New research from the University of Sydney (SU) found that the impact of kidney failure on life expectancy is much more significant for women than men. The findings, published today in the BMJ, highlight the need to identify the cause of such disparity.
Biostatistician and study lead author Dr Nicole De la Mata says it’s a worry that women die from kidney failure before their time compared with men. “We need to work out the reason for this difference, whether it relates to how people access healthcare, the treatment they get, or biological considerations,” she says.
“The life-years lost for women compared with men are far greater than I have seen for any other health condition, such as cardiovascular disease and cancer,” says study co-author Professor Angela Webster, from the SU’s NHMRC Clinical Trials Centre and Centre for Renal and Transplant Research at Westmead Hospital.
The SU researchers examined health records for over 80,000 people with kidney failure who identified as either male or female. The records were gathered from the Australian and New Zealand Dialysis and Transplant Registry (ANZDATA) and then linked to the national death registers, which record deaths and their causes, in both countries.
They found that women with kidney failure lost on average 3.6 years more life than men.
The researchers also compared death rates to what would be expected in the general population. They found that 11 women and seven men with kidney failure died for each death in the general population.
“It tells a more personal story for people with kidney disease; the analysis really illustrates how they are missing out on more years of life, compared to life expectancy in the general population,” says De la Mata.
The findings were especially surprising because, generally, women live longer than men. Previous studies have shown that although chronic kidney disease was more prevalent in women, men progressed to kidney failure faster. The analysis conducted by the SU team showed that women with kidney failure lost this natural survival advantage entirely. “No one has ever really realised the extent of the disadvantage for women with kidney disease before,” says Webster.
The age at which a person experienced kidney failure greatly affected death rates, with younger women having the most significant life expectancy and survival loss. A 15-year-old female with kidney failure would lose on average 33 years of life compared to expectations for the general population, whereas a male with kidney failure of the same age would lose 27 years.
“The reason for these sex differences needs further exploration – it could be due to biological reasons or differential health care access or treatment,” says De la Mata.
Divergence in health outcomes between men and women is not uncommon. Many diseases can present with significantly different sex-specific symptoms and severity, but Webster says women also get worse healthcare access than men. “There is a need to identify differences in access to healthcare, and strategies to close any gap,” she says.