New York: An unhappy marriage may actually slow the development of diabetes in men and promote successful treatment once they do get the disease, suggests an interesting study. It may be because wives are constantly regulating their husband's health behaviours, especially if he is in poor health or diabetic. And while this may improve the husband's health, it also can be seen as annoying and provoke hostility and emotional distress. "The study challenges the traditional assumption that negative marital quality is always detrimental to health," said lead investigator Hui Liu, associate professor of sociology at Michigan State University in the US. "It also encourages family scholars to distinguish different sources and types of marital quality. Sometimes, nagging is caring," Liu said. Diabetes requires frequent monitoring that the wives could be prodding the husband to do, boosting his health but also increasing marital strain over time. Using data from the US National Social Life, Health and Aging Project, Liu and colleagues analysed survey results from 1,228 married respondents over five years. At the onset of the study, the respondents were 57 to 85 years old -- 389 had diabetes at the end of the study. The researchers investigated the role of marital quality in diabetes risk and management and found two major gender differences: The most surprising finding was that, for men, an increase in negative marital quality lowered the risk of developing diabetes and increased the chances of managing the disease after its onset. For women, a good marriage was related to a lower risk of being diabetic five years later. Women may be more sensitive than men to the quality of a relationship and thus more likely to experience a health boost from a good quality relationship, Liu said. The findings appeared in the Journals of Gerontology Series B: Psychological Sciences and Social Sciences.