We investigated longitudinal serum MIS/AMH levels among 809 WIHS participants, of whom 122 (15.1%) were white, 462 (57.1%) were black, and 225 (27.8%) were Hispanic. By design, the age range at visit 1 was 36–40 (median 37.5 years), and at visit 2 was 41–46 years (median 43.3 years). The median time between visits was 5.3 years (range: 1.5–8.7 years). Of the 809 participants, 628 (77.6%) were HIV-infected and 181 (22.4%) were HIV-uninfected; all participants’ HIV status was the same at both study visits.
White women were more likely to be HIV-infected, were significantly older at the second visit (p=0.04) and had significantly lower BMI at both visits (p<0.001), as compared to black and Hispanic women (). A greater proportion of white and Hispanic women had never smoked compared to black women (p<0.001). Median MIS/AMH was lower at the second visit than the first for all three racial categories, as all subjects were older (; ). MIS/AMH did not differ significantly by race/ethnicity at either time point (p>0.05 for both visits) and there were no significant differences in magnitude of change in MIS/AMH values between time points by race. The median decrease between visits in MIS/AMH was 0.7 ng/mL for white women, and 0.6 ng/mL for black and Hispanic women. However, while all three racial groups had similar proportions of undetectables at the first visit, black and Hispanic women had a higher proportion at the second visit.
Demographics* of 809 WIHS Participants at each of two study visits
FIG. 1 Standard boxplots of Müllerian Inhibiting Substance (MIS; top panel) showing the median (white center line), interquartile range (IQR; black box), 1.5 times the IQR (whiskers), and values greater than 1.5 times the IQR (solid detached lines) and (more ...)
We first conducted univariate linear regression analysis to assess the effect of age on MIS/AMH, stratified by race. For a 1-year difference in age, MIS/AMH for the older women was 20.9% lower for white women, 22.8% lower for black women, and 22.1% lower for Hispanic women (p<0.001 for all 3 models; data not shown). Multivariate linear regression analysis () suggested a difference in the level of MIS/AMH by race. Controlling for age, BMI, HIV status, and smoking black women had an average MIS/AMH value that was 25.2% lower than the average MIS/AMH value for white women (p=0.037). The average MIS/AMH value for Hispanic women was 24.6% lower than for white women; however, this difference was only marginally significant (p=0.063). In addition to black race, another significant predictor of lower MIS/AMH was age (22.3% lower per 1-year increase in age, p<0.001). BMI, smoking, and HIV infection were not significantly associated with MIS/AMH in this analysis.
Independent Predictors of Müllerian Inhibiting Substance/Antimulleran Hormone among Participants in the Women’s Interagency HIV Study