Central obesity, as measured by waist circumference, is associated with an increased risk of end-stage renal disease (ESRD) among postmenopausal women, even those with a normal body mass index (BMI), according to a recently published study.
Nora Franceschini, MD, of the University of North Carolina in Chapel Hill, and collaborators studied 20,117 postmenopausal women who participated in the Women’s Health Initiative (WHI) program, a prospective population-based cohort study investigating postmenopausal women’s health in the United States.
During a mean follow-up of 11.6 years, ESRD developed in 212 women, and 3,104 women died. In adjusted analyses, compared with women who had a waist circumference of 88 cm or less, those with a larger waist circumference had a 2.6 times increased risk of ESRD and a 42% increased risk of death, researchers reported online ahead of print in the Journal of the American Society of Nephrology. The model adjusted for age, race, education, smoking, estimated glomerular filtration rate, and other factors.
In addition, each 1 cm increment in waist circumference was independently and significantly associated with a 3% increased risk of ESRD, even after additional adjusting for BMI, according to the researchers.
BMI also associated with ESRD and death. Compared with women who had a BMI of 18.5–24.9 kg/m2, those with a BMI of 30 kg/m2 or higher had a nearly 2-fold increased risk of ESRD and 21% increased risk of death.
“Waist circumference is a simple, easy to measure, low-cost, and feasible measure to implement in clinical care with potential added prognostic value for ESRD risk,” Dr. Franceschini’s team wrote. “Although interventions to reduce central adiposity are difficult to implement in clinical practice, increased awareness and prevention of central obesity postmenopausal women could be important public health targets to reduce ESRD risk in aging populations.”
The study population had a mean age of 63.9 years. Of the 20,117 subjects, 1,154 had chronic kidney disease (CKD), defined as an eGFR of 60 mL/min/1.73 m2 or less. Investigators obtained information on BMI and waist circumference at baseline and obtained information on new ESRD cases from the U.S. Renal Data System.
Strengths of the study by Dr. Franceschini’s group include a large sample size of postmenopausal women, use of a multicultural cohort, standardized measures of adiposity and other risk factors, prospectively obtained data, and a large number of ESRD events. Study limitations include the use of only a single measure of adiposity obtained at a screening visit and the fact that waist circumference cannot distinguish between subcutaneous and intra-abdominal fat.
The researchers noted that their findings cannot be generalized to men or premenopausal women, who were not included in the WHI cohort.