— By Andrea M. Pampaloni, Ph.D.
A higher body mass index is associated with an increased risk for urinary tract infections and pyelonephritis, particularly in females.
Any type of urinary tract infection (UTI) can be painful and bothersome, but it becomes a serious health risk when the infection affects the kidneys. This includes pyelonephritis, a type of urinary tract infection that generally begins in the urethra or bladder and travels to one or both kidneys and causes an infection, necessitating prompt medical attention. Similarly acute pyelonephritis (APN), a severe kidney infection that causes the kidneys to swell, can suddenly occur and potentially lead to permanent kidney damage.
A higher body mass index is associated with an increased risk for a UTI, particularly in females, and although UTIs affect both men and women, women are affected at a much greater rate than men.1 Women also are more likely to experience recurrent urinary tract infections (RUTI), and among premenopausal women who have RUTI, about half have obesity. They are also at greater risk of APN.2
There also appears to be a familial connection: women whose mothers have a history of UTIs are two to three times more likely to be at increased risk.3 Since a mother’s weight, from pre-conception throughout the child’s life, is the strongest predictor of obesity in her children, this risk can be significant.
The Link between Obesity and UTIs
UTIs are common infections and often can be treated with antibiotics, but patients with obesity can be at higher risk for several reasons:
- Obesity is an independent risk factor for a UTI in males.
- Obesity is an independent predictor of blood stream infection.
- Diabetes, a common comorbidity of obesity, can increase the risk of UTIs.
- Patients with obesity experience higher rates of post-surgical infection, including UTI.
- Chronic low-grade inflammation, common in people with obesity, weakens immune response.
- Increased subcutaneous fat and skin old increase the growth of microorganisms, delaying wound repair.
- People with obesity are less likely to be adequately hydrated, which can lead to UTIs, especially for older adults.
Because of these many links connecting obesity with an increased risk of infection, including UTIs, in people with obesity, weight loss can offer multiple benefits. A Very Low Calorie Diet (VLCD) program, such as New Direction Advanced, can lead to substantial weight loss and management with multiple other health benefits, including a reduced risk of infection. Increased hydration is another manageable step that can be recommended to prevent UTIs and potentially help with weight loss.
- Obesity and Risk of Infections: Results from Men and Women in the Swedish National March Cohort Obesity and risk of infections: results from men and women in the Swedish National March Cohort
- The Impact of Obesity on Urinary Tract Infection Risk
- Obesity and Recurrent Urinary Tract Infections in Premenopausal Women: A Retrospective Study