Unexpected Findings in Study on Gestational Diabetes Mellitus in Denmark
A study of gestational diabetes mellitus in Denmark turned into Cathrine Munk Scheuer and her team identifying significant differences in prevalence across the Danish regions that could not be explained merely by risk factors.
Cathrine Munk Scheuer is a medical doctor from the University of Copenhagen. She is currently employed as a Danish Diabetes Academy-funded PhD student at the Department of Gynaecology and Obstetrics at Nordsjællands Hospital Hillerød. Last year, she was listed as first author of a publication for the first time in her career on a study that contained some surprises.
Regional divergence and time trends in the prevalence of gestational diabetes mellitus: a national Danish cohort study was published in Acta Diabetologica in December 2022.
The article is co-written by Maria H. Andersen, Elisabeth R. Mathiesen, Lene Ringholm, Clara L. Müller, Jun-Mei Truong, Michelle M. Lie-Olsen, Martin Overgaard, H. David McIntyre, Dorte M. Jensen, Peter Damm, and Tine D. Clausen.
“At first, we wanted to examine whether the cohort of women giving birth at Nordsjællands Hospital Hillerød was comparable to the rest of the Danish population of birth-giving women. However, we quickly discovered the interesting regional differences in the prevalence of gestational diabetes mellitus and decided to investigate it further,“ says Cathrine Munk Scheuer.
Unexpected regional differences
Gestational diabetes mellitus (GDM) is a common medical condition complicating pregnancy. Its prevalence, however, varies in the literature, most likely due to differences in screening methods, diagnostic criteria, and the background population’s risk of diabetes, as mentioned in the study.
“The overall increase in GDM prevalence over time did not come as a surprise. However, it was unexpected to find that the differences in GDM prevalence across regions could not be explained at least partly by the health and socioeconomic factors included in our study. The difference may be explained by a complex combination of several other influencing parameters that were not available to be included – among these screening efficacy and pre-analytical factors in relation to the diagnostic test,” Cathrine explains.
Cathrine and her team observed up to a 97 % difference in GDM prevalence between Danish regions, and it was not explained by available risk factors. As the study shows, this occurred despite national guidelines, which raised the question of whether the observed differences could be explained by regional variations in screening efficacy, diagnostic procedures, or inequality in clinical health care.
“The efficacy of a screening program relies on a thorough identification of women at risk and the healthcare providers’ adherence to the national screening guideline. Risk factor identification may be more precise in areas with the possibility to prioritise early midwife consultations, which increases the likelihood of identifying risk factors otherwise overlooked. Healthcare providers’ adherence to guidelines may be superior in areas with high prevalence simply because a prevalent disease increases its awareness,” explains Cathrine.
Room for realistic improvement
These implications might raise alarm about inconsistencies in the Danish health system, but as Cathrine comments, no health system based on regional management is ever perfectly united. There is, however, always room for improvement.
“Even if we wished to do so, it is unrealistic to perfectly align the healthcare systems throughout Denmark. However, we can reduce a potential inequality in care and optimise adherence to guidelines by assuring sufficient education of and knowledge sharing between healthcare professionals,” says Cathrine.
This study can not only spark a discussion of optimising the adherence to national guidelines, as Cathrine mentions, but it can also impact future research.
“When evaluating GDM prevalence, outcomes, or maybe trying to identify predicting markers for GDM in Denmark as a whole, it is valuable to know that some underlying regional differences may affect the conclusions,” explains Cathrine.
Helpful supervisors and hopes for the future
These findings were exciting especially for Cathrine, seeing as it was her first manuscript as first author. In her own words, she had a lot to learn prior to the publication, but she got there with support from her supervisors.
“All my supervisors and co-supervisor have been a tremendous help in writing the manuscript, particularly Tine, D. Clausen, Dorte M. Jensen, and Peter Damm. They have all been extremely patient and still are,” says Cathrine.
Cathrine’s journey as a full-time researcher will halt in the fall of 2023 when she submits her thesis and goes back to clinical work. But through research, she has discovered an interest she wishes to maintain as part of her career, and she hopes to do more studies like this in the future.
“This study is finished, but it will get revived at my PhD defence, as it is a part of my thesis. Also, it has opened my eyes to the great opportunities of register-based research, and I hope this will not be my last register study,” says Cathrine Munk Scheuer.
Cathrine won first prize in the Poster Pitch Award at the DDA Annual Day 2022 with a pitch on another of her PhD studies. Read about other DDA/DDEA award winners here.
Regional divergence and time trends in the prevalence of gestational diabetes mellitus: a national Danish cohort study(Acta Diabetologica, Dec 2022, https://doi.org/10.1007/s00592-022-02013-8)
Cathrine Munk Scheuer
MD, PhD student
Department of Gynaecology and Obstetrics, Nordsjællands Hospital Hillerød