormone is produced. Besides diabetes, most hormonal disorders worldwide occur in the thyroid, says Chaker, with an underactive thyroid the primary cause. Little is known about the long-term effects of this condition. “Thyroid medication is very cheap, making research into the causes – and into the impact of the condition in particular – financially unattractive. It’s not lucrative, which is why we there’s a lot don’t know.”
However, this is exactly where Chaker’s own work comes in. She was recently awarded a Veni grant to conduct research into the influence of thyroid hormone on male-female outcome differences for cardiovascular disease. Her research shines a light on two neglected topics: the thyroid and male-female outcome differences in medicine. “I’m not the kind of person to say that we should include differences between the sexes in all medical research from now on. Sometimes we’re just the same, but it’s been established that thyroid disorders are mostly found in women and that thyroid hormone affects the heart.” How exactly all of this works is what Chaker will be examining over the next four years. Her research started on the symbolic date of 14 February – ‘the day of the heart’.
Layal Chaker studied Medicine and Clinical Epidemiology at Erasmus University Rotterdam (graduating cum laude). She obtained her doctorate (cum laude) in the Departments of Internal Medicine and Epidemiology at Erasmus MC, completing part of her research at the Harvard T.H. Chan School of Public Health. Since 2021, she has been a doctor of internal medicine and endocrinology in the Department of Internal Medicine and a clinical epidemiologist at the Department of Epidemiology at Erasmus MC. She is also an adjunct lecturer in the Department of Epidemiology at the Harvard T.H. Chan School of Public Health.