Acne and insulin resistance: A systematic review and meta-analysis

Abstract

To the Editor: Acne is more common in westernized societies, suggesting that environmental factors likely contribute to acne pathogenesis.1Cordain L. Lindeberg S. Hurtado M. Hill K. Eaton S.B. Brand-Miller J. Acne vulgaris: a disease of western civilization.Arch Dermatol. 2002; 138: 1584-1590Crossref PubMed Google Scholar Metabolic abnormalities may influence key factors in the development of acne, such as the proliferation of basal keratinocytes in the sebaceous-pilosebaceous unit and abnormal desquamation of follicular corneocytes.2Del Prete M. Mauriello M.C. Faggiano A. et al.Insulin resistance and acne: a new risk factor for men?.Endocrine. 2012; 42: 555-560Crossref PubMed Scopus (50) Google Scholar Therefore, we hypothesized that patients with acne would demonstrate higher levels of insulin resistance. In this systematic review and meta-analysis, we examined the relationship between insulin resistance and acne, as it may have important therapeutic and diagnostic implications, such as exploring insulin modifiers as an adjunctive acne treatment and screening acne patients for metabolic syndrome. PubMed and Embase were systematically searched for studies published prior to March 17, 2021 that evaluated insulin resistance in patients with acne. In PubMed and Embase (acne OR acne vulgaris) AND (insulin resistance OR diabetes OR blood glucose) were searched as Medical Subject Heading terms and keywords, respectively. Only clinical studies measuring values for Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), a validated laboratory measure of insulin resistance, in acne patients and control subjects were included.3Muniyappa R. Madan R. Assessing insulin sensitivity and resistance in humans.in: Feingold K.R. Anawalt B. Boyce A. Endotext [Internet]. MDText.com, Inc, 2000Google Scholar Studies were excluded if they were unpublished, abstracts, not written in English, or included patients with polycystic ovarian syndrome in order to exclude hyperandrogenism as a potential confounding variable. Database searches yielded 136 unique results. Thirteen articles met inclusion criteria and were included in the analysis (Supplementary Fig 1, available via Mendeley at https://data.mendeley.com/datasets/bfrm4wbdrz/2). The following data were extracted from each article: number of acne subjects, mean age of acne subjects, mean body mass index of acne subjects, acne severity, other acne qualifiers (postadolescent acne or treatment nonresponders), control subjects, mean HOMA-IR value in both acne and control groups, and quality assessment score (Supplementary Table 1, available via Mendeley at https://data.mendeley.com/datasets/bfrm4wbdrz/2). Meta-analysis compared the differences between acne and control patients. Hedges' g standardized mean difference between HOMA-IR values in acne patients and controls was calculated as the summary statistic. Results are reported from a random effects model. An I2 statistic was calculated to estimate heterogeneity across studies.4Egger M. Davey Smith G. Schneider M. Minder C. Bias in meta-analysis detected by a simple, graphical test.BMJ. 1997; 315: 629-634Crossref PubMed Scopus (32351) Google Scholar Moderating variables were studied in a mixed-effects model. Statistical analyses were conducted with R statistical software (version 4.0.5) using the meta package.5Balduzzi S. Rücker G. Schwarzer G. How to perform a meta-analysis with R: a practical tutorial.Evid Based Ment Health. 2019; 22: 153-160Crossref PubMed Scopus (952) Google Scholar Acne patients had higher HOMA-IR values than controls (standardized mean difference = 0.60; 95% CI, 0.33-0.88; P < .001) (Supplementary Fig 2, available via Mendeley at https://data.mendeley.com/datasets/bfrm4wbdrz/2). Onset of acne in the postadolescent period, average age of participants, sex of participants, average body mass index, publication year, or quality score were not significant modifying variables in our model. There was heterogeneity between studies (P < .001), which was a limitation of our study. Publication bias was assessed visually using a funnel plot and quantitatively with Egger's regression test of asymmetry (Supplementary Fig 3, available via Mendeley at https://data.mendeley.com/datasets/bfrm4wbdrz/2). Although some asymmetry exists, the large effect size of study 13 appears to mitigate the asymmetry (P = .47). However, due to the small number of studies with a large variation in effect sizes and standard errors, we do not have enough evidence that publication bias does not exist in this study. Dermatologists should be aware of the potential relationship between acne and insulin resistance and consider referring acne patients to primary care for further evaluation. Early treatment of insulin resistance can prevent the development of diabetes and cardiovascular disease. None disclosed.