Sex Differences in Chronic Kidney Disease

SEX DIFFERENCES IN CHRONIC KIDNEY DISEASE | FRESENIUS MEDICAL CARE

We have come a long way in understanding how chronic kidney disease (CKD) impacts men and women differently. Now we require a new effort to better understand why women are not only more likely to be diagnosed with CKD than men but have poorer outcomes as well.

Chronic Kidney Disease (CKD) affects an estimated 30 million U.S. adults or about 15 percent of the U.S adult population. According to the Centers for Disease Control (CDC), 18 percent of women are diagnosed with CKD compared to 13 percent of men. When women battle chronic illness such as CKD and end stage renal disease (ESRD), it can impact whole communities by interfering with their important role in child bearing , child rearing and sustaining families.

In general, women tend to live longer than men, but not so for those with ESRD. Women on dialysis have a higher hospitalization rate and readmission risk compared to men. Studies show significant differences in sex-related hospitalization rates with an average of 2.08 hospitalizations per year for women versus 1.68 hospitalizations per year for men on dialysis. In particular, young women exhibit increased hospitalization risk compared to men of the same age.

Research has shown that pregnancy can also increase the risk of kidney disease. For example, pre-eclampsia occurs in 3 to 10 percent of pregnancies and is associated with acute kidney injury (AKI), increased risk for hypertension as well as chronic kidney disease. Additionally, advanced CKD is a risk factor for adverse pregnancy outcomes. Women need special support to pursue and maintain safe pregnancies while living with CKD. With special care, including increased dialysis frequency and duration, successful pregnancies in ESRD have occurred.

Transplantation is another area where the playing field between men and women remains too far apart. Women are more likely to  be transplant  donors than men and less likely to be transplant recipients. In an editorial paper released on World Kidney Day, the authors discuss how across the world mothers and female spouses are more likely to donate kidneys, less likely to be on transplant waiting lists, and, when listed, remain on waiting lists longer than men. Socioeconomic factors appear to contribute to this disparity in part because employment and education status impact access to health care and renal transplant discussions and options.

While all the causes of increased adverse outcomes for women on dialysis  is  not entirely known, different characteristics around dialysis treatment may contribute to these differences. At dialysis initiation, women are less likely than men to start hemodialysis (HD) using an arteriovenous fistula (AVF) for their access. According to the 2017 USRDS Annual Data Report, 18.7 percent of male patients initiate hemodialysis with an  AVF  compared to 14.6 percent of women. Among prevalent hemodialysis  patients  almost 70 percent of men dialyze with an  AVF  compared to 55 percent of women. Women are far more likely than men to use an arteriovenous graft (AVG) or central venous catheter (CVC), which have  higher  incidence of infection and other complications.

This year’s World Kidney Day happened to coincide with International Women’s Day, focusing on education about women and chronic kidney disease. We share the organizers’ goal of improving health outcomes and access to care for women and girls around the world.

The data we have on these sex differences is just the start. We must better understand the interplay of sex-related difference in CKD and treatment outcomes, such as the interplay of hormones and the dosing of medication for men compared to women. We must learn more about economic and social disparities unique to women that impact women’s health and the health of our communities. Then we must turn to  finding  solutions that help reduce the disparities between men and women with CKD.

About Dr. Dugan Maddux:

Nephrologist Dugan Maddux champions FMCNA’s clinical innovation endeavors across the  continent,  and is  co-founder  of the Gamewood companies, including Acumen Physician Solutions. Blogger, writer and essayist, she developed the Nephrology Oral History project chronicling early dialysis pioneers and holds her BS degree in chemistry from Vanderbilt University and her MD degree from the University of North Carolina at Chapel Hill.  Dr. Maddux is  author  of the 2017 whitepaper Moving Toward Kidney Supportive Care.