Update lung transplantation guidelines due to unfounded gender differences, say researchers

23rd January 2025

Women are waiting longer for lung transplantation than men, a French retrospective study finds, showing changes to clinical guidelines and policies are needed to address gender inequalities.

Lung transplantation is a highly dynamic segment of solid organ transplant, where gender is known to play a central role, the study authors wrote in ERJ Open Research.

Previous research using US lung transplantation data had found women had a lower chance of receiving a transplant than men and waited longer before transplant.

For this study the authors evaluated the differences between men and women before transplantation, during and immediately after surgery and in the months and years following transplantation using data from the French Cohort in lung transplantation (COLT) database – the first to analyse all three periods of the transplantation pathway.

Overall, 1,710 participants (802 women and 908 men) were included in the study, with analysis showing women waited an average of six weeks longer for transplantation, spending 115 days on the transplant list compared with 73 days for men.

Women were less likely than men to undergo transplantation (91.6% vs 95.6%), the data showed.

At the time of registration on the lung transplant list, women were younger than men (47 years vs 54 years) and they displayed fewer comorbidities, including ischemic heart disease and cardiovascular risk factors.

In both genders, the main underlying disease was COPD/emphysema, followed by cystic fibrosis and interstitial lung disease.

Lung transplantation gender differences

In other differences, pre-transplant anti-human leukocyte antigen (HLA) antibodies were more prevalent in women than in men (46% vs 26%) for both class I and class II, with the number of pre-transplant class I anti-HLA antibodies associated with an increased waiting time.

It was also more common for women to receive lungs from height- and sex-matched donors, despite higher female-waiting list mortality and a higher proportion of male donors, the authors wrote.

They stressed that women with oversized lung transplantation, defined by predicted total lung capacity ratio and weight, did not have worse survival, therefore suggesting that size matching criteria could be less stringent.

Post-transplantation, women had a significantly higher survival rate than men, with 34.4% of female recipients dying compared with 42.7% of male recipients.

Survival rates were also higher among women than men at five years post-transplantation (70% vs 61%).

Corrective measures imperative

Study lead author Dr Adrien Tissot of from the Pulmonology Department at Nantes University Hospital, France, said people on the lung transplant waiting list had a poor quality of life and high mortality risk.

‘For these patients, waiting is suffering, and the longer the wait the worse these women are suffering,’ he said.

‘Clinicians, patients and policy makers must acknowledge this gender difference as it’s essential for appropriate action to be taken.’

Dr Tissot suggested early listing for women or revising the allocation policy of donor lung to recipient could be considered.

‘We believe our findings, such as the potential role of size matching and its consequence on access to lung transplantation, and length of time on the waiting list, may also apply in other countries where lung transplantation is performed,’ he said.

Also commenting on the findings, Dr Michael Perch, chair of the European Respiratory Society’s Group on Lung Transplantation and a senior consultant at Rigshospitalet in Copenhagen, Denmark, said there could be several reasons why women waited longer for transplantation, including differences in education and health literacy, socioeconomic differences, immunological factors and donor-recipient size matching.

‘Clinicians and policymakers alike must question why there is a focus on gender and size matching in transplantation when evidence shows that, in lungs, these factors do not determine a woman’s chance of survival, and it ultimately risks an increase of women dying while waiting for a transplant,’ he said.

‘It is unacceptable for women to be waiting longer than men for these lifesaving donations, so effective corrective measures must be introduced.’

Increased smartphone-recorded daily steps assessed over a two-year period associated with a beneficial effect on CV risk factors

12th August 2022

Greater smartphone-recorded daily steps over a 2-year period led to reductions in cardiovascular risk but which varied in men and women

Increased smartphone-recorded daily steps assessed over a two-year period are associated with a beneficial effect on cardiovascular risk factors, although not all of these positive effects are seen in both sexes according to a large cohort study by Japanese researchers.

There is a good deal of evidence indicating that a higher number of daily steps is associated with a reduced risk of all-cause mortality. In fact, a 2020 systematic review concluded that the evidence from longitudinal data consistently demonstrated that walking an additional 1000 steps per day can help lower the risk of all-cause and cardiovascular mortality.

However, an important limitation from virtually all of the studies included in the review is that the daily step-count was recorded at a single point in time (usually at baseline) in the majority of cases, although some studies did incorporate a second measurement. Smartphone-recorded daily steps have been suggested to be of practical use to individuals, clinicians, and researchers for monitoring physical activity.

Moreover, the use of smartphone-recorded daily steps has been suggested in the 2018 US physical activity guideline to enable self-monitoring, deliver messages, and provide support, all of which are helpful in promoting regular physical activity.

As a result, in the present study, the Japanese researchers made use of smartphone-recorded consecutive daily steps over a period of 2 years to explore if there was an associated change in cardiovascular disease-related measures.

To examine any link, the team used information held within a Japanese national health check-up, a national health insurance claims and a commercial mobile phone app database (used by workers who belonged to work-based health insurance schemes and which provided daily step information). The primary exposure of interest was the smartphone-recorded daily step count between two annual healthcare checks which were between 24 and 35 months apart.

The primary outcomes were changes in markers at follow-up health checks in comparison to baseline. The researchers included several measures including weight, body mass index (BMI), systolic and diastolic blood pressure, HDL and LDL cholesterol, triglycerides, fasting glucose levels and HbA1c (%). In addition, demographic, lifestyle and co-morbidity data were also collected and adjusted for in their analysis.

Smartphone-recorded daily steps and cardiovascular outcomes

A total of 15,708 participants with a mean age of 44.1 years (23.5% female) were included in the study and daily step information was available for a period of two years. Overall, the median number of daily steps was higher for men than women (6674 vs 5027).

For most changes, there was an almost linear and inverse relationship between changes in weight or BMI and the number of steps but also apparent differences between men and women. For example, in men, each additional 1000 steps/day was associated with a 0.32 loss in weight, -0.11 reduction in BMI and 0.37 lowering in waist. In women, however, the same inverse association was only evident above 5000 steps/day (0.18 loss in weight).

Similarly, the inverse relationship remained for systolic and diastolic blood pressure but only in men, with, for instance, a reduction in systolic pressure of 0.33mmHg for each additional 1000 steps/day. For lipid changes, both HDL and triglycerides were reduced with increased steps/day in both sexes although significant changes in LDL were only apparent for men.

Finally, while improvements in fasting glucose levels occurred in both sexes, there were similar effects on fasting glucose levels in both sexes though a significant negative association was observed for changes in % HbA1c but only for women.

The authors concluded that overall increases in smartphone-recorded daily steps was associated with positive changes in several cardiovascular risk factors although there were differences between the sexes for some factors. They added that smartphone-recorded steps may be a useful clinical tool to gauge cardiovascular health.

Citation
Hamaya R et al. Association of Smartphone‐Recorded Steps Over Years and Change in Cardiovascular Risk Factors Among Working‐Age Adults J Am Heart Assoc 2022