Public Health Update -- August 2002
As a result of growing concern over rising rates of type 2
diabetes in children, the Texas Legislature in 1999 mandated that
a pilot project be carried out to screen schoolchildren in nine
counties along the U.S.-Mexico border for acanthosis nigricans
AN is a hyperkeratinization of the skin and is a cutaneous
marker associated with systemic disorders such as hyperinsulinema
and insulin resistance. It also may serve as an indicator for risk
of type 2 diabetes. AN is a condition that easily can be evaluated
by means of a visual exam. It frequently manifests itself on the
nape and sides of the neck, but also can be found on the axillae,
elbows, knuckles, knees, and groin area. Hispanics, Native
Americans, and African-Americans have a higher prevalence of these
lesions and could be genetically predisposed and more sensitive to
higher insulin levels.
At the direction of the Texas Legislature, The University of
Texas System Texas-Mexico Border Health Coordination Office
initiated Acanthosis Nigricans: The Education and Screening Project
(ANTES) in September 1999. Under ANTES, children in Cameron,
Hidalgo, Jim Hogg, Webb, Willacy, Starr, Zapata, El Paso, and
Hudspeth counties are being screened for AN during hearing and
vision screenings in grade 3 and again during scoliosis screenings
conducted in grades 5 and 8 or grades 6 and 9. Children with AN are
referred to their primary care physicians for follow-up.
In 2001, the legislature passed House Bill 2989 to extend the
pilot to a full screening program in public and private schools
along the border. In addition, the legislature mandated that:
- The screening is to be conducted at the time of vision and
- The records are to be maintained at the school and are open
to local health departments;
- Each school is required to send to the coordination office a
report on the screening status of children in the school;
- If the child tests positive for AN, the person performing the
screen must send a report to the parent or guardian that includes
an explanation of AN and a statement on the need for further
Testing for AN
Physicians who receive a referral of a child with AN should
conduct the following tests.
Fasting Blood Glucose
The fasting plasma glucose (FPG) test and the oral glucose
tolerance test (OGTT) are both suitable tests for diabetes;
however, the FPG is strongly preferred because it is easier and
faster to perform, more convenient and acceptable to patients, and
less expensive. Fasting is defined as no consumption of food or
beverage other than water for at least eight hours before
An FPG level >126 mg/dL (7.0 mmol/L) or a two-hour postload
value in the OGTT >200 mg/dL (11.1 mmol/L) are indications for
retesting. Either test must be repeated on a different day to
confirm a diagnosis.
Nondiabetic individuals with an FPG >110 mg/dL (6.1 mmol/L)
but <126 mg/dL (7.0 mmol/L) are considered to have impaired
fasting glucose (IFG), and those with two-hour values in the OGTT
>140 mg/dL (7.8 mmol/L) but <200 mg/dL (11.1 mmol/L) are
defined as having impaired glucose tolerance (IGT). Both IFG and
IGT are risk factors for developing diabetes.
Normoglycemia is defined as plasma glucose levels <110 mg/dL
(6.1 mmol/L) in the FPG and a two-hour postload value <140 mg/dL
(7.8 mmol/L) in the OGTT.
(Source: American Diabetes Association. Clinical Practice
. 1999;22[suppl 1].)
Fasting Plasma Insulin
Fasting plasma insulin has been determined as a valid
measurement of insulin resistance; the normal range is 2 to 12
(Source: Stuart CA, Gilkison CR, Keenan BS, Nagamani M.
Hyperinsulinemia and acanthosis nigricans in African Americans.
J Natl Med Assoc
There are no current pharmacological interventions available for
AN. However, studies have shown that weight management and exercise
can decrease fasting plasma insulin concentrations. As a result,
risk associated with insulin resistance tends to decrease and AN
markers tend to fade. Therapeutic action for the child should
include weight management and exercise.
Recommendations for Weight Goals
Children with a body mass index (BMI) greater or equal to the
95th percentile are considered overweight. Those between the 85th
and 95th percentile are at risk of overweight.
A child with a BMI greater or equal to the 95th percentile
should undergo an in-depth medical assessment because these
children have a greater chance of maintaining obesity into
adulthood. A BMI above the 95th percentile also is associated with
elevated blood pressure, hyperlipidemia, and obesity-related
disease and mortality.
A child whose BMI falls between the 85th and 95th percentile
should be evaluated carefully, with particular attention given to
secondary complications of obesity.
Prolonged weight maintenance allows for a gradual decline in BMI
as a child grows in height and may be a sufficient goal for
children. However, in the event of secondary complications, weight
loss may be recommended.
(Source: Barlow SE, Dietz WH. Obesity evaluation and treatment:
Expert Committee recommendations.
Management of Individuals with AN
AN is a clinical surrogate for hyperinsulinemia; therefore, no
insulin exam is required. The management of individuals with AN is
similar to the approaches used in caring for the newly diagnosed
person with type 2 diabetes. Although blood glucose levels are
usually normal in the young, an FPG and a hemoglobin A1c
determination will confirm current glycemic status. The objective
in managing clients with AN is to reduce the severity of insulin
resistance, thereby lowering circulating insulin levels and sparing
the pancreas. For the nondiabetic individuals, the goal is to
prevent or delay the onset of diabetes.
(Source: Gilkison C, Stuart CA. Assessment of patients with
acanthosis nigricans skin lesion for hyperinsulinemia, insulin
resistance and diabetes risk.
For more information or patient materials on acanthosis
nigricans and ANTES, contact The University of Texas System
Texas-Mexico Border Health Coordination Office, The University of
Texas-Pan American, at (956) 381-3687, or log on to