Association of insulin-like growth factor (IGF)-1 gene polymorphisms with plasma levels of IGF-1 and acne severity

J Am Acad Dermatol. 2016 Oct;75(4):768-773. doi: 10.1016/j.jaad.2016.05.019. Epub 2016 Jul 27.

Abstract

Background: Polymorphisms of the insulin-like growth factor (IGF)-1 gene consisting of variable cytosine adenosine repeats in the promoter region may directly influence the expression of IGF-1.

Objective: We sought to assess the role of IGF-1 gene polymorphisms in determination of plasma IGF-1 levels, acne, and its severity.

Methods: In this case-control study, 80 patients with acne vulgaris of 4 severity grades as per Global Acne Grading System and 80 age- and gender-matched control subjects without acne were studied. All the study subjects were without any disorder or a history of drug intake likely to affect IGF-1 level within a year before the study inclusion date. IGF-1 polymorphism was determined by polymerase chain reaction and plasma levels of IGF-1 by enzyme-linked immunosorbent assay. Acne severity was assessed by Global Acne Grading System.

Results: Mean plasma IGF-1 level in acne cases was significantly higher than in non-acne controls (P = .04). Plasma IGF-1 level positively correlated with severity of acne (P = .01). Individuals homozygous for the 192-base pair (bp) allele had 4.29 times odds risk (95% confidence interval 1.38-13.33) of having acne and a significantly higher mean level of IGF-1 compared with non-192/non-192 participants. Individuals homozygous for the 192-bp allele had 3.08 times odds risk (95% confidence interval 1.15- 8.31) of having higher severity grade of acne compared with non-192/non-192 participants.

Limitations: A relatively small number of participants were studied.

Conclusions: Plasma IGF-1 levels positively correlate with severity of acne. The 192/192 homozygotes had higher risk of acne and higher severity grade of acne. Functional studies showing the relationship between IGF-1 promoter level polymorphism and actual gene expression in skin are warranted.

Keywords: acne; acne severity; insulin-like growth factor-1; polymorphism.

Publication types

  • Comparative Study

MeSH terms

  • Acne Vulgaris / diagnosis
  • Acne Vulgaris / epidemiology
  • Acne Vulgaris / genetics*
  • Adult
  • Analysis of Variance
  • Biomarkers / metabolism
  • Case-Control Studies
  • Confidence Intervals
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Genetic Predisposition to Disease*
  • Genotype
  • Humans
  • India
  • Insulin-Like Growth Factor I / genetics*
  • Insulin-Like Growth Factor I / metabolism
  • Male
  • Polymorphism, Genetic
  • Risk Assessment
  • Severity of Illness Index

Substances

  • Biomarkers
  • Insulin-Like Growth Factor I