SHBG and breast carcinoma: Many of these factors including age, education, smoking, alcohol consumption and body mass index have also been associated with hormone concentrations although the associations of hormones with other factors such as parity and age at first birth appear to be modest.27–29 However, adjustment for all these factors including body mass index had minimal impact on the associations of hormones and SHBG with breast cancer risk (as shown in Table 2).