Table 1.
Demographic and clinical characteristics of all included transmasculine patients in the Stanford Research Repository (STARR) 2016-2023. P-values are corrected (indicated by pc) for false discovery rate, between transmasculine patients with and without AN. Significant p values are in bold font (pc < 0.05).
Fig 1.
Schematics of demographic and comorbidities in transmasculine patients with and without acanthosis nigricans.
(A) Age in years at the date of data freeze (21/09/2023), (B) race, (C), ethnicity, and (D) comorbidities known to associate with AN in literature. P-values were calculated using Mann-Whitney test for age and Fisher’s exact test for race, ethnicity, and comorbidities. P-values were corrected for multiple hypothesis testing (m = 10).
Table 2.
Usage and types of gender-affirming care (GAC) in all included transmasculine patients (n = 945) in the Stanford Research Repository. None of the gender-affirming treatments when analyzed in aggregate nor individually by treatment type was associated with acanthosis nigricans (AN). Univariate analysis comparing patients with versus without AN was conducted using Fisher’s exact test. All statistic tests are two-tailed. Odds ratios (ORs) were calculated using the Baptista-Pike method. P-values are between transmasculine patients with and without AN.
Table 3.
Subset analysis to assess whether testosterone (T) type, dosage, or duration may associate with acanthosis nigricans (AN) in transmasculine patients. There was no significant difference between median years on exogenous T in patients with versus without AN. P-values are for transmasculine patients exposed to T with and without AN.
Table 4.
Multivariate logistic regression analysis of clinically relevant factors associated with acanthosis nigricans (AN) (N = 945) in transmasculine patients regardless of gender affirming care. Gender-affirming care was not a variable in the model as it was not correlated with AN in univariate analysis (Table 2) or subset analysis (Table 3). Significant p values are in bold font.
Table 5.
Among transmasculine patients with acanthosis nigricans (n = 43), AN appeared before, concurrently, or after diagnosis of co-morbidities. Some patients had multiple of these comorbidities and thus are represented in multiple columns.
Fig 2.
Graphical abstract of study findings and suggestions for screening and monitoring.
Odds ratio (OR) and 95% confidence intervals (as displayed in parentheses) were determined by multivariate logistic regression for Hispanic ethnicity, obesity, metabolic syndrome, prediabetes, and hypertension. Univariate analysis was conducted for association between exogenous testosterone and hypertension. Double daggers indicates that in majority of cases, acanthosis nigricans was diagnosed before comorbidities. BMI = Body Mass Index. HbA1c=Hemoglobin A1C. OR=Odds Ratio.