Nocturnal Hypoglycemia as a Cause of Fasting Hyperglycemia (Somogyi Phenomenon)

To the Editor: Tordjman and colleagues (Dec. 17 issue)¹ reported a well-designed investigation of the effects of nocturnal hypoglycemia on fasting plasma glucose concentrations in patients with insulin-dependent diabetes mellitus (IDDM). Their data, as interpreted by the authors, challenge the traditional clinical logic of many physicians and suggest that the Somogyi phenomenon may rarely, if ever, cause clinically important fasting hyperglycemia in patients with IDDM. Although their conclusions are well justified, several aspects of the methods used potentially limit the applicability of these findings to every patient with IDDM. First, the patients selected for study had relatively well-controlled IDDM (mean.