The size of a man’s neck is more likely to tell you how good he is in bed compared to what’s in his pants. A recent study conducted by Turkish researchers concludes that men with larger necks are at an increased risk of developing erectile dysfunction (ED) compared to men with skinnier necks.

“Neck circumference may be a new component of metabolic syndrome in ED,” the researchers explained. “We suggest that neck circumferences of 35cm or 16.3 inches and over may predict ED in patients with metabolic syndrome.”

According to the Mayo Clinic, men who suffer from erectile dysfunction are no longer able to get or keep an erection during sex. Erectile dysfunction can be caused by various biological and psychological factors including obesity, lack of exercise, smoking, alcohol consumption, illicit drugs, and stress. It is the most common sexual health problem diagnosed in men.

Scientists from the Johns Hopkins Bloomberg School of Public Health found that more than 18 million men over the age of 20 in the United States are affected by erectile dysfunction. Increased physical activity and preventative measures against cardiovascular disease and diabetes were associated with a decline in erectile dysfunction diagnoses.

“Physicians should be aggressive in screening and managing middle-aged and older patients for erectile dysfunction, especially among patients with diabetes or hypertension,” said Dr. Elizabeth Selvin from the Bloomberg School of Public Health’s Department of Epidemiology. “The associations of erectile dysfunction with diabetes and cardiovascular risk factors may serve as powerful motivators for men who need to make changes in their diet and lifestyle.”

The research team from the University School of Medicine in Ankara, Turkey, oversaw testing on more than 90 men between the age of 40 and 60. Men whose neck circumference exceeded 16 inches were more likely to suffer from erectile dysfunction compared to other men enrolled in the study.

“It is a very interesting study,” Dr. David Goldmeier from St. Mary’s Hospital in Paddington told The Sun. “Larger neck circumference is also associated with sleep apnea, which is itself associated with low desire.”

A slew of recent studies have established a link between sleep apnea and a loss of libido in women or erectile dysfunction in men. Data from a 2009 study showed that 70 percent of men who were treated for sleep apnea were also treated for erectile dysfunction. Scientists connected this decline in sexual activity to the fluctuation of sex hormones caused by sleeping or not sleeping.

Source: Akin Y, Gulmez H, Bozkurt A, Nuhoglu B, Usta MF. Usage of neck circumference as novel indicator of erectile dysfunction: a pilot study in Turkish population. Andrologia. 2013.