The United Nations has declared the theme for this year’s International Women’s Day as one of “Inspiring Change” to celebrate the achievements of women while still focusing on the gender gaps that persist globally. Sadly, gender inequities remain pervasive across society and certainly throughout health care.
As a young medical student, I could never understand why our medical curriculum did not better differentiate human biology, physiology and pharmacology between the sexes. Often, women are contemplated as “mini-men.”
By most measures it becomes apparent that medical progress has improved the lives and health status of women to a lesser extent than it has men. While women are outliving men by an average of 6.3 years, they enjoy only an additional 1.5 years of disability-free years of life. This paradox points to an emerging gender gap in medical advancement.
Indeed, with a “male-centric” focus, biomedical research has yielded meaningful improvements in the detection and management of diseases that affect men, such as heart disease, more so than those that disproportionately affect women, such as chronic pain, depression, autoimmune disease and breast cancer. And it is not only the research agenda that is male-focused, but so too the subjects.
There is a significant sex bias in drug trials with serious underrepresentation of females throughout biomedical studies, from basic research to human clinical trials. While the average chronic pain patient is a 55-year-old woman, the average chronic pain research subject is a male mouse.
Females are excluded from both animal and human clinical trials often due to concerns about the variability introduced by their hormonal cycles.
Simply, it is easier to study males.
And so it is that early stage clinical trials study predominantly male animals and young healthy men. As a result, novel medical therapies that progress through to late-stage clinical trials and ultimately to market may be less effective, less safe and less relevant for women. Sex differences in drug effects and metabolism have largely been overlooked. But they matter.
Variable pharmacodynamics, or drug metabolism, mean that there may be risk of drug toxicity or, conversely, a lack of therapeutic effect.
Illustrating this problem is the case of Ambien, a commonly prescribed sleep medication. Reports of excess sedation in women due to slower metabolism have prompted health regulators for the first time to recommend lower dosages of the drug in women.
The study of epigenetics or gene expression is revealing how a shared genetic substrate may be differentially expressed in men and women. Approximately 70 per cent of the human genome shows sex-biased expression contributing to the gender differences seen in biology, behaviour and susceptibilities.
Lifestyle factors and environmental exposures affect the health of women differently from men.
Heart disease is a case in point. The traditional risks, such as high cholesterol and blood pressure, are more specific to men. Diabetes, metabolic syndrome, smoking, hormonal status and stress increase risk to a greater extent in women than in men. Accounting for the differentiated expression of the genome between the sexes will be necessary to the development of gender-specific preventative health strategies.
So what will the winds of change and medical progress mean for women’s health? Hopefully, a deeper understanding of the gender differences that exist from bench to bedside and the development of strategies to prevent, detect and treat disease accordingly.
Dr. Jennifer Pearlman is a physician focused on women’s health and wellness, a staff physician at the Menopause Clinic at Mount Sinai Hospital in Toronto and medical director of PearlMDRejuvenation, a Women’s health and wellness facility.
