Women who feel insecure in close relationships may have lowered immune function, according to a recent preliminary study.

In a study of 61 randomly selected, healthy female nurses from Ancona, Italy, researchers found that those who avoided creating close, secure relationships showed signs of a weaker immune system than those who felt more secure in their relationships.

The study, published in the journal Psychosomatic Medicine, focused on how attachment style may lead to weaker immune systems.

Attachment style, a relatively stable trait, involves how people value themselves and how trustworthy and reliable they perceive others, Dr. Angelo Picardi, the study's leader author, wrote in an e-mail message.

Besides stress, social support and several other factors known to affect immunity, the study found the link between insecurity and poorer natural killer cell activity to be statistically significant, Picardi wrote.

Statistic significance means the relationship between insecurity in relationships and weakened immune function is not due to chance, said James Rosenberger, a statistics professor at Penn State.

Tiffany Taylor (freshman-division of undergraduate studies) said she would tend to believe the researchers' findings.

"One of my friends has trouble with good relationships with her parents," Taylor said. "She's always sick. She always has something wrong with her."

Since attachment processes only occur in some key relationships, like parent-child relationships and romantic relationships, the findings apply only to the way people perceive themselves and their most significant others, he said.

"Humans are born with a disposition to form and maintain some key relationships from infancy to old age," Picardi wrote.

"The term 'attachment' is used to refer to the emotional, cognitive, and behavioral processes involved in the development and maintenance of intimate social bonds."

In the study, attachment style was measured with several questionnaires, and immune cell function was measured using blood samples.

According to the original study, the results are consistent with previous research that suggests insecure attachment may be a risk factor for health, though the results should be interpreted with caution and replication and further research is needed.

"It would be important first to confirm our results and then to investigate whether such a reduction in natural killer cell activity could translate into increased disease susceptibility and poorer health," Picardi wrote.