Acanthosis Nigricans and Diabetes Risk Factors: Prevalence in Young Persons Seen in Southwestern US Primary Care Practices

Acanthosis Nigricans is a skin condition observed on the back of the neck, axillae and flexural areas in obese subjects (1). Using a cross- sectional design, this study examined 1133 young individuals, 43% of them being children. Authors were interested in analyzing whether acanthosis nigricans was associated with the risk factors for type 2 diabetes. Family history for type 2 diabetes, overweight, hypertension and minority ethnicity were considered as risk factors. The presence of acanthosis nigricans on the neck was recorded by primary care clinicians at the office. Authors reported that acanthosis increased with the increased of BMI, hypertension and the number of risk factors for type 2 diabetes. Consistent with this study, a large study of hypertension among elementary school children showed those with overweight and acanthosis were at least twice as likely to present hypertension after controlling for confounding factors (2). A recent study also showed that acanthosis nigricans increased with child BMI z-score (3). Using regression analysis, this study showed that acanthosis was independently associated with type 2 diabetes adjusted for BMI, age, and the number of diabetes risk factors.

Acanthosis is simpler and easier to screen compared with other risk factors for diabetes. The risk factor family history for type 2 diabetes is difficult to screen because of the bias of the recall. BMI requires accurate weighing with removal of shoes and most clothing. It also requires the use of a high-quality scale that should be calibrated. Blood pressure needs to be measured in children at least three times while the subjects are seated (4). BMI and blood pressure percentiles should be done for analysis. These risk factors take more time to screen and many clinicians do not record them, increasing rates of undiagnosed overweight and hypertension. Acanthosis is a non-invasive method for identifying individuals at risk for type 2 diabetes (5). However, there are a number of issues in the manuscript that are incompletely addressed. Overweight was overrepresented in the sample, (73% of adults) and as the design did not include blood sample, authors were not able to associate acanthosis with insulin-resistance.

This study demonstrates that acanthosis is associated with type 2 diabetes after controlling for other risk factors. Their findings confirm previous relationships seen in other studies and emphasize the importance of acanthosis as a risk factor for type 2 diabetes in a group of young individuals.

1- Stuart Ch, Gikinson CH, Smith M, Bosma A, Bruce K, Nagamani M. Acantthosis Nigricans as a Risk Factor for Non Insulin Dependent Diabetes Mellitus. Clin Pediatr. 1998; 37:73-80.

2- Urrutia-Rojas X, Egbuchunam CU, Bae S, Menchaca J, Bayona M, Rivers PA, Singh KP. High blood pressure in school children: prevalence and risk factors. BMC Pediatr. 2006 Nov 16; 6:32.

3- Bell LM, Byrne S, Thompson A, Ratnam N, Blair E, Bulsara M, Jones TW, Davis EA. Increasing body mass index z-score is continuously associated with complications of overweight in children, even in the healthy weight range. J Clin Endocrinol Metab. 2007 Feb; 92(2):517-22.

4- National High Blood Pressure Education Working Group on High Blood Pressure in Children and Adolescents: The Fourth Report on the Diagnosis, Evaluation and Treatment on High Blood Pressure in Children and Adolescents. Pediatrics. 2004; 114:555–576.

5- Stuart Ch, Driscoll MS, Lundquist Kf, Gilkinsob CR, Shaheb S, Smith MM. Acanthosis Nigricans. J Basic Clin Physiol Pharmacol. 1998; 9(2- 4):407-418.

Competing interests:   None declared