BOSTON – Patients with a high grade of acanthosis nigricans should be screened for insulin resistance, according to Dr. Sandhya Venkatswami.
His cross-sectional study found that 47 of 150 acanthosis nigricans patients (31%) were insulin resistant, with an acanthosis nigricans grade of 3 or 4 being more predictive of the condition.
Wikimedia Commons/Dr. Vandana Mehta Rai
Patients with grade III and IV acanthosis nigricans of the neck are at a higher risk for insulin resistance.
"We suggest that all patients with severe AN [acanthosis nigricans] grades should be evaluated for IR [insulin resistance] and thereby prevent further complications," wrote Dr. Venkatswami, who presented his findings during a poster session at the American Academy of Dermatology’s Summer Academy Meeting.
While previous studies have found acanthosis nigricans to be a marker for prediabetes, Dr. Venkatswami’s study found that taking severity into account helps to further identify patients who may be at risk.
He and his fellow investigators enrolled 150 consecutive patients with acanthosis nigricans of the neck (25 males), aged 18-64 years. The patients were graded according to acanthosis nigricans severity on a scale of I-IV.
Grade I was defined as acanthosis nigricans that was only visible on close inspection (21 patients); grade II was defined as acanthosis nigricans confined to the base of the skull (58 patients); grade III was defined as acanthosis nigricans that extended laterally to the posterior border of the sternocleidomastoid but was not visible when the patient was facing forward (48 patients); and grade IV was defined as acanthosis nigricans that was visible when the patient was facing forward, as the acanthosis nigricans encircled the neck (23 patients), said Dr. Venkatswami of the department of dermatology, Sri Ramachandra University, Chennai, India.
One patient with grade I acanthosis nigricans was found to be insulin resistant; 10 patients with grade II acanthosis nigricans were found to be insulin resistance; 20 patients with grade III acanthosis nigricans were insulin resistant; and 16 patients with grade IV showed a resistance to insulin.
Secondary study findings showed that patients with higher grades of texture of acanthosis nigricans were also more likely to be insulin resistant. That is, those with visible and extremely coarse "hills and valleys."
"AN lesions are asymptomatic and usually ignored by the patients unless they are of cosmetic concern. However, this is of clinical importance in diagnosing prediabetes," he noted in his poster.
Further studies will look to see if behavior modifications will help lower the risk for diabetes in patients with the condition.
Dr. Venkatswami did not disclose having any conflicts of interest.