Socioeconomic deprivation as measured by the index of multiple deprivation and its association with low sex hormone binding globulin in women

Objective: Sex hormone binding globulin (SHBG) is a marker of insulin resistance. Given established links between BMI and socioeconomic disadvantage, we investigated how SHBG varies by index of multiple deprivation (IMD). Research Design and Methods: Using laboratory data from a Midlands UK population of mixed ethnicity, we examined the relation between blood concentrations of SHBG and IMD in 1160 women aged between 17 and 71 years. Women with a serum SHBG >250 nmol/L were excluded. Results: Mean age was 28.7 (95% confidence interval (CI) 28.2-29.1) years. 48.2% of women were of Caucasian origin, 15.5% of Southern Asian ethnicity and 2.6% were of African or other origin (33.7% were of unknown origin). SHBG increased with age (Spearman’s ρ=0.195; p<0.001). A higher proportion of women of South Asian origin versus other ethnic groups had an SHBG <30 nmol/L (OR 1.93 (95% CI 1.37-2.71)). SHBG level was lower in individuals with greater socioeconomic disadvantage as measured by IMD (Spearman's ρ=-0.09; p=0.004 for SHBG versus IMD). In multivariate logistic regression, IMD women in the quartiles 2-5 (higher socioeconomic disadvantage) were more likely to have an SHBG <30 nmol/L (compatible with significant insulin resistance) versus quartile 1 (odds ratio (OR) 1.71 (95% confidence interval (CI) 1.17-2.53), adjusted for age (OR=0.97 (95% CI 0.95-0.98)) and ethnicity (for South Asian ethnicity OR=2.00 (95% CI 1.42-2.81) versus the rest). Conclusion: Lower SHBG levels in women are associated with a higher level of socioeconomic disadvantage. Given the known association between lower SHBG and higher plasma glucose, our findings suggest a link between socioeconomic disadvantage and future risk of type 2 diabetes.