A new study has found definitive associations between certain lifestyle and demographic factors and levels of a promising early biomarker of type 2 diabetes risk.
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.
Dr Simin Liu, professor of epidemiology and medicine at Brown, led an effort to measure SHBG levels in 13,547 women who take part of 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.
There are several reasons why tracking demographic and lifestyle associations with SHBG levels is important, Liu said. For one, they give doctors who want to assess type 2 diabetes risk or metabolic syndrome a basic frame of reference on what levels of SHBG might exist in patients based on their lifestyle and demographics.
The research may also help to strengthen possible strategies for intervention. Age cannot be affected, but physical activity, BMI, coffee intake, and estrogen therapy can all be adjusted. Knowing that these factors are linked to the biomarker suggests that experiments could be done to see whether changing those factors - exercising more, for example - could change levels of the protein over time in individuals, Liu said.
The study has been published online in the journal Clinical Chemistry.