Not just skin deep: Association of acne with elevated hemoglobin A1c levels in a retrospective case–control study of 1098 patients at an academic center

Prior studies on the association between acne and insulin resistance have found conflicting results. 1 We analyzed for an association be-tween acne and hemoglobin A1c (HbA1c), one of the diagnostic criteria for diabetes and a marker of insulin resistance. After institutional review board approval, institutional electronic medical records from 03/16/2020 to 12/31/2020 were screened for patients with documented HbA1c and the International Classification of Diseases-10 code acne (L70.9) and compared to a random control sample of dermatology patients without acne. Patients with diabetes or polycystic ovary syndrome were excluded to control for hyperandrogenism as a confounding variable. Mean HbA1c levels were compared between acne cases and controls using the two-sample t - test. Likelihood of acne cases having prediabetes (HbA1c ≥ 5.7%) compared to controls was assessed using Fisher's exact test. A multi-variable logistic regression model was used to evaluate the relationship between HbA1c and acne status, controlling for age, sex, body mass index (BMI), race, and ethnicity. Our study


L E T T E R T O T H E E D I T O R Not just skin deep: Association of acne with elevated hemoglobin A1c levels in a retrospective case-control study of 1098 patients at an academic center
To the Editor, Prior studies on the association between acne and insulin resistance have found conflicting results. 1 We analyzed for an association between acne and hemoglobin A1c (HbA1c), one of the diagnostic criteria for diabetes and a marker of insulin resistance.
After institutional review board approval, institutional electronic medical records from 03/16/2020 to 12/31/2020 were screened for patients with documented HbA1c and the International Classification of Diseases-10 code acne (L70.9) and compared to a random control sample of dermatology patients without acne.Patients with diabetes or polycystic ovary syndrome were excluded to control for hyperandrogenism as a confounding variable.Mean HbA1c levels were compared between acne cases and controls using the two-sample t-test.Likelihood of acne cases having prediabetes (HbA1c ≥ 5.7%) compared to controls was assessed using Fisher's exact test.A multivariable logistic regression model was used to evaluate the relationship between HbA1c and acne status, controlling for age, sex, body mass index (BMI), race, and ethnicity.
Our study demonstrates an association between acne and HbA1c levels, suggesting that acne patients may have increased risk of prediabetes.Prior studies investigating the association between acne and insulin resistance have shown conflicting results.
In a literature review of acne and insulin resistance, three studies showed significant correlation between homeostatic model assess-  2 Separately, two randomized controlled trials demonstrated that a low glycemic load diet was associated with decreased acne count, body fat, and body weight compared to a high glycemic load diet, 2 supporting a connection between high glycemic index, a cause of elevated HbA1c, and acne.Acne patients had higher HOMA-IR values than controls (standardized mean difference = 0.60; 95% CI 0.33-0.88;p < 0.001) in a recent systematic review. 3Our study supports that there is an association between acne and insulin resistance.One proposed biological mechanism behind this association is that insulin resistance increases serum insulin and insulin-like growth factor (IGF-1) levels, increasing inflammatory biomarkers and promoting sebum production by exporting FoxO1 out of the nucleus, ultimately contributing to acne development. 1mitations of our study include a retrospective design and using HbA1c as an alternative to HOMA-IR values as a measure of insulin resistance.However, HbA1c is significantly associated with insulin resistance in both healthy and impaired glucose tolerance individuals, 4 supporting our use of HbA1c as a predictor of insulin resistance.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.© 2023 The Authors.Journal of Cosmetic Dermatology published by Wiley Periodicals LLC.Demographics of acne and control patients.
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