We studied 35 obese African-American children (24F, 11M) who developed diabetes mellitus and evaluated their clinical characteristics. Diabetes mellitus was diagnosed if we found fasting plasma glucose >140 mg/dl or random plasma glucose >200, with or without ketoacidemia. All patients had weight for height > 120% for age and gender and acanthosis nigricans. The age at diagnosis ranged from 8.4 to 17.5 yr. The mean age of onset of diabetes, HbA1c level and insulin level were 13.4 y, 10.0% and 32.5μU/ml respectively. There was no evidence of anemia in any patient, and all patients who were tested (57% of the group) had a normal Hb electrophoresis. Forty-two percent had a positive family history of type I or type II diabetes mellitus; 64% presented with classical symptoms of polydipsia and polyuria with or without weight loss. Twenty-nine patients (83%) were started on insulin therapy; mean daily insulin requirement was 0.93 units/kg/day. Six patients (17%) were initially treated with an oral hypoglycemic agent, but subsequently 5 patients were switched to insulin. Islet cell antibodies were positive in 2 of 19 patients. One of these presented with ketosis. Both received insulin. Nine patients (26%) presented with ketosis, with or without acidosis. The mean HbA1c and insulin level were 9.3% and 12.9 μU/ml respectively. Twenty-six patients (74%) who did not present with ketosis had a mean insulin level of 39.6 μU/ml (3-fold higher). There was no significant difference in mean HbA1c between the two groups.
Conclusion: Obese African-American children with acanthosis nigricans may develop diabetes mellitus with clinical characteristics consistent with either type I or type II, but subsequently insulin therapy seems necessary in both groups.
