Wang Y, et al. - The researcher conducted this cohort study to define low sex hormone-binding globulin (SHBG) and to determine its prevalence and risk factors in US adults. The sample consisted of adults ≥ 20 years from the US National Health and Nutrition Examination Survey from 2013 to 2016 who had fasting serum SHBG. Participants in the study were 4,093 adults (weighted sample size of 204 789 616) with a mean (SD) age of 47.5 (17.0) years. Higher BMI, diabetes, ethnicity (other than Hispanic, non-Hispanic black, or non-Hispanic white), COPD, coronary heart disease, and smoking were all risk factors for this condition in both men and women. The criteria for low SHBG among US adults were established in this study. The estimated national prevalence of low SHBG in men was 3.3% and 2.7% in women in the United States.