Over the last decade researchers have amassed increasing evidence that relatively low levels of a protein called sex hormone binding globulin (SHBG) can indicate an elevated risk of type 2 diabetes and metabolic syndrome years in advance. In a collection of studies described in the new paper, published online September 18 in Clinical Chemistry, Dr. Simin Liu, professor of epidemiology and medicine at Brown University School of Public Health, led an effort to measure SHBG levels in 13,547 women who take part in the national Women’s Health Initiative. The team comprehensively investigated nongenetic factors associated with levels of the protein. The researchers found that age, use of estrogen replacement therapy, physical activity, and caffeinated coffee drinking were significantly higher with higher SHBG levels. On the other hand, a high body-mass index (BMI) correlated with low SHBG levels.