By Dr Ananya Mandal, MD
Obesity and urinary incontinence are both common disorders. The prevalence of obesity is on the rise worldwide with a 6% increase per year in the United States.
Over half of American women are overweight (BMI 25 to 29.9 kg/m2) or obese (BMI 30 kg/m2 or greater). Obesity is associated with several health conditions including heart disease, hypertension, diabetes, depression, arthritis, gall bladder and liver disease as well as cancer.
Obesity directly causes more than 300,000 deaths per year and is responsible for more than $100 billion in health expenditures annually.
Urinary incontinence is a term that refers to inability to hold in the urine and suffering from leaking urine especially when sneezing, laughing or any situation that raises the pressure within the abdomen.
Urinary incontinence affects almost 50% of middle-aged and older women worldwide and affects the quality of life severely. In the United States Urinary incontinence leads to a $30 billion in annual health expenditure.
Obesity and urinary incontinence
Several studies have shown that obesity and overweight is directly associated with urinary incontinence.
Obesity is an independent risk factor for stress related and mixed urinary incontinence and is the most important risk factor for daily urinary incontinence compared to any other factor.
Studies show that each 5-unit increase in body mass index (BMI) is associated with a 60 –100% increased risk of daily urinary incontinence. When followed up for 5 to 10 years the odds of urinary incontinence increases by 7% to 12% for each 1 kg/m2 unit increase in BMI.
This association or connection between obesity and incontinence is strongest for stress and mixed incontinence, and weaker for urge incontinence and overactive bladder syndrome.
Abdominal fat and urinary incontinence
Deposition of fat around the abdomen is one of the most important factors associating obesity and urinary incontinence.
BMI and an increasing waist-to-hip ratio are directly associated with urinary incontinence of the stress incontinence but not for urge and mixed incontinence.
Weight reduction and urinary incontinence
Similarly weight reduction and weight reduction surgeries have shown a beneficial effect on urinary incontinence symptoms. In obese women with a BMI of greater than 40 kg/m2 who are planning weight reduction surgery the prevalence of incontinence is nearly 60% to 70%.
In these women the prevalence of pure stress type of incontinence is 28%, pure urge type is 4% and mixed type is 32%.
Weight loss with behavioral and lifestyle measures including low calorie liquid diet and intensive lifestyle diet and exercise also lead to improvement in urinary incontinence symptoms.
Pathology behind obesity and urinary incontinence
The exact pathology that connects obesity and urinary incontinence is not clear. Some studies suggest that excess body weight increases abdominal pressure. This in turn increases bladder pressure and mobility of the urethra. This leads to stress urinary incontinence. This also causes an overactive bladder.
Obesity, like in later stages of pregnancy (that is commonly associated with incontinence) may lead to chronic strain, stretching and weakening of the nerves and muscles of the pelvic area. This could also contribute to urinary incontinence.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)
Last Updated: Mar 16, 2015