Oct. 31, 2008 -- A new study shows that obesity has a significant impact on male sexual health.

The study, published in The Journal of Sexual Medicine, focused on 2,435 Italian male patients who sought outpatient treatment for sexual dysfunction between 2001 and 2007. Among participants, 41.5% were normal weight, 42.4% were overweight, 12.1% were obese, and 4% were severely obese. The mean age was 52.

Patients had lab blood tests and a penile Doppler ultrasound to measure penile blood flow. They also were interviewed about their erectile dysfunction and completed a mental health questionnaire.

Giovanni Corona, MD, from the University of Florence, and colleagues found that the degree of obesity correlated with decrease in testosterone level. Among study participants, the more the severe the obesity, the lower the level of testosterone.

The study also concluded that conditions related to obesity, particularly hypertension (or high blood pressure), are the most significant causes of obesity-related mental health. Abnormal penile blood flow was found to be linked to high blood pressure.

For men, obesity's impact on sexual function appears to be a physical issue, not a self-esteem or emotional problem.

"The link between obesity and ED might be a useful motivation for men to improve their health-related lifestyle choices," Mario Maggi, MD, co-author of the study, says in a news release.