Men with large waists urinate more frequently than their slimmer counterparts, according to research in the August issue of the urology journal BJUI.

Researchers from Weill Medical College, Cornell University, New York, found that men with waists measuring 100cm plus reported up to three times more urinary problems than men with waists of 90cm or less.

They also found that larger waist measurements were associated with a greater prevalence of high blood pressure, cardiovascular disease, type 2 diabetes and erection and ejaculation problems.

"The global epidemic of obesity and diabetes had led to a striking increase in the number of people with metabolic syndrome, which includes central obesity, glucose intolerance and high cholesterol and blood pressure levels" says co-author Dr Steven A Kaplan.

"Together, these have been traditionally associated with an increased risk of heart disease and sexual problems. However, emerging data now suggest that metabolic syndrome may have a hereto unrecognised effect on how often men urinate. Our study sought to examine the relationship between men's waist measurements and how often they urinate."

The researchers studied 409 consecutive men aged from 40 to 91 with moderate or severe lower urinary tract symptoms (LUTS) who presented to the Institute for Bladder and Prostate Health at the Weill Medical College of Cornell University over a two-and-a-half year period. They had no previous treatment and a LUTS, International Prostate Symptom Score of eight or more.

Key findings included:

    Of the 409 men, 37.5% men had a waist circumference of less than 90cm, 33.5% of 90 to 99cm and 29% of 100cm or more. Men of different ages were fairly evenly distributed between the groups, with the exception of men aged 70 to 79 years, who were most likely to be in the 100cm or more group.

    Larger waist circumference was associated with more frequent urination -- 39% of the men in the large waist group urinated more than eight times in 24 hours, compared with 27% of the men in the middle group and 16% of the men with the smallest waists.

    Larger waist circumference was also associated with urinating more than twice during the night -- with 44% of men in the largest waist group reporting this, compared with 29% in the middle group and 15% in the smallest waist group.

    Men with larger waists were also more likely to report erection problems than men in the middle and smallest waist groups (74.5%, 50% and 32% respectively) and more likely to report ejaculation problems (65%, 40% and 21% respectively.)

    The same pattern was observed for high blood pressure (33.5%, 22% and 14.5% respectively), coronary artery disease (29%, 17% and 8%), type 2 diabetes (33%, 16% and 11%) and cholesterol (254mg/dL, 176 mg/dL and 148 mg/dL).

The researchers also analysed the relationship between waist size and the odds risk of greater problems from various urological, sexual, metabolic and cardiovascular problems. This showed that:

    Men in the largest waist group had a 39% higher odds risk of prostate volume problems than men in the smallest waist group. The odds risk of higher prostate-specific antigen levels was 111% greater and the odds risk of a higher International Prostate Symptom Score was 68%.

    The odds risk of erection problems was 132% higher and it was 202% higher for ejaculation problems. High blood pressure, type 2 diabetes and coronary artery disease were 131%, 188% and 250% higher.

"Our study shows that men with larger waist circumferences urinate more over a 24-hour period, and at night, than men with smaller waists and confirms higher levels of problems traditionally associated with metabolic syndrome" concludes Dr Kaplan. "Waist measurement may therefore represent an easy diagnostic tool when it comes to the likelihood of male urinary problems."